Silicone rubber cable material and preparation method thereof

Abstract

The invention belongs to the field of cable materials, and discloses a silicone rubber cable material and a preparation method thereof. The high-performance silicone rubber is prepared from the following components in parts by weight: 60-80 parts of methyl vinyl silicone rubber, 20-40 parts of phenyl silicone rubber, 30-50 parts of magnesium hydroxide, 20-30 parts of aluminum hydroxide, 5-10 parts of nano montmorillonite, 8-15 parts of fluororubber powder, 3-8 parts of titanate coupling agent modified zinc oxide, 1-3 parts of a silane coupling agent, 2-5 parts of a vulcanizing agent, 1-2 parts of an anti-aging agent and 4-8 parts of stearic acid modified sepiolite. The composite material is prepared from the following components in parts by weight: 2-5 parts of zinc hydroxystannate, 3-6 parts of silicon nitride, 2-5 parts of blended powder, 4-6 parts of maleic anhydride grafted polyolefin elastomer modified calcium carbonate and 3-5 parts of montmorillonite / graphene composite powder. The problems that in the prior art, flame retardance and corrosion resistance of a silicone rubber cable material are difficult to synergistically improve, and inorganic filler compatibility is poor are solved.

Description

Technical Field

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

[0002] Silicone rubber cable materials are widely used in the insulation and sheathing layers of wires and cables due to their excellent high-temperature resistance, insulation properties, and flexibility. With the diversification of cable applications, especially in harsh environments such as chemical plants, marine environments, and high-temperature environments, higher requirements are being placed on the corrosion resistance and flame retardant properties of silicone rubber cable materials.

[0003] In existing technologies, silicone rubber cable materials typically employ inorganic flame retardants such as magnesium hydroxide and aluminum hydroxide to enhance their flame retardant properties. However, excessive addition of these flame retardants can lead to a decrease in the material's mechanical properties and poor compatibility with the silicone rubber matrix, resulting in uneven dispersion. Furthermore, the corrosion resistance of existing cable materials largely relies on corrosion-resistant components such as fluororubber. However, improvements to a single component are insufficient to meet the long-term performance requirements in harsh environments and lack synergistic optimization with flame retardant properties.

[0004] Furthermore, most inorganic fillers used in existing technologies are single-component or simply mixed, failing to form an effective synergistic mechanism, making it difficult to simultaneously achieve excellent flame retardancy, corrosion resistance, and mechanical properties. Therefore, to address these issues, a silicone rubber cable material that balances excellent corrosion resistance, high flame retardancy, and good mechanical properties is proposed. Summary of the Invention

[0005] The present invention aims to provide a silicone rubber cable material and its preparation method, addressing the problems in the prior art where it is difficult to synergistically improve the flame retardancy and corrosion resistance of silicone rubber cable materials, and the poor compatibility of inorganic fillers.

[0006] To achieve the above objectives, the present invention provides the following technical solution: The technical solution provided by this invention is: A silicone rubber cable material is composed of the following components in parts by weight: 60-80 parts methyl vinyl silicone rubber, 20-40 parts phenyl silicone rubber, 30-50 parts magnesium hydroxide, 20-30 parts aluminum hydroxide, 5-10 parts nano montmorillonite, 8-15 parts fluororubber powder, 3-8 parts zinc oxide modified with titanate coupling agent, 1-3 parts silane coupling agent, 2-5 parts vulcanizing agent, 1-2 parts antioxidant, 4-8 parts stearic acid modified sepiolite, 2-5 parts zinc hydroxystannate, 3-6 parts silicon nitride, 2-5 parts blended powder, 4-6 parts maleic anhydride grafted polyolefin elastomer modified calcium carbonate, and 3-5 parts montmorillonite / graphene composite powder. The fluororubber powder has a particle size of 1-5 μm, and the zinc oxide has a particle size of 50-100 nm. The silane coupling agent is KH550 or KH560, the vulcanizing agent is dicumyl peroxide, and the antioxidant is 2,2,4-trimethyl-1,2-dihydroquinoline polymer.

[0007] Furthermore, the vinyl content of the methyl vinyl silicone rubber is 0.1-0.3 mol%, and the phenyl content of the phenyl silicone rubber is 5-10 mol%.

[0008] Furthermore, the nano-montmorillonite is an organically modified nano-montmorillonite, and the organic modifier is hexadecyltrimethylammonium bromide.

[0009] Furthermore, the preparation method of the maleic anhydride-grafted polyolefin elastomer-modified calcium carbonate is as follows: calcium carbonate is pulverized to a particle size of 50-100 nm and dried at 105-115℃ for 2-3 h; calcium carbonate and maleic anhydride-grafted polyolefin elastomer (POE-g-MAH) are mixed at a weight ratio of 100:6-8, added to a high-speed mixer, and stirred at 120-130℃ for 40-60 min at a stirring speed of 1800-2200 r / min. After cooling, it is pulverized through a 250-mesh sieve to obtain maleic anhydride-grafted polyolefin elastomer-modified calcium carbonate; wherein, the grafting rate of the maleic anhydride-grafted polyolefin elastomer is 1.2-1.8%.

[0010] Furthermore, the montmorillonite / graphene composite powder is composed of organically modified nano-montmorillonite and graphene in a weight ratio of 9:1. The preparation method is as follows: graphene is dispersed in anhydrous ethanol and ultrasonically dispersed for 30-40 min to obtain a graphene dispersion; organically modified nano-montmorillonite is added to the graphene dispersion and stirred at 70-80℃ for 2-3 h at a stirring speed of 800-1000 r / min; subsequently, it is vacuum dried and pulverized to a particle size of 80-120 nm to obtain the montmorillonite / graphene composite powder.

[0011] Furthermore, the preparation method of the stearic acid modified sepiolite is as follows: sepiolite is crushed to a particle size of 20-50 μm, mixed with stearic acid at a weight ratio of 100:3-5, stirred and reacted at 110-130℃ for 1.5-2.5 h, with a stirring speed of 400-600 r / min, and after cooling, it is passed through a 200-mesh sieve to obtain stearic acid modified sepiolite.

[0012] Furthermore, the zinc hydroxystannate is nanoscale with a particle size of 30-80 nm.

[0013] Furthermore, the silicon nitride is α-phase silicon nitride with a particle size of 100-200 nm.

[0014] Furthermore, the blended powder is made by blending talc powder and fumed silica in a weight ratio of 6:4. The preparation method is as follows: talc powder is pulverized to a particle size of 50-100 nm, and added together with fumed silica into a high-speed mixer. Ethanol is used as the dispersion medium, and the mixture is stirred at high speed at 80-100℃ for 30-60 min at a stirring speed of 1500-2000 r / min. Subsequently, the mixture is vacuum dried and pulverized through a 300-mesh sieve to obtain the blended powder.

[0015] A method for preparing a silicone rubber cable material includes the following steps: S1 Raw Material Pretreatment: Nano-montmorillonite and hexadecyltrimethylammonium bromide are mixed at a weight ratio of 100:5-10, stirred at 80-90℃ for 2-3 hours, filtered and dried to obtain organically modified nano-montmorillonite; magnesium hydroxide and aluminum hydroxide are respectively mixed with silane coupling agent at a weight ratio of 100:1-2, stirred at 80-90℃ for 2-3 hours, and dried for later use; sepiolite is pulverized to a particle size of 20-50μm, mixed with stearic acid at a weight ratio of 100:3-5, and stirred at 110-130℃ for 1.5-2.5 hours, with a stirring speed of [missing information]. Stearic acid-modified sepiolite was obtained by cooling and passing through a 200-mesh sieve at 400-600 r / min; talc powder was pulverized to a particle size of 50-100 nm and added to a high-speed mixer with fumed silica at a weight ratio of 6:4, using ethanol as the dispersion medium, and stirred at 80-100℃ for 30-60 min at a stirring speed of 1500-2000 r / min. The mixture was then vacuum dried, pulverized, and passed through a 300-mesh sieve to obtain a blended powder; maleic anhydride-grafted polyolefin elastomer-modified calcium carbonate was prepared; montmorillonite / graphene composite powder was prepared. S2 compounding: Add methyl vinyl silicone rubber and phenyl silicone rubber to a mixer and plasticize at 100-120℃ for 5-10 minutes. Add fluororubber powder, titanate coupling agent modified zinc oxide, antioxidant, stearic acid modified sepiolite, zinc hydroxystannate, silicon nitride, blended powder, maleic anhydride grafted polyolefin elastomer modified calcium carbonate and montmorillonite / graphene composite powder, and continue mixing for 8-15 minutes. Then add pretreated magnesium hydroxide, aluminum hydroxide and organic modified nano montmorillonite, as well as the remaining silane coupling agent, and mix for 10-20 minutes. Finally, add vulcanizing agent and mix for 3-5 minutes to obtain the compound. S3 vulcanization: Place the compounded rubber into a vulcanizing machine and vulcanize for 15-30 minutes at 160-180℃ and 10-15MPa. S4 Granulation: The vulcanized rubber compound is cooled to room temperature and then granulated by a pelletizer to obtain silicone rubber cable material.

[0016] The beneficial effects of this technical solution are: (1) Stearic acid-modified sepiolite is used as the core modifying component. Through the chemical combination of stearic acid and sepiolite, the surface properties of sepiolite are optimized, the interfacial tension between it and the silicone rubber organic matrix is ​​reduced, and this inorganic filler can be uniformly dispersed in the matrix, avoiding the impact of agglomeration on the material properties. The fibrous structure of sepiolite itself can form physical support, and with the synergistic effect of the blended powder, the density of the material structure is further improved. The blended powder is composed of talc powder and fumed silica in a specific ratio. The layered structure of talc powder can construct a physical barrier layer, and the high specific surface area of ​​fumed silica can enhance the bonding force with other components. The two work together to fill the voids inside the matrix, providing a structural reinforcement basis for the material.

[0017] (2) Zinc hydroxystannate forms a highly efficient flame-retardant synergistic system with magnesium hydroxide and aluminum hydroxide. Zinc hydroxystannate can participate in the flame-retardant reaction at high temperatures, promoting the formation of a char layer. This complements the dehydration and cooling effects of traditional inorganic flame retardants, creating multiple flame-retardant defenses. Silicon nitride exhibits outstanding chemical stability. Its acid and alkali resistance and high-temperature resistance, combined with the corrosion resistance of fluororubber powder, form a double corrosion barrier on the material surface, resisting the erosion of various corrosive media. Zinc oxide modified with titanate coupling agent not only enhances the compatibility between inorganic fillers and organic matrices but also helps to inhibit free radical reactions during combustion, forming a functional complementarity with other flame-retardant components.

[0018] (3) The composite matrix of methyl vinyl silicone rubber and phenyl silicone rubber takes into account both the flexibility and high temperature resistance of the material, providing a stable load-bearing foundation for each functional filler. The layered structure of organically modified nano-montmorillonite can further enhance the flame retardant barrier effect and form a multi-dimensional structural support with sepiolite and blended powder. Silane coupling agent, as an interface modifier, improves the interfacial bonding strength between inorganic filler and organic matrix, while vulcanizing agent and antioxidant ensure the stability of the material molding process and the durability of long-term use. The components complement each other in function and synergistically enhance each other in performance, enabling the material to achieve excellent flame retardancy and corrosion resistance without sacrificing mechanical properties, making it suitable for a variety of complex application scenarios. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the preparation process of a silicone rubber cable material and its preparation method proposed in this invention. Detailed Implementation

[0020] 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 some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] The specific implementation process is as follows: Example 1: Please see Figure 1 The present invention provides a technical solution: a silicone rubber cable material and its preparation method, comprising the following components: Methyl vinyl silicone rubber (110-2S) 60kg, phenyl silicone rubber (IOTA120) 40kg, magnesium hydroxide 30kg, aluminum hydroxide 20kg, nano montmorillonite 5kg, fluororubber powder (FKM200) 8kg, titanate coupling agent modified zinc oxide 3kg, silane coupling agent KH550 1kg, vulcanizing agent S-80 2kg, antioxidant 4010NA 1kg, stearic acid modified sepiolite 4kg, zinc hydroxystannate 2kg, silicon nitride 3kg, blended powder 2kg, maleic anhydride grafted polyolefin elastomer modified calcium carbonate 4kg, montmorillonite / graphene composite powder 3kg.

[0022] Preparation method Preparation of zinc oxide modified with titanate coupling agent: Take 2.91 kg of zinc oxide and dry it at 100℃ for 3 h; take 0.09 kg of titanate coupling agent NDZ-201 and dissolve it in 1.125 kg of anhydrous ethanol to prepare a modified solution with a mass fraction of 8%; add the dried zinc oxide to the modified solution and stir at 75℃ for 3 h; after filtration, dry it at 110℃ for 4 h, grind it through a 200 mesh sieve to obtain 3 kg of zinc oxide modified with titanate coupling agent (mass ratio of zinc oxide to titanate coupling agent 100:3).

[0023] Preparation of maleic anhydride-grafted polyolefin elastomer-modified calcium carbonate: Take 3.77 kg of calcium carbonate, crush it to a particle size of 50-100 nm, and dry it at 105 °C for 2 h; take 0.23 kg of maleic anhydride-grafted polyolefin elastomer (POE-g-MAH, grafting rate 1.2%), mix it with calcium carbonate (weight ratio 100:6); add it to a high-speed mixer, stir at 120 °C for 40 min at a stirring speed of 1800 r / min; after cooling, crush it through a 250 mesh sieve to obtain 4 kg of maleic anhydride-grafted polyolefin elastomer-modified calcium carbonate.

[0024] Preparation of montmorillonite / graphene composite powder: 0.3 kg of graphene was dispersed in 5 kg of anhydrous ethanol and ultrasonically dispersed for 30 min to obtain a graphene dispersion; 2.7 kg of organically modified nano-montmorillonite (weight ratio of 9:1 to graphene) was added to the graphene dispersion; the mixture was stirred at 70 °C for 2 h at a stirring speed of 800 r / min; after vacuum drying, the powder was pulverized to a particle size of 80-120 nm to obtain 3 kg of montmorillonite / graphene composite powder.

[0025] S1 raw material pretreatment: Take 5 kg of nano-montmorillonite and add 0.25 kg of hexadecyltrimethylammonium bromide (weight ratio 100:5), stir at 80℃ for 2 h; filter and dry to obtain organically modified nano-montmorillonite.

[0026] Take 30 kg of magnesium hydroxide and add 0.3 kg of silane coupling agent KH-560 (weight ratio 100:1); take 20 kg of aluminum hydroxide and add 0.2 kg of silane coupling agent (weight ratio 100:1); stir at 80℃ for 2 hours and dry for later use.

[0027] Take 4 kg of sepiolite, crush it to a particle size of 20-50 μm, add 0.12 kg of stearic acid (weight ratio 100:3); stir and react at 110℃ for 1.5 h at a stirring speed of 400 r / min; after cooling, pass it through a 200 mesh sieve to obtain stearic acid modified sepiolite.

[0028] Take 1.2 kg of talc powder and crush it to a particle size of 50-100 nm; take 0.8 kg of fumed silica (weight ratio of 6:4 with talc powder) and add them together to a high-speed mixer; use ethanol as the dispersion medium and stir at 80°C for 30 min at a stirring speed of 1500 r / min; after vacuum drying and crushing through a 300-mesh sieve, 2 kg of blended powder is obtained.

[0029] S2 Mixed Crafting: Methyl vinyl silicone rubber and phenyl silicone rubber were added to a mixer and plasticized at 100°C for 5 minutes. Fluororubber powder, titanate coupling agent modified zinc oxide, antioxidant, stearic acid modified sepiolite, zinc hydroxystannate, silicon nitride, blended powder, maleic anhydride grafted polyolefin elastomer modified calcium carbonate, and montmorillonite / graphene composite powder were added and mixed for another 8 minutes. Pretreated magnesium hydroxide, aluminum hydroxide, and organically modified nano-montmorillonite, as well as the remaining silane coupling agent (1 kg - 0.3 kg - 0.2 kg = 0.5 kg), were added and mixed for 10 minutes. Finally, vulcanizing agent was added and mixed for 3 minutes to obtain the compound.

[0030] S3 vulcanization: Place the rubber compound into a vulcanizing machine and vulcanize it for 15 minutes at 160℃ and 10MPa.

[0031] S4 granulation: The vulcanized rubber compound is cooled to room temperature and then pelletized by a pelletizer to obtain silicone rubber cable material.

[0032] Test Project Test Results Oxygen Index 35.8% Tensile strength 9.8MPa Strength retention rate after hydrochloric acid immersion 91.3% Strength retention rate after soaking in sodium hydroxide 92.1% This embodiment demonstrates the basic performance after adjusting the lower limit ratio of each component plus the added ingredient. The oxygen index is improved compared to the original scheme, thanks to the synergistic barrier effect of the montmorillonite / graphene composite powder and the original flame retardant system. The tensile strength is significantly improved, primarily due to the "rigid particle toughening" effect of maleic anhydride-grafted polyolefin elastomer-modified calcium carbonate, which compensates for the weakening of mechanical properties by inorganic fillers. The acid and alkali resistance is steadily improved, as the montmorillonite / graphene composite powder and silicon nitride form multiple corrosion-resistant barriers, further resisting the erosion of corrosive media.

[0033] Example 2: Please see Figure 1 The present invention provides a technical solution: a silicone rubber cable material and its preparation method, comprising the following components: Methyl vinyl silicone rubber (110-2S) 70kg, phenyl silicone rubber (IOTA120) 30kg, magnesium hydroxide 40kg, aluminum hydroxide 25kg, nano montmorillonite 8kg, fluororubber powder (FKM200) 12kg, titanate coupling agent modified zinc oxide 5kg, silane coupling agent KH560 2kg, vulcanizing agent S-80 3kg, antioxidant 4010NA 1.5kg, stearic acid modified sepiolite 6kg, zinc hydroxystannate 3.5kg, silicon nitride 4.5kg, blended powder 3.5kg, maleic anhydride grafted polyolefin elastomer modified calcium carbonate 5kg, montmorillonite / graphene composite powder 4kg.

[0034] Preparation method Preparation of zinc oxide modified with titanate coupling agent: Take 4.85 kg of zinc oxide and dry it at 100℃ for 3 h; take 0.15 kg of titanate coupling agent NDZ-201 and dissolve it in 1.875 kg of anhydrous ethanol to prepare a modified solution with a mass fraction of 8%; add the dried zinc oxide to the modified solution and stir the reaction at 75℃ for 3 h; after filtration, dry it at 110℃ for 4 h, grind it through a 200-mesh sieve to obtain 5 kg of zinc oxide modified with titanate coupling agent (mass ratio of zinc oxide to titanate coupling agent 100:3).

[0035] Preparation of maleic anhydride-grafted polyolefin elastomer-modified calcium carbonate: Take 4.63 kg of calcium carbonate, crush it to a particle size of 50-100 nm, and dry it at 110 °C for 2.5 h; take 0.37 kg of maleic anhydride-grafted polyolefin elastomer (POE-g-MAH, grafting rate 1.5%), mix it with calcium carbonate (weight ratio 100:8); add it to a high-speed mixer, stir at 125 °C for 50 min at a stirring speed of 2000 r / min; after cooling, crush it through a 250 mesh sieve to obtain 5 kg of maleic anhydride-grafted polyolefin elastomer-modified calcium carbonate.

[0036] Preparation of montmorillonite / graphene composite powder: 0.4 kg of graphene was dispersed in 8 kg of anhydrous ethanol and ultrasonically dispersed for 35 min to obtain a graphene dispersion; 3.6 kg of organically modified nano-montmorillonite (weight ratio of 9:1 to graphene) was added to the graphene dispersion; the mixture was stirred at 75 °C for 2.5 h at a stirring speed of 900 r / min; after vacuum drying, the powder was pulverized to a particle size of 80-120 nm to obtain 4 kg of montmorillonite / graphene composite powder.

[0037] S1 raw material pretreatment: Take 8 kg of nano-montmorillonite and add 0.64 kg of hexadecyltrimethylammonium bromide (weight ratio 100:8), stir at 85℃ for 2.5 h; filter and dry to obtain organic modified nano-montmorillonite.

[0038] Take 40 kg of magnesium hydroxide and add 0.6 kg of silane coupling agent KH-560 (weight ratio 100:1.5); take 25 kg of aluminum hydroxide and add 0.375 kg of silane coupling agent (weight ratio 100:1.5); stir at 85℃ for 2.5 h and dry for later use.

[0039] Take 6 kg of sepiolite, crush it to a particle size of 20-50 μm, add 0.24 kg of stearic acid (weight ratio 100:4); stir and react at 120℃ for 2 h at a stirring speed of 500 r / min; after cooling, pass it through a 200-mesh sieve to obtain stearic acid modified sepiolite.

[0040] Take 2.1 kg of talc powder and crush it to a particle size of 50-100 nm; take 1.4 kg of fumed silica (weight ratio of 6:4 with talc powder) and add them together to a high-speed mixer; use ethanol as the dispersion medium and stir at 90°C for 45 min at a stirring speed of 1800 r / min; after vacuum drying and crushing through a 300-mesh sieve, 3.5 kg of blended powder is obtained.

[0041] S2 Mixed Crafting: Methyl vinyl silicone rubber and phenyl silicone rubber were added to a mixer and plasticized at 110°C for 8 minutes. Fluororubber powder, titanate coupling agent modified zinc oxide, antioxidant, stearic acid modified sepiolite, zinc hydroxystannate, silicon nitride, blended powder, maleic anhydride grafted polyolefin elastomer modified calcium carbonate, and montmorillonite / graphene composite powder were added and mixed for another 12 minutes. Pretreated magnesium hydroxide, aluminum hydroxide, and organically modified nano-montmorillonite, as well as the remaining silane coupling agent (2 kg - 0.6 kg - 0.375 kg = 1.025 kg), were added and mixed for 15 minutes. Finally, vulcanizing agent was added and mixed for 4 minutes to obtain the compound.

[0042] S3 vulcanization: Place the rubber compound into a vulcanizing machine and vulcanize it for 22 minutes at 170°C and 12MPa.

[0043] S4 granulation: The vulcanized rubber compound is cooled to room temperature and then pelletized by a pelletizer to obtain silicone rubber cable material.

[0044] Test Project Test Results Oxygen Index 39.6% Tensile strength 10.7MPa Strength retention rate after hydrochloric acid immersion 96.8% Strength retention rate after soaking in sodium hydroxide 97.3% This embodiment demonstrates the optimal overall performance after adjusting the intermediate proportions of each component and adding the new ingredients. The oxygen index is significantly improved; the interlayer barrier of the montmorillonite / graphene composite powder, combined with the high thermal conductivity of graphene, synergistically slows down the transfer of heat during combustion, forming a highly efficient flame-retardant system with zinc hydroxystannate and magnesium hydroxide. Tensile strength reaches its peak; maleic anhydride-grafted polyolefin elastomer-modified calcium carbonate optimizes interfacial bonding, while the supporting effect of stearic acid-modified sepiolite and the blended powder is superimposed, resulting in significantly better mechanical properties than the original scheme. Optimal acid and alkali corrosion resistance is achieved; the synergistic effect of multiple corrosion-resistant barriers and a dense structure ensures almost no performance degradation in corrosive media.

[0045] Example 3: Please see Figure 1 The present invention provides a technical solution: a silicone rubber cable material and its preparation method, comprising the following components: Methyl vinyl silicone rubber (110-2S) 80kg, phenyl silicone rubber (IOTA120) 20kg, magnesium hydroxide 50kg, aluminum hydroxide 30kg, nano montmorillonite 10kg, fluororubber powder (FKM200) 15kg, titanate coupling agent modified zinc oxide 8kg, silane coupling agent KH550 3kg, vulcanizing agent S-80 5kg, antioxidant 4010NA 2kg, stearic acid modified sepiolite 8kg, zinc hydroxystannate 5kg, silicon nitride 6kg, blended powder 5kg, maleic anhydride grafted polyolefin elastomer modified calcium carbonate 6kg, montmorillonite / graphene composite powder 5kg.

[0046] Preparation method Preparation of zinc oxide modified with titanate coupling agent: Take 7.77 kg of zinc oxide and dry it at 100℃ for 3 h; take 0.23 kg of titanate coupling agent NDZ-201 and dissolve it in 2.875 kg of anhydrous ethanol to prepare a modified solution with a mass fraction of 8%; add the dried zinc oxide to the modified solution and stir at 75℃ for 3 h; after filtration, dry it at 110℃ for 4 h, grind it through a 200-mesh sieve to obtain 8 kg of zinc oxide modified with titanate coupling agent (mass ratio of zinc oxide to titanate coupling agent 100:3).

[0047] Preparation of maleic anhydride-grafted polyolefin elastomer-modified calcium carbonate: Take 5.56 kg of calcium carbonate, crush it to a particle size of 50-100 nm, and dry it at 115 °C for 3 h; take 0.44 kg of maleic anhydride-grafted polyolefin elastomer (POE-g-MAH, grafting rate 1.8%), mix it with calcium carbonate (weight ratio 100:8); add it to a high-speed mixer, stir at 130 °C for 60 min at a stirring speed of 2200 r / min; after cooling, crush it through a 250 mesh sieve to obtain 6 kg of maleic anhydride-grafted polyolefin elastomer-modified calcium carbonate.

[0048] Preparation of montmorillonite / graphene composite powder: 0.5 kg of graphene was dispersed in 10 kg of anhydrous ethanol and ultrasonically dispersed for 40 min to obtain a graphene dispersion; 4.5 kg of organically modified nano-montmorillonite (weight ratio of 9:1 to graphene) was added to the graphene dispersion; the mixture was stirred at 80 °C for 3 h at a stirring speed of 1000 r / min; after vacuum drying, the powder was pulverized to a particle size of 80-120 nm to obtain 5 kg of montmorillonite / graphene composite powder.

[0049] S1 raw material pretreatment: Take 10 kg of nano-montmorillonite and add 1.0 kg of hexadecyltrimethylammonium bromide (weight ratio 100:10), stir at 90℃ for 3 h; filter and dry to obtain organic modified nano-montmorillonite.

[0050] Take 50 kg of magnesium hydroxide and add 1.0 kg of silane coupling agent KH-560 (weight ratio 100:2); take 30 kg of aluminum hydroxide and add 0.6 kg of silane coupling agent (weight ratio 100:2); stir at 90℃ for 3 hours and dry for later use.

[0051] Take 8 kg of sepiolite, crush it to a particle size of 20-50 μm, add 0.4 kg of stearic acid (weight ratio 100:5); stir and react at 130℃ for 2.5 h at a stirring speed of 600 r / min; after cooling, pass it through a 200 mesh sieve to obtain stearic acid modified sepiolite.

[0052] Take 3.0 kg of talc powder and crush it to a particle size of 50-100 nm; take 2.0 kg of fumed silica (weight ratio of 6:4 with talc powder) and add them together to a high-speed mixer; use ethanol as the dispersion medium and stir at 100℃ for 60 min at a stirring speed of 2000 r / min; after vacuum drying and crushing through a 300 mesh sieve, 5 kg of blended powder is obtained.

[0053] S2 Mixed Crafting: Methyl vinyl silicone rubber and phenyl silicone rubber were added to a mixer and plasticized at 120°C for 10 min. Fluororubber powder, zinc oxide modified with titanate coupling agent, antioxidant, stearic acid modified sepiolite, zinc hydroxystannate, silicon nitride, blended powder, maleic anhydride grafted polyolefin elastomer modified calcium carbonate, and montmorillonite / graphene composite powder were added and mixed for another 15 min. Pretreated magnesium hydroxide, aluminum hydroxide, and organically modified nano-montmorillonite, as well as the remaining silane coupling agent (3 kg - 1.0 kg - 0.6 kg = 1.4 kg), were added and mixed for 20 min. Finally, vulcanizing agent was added and mixed for 5 min to obtain the compound.

[0054] S3 vulcanization: Place the rubber compound into a vulcanizing machine and vulcanize it at 180℃ and 15MPa for 30 minutes.

[0055] S4 granulation: The vulcanized rubber compound is cooled to room temperature and then pelletized by a pelletizer to obtain silicone rubber cable material.

[0056] Test Project Test Results Oxygen Index 41.3% Tensile strength 10.5MPa Strength retention rate after hydrochloric acid immersion 98.1% Strength retention rate after soaking in sodium hydroxide 98.5% This embodiment reflects the performance characteristics after adding the upper limit ratio of each component to the new component. The oxygen index reaches the highest level. The high amount of montmorillonite / graphene composite powder forms multiple barriers with the original flame retardant system, and the high stability of graphene further inhibits the combustion reaction. Although the tensile strength is slightly lower than that of Example 2, it is still higher than the upper limit of the original scheme. Maleic anhydride grafted polyolefin elastomer modified calcium carbonate effectively alleviates the agglomeration problem caused by high filler addition and ensures stable mechanical properties. The acid and alkali corrosion resistance reaches the optimal level. The high content of the new composite powder forms a dense protective layer with silicon nitride and fluororubber powder, completely resisting the penetration of corrosive media.

[0057] Example 4: Please see Figure 1 The present invention provides a technical solution: a silicone rubber cable material and its preparation method, comprising the following components: Methyl vinyl silicone rubber (110-2S) 65kg, phenyl silicone rubber (IOTA120) 35kg, magnesium hydroxide 35kg, aluminum hydroxide 22kg, nano montmorillonite 6kg, fluororubber powder (FKM200) 10kg, titanate coupling agent modified zinc oxide 4kg, silane coupling agent KH560 1.5kg, vulcanizing agent S-80 2.5kg, antioxidant 4010NA 1.2kg, stearic acid modified sepiolite 5kg, zinc hydroxystannate 2.5kg, silicon nitride 3.5kg, blended powder 2.5kg, maleic anhydride grafted polyolefin elastomer modified calcium carbonate 4.5kg, montmorillonite / graphene composite powder 3.5kg.

[0058] Preparation method Preparation of zinc oxide modified with titanate coupling agent: Take 3.88 kg of zinc oxide and dry it at 100℃ for 3 h; take 0.12 kg of titanate coupling agent NDZ-201 and dissolve it in 1.5 kg of anhydrous ethanol to prepare a modified solution with a mass fraction of 8%; add the dried zinc oxide to the modified solution and stir the reaction at 75℃ for 3 h; after filtration, dry it at 110℃ for 4 h, grind it through a 200 mesh sieve to obtain 4 kg of zinc oxide modified with titanate coupling agent (mass ratio of zinc oxide to titanate coupling agent 100:3).

[0059] Preparation of maleic anhydride-grafted polyolefin elastomer-modified calcium carbonate: Take 4.25 kg of calcium carbonate, crush it to a particle size of 50-100 nm, and dry it at 108 °C for 2.2 h; take 0.25 kg of maleic anhydride-grafted polyolefin elastomer (POE-g-MAH, grafting rate 1.4%), mix it with calcium carbonate (weight ratio 100:6); add it to a high-speed mixer, stir at 122 °C for 45 min at a stirring speed of 1900 r / min; after cooling, crush it through a 250 mesh sieve to obtain 4.5 kg of maleic anhydride-grafted polyolefin elastomer-modified calcium carbonate.

[0060] Preparation of montmorillonite / graphene composite powder: 0.35 kg of graphene was dispersed in 7 kg of anhydrous ethanol and ultrasonically dispersed for 32 min to obtain a graphene dispersion; 3.15 kg of organically modified nano-montmorillonite (weight ratio of 9:1 to graphene) was added to the graphene dispersion; the mixture was stirred at 72℃ for 2.2 h at a stirring speed of 850 r / min; after vacuum drying, the powder was pulverized to a particle size of 80-120 nm to obtain 3.5 kg of montmorillonite / graphene composite powder.

[0061] S1 raw material pretreatment: Take 6 kg of nano-montmorillonite and add 0.36 kg of hexadecyltrimethylammonium bromide (weight ratio 100:6), stir at 82℃ for 2.2 h; filter and dry to obtain organic modified nano-montmorillonite.

[0062] Take 35 kg of magnesium hydroxide and add 0.42 kg of silane coupling agent KH-560 (weight ratio 100:1.2); take 22 kg of aluminum hydroxide and add 0.264 kg of silane coupling agent (weight ratio 100:1.2); stir at 82℃ for 2.2 h and dry for later use.

[0063] Take 5 kg of sepiolite, crush it to a particle size of 20-50 μm, add 0.175 kg of stearic acid (weight ratio 100:3.5); stir and react at 115℃ for 1.8 h at a stirring speed of 450 r / min; after cooling, pass through a 200-mesh sieve to obtain stearic acid modified sepiolite.

[0064] Take 1.5 kg of talc powder and crush it to a particle size of 50-100 nm; take 1.0 kg of fumed silica (weight ratio of 6:4 with talc powder) and add them together to a high-speed mixer; use ethanol as the dispersion medium and stir at high speed for 35 min at 85℃ with a stirring speed of 1600 r / min; after vacuum drying and crushing through a 300 mesh sieve, 2.5 kg of blended powder is obtained.

[0065] S2 Mixed Crafting: Methyl vinyl silicone rubber and phenyl silicone rubber were added to a mixer and plasticized at 105°C for 6 minutes. Fluororubber powder, titanate coupling agent modified zinc oxide, antioxidant, stearic acid modified sepiolite, zinc hydroxystannate, silicon nitride, blended powder, maleic anhydride grafted polyolefin elastomer modified calcium carbonate, and montmorillonite / graphene composite powder were added and mixed for another 10 minutes. Pretreated magnesium hydroxide, aluminum hydroxide, and organically modified nano-montmorillonite, as well as the remaining silane coupling agent (1.5 kg - 0.42 kg - 0.264 kg = 0.816 kg), were added and mixed for 12 minutes. Finally, vulcanizing agent was added and mixed for 3.5 minutes to obtain the compound.

[0066] S3 vulcanization: Place the rubber compound into a vulcanizing machine and vulcanize it for 18 minutes at 165°C and 11MPa.

[0067] S4 granulation: The vulcanized rubber compound is cooled to room temperature and then pelletized by a pelletizer to obtain silicone rubber cable material.

[0068] Test Project Test Results Oxygen Index 37.2% Tensile strength 10.1MPa Strength retention rate after hydrochloric acid immersion 93.5% Strength retention rate after soaking in sodium hydroxide 94.2% This embodiment presents a balanced performance after adjusting for lower-than-expected proportions and adding new components. The oxygen index meets high flame retardancy standards; the montmorillonite / graphene composite powder synergistically enhances flame retardancy efficiency with the existing flame-retardant components. Tensile strength is at a high level; the interface optimization effect of maleic anhydride-grafted polyolefin elastomer-modified calcium carbonate is significant, ensuring stable mechanical properties of the material. It exhibits good acid and alkali corrosion resistance; the newly added composite powder forms a synergistic protective effect with the existing corrosion-resistant components, making it suitable for applications in typical complex environments.

[0069] Example 5: Please see Figure 1 The present invention provides a technical solution: a silicone rubber cable material and its preparation method, comprising the following components: Methyl vinyl silicone rubber (110-2S) 75kg, phenyl silicone rubber (IOTA120) 25kg, magnesium hydroxide 45kg, aluminum hydroxide 28kg, nano montmorillonite 9kg, fluororubber powder (FKM200) 14kg, titanate coupling agent modified zinc oxide 7kg, silane coupling agent KH550 2.5kg, vulcanizing agent S-80 4kg, antioxidant 4010NA 1.8kg, stearic acid modified sepiolite 7kg, zinc hydroxystannate 4kg, silicon nitride 5kg, blended powder 4kg, maleic anhydride grafted polyolefin elastomer modified calcium carbonate 5.5kg, montmorillonite / graphene composite powder 4.5kg.

[0070] Preparation method Preparation of zinc oxide modified with titanate coupling agent: Take 6.80 kg of zinc oxide and dry it at 100℃ for 3 h; take 0.20 kg of titanate coupling agent NDZ-201 and dissolve it in 2.5 kg of anhydrous ethanol to prepare a modified solution with a mass fraction of 8%; add the dried zinc oxide to the modified solution and stir the reaction at 75℃ for 3 h; after filtration, dry it at 110℃ for 4 h, grind it through a 200 mesh sieve to obtain 7 kg of zinc oxide modified with titanate coupling agent (mass ratio of zinc oxide to titanate coupling agent 100:3).

[0071] Preparation of maleic anhydride-grafted polyolefin elastomer-modified calcium carbonate: Take 5.19 kg of calcium carbonate, crush it to a particle size of 50-100 nm, and dry it at 112℃ for 2.8 h; take 0.31 kg of maleic anhydride-grafted polyolefin elastomer (POE-g-MAH, grafting rate 1.7%), mix it with calcium carbonate (weight ratio 100:6); add it to a high-speed mixer, stir at 128℃ for 55 min at a stirring speed of 2100 r / min; after cooling, crush it through a 250 mesh sieve to obtain 5.5 kg of maleic anhydride-grafted polyolefin elastomer-modified calcium carbonate.

[0072] Preparation of montmorillonite / graphene composite powder: 0.45 kg of graphene was dispersed in 9 kg of anhydrous ethanol and ultrasonically dispersed for 38 min to obtain a graphene dispersion; 4.05 kg of organically modified nano-montmorillonite (weight ratio of 9:1 to graphene) was added to the graphene dispersion; the mixture was stirred at 78 °C for 2.8 h at a stirring speed of 950 r / min; after vacuum drying, the powder was pulverized to a particle size of 80-120 nm to obtain 4.5 kg of montmorillonite / graphene composite powder.

[0073] S1 raw material pretreatment: Take 9 kg of nano-montmorillonite and add 0.81 kg of hexadecyltrimethylammonium bromide (weight ratio 100:9), stir at 88℃ for 2.8 h; filter and dry to obtain organic modified nano-montmorillonite.

[0074] Take 45 kg of magnesium hydroxide and add 0.81 kg of silane coupling agent KH-560 (weight ratio 100:1.8); take 28 kg of aluminum hydroxide and add 0.504 kg of silane coupling agent (weight ratio 100:1.8); stir at 88℃ for 2.8 h and dry for later use.

[0075] Take 7 kg of sepiolite, crush it to a particle size of 20-50 μm, add 0.315 kg of stearic acid (weight ratio 100:4.5); stir and react at 125℃ for 2.3 h at a stirring speed of 550 r / min; after cooling, pass it through a 200-mesh sieve to obtain stearic acid modified sepiolite.

[0076] Take 2.4 kg of talc powder and crush it to a particle size of 50-100 nm; take 1.6 kg of fumed silica (weight ratio of 6:4 with talc powder) and add them together to a high-speed mixer; use ethanol as the dispersion medium and stir at 95°C for 50 min at a stirring speed of 1900 r / min; after vacuum drying and crushing through a 300-mesh sieve, 4 kg of blended powder is obtained.

[0077] S2 Mixed Crafting: Methyl vinyl silicone rubber and phenyl silicone rubber were added to a mixer and plasticized at 115°C for 9 minutes. Fluororubber powder, titanate coupling agent modified zinc oxide, antioxidant, stearic acid modified sepiolite, zinc hydroxystannate, silicon nitride, blended powder, maleic anhydride grafted polyolefin elastomer modified calcium carbonate, and montmorillonite / graphene composite powder were added and mixed for another 14 minutes. Pretreated magnesium hydroxide, aluminum hydroxide, and organically modified nano-montmorillonite, as well as the remaining silane coupling agent (2.5 kg - 0.81 kg - 0.504 kg = 1.186 kg), were added and mixed for 18 minutes. Finally, vulcanizing agent was added and mixed for 4.5 minutes to obtain the compound.

[0078] S3 vulcanization: The rubber compound was placed in a vulcanizing machine and vulcanized at 175℃ and 14MPa for 28 minutes.

[0079] S4 granulation: The vulcanized rubber compound is cooled to room temperature and then pelletized by a pelletizer to obtain silicone rubber cable material.

[0080] Test Project Test Results Oxygen Index 40.1% Tensile strength 10.4MPa Strength retention rate after hydrochloric acid immersion 95.7% Strength retention rate after soaking in sodium hydroxide 96.2% This embodiment demonstrates the superior performance achieved with a slightly higher proportion and the addition of new components. The oxygen index is close to the highest level of Example 3, indicating a significant synergistic effect between the new composite powder and the original flame-retardant system. Tensile strength remains high; the synergistic dispersion effect of maleic anhydride-grafted polyolefin elastomer-modified calcium carbonate and stearic acid-modified sepiolite ensures excellent mechanical properties even with high filler content. Excellent acid and alkali corrosion resistance is demonstrated; the high content of the new components forms a dense barrier with the original corrosion-resistant components, making it suitable for demanding and specialized applications.

[0081] Comparative Example 1: Please see Figure 1 The present invention provides a comparative scheme: Component differences: 6 kg of sepiolite was used instead of 6 kg of stearic acid-modified sepiolite, and the rest was the same as in Example 2.

[0082] Differences in preparation steps: There is no preparation step of stearic acid modified sepiolite in the raw material pretreatment. Sepiolite is added during mixing instead of stearic acid modified sepiolite. The rest is the same as in Example 2.

[0083] Test Project Test Results Oxygen Index 36.5% Tensile strength 8.3MPa Strength retention rate after hydrochloric acid immersion 89.2% Strength retention rate after soaking in sodium hydroxide 89.8% This comparative example reflects the performance defects of sepiolite without stearic acid modification. The oxygen index is lower than in Example 2 because the unmodified sepiolite surface is hydrophilic, resulting in poor compatibility with the organic matrix and agglomeration, which disrupts the integrity of the flame-retardant system. Tensile strength is significantly reduced, primarily because sepiolite agglomeration leads to weak bonding between the filler and matrix interface, easily causing stress concentration under load, thus affecting the overall mechanical properties of the material. Resistance to acid and alkali corrosion is poor; the agglomerated sepiolite cannot form a uniform physical support and barrier structure, allowing corrosive media to easily penetrate through gaps and damage the internal structure of the material, proving that stearic acid modification is key to improving the compatibility of sepiolite.

[0084] Comparative Example 2: Please see Figure 1 The present invention provides a comparative scheme: component difference: 3.5 kg of non-blended powder, the rest is the same as in Example 2.

[0085] Differences in preparation steps: There is no preparation step for blended powder in the raw material pretreatment, and no blended powder is added during mixing. The rest is the same as in Example 2.

[0086] Test Project Test Results Oxygen Index 35.2% Tensile strength 9.1MPa Strength retention rate after hydrochloric acid immersion 91.5% Strength retention rate after soaking in sodium hydroxide 92.0% This comparative example demonstrates the performance shortcomings of lacking blended powders. The oxygen index is significantly lower than in Example 2 because the lack of synergistic barrier effect between talc and fumed silica prevents the formation of a dense physical barrier, allowing heat and gas to easily diffuse during combustion and weakening the flame-retardant effect. The tensile strength decreases, primarily due to the insufficient density of the internal structure caused by the absence of blended powders. The layered support of talc and the interfacial reinforcement of fumed silica cannot be fully utilized, affecting the bonding strength between the matrix and the filler. The acid and alkali corrosion resistance is poor, with increased internal porosity allowing for easy penetration by corrosive media, proving that blended powders play an irreplaceable role in improving the structural integrity and functional synergy of materials.

[0087] Comparative Example 3: Please see Figure 1The present invention provides a comparative scheme: the composition difference is that there is no hydroxystannate zinc 3.5 kg and silicon nitride 4.5 kg, and the rest is the same as in Example 2.

[0088] Differences in preparation steps: Zinc hydroxystannate and silicon nitride are not added during mixing; otherwise, it is the same as in Example 2.

[0089] Test Project Test Results Oxygen Index 33.8% Tensile strength 9.3MPa Strength retention rate after hydrochloric acid immersion 87.6% Strength retention rate after soaking in sodium hydroxide 88.3% This comparative example highlights the performance deficiencies caused by the lack of zinc hydroxystannate and silicon nitride. The oxygen index drops significantly because the lack of the synergistic flame-retardant effect of zinc hydroxystannate prevents the formation of an efficient char layer. Traditional flame retardants can only provide a simple dehydration and cooling effect, resulting in a weak flame-retardant defense. Tensile strength decreases slightly, mainly due to the lack of physical support from silicon nitride, leading to insufficient internal structural support. Acid and alkali corrosion resistance deteriorates significantly, primarily because the corrosion barrier effect of silicon nitride is not realized. The corrosion resistance of fluororubber powder alone is insufficient to resist corrosive media, and the internal structure of the material is easily damaged. This demonstrates that zinc hydroxystannate and silicon nitride are key functional components for improving the flame retardancy and corrosion resistance of the material.

[0090] Comparative Example 4: Please see Figure 1 The present invention provides a comparative scheme: component difference: 3.5 kg of talc powder is used to replace 3.5 kg of blended powder, and the rest is the same as in Example 2.

[0091] Differences in preparation steps: There is no preparation step for blended powder in the raw material pretreatment, and talc powder is added instead of blended powder during mixing. The rest is the same as in Example 2.

[0092] Test Project Test Results Oxygen Index 34.5% Tensile strength 8.8MPa Strength retention rate after hydrochloric acid immersion 90.3% Strength retention rate after soaking in sodium hydroxide 90.9% This comparative example demonstrates the inadequacy of using talc powder alone as a substitute for blended powders. The oxygen index is lower than in Example 2 because the lack of the synergistic effect of the high specific surface area of ​​fumed silica means that the layered structure of talc alone cannot form a dense physical barrier layer, limiting flame retardant efficiency. Tensile strength is significantly reduced, primarily due to the lack of enhancement of interfacial bonding strength by fumed silica; insufficient bonding between talc powder and the matrix leads to easy interfacial delamination under stress. Acid and alkali corrosion resistance is slightly poor; talc powder alone cannot effectively fill the internal voids, allowing corrosive media to easily penetrate through tiny gaps. This proves that the synergistic effect of talc powder and fumed silica in blended powders is superior to that of a single filler and is a crucial factor in improving the overall performance of the material.

[0093] Comparative Example 5: Please see Figure 1 The present invention provides a comparative scheme: Component differences: 6 kg of stearic acid-modified sepiolite, 3.5 kg of zinc hydroxystannate, 4.5 kg of silicon nitride and 3.5 kg of blended powder, magnesium hydroxide is adjusted to 50 kg and aluminum hydroxide is adjusted to 30 kg, the rest is the same as in Example 2.

[0094] Differences in preparation steps: The raw material pretreatment does not include the preparation steps of stearic acid modified sepiolite and blended powder, and the above four components are not added during mixing. The rest is the same as in Example 2.

[0095] Test Project Test Results Oxygen Index 29.3% Tensile strength 6.8MPa Strength retention rate after hydrochloric acid immersion 65.7% Strength retention rate after soaking in sodium hydroxide 67.2% This comparative example reflects the performance limitations of conventional solutions in existing technologies. The oxygen index is the lowest; due to the lack of the synergistic flame-retardant effect of zinc hydroxystannate and the physical barrier effect of the blended powder and sepiolite, it is difficult to form an efficient flame-retardant system relying solely on high amounts of magnesium hydroxide and aluminum hydroxide, resulting in poor flame-retardant performance. Tensile strength is the worst; the high amount of traditional flame retardants leads to severe filler agglomeration, damaging the integrity of the matrix structure and resulting in extremely low interfacial bonding strength. Acid and alkali corrosion resistance is extremely poor; lacking the corrosion barrier of silicon nitride and the synergistic protection of various functional components, corrosive media easily penetrate, leading to severe damage to the internal structure of the material. This fully demonstrates that the newly added stearic acid-modified sepiolite, zinc hydroxystannate, silicon nitride, and blended powder in this technical solution play a decisive role in improving the overall performance of the material.

[0096] Through a comprehensive comparative analysis of the above five examples and five comparative examples, regardless of whether the components used in Example 1 (lower limit ratio), Example 4 (slightly lower limit ratio), Example 2 (intermediate ratio), Example 5 (slightly upper limit ratio), or Example 3 (upper limit ratio), the oxygen index of the product remained stable between 35.8% and 41.3%, the tensile strength remained between 9.8 MPa and 10.7 MPa, and the strength retention rates after immersion in hydrochloric acid and sodium hydroxide were no less than 91.3% and 92.1%, respectively. Compared with the original scheme, all core performance indicators showed a significant leap, and the product exhibited better performance stability over a wide component range. Among them, Example 2, as the optimal ratio scheme, achieved an oxygen index of 39.6%, a tensile strength of 10.7 MPa, and a strength retention rate exceeding 96% after acid and alkali corrosion resistance. The product demonstrated balanced performance and was at an excellent level in the industry, fully proving that the original key components and the newly added components, when properly proportioned, can maximize synergistic effects.

[0097] Stearic acid-modified sepiolite addresses the industry pain points of poor compatibility and easy agglomeration between traditional inorganic fillers and silicone rubber organic matrices by optimizing surface properties through stearic acid modification. Its fibrous structure forms a physical support after uniform dispersion. Combined with the synergistic effect of blended powders (a specific ratio of talc and fumed silica 6:4), a dense multidimensional structural support system is constructed, effectively filling the internal voids of the matrix and laying the structural foundation for performance improvement. Maleic anhydride-grafted polyolefin elastomer-modified calcium carbonate significantly improves the interfacial bonding force between inorganic fillers and organic matrices through the chemical reaction between the grafted groups and the hydroxyl groups on the surface of calcium carbonate, as well as the good compatibility between the polyolefin segments and the silicone rubber matrix. The rigid particle toughening effect compensates for the weakening of mechanical properties by traditional inorganic flame retardants, enabling the material to maintain excellent tensile strength even with high filler content. Zinc hydroxystannate forms a highly efficient flame-retardant synergistic system with traditional magnesium hydroxide and aluminum hydroxide. By complementing each other in promoting char layer formation and dehydration / cooling, it constructs multiple flame-retardant defenses. Montmorillonite / graphene composite powder utilizes the layered barrier structure of organically modified montmorillonite synergistically with the high specific surface area and high thermal conductivity of graphene to delay heat and gas transfer during combustion, further enhancing the flame-retardant effect. Silicon nitride, with its excellent chemical stability, forms a dual corrosion-resistant barrier with fluororubber powder. The high stability of the montmorillonite / graphene composite powder can be superimposed on this barrier, significantly enhancing the material's resistance to acid and alkali corrosion. The complementary functions and synergistic effects of these components represent a technological breakthrough that cannot be achieved through single-component improvements in existing technologies.

[0098] The performance data from the comparative examples further confirm the irreplaceable and synergistic value of the original key components and the newly added ingredients in this technical solution. Comparative Example 1, where unmodified sepiolite replaced stearic acid-modified sepiolite, resulted in agglomeration due to poor compatibility. Even with the addition of the new ingredients, the tensile strength still decreased to 8.3 MPa, and the acid and alkali resistance retention rate was less than 89.8%, highlighting the crucial role of stearic acid modification in optimizing filler dispersion and interfacial bonding. Comparative Example 2, lacking the blended powder, saw its oxygen index drop to 35.2% and tensile strength to 9.1%, demonstrating that the synergistic barrier and reinforcing effects of talc and fumed silica cannot be replaced by a single component, and the new ingredients alone cannot compensate for the lack of structural support. Comparative Example 3, lacking zinc hydroxystannate and silicon nitride, had an oxygen index of only 33.8% and an acid and alkali resistance retention rate of less than 88.3%, demonstrating the decisive influence of the flame-retardant synergistic effect of zinc hydroxystannate and the corrosion-resistant barrier effect of silicon nitride on performance. The newly added composite powder can only help improve some performance. In Comparative Example 4, when talc powder was replaced with a single talc powder, the oxygen index and tensile strength decreased to 34.5% and 8.8%, respectively. This indicates that the synergistic effect of talc powder and fumed silica in the blended powder is better than that of a single filler, and the newly added component cannot offset the lack of this synergistic effect. Comparative Example 5, as a conventional solution in the prior art, did not add any key functional components or new components. Even with the increase in the amount of traditional flame retardants magnesium hydroxide and aluminum hydroxide, the oxygen index was still only 29.3%, the tensile strength was as low as 6.8%, and the acid and alkali resistance strength retention rate was less than 67.2%. All performances were far lower than those in the embodiment of this technical solution, which directly reflects the performance bottleneck of the prior art and highlights the breakthrough improvement brought about by the synergy between the new component and the original key components in this technical solution.

[0099] This technical solution improves the compatibility of inorganic fillers by modifying sepiolite with stearic acid, ensuring the uniform dispersion of other functional components. The blended powder and montmorillonite / graphene composite powder synergistically construct multiple physical barrier layers, enhancing flame retardancy and mechanical support. Zinc hydroxystannate optimizes the flame retardant system, improving flame retardant efficiency. Silicon nitride and montmorillonite / graphene composite powder are superimposed to form multiple corrosion-resistant barriers, expanding application scenarios in harsh environments. Maleic anhydride-grafted polyolefin elastomer-modified calcium carbonate optimizes interfacial bonding, ensuring stable mechanical properties. Each component complements traditional components such as methyl vinyl silicone rubber, phenyl silicone rubber, and organically modified nano-montmorillonite, completely avoiding performance imbalances caused by single-component improvements. Compared with existing technologies, this solution can achieve ultra-high flame retardant performance without relying on high amounts of traditional flame retardants. It not only solves the problem of decreased mechanical properties caused by high filler addition in traditional solutions, but also significantly improves the stability of materials in harsh corrosive environments. This allows the product to be adapted to various complex application scenarios such as chemical, marine, and high-temperature environments, breaking the technical limitations of existing silicone rubber cable materials that are difficult to balance high flame retardancy, strong corrosion resistance, and excellent mechanical properties.

[0100] To further illustrate the beneficial technical effects of the silicone rubber cable materials and their preparation methods in the various embodiments of the present invention, relevant performance tests were conducted on the silicone rubber cable materials and their preparation methods in Examples 1-5 and Comparative Examples 1-5. The testing method is as follows: 1. Oxygen Index: Prepare a standard sample, ignite it in an oxygen-nitrogen mixed gas stream, and determine the minimum oxygen concentration required for the sample to maintain combustion.

[0101] 2. Tensile strength: The specimen is made into a standard dumbbell shape and stretched at a constant speed using a tensile testing machine. The maximum tensile stress at which the specimen breaks is recorded.

[0102] 3. Strength retention rate after hydrochloric acid immersion: The sample was immersed in 5% hydrochloric acid solution for 240 hours, removed and dried, and the tensile strength was tested. The ratio of the tensile strength to the strength before immersion was calculated.

[0103] 4. Strength retention rate after sodium hydroxide immersion: Immerse the sample in a 5% sodium hydroxide solution for 240 hours, remove and dry it, test the tensile strength, and calculate the ratio of the strength before immersion.

[0104] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific technical solutions or characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A silicone rubber cable material, characterized in that, It is composed of the following components in parts by weight: 60-80 parts methyl vinyl silicone rubber, 20-40 parts phenyl silicone rubber, 30-50 parts magnesium hydroxide, 20-30 parts aluminum hydroxide, 5-10 parts nano montmorillonite, 8-15 parts fluororubber powder, 3-8 parts zinc oxide modified with titanate coupling agent, 1-3 parts silane coupling agent, 2-5 parts vulcanizing agent, 1-2 parts antioxidant, 4-8 parts stearic acid modified sepiolite, 2-5 parts zinc hydroxystannate, 3-6 parts silicon nitride, 2-5 parts blended powder, 4-6 parts maleic anhydride grafted polyolefin elastomer modified calcium carbonate, and 3-5 parts montmorillonite / graphene composite powder. The fluororubber powder has a particle size of 1-5 μm, and the zinc oxide has a particle size of 50-100 nm. The silane coupling agent is KH550 or KH560, the vulcanizing agent is dicumyl peroxide, and the antioxidant is 2,2,4-trimethyl-1,2-dihydroquinoline polymer.

2. The silicone rubber cable material according to claim 1, characterized in that, The methyl vinyl silicone rubber has a vinyl content of 0.1-0.3 mol%, and the phenyl silicone rubber has a phenyl content of 5-10 mol%.

3. The silicone rubber cable material according to claim 1, characterized in that, The nano-montmorillonite is an organically modified nano-montmorillonite, and the organic modifier is hexadecyltrimethylammonium bromide.

4. The silicone rubber cable material according to claim 1, characterized in that, The preparation method of maleic anhydride-grafted polyolefin elastomer-modified calcium carbonate is as follows: calcium carbonate is pulverized to a particle size of 50-100 nm and dried at 105-115℃ for 2-3 h; calcium carbonate and maleic anhydride-grafted polyolefin elastomer (POE-g-MAH) are mixed at a weight ratio of 100:6-8, added to a high-speed mixer, and stirred at 120-130℃ for 40-60 min at a stirring speed of 1800-2200 r / min. After cooling, it is pulverized through a 250-mesh sieve to obtain maleic anhydride-grafted polyolefin elastomer-modified calcium carbonate; wherein, the grafting rate of maleic anhydride-grafted polyolefin elastomer is 1.2-1.8%.

5. The silicone rubber cable material according to claim 1, characterized in that, The montmorillonite / graphene composite powder is composed of organically modified nano-montmorillonite and graphene in a weight ratio of 9:

1. The preparation method is as follows: graphene is dispersed in anhydrous ethanol and ultrasonically dispersed for 30-40 min to obtain a graphene dispersion; organically modified nano-montmorillonite is added to the graphene dispersion and stirred at 70-80℃ for 2-3 h at a stirring speed of 800-1000 r / min; then vacuum dried and pulverized to a particle size of 80-120 nm to obtain the montmorillonite / graphene composite powder.

6. The silicone rubber cable material according to claim 1, characterized in that, The preparation method of stearic acid modified sepiolite is as follows: sepiolite is crushed to a particle size of 20-50 μm, mixed with stearic acid at a weight ratio of 100:3-5, stirred and reacted at 110-130℃ for 1.5-2.5 h, with a stirring speed of 400-600 r / min, and after cooling, it is passed through a 200-mesh sieve to obtain stearic acid modified sepiolite.

7. The silicone rubber cable material according to claim 1, characterized in that, The zinc hydroxystannate is nanoscale with a particle size of 30-80 nm.

8. The silicone rubber cable material according to claim 1, characterized in that, The silicon nitride is α-phase silicon nitride with a particle size of 100-200 nm.

9. The silicone rubber cable material according to claim 1, characterized in that, The blended powder is made by blending talc powder and fumed silica in a weight ratio of 6:

4. The preparation method is as follows: talc powder is pulverized to a particle size of 50-100 nm, and added together with fumed silica into a high-speed mixer. Ethanol is used as the dispersion medium, and the mixture is stirred at high speed at 80-100℃ for 30-60 min at a stirring speed of 1500-2000 r / min. Subsequently, the mixture is vacuum dried and pulverized through a 300-mesh sieve to obtain the blended powder.

10. A method for preparing silicone rubber cable material as described in any one of claims 1-9, characterized in that, Includes the following steps: S1 Raw Material Pretreatment: Nano-montmorillonite and hexadecyltrimethylammonium bromide are mixed at a weight ratio of 100:5-10, stirred at 80-90℃ for 2-3 hours, filtered and dried to obtain organically modified nano-montmorillonite; magnesium hydroxide and aluminum hydroxide are respectively mixed with silane coupling agent at a weight ratio of 100:1-2, stirred at 80-90℃ for 2-3 hours, and dried for later use; sepiolite is pulverized to a particle size of 20-50μm, mixed with stearic acid at a weight ratio of 100:3-5, and stirred at 110-130℃ for 1.5-2.5 minutes. The mixture was stirred at 400-600 r / min, cooled, and passed through a 200-mesh sieve to obtain stearic acid-modified sepiolite. Talc powder was pulverized to a particle size of 50-100 nm and added to a high-speed mixer with fumed silica at a weight ratio of 6:

4. Ethanol was used as the dispersion medium, and the mixture was stirred at 80-100℃ for 30-60 min at a stirring speed of 1500-2000 r / min. After vacuum drying and pulverization through a 300-mesh sieve, a blended powder was obtained. Maleic anhydride-grafted polyolefin elastomer-modified calcium carbonate was prepared. Preparation of montmorillonite / graphene composite powder; S2 compounding: Add methyl vinyl silicone rubber and phenyl silicone rubber to a mixer and plasticize at 100-120℃ for 5-10 minutes. Add fluororubber powder, titanate coupling agent modified zinc oxide, antioxidant, stearic acid modified sepiolite, zinc hydroxystannate, silicon nitride, blended powder, maleic anhydride grafted polyolefin elastomer modified calcium carbonate and montmorillonite / graphene composite powder, and continue mixing for 8-15 minutes. Then add pretreated magnesium hydroxide, aluminum hydroxide and organic modified nano montmorillonite, as well as the remaining silane coupling agent, and mix for 10-20 minutes. Finally, add vulcanizing agent and mix for 3-5 minutes to obtain the compound. S3 vulcanization: Place the compounded rubber into a vulcanizing machine and vulcanize for 15-30 minutes at 160-180℃ and 10-15MPa. S4 Granulation: The vulcanized rubber compound is cooled to room temperature and then granulated by a pelletizer to obtain silicone rubber cable material.

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