A silicone rubber and a method for producing the same

Abstract

The application discloses a kind of silicone rubber and preparation method thereof, belong to the technical field of silicone rubber, the raw materials needed for preparing the silicone rubber include: vinyl silicone rubber green rubber, zinc acrylate, platinum catalyst, hydrogen-containing silicone oil crosslinking agent, silicon carbide nanowire.The covalent network based on the basis of vinyl silicone rubber green rubber is constructed in the silicone rubber, and the ion network is formed with zinc acrylate and silicon carbide nanowire, the technical problem that double network structure not only can improve the overflow glue that easily appears in the process of preparing silicone rubber, but also can make silicone rubber obtain good mechanical properties.

Description

Technical Field

[0001] This invention relates to the field of silicone rubber technology, and more particularly to a silicone rubber and its preparation method. Background Technology

[0002] Silicone rubber, as a high-performance elastomer, is widely used in medical, electronics, and automotive fields. However, its preparation often faces technical challenges such as overflow, insufficient toughness, and poor self-healing properties. For example, the low viscosity of uncured silicone rubber makes it prone to overflowing from the mold parting surface during injection molding and compression molding. Traditional processes can suppress flow by adding excessive silica, but this significantly reduces the material's flexibility. Secondly, the low Si-O bond energy in the silicone rubber backbone and the lack of an effective energy dissipation mechanism result in low tensile strength, making it difficult to meet the demands of high-load applications. Furthermore, the irreversible covalent crosslinking network of traditional silicone rubber makes it difficult to self-repair after damage, severely impacting the product's lifespan. Summary of the Invention

[0003] The main objective of this invention is to provide a silicone rubber and its preparation method, thereby solving the technical problem of overflow during the preparation of silicone rubber.

[0004] To achieve the above objectives, the present invention provides a silicone rubber, wherein the raw materials required for preparing the silicone rubber include: vinyl silicone rubber raw rubber, zinc acrylate, platinum catalyst, hydrogen-containing silicone oil crosslinking agent, and silicon carbide nanowires.

[0005] In some embodiments of the present invention, the vinyl content in the vinyl silicone rubber raw material is 0.8% to 1.2% by mass.

[0006] In some embodiments of the present invention, the zinc acrylate has a purity of ≥99% and an average particle size of ≤5μm.

[0007] In some embodiments of the present invention, the Pt content in the platinum catalyst is 3000ppm to 5000ppm.

[0008] In some embodiments of the present invention, the hydrogen content in the hydrogen-containing silicone oil crosslinking agent is 0.8% to 1.2% by mass.

[0009] In some embodiments of the present invention, the average diameter of the silicon carbide nanowires is 20 nm to 50 nm.

[0010] In some embodiments of the present invention, the aspect ratio of the silicon carbide nanowires ranges from 50 to 70; and / or, the specific surface area of ​​the silicon carbide nanowires is 150 m². 2 / g~300 m 2 / g.

[0011] In some embodiments of the present invention, the raw materials required for preparing the silicone rubber also include aramid nanofibers and polyimide nanofibers.

[0012] In some embodiments of the present invention, the raw materials required for preparing the silicone rubber, calculated by weight, include: 100 parts of vinyl silicone rubber raw rubber, 3 to 5 parts of zinc acrylate, 0.5 to 1.5 parts of platinum catalyst, 2 to 3 parts of hydrogen-containing silicone oil crosslinking agent, and 1 to 2 parts of silicon carbide nanowires.

[0013] The present invention also provides a method for preparing the silicone rubber as described above, comprising the following steps:

[0014] S10. Zinc acrylate and an organic solvent are mixed, ball-milled, and vacuum-dried to remove the organic solvent to obtain pretreated zinc acrylate.

[0015] S20. Add vinyl silicone rubber raw material and silicon carbide nanowires to a mixer for the first mixing, then add the pretreated zinc acrylate for the second mixing, then add hydrogen-containing silicone oil crosslinking agent for the third mixing to obtain the rubber compound.

[0016] S30. The rubber compound and the platinum catalyst are injected into a twin-screw extruder, mixed, extruded into a mold, and vulcanized to obtain silicone rubber.

[0017] In some embodiments of the present invention, in step S30, the vulcanization molding process includes a first vulcanization molding stage and a second vulcanization molding stage, wherein the temperature of the first vulcanization molding stage is 90°C to 110°C and the temperature of the second vulcanization molding stage is 150°C to 180°C.

[0018] The beneficial effects that this invention can achieve are:

[0019] This invention constructs a covalent network based on vinyl silicone rubber raw material in silicone rubber, and an ionic network composed of zinc acrylate and silicon carbide nanowires. This dual-network structure improves the mechanical properties of silicone rubber. Furthermore, the zinc acrylate-based ionic network is a reversible ionic network; under the influence of shear force during the dispensing stage, the Zn content in the rubber compound... 2+ The ionic bonds with carboxylate groups undergo a brief dissociation, leading to a decrease in viscosity and thus exhibiting better flowability, thereby ensuring good mold filling properties. When the injection process stops, i.e., in a static state, the Zn in the compound... 2+The compound can be re-coordinated with carboxylate ions in a short time, instantly restoring the viscosity of the rubber compound to near or near its initial value. This effectively locks in the flow of the rubber compound, fundamentally solving the problem of overflow that easily occurs during the preparation of silicone rubber. It also enhances the self-healing effect of silicone rubber. Furthermore, this invention combines zinc acrylate and silicon carbide nanowires. The addition of silicon carbide nanowires can enhance the stability and conductivity of the ion network structure, allowing the viscosity of the rubber compound to quickly recover to or near its initial value after injection shearing. This locks in the flow of the rubber compound in a very short time, further preventing overflow and further enhancing the self-healing properties of silicone rubber. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0021] Figure 1 This is a schematic flowchart of a method for preparing silicone rubber according to the present invention. Detailed Implementation

[0022] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0024] In this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Furthermore, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, such a combination should be considered non-existent and not within the scope of protection claimed by this invention.

[0025] This invention provides a silicone rubber, the components required to prepare the silicone rubber including: vinyl silicone rubber raw rubber, zinc acrylate, platinum catalyst, hydrogen-containing silicone oil crosslinking agent, and silicon carbide nanowires.

[0026] In this invention, vinyl silicone rubber raw rubber serves as the main network structure of silicone rubber, zinc acrylate serves as a dynamic ionic crosslinking point, and platinum catalyst can catalyze the covalent crosslinking of Si-H and vinyl groups. Hydrogen-containing silicone oil crosslinking agent helps to achieve the construction of the covalent crosslinking network, and silicon carbide nanowires can enhance the conduction of the ionic network, enabling the rubber compound to achieve rapid viscosity recovery after injection shearing, locking the flow of the rubber compound, further preventing the occurrence of overflow, and improving the mechanical strength of silicone rubber.

[0027] This invention constructs a covalent network based on vinyl silicone rubber raw material in silicone rubber, and an ionic network composed of zinc acrylate and silicon carbide nanowires. This dual-network structure improves the mechanical properties of silicone rubber. Furthermore, the zinc acrylate-based ionic network is a reversible ionic network; under the influence of shear force during the dispensing stage, the Zn content in the rubber compound... 2+ The ionic bonds with carboxylate groups undergo a brief dissociation, leading to a decrease in viscosity and thus exhibiting better flowability, thereby ensuring good mold filling properties. When the injection process stops, i.e., in a static state, the Zn in the compound... 2+ The compound can be re-coordinated with carboxylate ions in a short time, instantly restoring the viscosity of the rubber compound to near or near its initial value. This effectively locks in the flow of the rubber compound, fundamentally solving the problem of overflow that easily occurs during the preparation of silicone rubber. It also enhances the self-healing effect of silicone rubber. Furthermore, this invention combines zinc acrylate and silicon carbide nanowires. The addition of silicon carbide nanowires can enhance the stability and conductivity of the ion network structure, allowing the viscosity of the rubber compound to quickly recover to or near its initial value after injection shearing. This locks in the flow of the rubber compound in a very short time, further preventing overflow and further enhancing the self-healing properties of silicone rubber.

[0028] In some embodiments, the molecular weight of the vinyl silicone rubber raw material is 600,000 to 800,000, and the mass content of vinyl in the vinyl silicone rubber raw material is 0.8% to 1.2%, which helps the silicone rubber to build a stable covalent network.

[0029] In some embodiments, the purity of zinc acrylate is greater than or equal to 99%, and the average particle size is ≤5μm. For example, the average particle size can be 1μm to 5μm.

[0030] In some embodiments, the Pt content in the platinum catalyst is 3000ppm to 5000ppm by mass, which can promote the construction of covalent networks.

[0031] In some embodiments, the hydrogen content in the hydrogen-containing silicone oil crosslinking agent is 0.8% to 1.2% by mass, which can promote the construction of covalent networks.

[0032] In some embodiments, the average diameter of the silicon carbide nanowires is 20nm~50nm, which can be 20nm, 30nm, 40nm, 50nm, etc. This can increase the contact area between the silicon carbide nanowires and other raw materials, promote the construction of ion networks, form a silicon carbide nanowire-ion cluster network, strengthen the rapid coordination between ions, suppress the overflow phenomenon, and also improve the mechanical properties of silicone rubber and increase the tensile modulus of silicone rubber.

[0033] In some embodiments, the aspect ratio of silicon carbide nanowires is in the range of 50 to 70, which is beneficial for enhancing ion network conduction, strengthening rapid coordination between ions, suppressing glue overflow, improving the mechanical properties of silicone rubber, and increasing the tensile modulus of silicone rubber.

[0034] In some embodiments, the specific surface area of ​​the silicon carbide nanowires is 150 m². 2 / g~300 m 2 / g, with a large specific surface area, is beneficial for enhancing ion network conduction, strengthening rapid coordination between ions, suppressing overflow phenomenon, and also improving the mechanical properties of silicone rubber and increasing the tensile modulus of silicone rubber.

[0035] In some embodiments, the raw materials for preparing silicone rubber, by weight, include the following components: 100 parts of vinyl silicone rubber raw rubber, 3 to 5 parts of zinc acrylate, 0.5 to 1.5 parts of platinum catalyst, 2 to 3 parts of hydrogen-containing silicone oil crosslinking agent, and 1 to 2 parts of silicon carbide nanowires.

[0036] In some embodiments, the raw materials for preparing silicone rubber, by weight, include the following components: 100 parts of vinyl silicone rubber raw rubber, 3.5 parts of zinc acrylate, 0.8 parts of platinum catalyst, 2.2 parts of hydrogen-containing silicone oil crosslinking agent, and 1.5 parts of silicon carbide nanowires.

[0037] In some embodiments, the raw materials for silicone rubber also include aramid nanofibers and polyimide microfibers, which increase the number of nano- and micro-sized fibers. These fibers can fill molecular-level defects in the silicone rubber, prevent the propagation of microcracks, and further improve the mechanical properties of the silicone rubber.

[0038] In some embodiments, the aramid nanofibers have a diameter range of 5 nm to 10 nm and an aspect ratio ≥ 1000, while the polyimide nanofibers have a diameter range of 1 μm to 2 μm and a length range of 50 μm to 100 μm.

[0039] In some embodiments, based on 100 parts by weight of vinyl silicone rubber raw rubber, the amount of aramid nanofiber added is 0.5 to 1.2 parts, and the amount of polyimide microfiber added is 0.8 to 1.5 parts.

[0040] This invention also provides a method for preparing silicone rubber, referring to... Figure 1 This includes the following steps:

[0041] S10. Zinc acrylate and an organic solvent are mixed, ball-milled, and vacuum-dried to remove the organic solvent to obtain pretreated zinc acrylate.

[0042] S20. Add vinyl silicone rubber raw material and silicon carbide nanowires to a mixer for the first mixing, then add the pretreated zinc acrylate from step S10 for the second mixing, then add hydrogen-containing silicone oil crosslinking agent for the third mixing to obtain the rubber compound.

[0043] S30. The rubber compound and the platinum catalyst are injected into a twin-screw extruder, mixed, extruded into a mold, and vulcanized to obtain silicone rubber.

[0044] In this invention, step S10 pretreatment of zinc acrylate yields nano-sized zinc acrylate, ensuring that the average particle size of the nano-sized zinc acrylate is less than or equal to 20 nm, which can increase the Zn content. 2+ Exposure levels are beneficial for obtaining Zn 2+ The ion clusters formed with carboxylate groups enhance Zn 2+ It can accelerate the formation of ionic bonds with carboxylate groups and improve the dispersibility of zinc acrylate in rubber compounds, facilitating the construction of ionic networks in silicone rubber.

[0045] In some embodiments, the balls used in the ball milling process are zirconia balls. The collision of zirconia balls can generate local high temperatures, greater than or equal to 200°C, which can increase the crystal defects in zinc acrylate, improve the surface energy of zinc acrylate, thereby enhancing the interfacial bonding strength between zinc acrylate and silicone rubber, and between zinc acrylate and silicon carbide nanowires, thus improving the mechanical properties of silicone rubber and increasing tensile strength.

[0046] In some embodiments, the organic solvent includes anhydrous ethanol. Ethanol molecules in anhydrous ethanol can insert into the interlayer of the zinc acrylate lattice to assist in deagglomeration and prevent agglomeration. They can also be adsorbed onto the surface of zinc acrylate to prevent zinc acrylate particles from agglomerating, thereby improving the dispersibility of zinc acrylate.

[0047] In some embodiments, the mass ratio of zinc acrylate to organic solvent is 1:3 to 1:5.

[0048] In some embodiments, the ball milling time is 2h to 3h, and the ball milling speed is 300rpm to 500rpm.

[0049] In step S10, the purpose of vacuum drying is to remove residual organic solvents. In some embodiments, vacuum drying can be performed at 60°C to 70°C to remove residual organic solvents.

[0050] In some embodiments, the temperature of the first mixing in step S20 is 40°C to 50°C, and the time is 5 min to 10 min.

[0051] In some embodiments, the temperature of the second mixing in step S20 is 75°C to 85°C, and the time is 20 min to 30 min.

[0052] In some embodiments, the temperature of the third mixing in step S20 is 100°C to 105°C, and the time is 5 min to 10 min.

[0053] In some embodiments, at least one of aramid nanofibers and polyimide microfibers is added in step S20.

[0054] In some embodiments, aramid nanofibers are added during the first mixing stage. Specifically, aramid nanofibers are dispersed in a mixed solution of DMSO and KOH to obtain an aramid nanofiber suspension. The aramid nanofiber suspension is preheated to 40°C~45°C, and then the preheated aramid nanofiber suspension, vinyl silicone rubber raw material, and silicon carbide nanowires are added to a Banbury mixer, followed by the aforementioned first mixing operation. Preheating the aramid nanofiber suspension helps reduce its viscosity and enhances its uniform mixing with the vinyl silicone rubber raw material and silicon carbide nanowires.

[0055] In some embodiments, the mass ratio of DMSO to KOH is 95:5.

[0056] In some embodiments, the mass ratio of aramid nanofibers to the mixed solution of DMSO and KOH is (2~3):100. Under the above ratio conditions, not only can the fiber concentration be prevented from being too low and the distance between fibers from increasing, resulting in insufficient improvement of the mechanical properties of silicone rubber, but also the viscosity of the rubber compound can be prevented from being too high due to the easy formation of a three-dimensional network structure caused by excessively high concentration.

[0057] In some embodiments, polyimide microfibers are added during the second mixing process. Specifically, after the first mixing is completed, pretreated zinc acrylate is added, and polyimide microfibers are added simultaneously for the second mixing.

[0058] In some embodiments, the extrusion temperature is 80°C~90°C, and the shear rate is 100 s. -1 ~120s -1 .

[0059] In some embodiments, the vulcanization temperature is 90°C to 180°C.

[0060] In some embodiments, vulcanization molding includes a first vulcanization molding stage and a second vulcanization molding stage.

[0061] In some embodiments, the temperature of the first vulcanization molding is 90°C to 110°C, and the temperature of the second vulcanization molding is 150°C to 180°C. During the first vulcanization molding stage, Zn... 2+ The platinum catalyst can rapidly coordinate with carboxylate groups to form a dynamically reversible ionic cross-linking network, which can instantly increase the structural viscosity of the rubber compound, giving it the characteristic of "shear thinning-rapid recovery." This allows the viscosity of the rubber compound to recover to or near its initial state within a short time after injection molding. In the second vulcanization stage, the platinum catalyst can promote the addition reaction of Si-H and vinyl groups, constructing a covalent network and encapsulating Zn. 2+ The ion clusters formed by Zn and carboxylate groups restrict Zn 2+ The migration of these molecules improves the mechanical properties of silicone rubber and enhances its self-healing efficiency. In this embodiment, a basic covalent network and an ionic network are constructed through two vulcanization processes, which not only solves the problem of silicone rubber overflow but also improves its mechanical properties.

[0062] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following specific embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0063] Example 1

[0064] The steps for preparing silicone rubber in Example 1 are as follows:

[0065] S10. Zinc acrylate and anhydrous ethanol are mixed according to the weight parts in Table 1. The mass ratio of zinc acrylate to anhydrous ethanol is 1:3. Zirconia balls are used as the ball milling tool. The ball milling speed is 400 rpm and the mixture is milled for 2 hours. Then, the mixture is vacuum dried at 60°C to remove the residual anhydrous ethanol to obtain pretreated zinc acrylate. The average particle size of the pretreated zinc acrylate is less than or equal to 20 nm.

[0066] S20. Add vinyl silicone rubber raw material and silicon carbide nanowires to a mixer according to the weight parts in Table 1, and perform a first mixing at 45°C for 5 minutes. Then add the pretreated zinc acrylate described in step S10, and perform a second mixing at 85°C for 20 minutes. Next, add the hydrogen-containing silicone oil crosslinking agent, and perform a third mixing at 100°C for 8 minutes to obtain the rubber compound. The vinyl silicone rubber raw material has a molecular weight of 800,000, and the specific surface area of ​​the silicon carbide nanowires is in the range of 200 m². 2 / g, aspect ratio of 70, average diameter of 50nm, vinyl content of 1.0%, zinc acrylate purity of ≥99%, average particle size of 1μm, and hydrogen content of 1.0% in the hydrogen-containing silicone oil.

[0067] S30. Inject the rubber compound and platinum catalyst into a twin-screw extruder, mix, and extrude at 80°C for 100 seconds. -1The shearing rate is used to shear and extrude the material into a mold. The material is then vulcanized at 90°C for 10 minutes and then vulcanized at 160°C for 10 minutes to obtain silicone rubber.

[0068] Example 2

[0069] Example 2 prepared silicone rubber following the steps of Example 1, except that the weight parts of the raw materials were different in Example 2, as detailed in Table 1.

[0070] Example 3

[0071] Example 3 prepared silicone rubber following the steps of Example 1, except that the weight parts of the raw materials were different in Example 3, as detailed in Table 1.

[0072] Example 4

[0073] Example 4 describes the preparation of silicone rubber following the steps of Example 1, except that the weight parts of the raw materials are different in Example 4, as detailed in Table 1.

[0074] Example 5

[0075] Example 5 prepared silicone rubber following the steps of Example 1, except that the weight parts of the raw materials were different in Example 5, as detailed in Table 1.

[0076] Example 6

[0077] Example 6 prepared silicone rubber following the steps of Example 1, except that in step S10 of Example 6, the mass ratio of zinc acrylate and anhydrous ethanol was controlled to be 1:5.

[0078] Example 7

[0079] Example 7 prepared silicone rubber following the steps of Example 1, except that in step S20 of Example 7, the temperature of the first mixing was 70°C.

[0080] Example 8

[0081] Example 8 prepared silicone rubber following the steps of Example 1, except that in step S20 of Example 8, the temperature of the second mixing was 70°C.

[0082] Example 9

[0083] Example 9 prepared silicone rubber following the steps of Example 1, except that in step S20 of Example 9, the temperature of the third mixing was 70°C.

[0084] Example 10

[0085] Example 10 prepared silicone rubber following the steps of Example 1, except that in step S30 of Example 10, the temperature for the first vulcanization molding was 100°C.

[0086] Example 11

[0087] Example 11 prepared silicone rubber according to the steps of Example 1, except that in step S30 of Example 11, the temperature of the second vulcanization molding was 150°C.

[0088] Example 12

[0089] Example 12 prepared silicone rubber following the steps of Example 1, except that in step S30 of Example 12, the shear rate was 120 s. -1 .

[0090] Example 13

[0091] Example 13 prepared silicone rubber according to the steps of Example 1, except that in step S20 of Example 13, 1 part of aramid nanofiber and 1.5 parts of polyimide microfiber were added. The diameter of the aramid nanofiber was 10 nm and the aspect ratio was 1500. The diameter of the polyimide nanofiber was 2 μm and the length was 50 μm.

[0092] Step S20 is as follows: Aramid nanofibers are dispersed in a mixed solution of DMSO and KOH (mass ratio 95:5) to obtain an aramid nanofiber suspension. The mass ratio of aramid nanofibers to the mixed solution in the aramid nanofiber suspension is 2:100. The aramid nanofiber suspension is preheated to 45°C. Vinyl silicone rubber raw material and silicon carbide nanowires are added to a mixer according to the weight parts in Table 1. The mixture is first mixed at 45°C for 5 minutes. Then, the pretreated zinc acrylate and polyimide microfibers described in step S10 are added. The mixture is second mixed at 85°C for 30 minutes. Next, the hydrogen-containing silicone oil crosslinking agent is added. The mixture is third mixed at 100°C for 8 minutes to obtain a rubber compound. The molecular weight of the vinyl silicone rubber raw material is 800,000, and the specific surface area of ​​the silicon carbide nanowires is 200 m². 2 / g, aspect ratio of 70, average diameter of 50nm, vinyl content of 1.0%, zinc acrylate purity of ≥99%, average particle size of 1μm, and hydrogen content of 1.0% in the hydrogen-containing silicone oil.

[0093] Comparative Example 1

[0094] Comparative Example 1 prepared silicone rubber following the steps of Example 1, except that silicon carbide nanowires were not added to the raw material formulation of Comparative Example 1.

[0095] Comparative Example 2

[0096] Comparative Example 1 prepared silicone rubber according to the steps of Example 1, except that Comparative Example 2 added particulate silicon carbide with an average particle size of 50 nm.

[0097] Comparative Example 3

[0098] Comparative Example 3 prepared silicone rubber according to the steps of Example 1, except that Comparative Example 3 did not perform step S10 on zinc acrylate.

[0099] Table 1

[0100]

[0101] Performance testing

[0102] Test 1, Anti-overflow test: A stainless steel inclined plate with an inclination of 85° and a surface roughness of 0.8μm was heated to 150℃±1℃ and kept at that temperature for 30min. The adhesive extruded into the mold by the examples and comparative examples after step S30 was collected and placed in an environment of 23±2℃ and 50±5%RH for 24 hours. Then it was coated onto the end of the stainless steel inclined plate. The timer was started and the position flowed to after 10min was recorded. The distance from that position to the end was measured and the average value of three parallel experiments was taken.

[0103] Judgment criteria: Flow distance ≤ 3mm is considered qualified.

[0104] Test 2, Tensile strength and elongation at break: The tensile test was conducted on a U-CANUT-2060 tensile testing machine, according to the test standard GB / T528-2009, at a test temperature of 25℃ and a tensile speed of 500mm / min. The results of the tensile strength and elongation at break are shown in Table 2.

[0105] Table 2

[0106]

[0107] According to Tables 1 and 2, the flow distance of the rubber compounds prepared in Examples 1 to 13 is within 3 mm, indicating that they have good anti-overflow properties. They also have good tensile strength and elongation at break, and excellent mechanical properties. In particular, Example 13 added aramid nanofibers and polyimide nanofibers, which not only enhanced the mechanical properties of silicone rubber, but also improved the anti-overflow problem to a certain extent.

[0108] Comparative Example 1 did not add silicon carbide nanowires, Comparative Example 2 added silicon carbide in granular form, and Comparative Example 3 did not pretreat zinc acrylate. All of these reduced the anti-spillage performance of silicone rubber to some extent and also affected its mechanical properties.

[0109] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A silicone rubber, characterized in that, The raw materials required to prepare the silicone rubber include: vinyl silicone rubber raw rubber, zinc acrylate, platinum catalyst, hydrogen-containing silicone oil crosslinking agent, and silicon carbide nanowires; The silicon carbide nanowires have an average diameter of 20 nm to 50 nm, an aspect ratio of 50 to 70, and a specific surface area of ​​150 m². 2 / g~300 m 2 / g; Based on weight, the composition includes 100 parts of vinyl silicone rubber raw material, 3 to 5 parts of zinc acrylate, 0.5 to 1.5 parts of platinum catalyst, 2 to 3 parts of hydrogen-containing silicone oil crosslinking agent, and 1 to 2 parts of silicon carbide nanowires. The zinc acrylate is processed as follows: the zinc acrylate is mixed with an organic solvent, ball-milled, and vacuum-dried to remove the organic solvent.

2. The silicone rubber according to claim 1, characterized in that, The vinyl content in the raw vinyl silicone rubber is 0.8% to 1.2% by mass.

3. The silicone rubber according to claim 1, characterized in that, The zinc acrylate has a purity of ≥99% and an average particle size of ≤5μm.

4. The silicone rubber according to claim 1, characterized in that, The Pt content in the platinum catalyst is 3000ppm~5000ppm.

5. The silicone rubber according to claim 1, characterized in that, The hydrogen content in the hydrogen-containing silicone oil crosslinking agent is 0.8% to 1.2% by mass.

6. The silicone rubber according to claim 1, characterized in that, The raw materials required to prepare the silicone rubber also include aramid nanofibers and polyimide nanofibers.

7. A method for preparing the silicone rubber according to any one of claims 1 to 6, characterized in that, Includes the following steps: S10. Zinc acrylate and an organic solvent are mixed, ball-milled, and vacuum-dried to remove the organic solvent to obtain pretreated zinc acrylate. S20. Add vinyl silicone rubber raw material and silicon carbide nanowires to a mixer for the first mixing, then add the pretreated zinc acrylate for the second mixing, then add hydrogen-containing silicone oil crosslinking agent for the third mixing to obtain the rubber compound. S30. The rubber compound and platinum catalyst are injected into a twin-screw extruder, mixed, extruded into a mold, and vulcanized to obtain silicone rubber.

8. The method for preparing silicone rubber according to claim 7, characterized in that, In step S30, the vulcanization molding process includes a first vulcanization molding stage and a second vulcanization molding stage. The temperature of the first vulcanization molding stage is 90℃~110℃, and the temperature of the second vulcanization molding stage is 150℃~180℃.

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