A negative pressure preparation method for silicone rubber foam material and its application

Abstract

This invention discloses a negative pressure preparation method for silicone rubber foam material, comprising the following steps: Step 1, ingredient preparation, Component A comprising the following components by mass: 100 parts vinyl silicone oil, 1-100 parts hydroxyl silicone oil, 0.05-2 parts catalyst, 10-90 parts reinforcing filler, and 0.5-5 parts cell stabilizer; Component B comprising the following components by mass: 100 parts vinyl silicone oil, 1-10 parts hydrogen-containing silicone oil, 0.5-3 parts inhibitor, and 10-50 parts foaming agent. Step 1: Mix 10-50 parts of foaming agent; Step 2: Mix components A and B evenly and inject into the mold; Step 3: Initial foaming and shaping: Close the mold and evacuate to maintain a negative pressure state inside the mold cavity, with a negative pressure value range of -0.1 to -0.08 MPa. Place the mold in an oven for heating; Step 4: Secondary vulcanization: Return the air intake in the mold cavity to normal pressure, open the mold and remove the inner core blank; Place the inner core blank in an oven at 150-180℃ for secondary vulcanization for 1-3 hours to obtain silicone rubber foam material. Silicone rubber foam material has good mechanical properties and can be used in pillow cores.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to a negative pressure preparation method and application of silicone rubber foam material. Background Technology

[0002] As a crucial support item during sleep, the material properties of a pillow directly affect its comfort and health. Currently, common materials on the market, such as memory foam, latex, down, or synthetic fibers, all have certain limitations, such as poor breathability, allergies, insufficient support, or hygiene concerns. Silicone rubber foam, due to its excellent high and low temperature resistance, physiological inertness, high resilience, and good biocompatibility, has become an ideal choice for high-end bedding, especially showing significant potential in the development of one-piece molded pillow cores made entirely of silicone.

[0003] However, when applying silicone rubber foam materials to large-volume, complex curved furniture products such as pillows and mattresses, traditional foaming molding processes face severe industrialization challenges. Existing technological approaches exhibit significant contradictions: under normal pressure, the free expansion of gas generated by the decomposition of the foaming agent is difficult to control, easily leading to the formation of large, uneven cell structures within the product, severely affecting the uniformity and stability of product performance. While advanced foaming technologies such as supercritical fluids can effectively improve cell quality, their complex processes and high equipment requirements currently limit their application to small or simple molds, making it difficult to economically and efficiently adapt to the integrated molding and large-scale production needs of large-volume products. Furthermore, to achieve complex shapes, the traditional secondary processing of foaming followed by cutting cuts the cells, disrupting the material's structural integrity. This not only reduces support performance but also introduces stress concentration points, significantly increasing the risk of tearing and failure during long-term use.

[0004] Therefore, it is necessary to develop a negative pressure preparation method for silicone rubber foam pillow cores, which can integrally mold silicone rubber foam pillow cores with high air permeability, high resilience and uniform cell structure in one step, and expand its application in household products. Summary of the Invention

[0005] To overcome the shortcomings of the above-mentioned technologies, the first objective of this invention is to provide a negative pressure preparation method, which produces a silicone rubber foam material with uniform pores and high air permeability and support durability.

[0006] A negative pressure preparation method for silicone rubber foam material includes the following steps:

[0007] Step 1: Prepare components A and B. Component A comprises the following parts by weight: 100 parts vinyl silicone oil, 1-100 parts hydroxyl silicone oil, 0.05-2 parts catalyst, 10-90 parts reinforcing filler, and 0.5-5 parts cell stabilizer. Component B comprises the following parts by weight: 100 parts vinyl silicone oil, 1-10 parts hydrogen-containing silicone oil, 0.5-3 parts inhibitor, 0-10 parts coupling agent, 10-50 parts foaming agent, and 10-50 parts foaming aid.

[0008] Step 2: Mix components A and B evenly at a mass ratio of 1:1, and then inject the mixture into a mold. The mold is equipped with a vacuum gauge and valves for vacuuming and air intake.

[0009] Step 3: Initial foaming and shaping. Close the mold and evacuate to maintain a negative pressure state inside the mold cavity. The negative pressure value range is -0.1~-0.08MPa. Place the mold in an oven at 90~100℃ and heat for 5~15 minutes.

[0010] Step 4, secondary vulcanization: The air intake of the mold cavity is restored to normal pressure, the mold is opened and the inner core blank is taken out; the inner core blank is placed in an oven at 150~180℃ for secondary vulcanization for 1~3 hours to obtain the silicone rubber foam material.

[0011] As a preferred technical solution, the mold cavity temperature in step two is 30~90℃.

[0012] As a preferred technical solution, the cell stabilizer is polyether-modified silicone oil.

[0013] As a preferred technical solution, the polyether modified silicone oil contains 20% to 60% polyether segments by mass.

[0014] As a preferred technical solution, the polyether segment is copolymerized from ethylene oxide and propylene oxide, and the content of ethylene oxide is 30~70 mol.

[0015] As a preferred technical solution, component B further includes 1 to 15 parts of thermally conductive filler; the thermally conductive filler is at least one of alumina, aluminum nitride, and zinc oxide.

[0016] As a preferred technical solution, component A further includes 0.5 to 1 part color paste and 1 to 20 parts antibacterial agent.

[0017] As a preferred technical solution, the vinyl silicone oil has a vinyl content of 0.1~20 mol% and a viscosity of 100-100000 mPa·s at 25°C; the hydroxyl silicone oil has a hydroxyl content of 0.4~10 mol% and a viscosity of 100~10000 mPa·s at 25°C.

[0018] As a preferred technical solution, the reinforcing filler is at least one of the following: silica, nano-calcium carbonate, hollow glass microspheres, hydrophobic fumed silica, graphene, cotton fiber, and bamboo fiber.

[0019] As a preferred technical solution, the antibacterial agent is at least one of nano silver silicate, nano titanium dioxide, nano silver phosphate, and nano zinc oxide.

[0020] As a preferred technical solution, the hydrogen-containing silicone oil is an organopolysiloxane containing at least one Si-H bond, selected from at least one organopolysiloxane containing hydrogen at the end, hydrogen at the side, or hydrogen at both the end and the side, with a hydrogen content of 0.03-2 mol% and a viscosity of 50-1000 mPa·s at 25°C.

[0021] As a preferred technical solution, the inhibitor is one or two of diethyl maleate, 3-buten-1-yn-1-ylbenzene, and cyclohexynol.

[0022] As a preferred technical solution, the coupling agent is at least one selected from γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, dodecyltrimethoxysilane, and n-octyltrimethoxysilane.

[0023] As a preferred technical solution, the foaming agent is at least one of 4,4'-oxobisbenzenesulfonyl hydrazine, 1,3-benzenedisulfonyl hydrazine, benzenesulfonyl hydrazine, p-toluenesulfonyl hydrazine, 4,4'-oxobisbenzenesulfonylaminourea, and sodium bicarbonate.

[0024] As a preferred technical solution, the foaming agent is at least one selected from water, ethanol, methanol, ethylene glycol, polyethylene glycol, and phenylethanol.

[0025] To overcome the shortcomings of the above-mentioned technologies, the second objective of this invention is to provide an application of a negative pressure preparation method, specifically, to use the negative pressure preparation method to prepare a silicone rubber foam material and use it as the inner core of an integrated pillow.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] 1. This invention applies a specific negative pressure environment to a sealed mold during the foaming and setting stage, effectively controlling the foaming process within the silicone rubber system. Under a negative pressure environment of -0.1 to -0.08 MPa, the gas solubility in the mixture changes, and the number of bubble nuclei generated by the decomposition of the foaming agent increases significantly and their distribution becomes more uniform. Simultaneously, the negative pressure environment inhibits excessively rapid bubble growth, promoting uniform and slow expansion of bubbles during the formation of the cross-linked network, ultimately forming an ideal closed-cell structure with fine pore size, narrow distribution, and independent pores. This controllable microstructure is key to achieving excellent air permeability, low compressive stress, and high durability in the material.

[0028] 2. The present invention uses polyether-modified silicone oil as a cell stabilizer. The polyether-modified silicone oil has a polyether segment content of 20% to 60% by mass and an ethylene oxide content of 30 to 70 mol%. It has a suitable HLB content, which can effectively overcome the inherent problem of uneven cell structure in foamed thick-walled materials and obtain a cell structure that is significantly more uniform and denser.

[0029] 3. The negative pressure preparation method of the present invention can integrally form the pillow core, eliminating the need for subsequent mechanical processing, thereby greatly simplifying the process, improving efficiency, reducing energy consumption and labor costs, and more importantly, avoiding damage to the foam structure caused by secondary processing, thus ensuring the mechanical properties of the pillow core from the source. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the mold structure of the present invention;

[0031] The implementation, functional features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0032] The following examples further illustrate the features and other related characteristics of the present invention in detail, to facilitate understanding by those skilled in the art:

[0033] An embodiment of the present invention provides a negative pressure preparation method for silicone rubber foam material, comprising the following steps:

[0034] Step 1, prepare components A and B: Component A comprises the following parts by weight: 100 parts vinyl silicone oil, 1-100 parts hydroxyl silicone oil, 0.05-2 parts catalyst, 10-90 parts reinforcing filler, and 0.5-5 parts cell stabilizer; Component B comprises the following parts by weight: 100 parts vinyl silicone oil, 1-10 parts hydrogen-containing silicone oil, 0.5-3 parts inhibitor, 0-10 parts coupling agent, 10-50 parts foaming agent, and 10-50 parts foaming aid.

[0035] Step 2: Mix components A and B evenly at a mass ratio of 1:1, and then inject the mixture into a mold. The mold is equipped with a vacuum gauge and valves for vacuuming and air intake.

[0036] Step 3: Initial foaming and shaping. Close the mold and evacuate it to maintain a negative pressure state inside the mold cavity. The negative pressure value range is -0.1~-0.08MPa. Place the mold in an oven at 90~100℃ and heat for 5~15 minutes.

[0037] Step 4, secondary vulcanization: The air intake of the mold cavity is restored to normal pressure, the mold is opened and the inner core blank is taken out; the inner core blank is placed in an oven at 150~180℃ for secondary vulcanization for 1~3 hours to obtain the silicone rubber foam material.

[0038] In some examples, the mold cavity temperature in step two is 30~90°C, which is not a low temperature, allowing the reaction of components A and B to be avoided before they are fully mixed.

[0039] In some examples, the cell stabilizer is polyether-modified silicone oil. Polyether-modified silicone oil is an organosilicon nonionic surfactant that can reduce the surface tension of bubbles during foaming, making them more stable.

[0040] In some examples, the polyether-modified silicone oil contains 20% to 60% polyether segments by mass. These polyether segments are copolymerized from ethylene oxide and propylene oxide, with the ethylene oxide content ranging from 30 to 70 mol%. The polyether-modified silicone oil has a suitable HLB content, which can regulate the surface tension of bubbles during foaming, resulting in uniform and stable bubbles. This leads to the final formation of an ideal closed-cell structure with fine, narrowly distributed, and independent pores in the foamed material.

[0041] In some examples, component B further includes 1 to 15 parts of thermally conductive filler; the thermally conductive filler is at least one of alumina, aluminum nitride, and zinc oxide, which can improve the heat dissipation capacity of the silicone rubber foam material.

[0042] In some examples, component A also contains 0.5 to 1 part colorant and 1 to 20 parts antibacterial agent.

[0043] In some examples, the antibacterial agent is at least one of nano-silver silicate, nano-titanium dioxide, nano-silver phosphate, and nano-zinc oxide.

[0044] In some examples, the vinyl silicone oil has a vinyl content of 0.1-20 mol% and a viscosity of 100-100000 mPa·s at 25°C.

[0045] In some examples, the hydroxyl content in the hydroxyl silicone oil is 0.4~10 mol%, and the viscosity at 25°C is 100~10000 mPa·s.

[0046] In some examples, the reinforcing filler is at least one of silica, nano-calcium carbonate, hollow glass microspheres, graphene, cotton fiber, and bamboo fiber.

[0047] In some examples, the hydrogen-containing silicone oil is an organopolysiloxane containing at least one Si-H bond, selected from at least one organopolysiloxane containing hydrogen at the end, hydrogen at the side, or hydrogen at both the end and the side, with a hydrogen content of 0.03-2 mol% and a viscosity of 50-1000 mPa·s at 25°C.

[0048] In some examples, the inhibitor is one or two of diethyl maleate, 3-buten-1-yn-1-ylbenzene, and cyclohexynol.

[0049] In some examples, the coupling agent is at least one of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, dodecyltrimethoxysilane, and n-octyltrimethoxysilane, used to improve the interfacial compatibility between the reinforcing filler and the silicone rubber.

[0050] In some examples, the foaming agent is at least one of 4,4'-oxobisbenzenesulfonyl hydrazine, 1,3-benzenedisulfonyl hydrazine, benzenesulfonyl hydrazine, p-toluenesulfonyl hydrazine, 4,4'-oxobisbenzenesulfonamide, and sodium bicarbonate.

[0051] In some examples, the foaming agent is at least one of water, ethanol, methanol, ethylene glycol, polyethylene glycol, and phenylethanol.

[0052] An embodiment of the present invention provides an integrated molded pillow core, which is prepared by the negative pressure preparation method, except that it employs the following... Figure 1 The mold shown, with the remaining steps unchanged, can be used to produce the pillow core. The mold includes a lower frame 1 and an upper cover 2, which are sealed together by bolts 3. The shape of the mold cavity is consistent with the shape of the pillow core. The formed pillow does not need to be cut, eliminating the need for subsequent machining, thus greatly simplifying the process, improving efficiency, reducing energy consumption and labor costs, and, more importantly, avoiding damage to the foam structure caused by secondary processing, ensuring the mechanical properties of the pillow core from the source.

[0053] Example 1

[0054] Embodiment 1 of the present invention provides a silicone rubber foam material, which is prepared according to the following steps:

[0055] Step 1: (1) Prepare component A: In a two-roll kneader, add vinyl silicone oil, hydroxyl silicone oil, reinforcing filler, cell stabilizer and antibacterial agent in sequence, stir at room temperature until uniformly mixed, heat the mixture to 120-130℃, and continue stirring under vacuum for 2-5 h; after the mixture cools to below 50℃, add catalyst and color paste, and continue stirring for 30 min. The entire stirring process is carried out under vacuum and circulating nitrogen atmosphere, and finally discharge to obtain component A. (2) Preparation of component B: In a two-roll kneader, vinyl silicone oil and coupling agent are added in sequence and stirred at room temperature until they are evenly mixed. The mixture is heated to 120-130°C and stirred continuously under vacuum for 2-5 hours. After the material cools down to below 50°C, foaming agent, foaming aid, hydrogen-containing silicone oil and inhibitor are added in sequence and stirred for 1 hour to prevent the foaming agent and foaming aid from decomposing and becoming ineffective in advance. This process is also carried out under vacuum and circulating nitrogen atmosphere. Finally, the material is discharged to obtain component B.

[0056] Step 2: Mix components A and B evenly at a mass ratio of 1:1, and immediately inject the mixture into a specially made mold equipped with a vacuum gauge and an air intake valve.

[0057] Step 3: After closing the mold, evacuate to maintain a negative pressure of -0.08 to -0.1 MPa inside the mold cavity. Place the mold under negative pressure in a 90℃ oven and heat for 10 minutes to allow the material to initially foam and set.

[0058] Step 4: After restoring the mold cavity to normal pressure through the air inlet valve, open the mold and remove the pre-shaped foamed material. Place the foamed material in a 150℃ oven for secondary vulcanization for 2 hours to further complete cross-linking, eliminate by-products, and finally obtain a silicone rubber foamed material with uniform cell structure and stable performance.

[0059] Examples 1-6 and Comparative Examples 1-4 prepared silicone rubber foam materials by changing the raw material formulation and reaction operation according to Table 1.

[0060] Comparative Example 2 has the same A component formulation as Example 3, but does not use polyether-modified silicone oil.

[0061] Comparative Example 3 has the same A component formulation as Example 1, but the polyether modified silicone oil used has an ethylene oxide (EO) content of 20 mol% and an propylene oxide (PO) content of 80 mol%.

[0062] Comparative Example 5 has the same formulation as Example 1, except that in step three, no vacuuming is performed after injection molding. The mold is closed under normal pressure and then placed directly in a 90°C oven for 10 minutes to foam and set. Subsequent steps are the same as in Example 1.

[0063] Table 1 shows the formulations for Examples 1-6.

[0064] Table 2 shows the formulations for Comparative Examples 1-4.

[0065]

[0066] Performance testing: The high-performance polysiloxane foam materials prepared in Examples 1-6 and Comparative Examples 1-5 were subjected to the following tests.

[0067] I. The apparent density of silicone rubber foam material was tested according to GB / T6343-2009 standard. Five samples were measured for each example, and the average value of the results was taken.

[0068] II. The compression set properties of silicone rubber foam materials were tested according to GB / T6669-2008 standard. The test conditions were as follows: the sample was compressed to 50% of its original thickness at 80℃, held for 72 hours, removed, cooled to room temperature, and its thickness was measured. The compression set rate was then calculated. The compression set rate was calculated using the following formula: Compression set rate = (Original thickness - Restored thickness) / Original thickness × 100%.

[0069] 3. Test the compressive stress of silicone rubber foam material according to GB / T7757-2009 standard, record the stress value required when the sample is compressed to 50% strain, measure 5 samples for each example, and take the average value of the results.

[0070] IV. The tensile strength and elongation at break of silicone rubber foam materials were tested according to GB / T528-2009 standard. Dumbbell-shaped Type I specimens were used, with samples taken from both the transverse and longitudinal directions. The final result was the average of the test data in both directions.

[0071] V. Test the vacuum water absorption rate of silicone rubber foam material according to GB / T 17794-2022 standard.

[0072] Table 2 Test results of Examples 1-6 and Comparative Examples 1-5

[0073]

[0074] (1) By comparing Example 1 and Comparative Example 5, it can be seen that under the same formula, applying a specific negative pressure significantly reduces the average cell diameter of the product and also significantly improves the compression set.

[0075] First, it shows that under negative pressure, the pressure difference between the internal pressure of the bubbles formed by the foaming agent and the negative pressure of the mold cavity is small during initial shaping. Under normal pressure in the mold cavity, the pressure difference between the internal pressure of the bubbles formed by the foaming agent and the normal pressure is larger. The bubbles need to expand until the internal and external pressures of the bubbles are balanced before they stabilize. Therefore, under conditions of large pressure difference, the bubbles expand easily, leading to an increase in bubble diameter. Conversely, under small pressure difference, the gas expansion rate slows down, preventing excessive expansion of the bubbles. Second, silicone rubber foam materials with uniform distribution and small pore size have lower compression set, higher tensile strength, and lower vacuum water absorption.

[0076] (2) A comparison of Example 1 and Comparative Example 2 shows that the lack of polyether silicone oil leads to uneven bubble distribution in silicone rubber foam, which in turn affects the mechanical properties of silicone rubber foam. A comparison of Example 1 and Comparative Example 3 shows that even under negative pressure, it is difficult to obtain ideal cell structure in silicone rubber foam by using unsuitable polyether silicone oil. This is because polyether silicone oil includes polyether segments, which are copolymerized from ethylene oxide and propylene oxide. Increasing the ethylene oxide content of the polyether segments can improve the hydrophilicity of polyether silicone oil; while increasing the propylene oxide content of the polyether segments can improve the oleophilicity of polyether silicone oil. The preferred polyether modified silicone oil of this invention contains polyether segments, and the ethylene oxide content of the polyether segments is 30~70 mol%, so that the silicone rubber foam has a suitable HLB value, which can make the raw materials of the rubber foam compatible, and at the same time, the surface tension of the bubbles makes the bubble diameter appropriate and the distribution uniform.

[0077] (3) By analyzing the data trends of Examples 1-6, it can be found that by adjusting the amount of hydroxyl silicone oil, the type of reinforcing filler and the combination of foaming agents, the density and hardness of the product can be controlled to meet the needs of different scenarios.

[0078] A comparison of Examples 1-3 shows that as the mass fractions of hydroxyl silicone oil and hydrogen-containing silicone oil increase, the apparent density and average cell diameter of the silicone rubber foam material decrease. This is because the hydrogen-containing silicone oil not only undergoes an addition reaction with vinyl silicone oil to build a more stable three-dimensional cross-linked network, thus giving the material superior fatigue resistance and mechanical integrity, but also undergoes a condensation reaction with hydroxyl silicone oil to generate bubbles, leading to a decrease in the apparent density of the silicone rubber foam material. Furthermore, the hydroxyl silicone oil further reduces the surface tension of the bubbles, resulting in a smaller bubble volume. The more pores inside the silicone rubber foam material, the lower its compression set and the better its elasticity, but the tensile strength will also decrease accordingly. Considering all factors, the silicone rubber foam material...

[0079] By comparing Examples 1 and 4 with Comparative Example 1, it can be seen that simply increasing the amount of hydroxyl silicone oil will lead to a decrease in the mechanical properties of the silicone rubber foam material. This is because hydroxyl silicone oil will react with hydrogen-containing silicone oil, thereby consuming the hydrogen-containing silicone oil, which will prevent the vinyl silicone oil from crosslinking with a sufficient amount of hydrogen-containing silicone oil, resulting in a decrease in its mechanical properties.

[0080] A comparison between Example 1 and Comparative Example 4 shows that the lack of hydroxyl silicone oil in silicone rubber foam materials leads to the formation of through-pores, resulting in increased water absorption and significantly affecting the mechanical properties of the foam material. Furthermore, the absence of hydroxyl silicone oil in silicone rubber foam materials results in higher viscosity of the raw material components, making it difficult to fully and uniformly mix the inorganic fillers in the silicone oil, which also affects the final mechanical properties of the silicone rubber foam material.

[0081] (4) When a large amount of inorganic filler is added to the silicone rubber foam material, a coupling agent can be added in appropriate amounts to improve the compatibility of the inorganic filler with other organic components.

[0082] (5) All embodiments directly produce the pillow core in one step, avoiding secondary processing. Performance test data show that the product prepared by this method has excellent comprehensive performance, especially low compression set and low vacuum water absorption rate, indicating that it forms a closed-cell elastomer with complete structure, independent pores and high degree of cross-linking, which fundamentally solves the industry problems such as performance degradation and poor durability caused by the traditional foaming and cutting process.

[0083] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are also included in the same way.

Claims

1. A negative pressure preparation method for silicone rubber foam material, characterized in that, Includes the following steps: Step 1: Prepare components A and B. Component A comprises the following parts by weight: 100 parts vinyl silicone oil, 1-100 parts hydroxyl silicone oil, 0.05-2 parts catalyst, 10-90 parts reinforcing filler, and 0.5-5 parts cell stabilizer. Component B comprises the following parts by weight: 100 parts vinyl silicone oil, 1-10 parts hydrogen-containing silicone oil, 0.5-3 parts inhibitor, 0-10 parts coupling agent, 10-50 parts foaming agent, and 10-50 parts foaming aid. Step 2: Mix components A and B evenly at a mass ratio of 1:1, and then inject the mixture into a mold. The mold is equipped with a vacuum gauge and valves for vacuuming and air intake. Step 3: Initial foaming and shaping. Close the mold and evacuate to maintain a negative pressure state inside the mold cavity. The negative pressure value range is -0.1~-0.08MPa. Place the mold in an oven at 90~100℃ and heat for 5~15 minutes. Step 4, secondary vulcanization: The air intake in the mold cavity is restored to normal pressure, the mold is opened and the inner core blank is taken out; the inner core blank is placed in an oven at 150~180℃ for secondary vulcanization for 1~3 hours to obtain the silicone rubber foam material; The mold cavity temperature in step two is 30~90℃; The cell stabilizer is polyether-modified silicone oil; the polyether-modified silicone oil contains 20% to 60% polyether segments by mass; the polyether segments are copolymerized from ethylene oxide and propylene oxide, and the content of ethylene oxide is 30 to 70 mol.

2. The negative pressure preparation method for silicone rubber foam material according to claim 1, characterized in that, The B component further comprises 1 to 15 parts of thermally conductive filler; the thermally conductive filler is at least one of alumina, aluminum nitride, and zinc oxide.

3. The negative pressure preparation method for silicone rubber foam material according to claim 1, characterized in that, Component A also contains 0.5 to 1 part colorant and 1 to 20 parts antibacterial agent.

4. The negative pressure preparation method for a silicone rubber foam material according to claim 1, characterized in that, The vinyl silicone oil has a vinyl content of 0.1-20 mol% and a viscosity of 100-100000 mPa·s at 25°C; the hydrogen-containing silicone oil is an organopolysiloxane containing at least one Si-H bond, selected from at least one organopolysiloxane with terminal hydrogen, side hydrogen, or end-side hydrogen, with a hydrogen content of 0.03-2 mol% and a viscosity of 50-1000 mPa·s at 25°C; the hydroxyl silicone oil has a hydroxyl content of 0.4-10 mol% and a viscosity of 100-10000 mPa·s at 25°C; the inhibitor is one or two of diethyl maleate, 3-buten-1-yn-1-ylbenzene, and cyclohexynyl alcohol. The coupling agent is at least one of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, dodecyltrimethoxysilane, and n-octyltrimethoxysilane; The foaming agent is at least one of 4,4'-oxobisbenzenesulfonyl hydrazine, 1,3-benzenedisulfonyl hydrazine, benzenesulfonyl hydrazine, p-toluenesulfonyl hydrazine, 4,4'-oxobisbenzenesulfonylaminourea, and sodium bicarbonate; the foaming aid is at least one of water, ethanol, methanol, ethylene glycol, polyethylene glycol, and phenylethanol; the reinforcing filler is at least one of silica, nano-calcium carbonate, hollow glass microspheres, graphene, cotton fiber, and bamboo fiber.

5. The negative pressure preparation method for a silicone rubber foam material according to claim 3, characterized in that, The antibacterial agent is at least one of nano-silver silicate, nano-titanium dioxide, nano-silver phosphate, and nano-zinc oxide.

6. The application of the silicone rubber foam material prepared by the negative pressure preparation method of the silicone rubber foam material according to any one of claims 1 to 5 as an integrally molded pillow core.

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