High-heat-resistance silicone tube material and preparation method thereof

Abstract

The invention relates to the field of polymer silicone tubes, provides a high-heat-resistance silicone tube material and a preparation method thereof, and aims to solve the problem that the existing silicone tube is insufficient in heat resistance and flame retardance. The material comprises amino silane modified nickel-doped melamine polyphosphate particles, methyl phenyl silicone rubber, white carbon black, hydrogen-terminated dimethyl siloxane, di-tert-butyl peroxide, acetylene carbon black, a KH570 silane coupling agent and MQ methyl silicone resin. Wherein the core component is nickel-doped melamine polyphosphate particles modified by a KH-550 amino silane coupling agent, a core-shell structure is adopted, and the preparation method comprises the steps of matrix sizing material plastifying, composite modified filler dispersing, banburying and mixing, curing treatment, extrusion molding and the like. Nickel-doped melamine polyphosphate core particles are prepared through a hydrothermal method, and then a core-shell structure is formed through amino silane modification, so that the synergistic flame-retardant effect is achieved, the heat resistance and flame retardance of the silicone tube are remarkably improved, and the silicone tube has wide industrial application prospects.

Description

Technical Field

[0001] The present invention relates to the field of polymer silicone tubes, and in particular to a high-heat-resistant silicone tube material and a preparation method thereof. Background Art

[0002] With the rapid advancement of modern industrial technology, high-temperature fluid conveyance systems are playing an increasingly important role in key sectors such as petrochemicals, automotive manufacturing, aerospace, and nuclear power equipment. In these demanding industrial environments, pipes must withstand long-term exposure to high temperatures, high pressures, and various corrosive media, while also facing sudden high-temperature shocks and potential fire risks. Consequently, stringent requirements are placed on the pipe's heat resistance and flame retardancy. Not only must the material maintain excellent mechanical strength and dimensional stability under sustained high-temperature conditions, but it must also effectively prevent the spread of combustion when exposed to flames or high temperatures, ensuring safe system operation. Silicone tubing, with its excellent flexibility, chemical stability, and biocompatibility, holds great potential for application in high-temperature fluid conveyance. Developing silicone tubing materials with superior heat resistance and flame retardancy will not only significantly improve the safety and reliability of high-temperature industrial systems, extend equipment life, and reduce maintenance costs, but will also drive related industries to expand into applications operating in higher temperatures and harsher environments, providing a solid material foundation for the sustainable development of modern industry.

[0003] Although silicone tube materials excel in many aspects, the products currently on the market still have significant deficiencies in heat resistance and flame retardancy, making it difficult to meet the increasingly stringent demands of industrial applications. Traditional silicone tubing is prone to thermal aging in long-term high-temperature environments, causing the material to harden and crack, and a sharp decline in mechanical properties. The operating temperature is usually limited to below 200°C, and it cannot adapt to working environments with higher temperatures. At the same time, conventional silicone materials have relatively poor flame retardancy. When exposed to open flames or high heat, they easily burn and produce toxic fumes, posing a serious safety hazard. For example, the Chinese patent with publication number CN108129846A discloses a high-temperature resistant silicone tube that improves performance by adding specific fillers, but suffers from insufficient heat resistance and flame retardancy. The fundamental reason for these performance defects is that the thermal motion of the silicone matrix molecular chain at high temperatures intensifies, resulting in the destruction of the cross-linked structure, and there is a lack of effective flame retardant mechanisms to inhibit the free radical chain reaction during the combustion process. In addition, traditional modification methods often add flame retardants through simple physical blending, resulting in poor compatibility between the flame retardant components and the silicone matrix. This not only affects the overall performance of the material, but may also cause the flame retardant to precipitate or decompose during high-temperature use, further reducing the heat resistance and flame retardant effect of the material. Summary of the Invention

[0004] (1) Technical problems to be solved: The purpose of the present invention is to provide a high-heat-resistant silicone tube material and a preparation method thereof, so as to solve the problem that the current silicone tube has insufficient heat resistance and flame retardancy.

[0005] (2) Technical solution: In order to achieve the above-mentioned object, the present invention provides the following technical solution: A high-heat-resistant silicone tube material comprises the following raw materials in parts by weight: 10.0-20.0 parts of aminosilane-modified nickel-doped melamine polyphosphate particles; 100.0-150.0 parts of methylphenyl silicone rubber, 20.0-50.0 parts of white carbon black, 15.0-25.0 parts of hydrogen-terminated dimethyl (siloxane and polysiloxane), 0.5-2.0 parts of di-tert-butyl peroxide, 1.0-5.0 parts of acetylene black, 1.0-3.0 parts of KH570 silane coupling agent, and 2.0-5.0 parts of MQ methyl silicone resin; The aminosilane-modified nickel-doped melamine polyphosphate particles are nickel-doped melamine polyphosphate particles modified with KH-550 aminosilane coupling agent; The aminosilane-modified nickel-doped melamine polyphosphate particles are core-shell particles, wherein the nickel-doped melamine polyphosphate particles are the core and the KH-550 aminosilane-modified layer is the shell, and the shell thickness is 2.0 to 10.0 nm; The nickel-doped melamine polyphosphate particles are composite particles with a synergistic flame retardant effect, which are formed by doping nickel ions into the melamine polyphosphate lattice through a hydrothermal method.

[0006] Furthermore, the preparation method of the aminosilane-modified nickel-doped melamine polyphosphate particles is as follows: in parts by weight, 8.0 to 15.0 parts of nickel-doped melamine polyphosphate particles are dispersed in 80.0 to 120.0 parts of anhydrous ethanol, and the mixture is dispersed for 30.0 to 60.0 min at a reaction temperature of 35.0 to 45.0° C. and a stirring rate of 200.0 to 300.0 rpm under mechanical stirring to obtain a uniform suspension, and then 1.0 to 3.0 parts of KH-550 aminosilane coupling agent and 20.0 to 30.0 parts of anhydrous ethanol are mixed and stirred until completely dissolved, and then the aminosilane solution is slowly added dropwise to the nickel-doped melamine polyphosphate particle suspension at a drop rate of 0.5 to 2.0 mL / min under a nitrogen protective atmosphere, and the reaction temperature is controlled to be 70.0 to 80.0° C. during the dropwise addition process, and the reaction time is continued under reflux conditions for 3.0 to 6.0 minutes after the dropwise addition is completed. h, then the reaction system was cooled to room temperature at a cooling rate of 3.0-5.0°C / min, and the solid product was collected by centrifugation at a speed of 3000.0-5000.0 rpm for 10.0-15.0 min. The solid product was washed with anhydrous ethanol 2.0-3.0 times to remove unreacted aminosilane, and finally the product was dried in a vacuum drying oven at 60.0-80.0°C for 8.0-12.0 h to obtain aminosilane-modified nickel-doped melamine polyphosphate particles.

[0007] Furthermore, the mass ratio of the KH-550 aminosilane coupling agent to the nickel-doped melamine polyphosphate particles is 1:(5.0-8.0).

[0008] Furthermore, the preparation method of the nickel-doped melamine polyphosphate particles is as follows: 10.0-15.0 parts of melamine polyphosphate and 200.0-250.0 parts of deionized water are added to a container by weight, heated to a reaction temperature of 35.0-45.0°C under mechanical stirring, and dispersed for 30.0-40.0 min at a stirring rate of 200.0-400.0 rpm to obtain a uniformly dispersed milky white suspension, and then 4.5-8.0 parts of nickel nitrate hexahydrate and 100.0-120.0 parts of deionized water are stirred in the container until completely dissolved to obtain a green transparent solution, and then the nickel nitrate solution is added dropwise to the melamine polyphosphate suspension at a drop rate of 1.0-3.0 mL / min with the help of a constant flow pump under vigorous mechanical stirring conditions, the reaction temperature is continuously maintained at 35.0-45.0°C during the dropwise addition process, and the stirring reaction time is continued for 4.0-6.0 minutes after the dropwise addition is completed. h, then the reaction system was transferred to a polytetrafluoroethylene reactor and sealed with stainless steel. The reaction was hydrothermally reacted in an oven at a reaction temperature of 55.0-65.0°C for 10.0-14.0 h. After the reaction, the reactor was naturally cooled to room temperature, and unreacted ions were removed by vacuum filtration and repeated rinsing with deionized water for 3.0-5.0 times. Finally, the wet product was dried in a vacuum drying oven at 70.0-80.0°C for 10.0-14.0 h and ground multiple times to obtain light green nickel-doped melamine polyphosphate granular powder.

[0009] Furthermore, the mass ratio of the melamine polyphosphate to nickel nitrate hexahydrate is (10.0-15.0):(4.5-8.0).

[0010] Furthermore, the average diameter of the aminosilane-modified nickel-doped melamine polyphosphate particles is 200.0-800.0 nm.

[0011] This invention utilizes a core-shell structure of nickel-doped melamine polyphosphate particles modified with KH-550 aminosilane coupling agent to enhance the heat resistance and flame retardancy of silicone tubing materials. Nickel ions are hydrothermally incorporated into the melamine polyphosphate lattice, forming a composite particle core with a synergistic flame retardant effect. The introduction of nickel ions not only catalyzes the formation of a more stable carbon layer at high temperatures but also promotes the dilution of combustible gas concentrations by nitrogen generated by melamine decomposition, thereby achieving dual flame retardancy in both the gas and condensed phases. On this basis, surface modification with KH-550 aminosilane coupling agent resulted in the formation of an aminosilane-modified shell with a thickness of 2.0–10.0 nm on the surface of nickel-doped melamine polyphosphate particles. This core-shell structure fosters good interfacial compatibility and chemical bonding between the modified particles and the silica matrix. The amino groups in the aminosilane molecules react with the silica matrix to form stable covalent bonds, while the siloxane structure shares a similar chemical structure with the silica matrix, significantly improving the dispersion and interfacial bonding strength of the flame-retardant filler within the silica matrix. This multi-layered synergistic mechanism mutually enhances the intrinsic flame retardancy of the nickel-doped melamine polyphosphate and the interfacial optimization effect of the aminosilane-modified shell. This not only improves the uniform dispersion of the flame-retardant filler within the silica matrix, but also enhances the compactness and stability of the char layer under high-temperature conditions. It also improves the dimensional stability and mechanical property retention of the material under high-temperature conditions. Ultimately, this significantly enhances the heat resistance and flame retardancy of the silicone tubing material, meeting the stringent safety and reliability requirements for high-temperature industrial applications.

[0012] The present invention also discloses a method for preparing a high-heat-resistant silicone tube material, comprising the following steps: S1. The methylphenyl silicone rubber was placed in an open mill and masticated at 80.0~100.0 ° C, the roller speed was 15.0~25.0 rpm, the roller pitch was 1.0~3.0 mm, the mastication time was 8.0~15.0 min, the compound temperature was controlled at 100~120.0 ° C, and after mastication, it was cooled to 21.0~25.0 ° C for standby; S2. Add silica, aminosilane-modified nickel-doped melamine polyphosphate particles, and acetylene black to a high-speed mixer and disperse at 40.0-60.0°C at 800.0-1200.0 rpm. Simultaneously, add KH-570 silane coupling agent dropwise at a rate of 0.5-1.0 mL / min for a total mixing time of 10.0-20.0 min to obtain a composite modified filler system. S3. The base rubber obtained in step S1 was put into an internal mixer at a speed of 40.0~80.0 rpm, heated to 110.0~140.0 ° C, the composite filler obtained in step S2 was added and mixed for 3.0~6.0 min, followed by the addition of MQ methyl silicone resin and hydrogen-terminated dimethyl (siloxane and polysiloxane), and mixing was continued for 8.0~15.0 min. The discharge temperature was controlled at 120.0~150.0 ° C; the obtained internal rubber was transferred to an open mill, cooled to 50.0~60.0 ° C, di-tert-butyl peroxide was added, and the mixture was mixed at a roller speed of 20.0~40.0 rpm for 3.0~8.0 min. The rubber temperature was controlled at 80~90.0 ° C to obtain a composite rubber; S4. The composite rubber was placed in an environment of 21.0~25.0 ° C and a relative humidity of 50.0~65.0% for 12.0~24.0 h, and the surface was covered with a 0.05~0.10 mm polyethylene film; S5. The matured rubber compound is extruded into a single-screw extruder with the body temperature set between 90.0°C and 120.0°C, the die temperature between 100.0°C and 130.0°C, the screw speed between 15.0 and 35.0 rpm, the extrusion speed between 2.0 and 8.0 m / min, and the ratio of the pulling speed to the extrusion speed between 1.0 and 1.2. The extruded hose is sequentially vulcanized in two stages to complete the preparation of the high-heat-resistant silicone hose.

[0013] Furthermore, the two-stage vulcanization includes: primary vulcanization: in a hot air environment at 170.0~200.0°C, continuously vulcanize at a pressure of 0.3~0.8 MPa for 5.0~12.0 min; secondary vulcanization: placing the primary vulcanized hose in a hot air circulation oven at 200.0~250.0°C and continuing to vulcanize for 2.0~6.0 h, with the heating rate controlled at 5.0~15.0°C / min.

[0014] The present invention adopts a preparation scheme of a methylphenyl silicone rubber matrix combined with a composite modified filler system, which is mainly used to enhance the heat resistance and flame retardancy of silicone tube materials. Methylphenyl silicone rubber is used as the matrix material, and the phenyl side groups introduced into its molecular chain can significantly improve the high temperature resistance of the material. The rigid structure of the benzene ring effectively limits the thermal motion of the molecular chain segments at high temperatures, thereby enhancing the thermal stability of the silicone matrix. The composite modified filler system realizes multiple performance enhancement mechanisms through the synergistic combination of white carbon black, aminosilane-modified nickel-doped melamine polyphosphate particles and acetylene carbon black. Among them, white carbon black as a reinforcing filler can significantly improve the mechanical strength and dimensional stability of the silicone, acetylene carbon black improves the thermal conductivity efficiency of the material through its excellent thermal conductivity, and aminosilane-modified nickel-doped melamine polyphosphate particles play a key flame retardant role. During the filler pretreatment process, the dropwise addition of KH-570 silane coupling agent further enhances the interfacial compatibility between various fillers and the silicone matrix, forming a stable chemical bonding network. The addition of MQ methyl silicone resin and hydrogen-terminated dimethylsiloxane and polysiloxane not only increases the crosslink density of the silicone network but also enhances the material's heat resistance through its unique molecular structure. The MQ resin's three-dimensional network structure effectively inhibits molecular chain degradation at high temperatures, while the hydrogen-terminated structure provides additional crosslinking reaction sites. Di-tert-butyl peroxide, a crosslinking agent, decomposes during the vulcanization process to produce free radicals that trigger crosslinking reactions between silicone molecular chains, forming a stable three-dimensional network structure. The two-stage vulcanization process design enables precise control of the crosslinking reaction. The initial vulcanization stage ensures basic molding and initial crosslinking of the rubber compound, while the secondary vulcanization stage, through higher temperatures and longer treatment times, further enhances the crosslinking reaction while eliminating byproducts produced during the vulcanization process. Ultimately, a three-dimensional network structure with excellent heat resistance and flame retardancy is formed. This multi-component synergistic design fully utilizes the performance advantages of each component, achieving a comprehensive improvement in the overall performance of the silicone tubing material.

[0015] (3) Beneficial technical effects 1. The present invention synergistically constructs a dense carbon layer and a stable interface through the core-shell structure flame-retardant filler and the silicone matrix, significantly improving the heat resistance and flame retardancy of the silicone tube, solving the problems of non-dense pyrolysis carbon layer and easy fall-off of filler under high temperature conditions. It is suitable for scenarios such as cable sheathing and high-temperature fluid transportation, and has excellent structural stability, interface compatibility and gas-condensation dual-phase flame retardancy. Compared with a single filler system, it has stronger synergy and irreplaceability, and promotes the engineering application of high-performance flame-retardant silicone materials in the field of safety and fire protection.

[0016] 2. The present invention synergistically constructs a dense cross-linked network through phenyl silicone rubber and multi-phase modified fillers, significantly improving heat resistance and flame retardancy, solving problems such as poor pyrolysis carbonization and dimensional instability of silicone tubes at high temperatures, and combining structural stability and processing practicality, with superior synergy and irreplaceability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the XRD phase analysis diagram of nickel-doped melamine polyphosphate particles prepared in Example 1 of the present invention.

[0018] Figure 2 This is a core-shell morphology image and EDS elemental analysis image of the aminosilane-modified nickel-doped melamine polyphosphate particles prepared in Example 1 of the present invention.

[0019] Figure 3 This is the surface morphology of the silicone tube prepared in Example 1 of the present invention after the heat aging test.

[0020] Figure 4 This is the surface morphology of the silicone tube prepared in Comparative Example 1 of the present invention after the heat aging test.

[0021] Figure 5 This is a morphology picture of aminosilane-modified nickel-doped melamine polyphosphate particles prepared in Comparative Example 4 of the present invention. DETAILED DESCRIPTION

[0022] To make the objectives, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0023] Example 1: A high heat-resistant silicone tube material, comprising the following raw materials in parts by weight: 10.0 parts of aminosilane-modified nickel-doped melamine polyphosphate particles; 100.0 parts of methylphenyl silicone rubber, 20.0 parts of white carbon black, 15.0 parts of hydrogen-terminated dimethyl (siloxane and polysiloxane), 0.5 parts of di-tert-butyl peroxide, 1.0 part of acetylene black, 1.0 part of KH570 silane coupling agent, and 2.0 parts of MQ methyl silicone resin; The aminosilane-modified nickel-doped melamine polyphosphate particles of this embodiment are nickel-doped melamine polyphosphate particles modified by KH-550 aminosilane coupling agent; the aminosilane-modified nickel-doped melamine polyphosphate particles are core-shell particles, in which the nickel-doped melamine polyphosphate particles are the core, the KH-550 aminosilane modified layer is the shell, and the shell thickness is 2.0 nm; the nickel-doped melamine polyphosphate particles are composite particles with a synergistic flame retardant effect formed by doping nickel ions into the melamine polyphosphate lattice by a hydrothermal method.

[0024] The preparation method of the aminosilane-modified nickel-doped melamine polyphosphate particles of the present embodiment is as follows: 8.0 parts of nickel-doped melamine polyphosphate particles are dispersed in 80.0 parts of anhydrous ethanol, and the mixture is dispersed for 30.0 min at a reaction temperature of 35.0°C and a stirring rate of 200.0 rpm under mechanical stirring to obtain a uniform suspension, and then 1.0 part of KH-550 aminosilane coupling agent is mixed with 20.0 parts of anhydrous ethanol and stirred until completely dissolved, and then the aminosilane solution is slowly added dropwise to the nickel-doped melamine polyphosphate particle suspension at a drop rate of 0.5 mL / min under a nitrogen protective atmosphere, the reaction temperature is controlled to 70.0°C during the dropwise addition process, and the reaction time is continued under reflux conditions for 3.0 h after the dropwise addition is completed, and then the reaction system is cooled to room temperature at a cooling rate of 3.0°C / min, and centrifuged at a speed of 3000.0 rpm for 10.0 min. The solid product was collected for 10 min, washed with anhydrous ethanol 2.0 times to remove unreacted aminosilane, and finally dried in a vacuum drying oven at 60.0°C for 8.0 h to obtain aminosilane-modified nickel-doped melamine polyphosphate particles.

[0025] The preparation method of the nickel-doped melamine polyphosphate particles of this embodiment is as follows: in parts by weight, 12 parts of melamine polyphosphate and 215 parts of deionized water are added to a container, the temperature is raised to a reaction temperature of 38.0°C under mechanical stirring, the stirring rate is 260 rpm, and the dispersion is carried out for 33 min to obtain a uniformly dispersed milky white suspension, then 6 parts of nickel nitrate hexahydrate and 106 parts of deionized water are stirred in the container until they are completely dissolved to obtain a green transparent solution, then the nickel nitrate solution is added dropwise to the melamine polyphosphate suspension at a dropping rate of 2 mL / min with the help of a constant flow pump under vigorous mechanical stirring conditions, the reaction temperature is continuously maintained at 38.0°C during the dropwise addition process, and the stirring reaction is continued for 5 h after the dropwise addition is completed, and then the reaction system is transferred to a polytetrafluoroethylene reactor and sealed with stainless steel, and hydrothermally reacted in an oven at a reaction temperature of 58.0°C for 11 h. After the reaction, the reactor was naturally cooled to room temperature, and the unreacted ions were removed by vacuum filtration and repeated rinsing with deionized water four times. Finally, the wet product was dried in a vacuum drying oven at 73.0°C for 11 h and ground several times to obtain light green nickel-doped melamine polyphosphate granular powder.

[0026] The average diameter of the aminosilane-modified nickel-doped melamine polyphosphate particles of this embodiment is 380 nm.

[0027] A method for preparing a high-heat-resistant silicone tube material in this embodiment includes the following steps: S1. The methylphenyl silicone rubber was placed in an open mill and masticated at 86.0 ° C, the roller speed was 18 rpm, the roller pitch was 2 mm, the mastication time was 10 min, the rubber temperature was controlled at 106 ° C, and after mastication, it was cooled to 22.0 ° C for standby; S2. Add silica, aminosilane-modified nickel-doped melamine polyphosphate particles, and acetylene black to a high-speed mixer and disperse at 920 rpm at 46.0°C. Simultaneously, KH-570 silane coupling agent was added dropwise at a rate of 1.0 mL / min for a total mixing time of 13 min to prepare a composite modified filler system. S3. The base rubber obtained in step S1 was put into an internal mixer at a speed of 52 rpm and heated to 119.0 ° C. The composite filler obtained in step S2 was added and mixed for 4 min. Then, MQ methyl silicone resin and hydrogen-terminated dimethyl (siloxane and polysiloxane) were added and mixed for 10 min. The discharge temperature was controlled at 129.0 ° C. The obtained internal mixer was transferred to an open mill, cooled to 53.0 ° C, and di-tert-butyl peroxide was added. The mixture was mixed at a roller speed of 26 rpm for 4 min. The temperature of the rubber was controlled at 83 ° C to obtain a composite rubber. S4. The composite rubber was placed in an environment of 22.0 ° C and a relative humidity of 55.0% for 16h, and the surface was covered with a 0.07mm polyethylene film; S5. The matured rubber compound was extruded into a single-screw extruder with the body temperature set at 99.0°C, the die temperature at 109.0°C, the screw speed at 21 rpm, the extrusion speed at 4 m / min, and the ratio of the pulling speed to the extrusion speed controlled at 1.1. The extruded hose was subjected to a two-stage vulcanization to complete the preparation of a high-heat-resistant silicone hose. The two-stage vulcanization process included: initial vulcanization in a hot air environment at 179.0°C, maintaining a pressure of 0.5 MPa for 7 min; secondary vulcanization: the initially vulcanized hose was placed in a hot air circulation oven at 215.0°C and vulcanized for another 3 h at a heating rate of 8.0°C / min.

[0028] Example 2: A high heat-resistant silicone tube material comprises the following raw materials in parts by weight: 13 parts of aminosilane-modified nickel-doped melamine polyphosphate particles; 115 parts of methylphenyl silicone rubber, 29 parts of white carbon black, 18 parts of hydrogen-terminated dimethyl (siloxane and polysiloxane), 1.0 part of di-tert-butyl peroxide, 2 parts of acetylene black, 2 parts of KH570 silane coupling agent, and 3 parts of MQ methyl silicone resin.

[0029] The aminosilane-modified nickel-doped melamine polyphosphate particles of this embodiment are nickel-doped melamine polyphosphate particles modified by KH-550 aminosilane coupling agent; the aminosilane-modified nickel-doped melamine polyphosphate particles are core-shell particles, in which the nickel-doped melamine polyphosphate particles are the core, the KH-550 aminosilane modified layer is the shell, and the shell thickness is 4.4 nm; the nickel-doped melamine polyphosphate particles are composite particles with a synergistic flame retardant effect formed by doping nickel ions into the melamine polyphosphate lattice by a hydrothermal method.

[0030] The preparation method of the aminosilane-modified nickel-doped melamine polyphosphate particles of the present embodiment is as follows: in parts by weight, 10 parts of nickel-doped melamine polyphosphate particles are dispersed in 92 parts of anhydrous ethanol, and the mixture is dispersed for 39 minutes at a reaction temperature of 38.0°C and a stirring rate of 230 rpm under mechanical stirring to obtain a uniform suspension, and then 2 parts of KH-550 aminosilane coupling agent are mixed with 23 parts of anhydrous ethanol and stirred until completely dissolved, and then the aminosilane solution is slowly added dropwise to the nickel-doped melamine polyphosphate particle suspension at a dropping rate of 1.0 mL / min under a nitrogen protective atmosphere, the reaction temperature is controlled to 73.0°C during the dropping process, and the reaction time is continued under reflux conditions for 4 hours after the dropping is completed, and then the reaction system is cooled to room temperature at a cooling rate of 4.0°C / min, and centrifuged at a speed of 3600 rpm for 12 minutes. The solid product was collected for 10 min, washed twice with anhydrous ethanol to remove unreacted aminosilane, and finally dried in a vacuum drying oven at 66.0°C for 9 h to obtain aminosilane-modified nickel-doped melamine polyphosphate particles.

[0031] The preparation method of the nickel-doped melamine polyphosphate particles of the present embodiment is as follows: in parts by weight, 10.0 parts of melamine polyphosphate and 200.0 parts of deionized water are added to a container, the temperature is raised to a reaction temperature of 35.0°C under mechanical stirring, the stirring rate is 200.0 rpm, and the dispersion is carried out for 30.0 min to obtain a uniformly dispersed milky white suspension, and then 4.5 parts of nickel nitrate hexahydrate and 100.0 parts of deionized water are stirred in the container until they are completely dissolved to obtain a green transparent solution, and then the nickel nitrate solution is dropwise added to the melamine polyphosphate suspension at a drop rate of 1.0 mL / min with the help of a constant flow pump under vigorous mechanical stirring. The reaction temperature is continuously maintained at 35.0°C during the dropwise addition process. After the dropwise addition is completed, the stirring reaction time is continued for 4.0 h. Thereafter, the reaction system is transferred to a polytetrafluoroethylene reactor and sealed with stainless steel, and hydrothermally reacted in an oven at a reaction temperature of 55.0°C for 10.0 min. h. After the reaction, the reactor was naturally cooled to room temperature, and unreacted ions were removed by vacuum filtration and repeated rinsing with deionized water 3.0 times. Finally, the wet product was dried in a vacuum drying oven at 70.0°C for 10.0 h and ground several times to obtain light green nickel-doped melamine polyphosphate granular powder.

[0032] The average diameter of the aminosilane-modified nickel-doped melamine polyphosphate particles of this embodiment is 200.0 nm.

[0033] A method for preparing a high-heat-resistant silicone tube material in this embodiment includes the following steps: S1. The methylphenyl silicone rubber was placed in an open mill and masticated at 80.0 ° C, the roller speed was 15.0rpm, the roller pitch was 1.0 mm, the mastication time was 8.0 min, the compound temperature was controlled at 100 ° C, and after mastication, it was cooled to 21.0 ° C for standby; S2. Add silica, aminosilane-modified nickel-doped melamine polyphosphate particles, and acetylene black to a high-speed mixer and disperse at 800 rpm at 40°C. Simultaneously, KH-570 silane coupling agent was added dropwise at a rate of 0.5 mL / min for a total mixing time of 10 min to prepare a composite modified filler system. S3. The base rubber obtained in step S1 was put into an internal mixer at a speed of 40.0 rpm, heated to 110.0 ° C, and the composite filler obtained in step S2 was added and mixed for 3.0 min. Subsequently, MQ methyl silicone resin and hydrogen-terminated dimethyl (siloxane and polysiloxane) were added and mixed for 8.0 min. The discharge temperature was controlled at 120.0 ° C; the obtained internal rubber was transferred to an open mill, cooled to 50.0 ° C, and di-tert-butyl peroxide was added. The mixture was mixed at a roller speed of 20.0 rpm for 3.0 min, and the rubber temperature was controlled to 80 ° C to obtain a composite rubber. S4. The composite rubber was placed in an environment of 21.0 ° C and a relative humidity of 50.0% for 12.0h, and the surface was covered with a 0.05mm polyethylene film; S5. The matured rubber compound was extruded into a single-screw extruder with the body temperature set at 90.0°C, the die temperature at 100.0°C, the screw speed at 15.0 rpm, the extrusion speed at 2.0 m / min, and the ratio of the pulling speed to the extrusion speed controlled at 1.0. The extruded hose was subjected to a two-stage vulcanization to complete the preparation of a high-heat-resistant silicone hose. The two-stage vulcanization process included: initial vulcanization in a hot air environment at 170.0°C, maintaining a pressure of 0.3 MPa for 5.0 min; secondary vulcanization: the initially vulcanized hose was placed in a hot air circulation oven at 200.0°C and vulcanized for another 2.0 h at a heating rate of 5.0°C / min.

[0034] Example 3: A high heat-resistant silicone tube material comprises the following raw materials in parts by weight: 16 parts of aminosilane-modified nickel-doped melamine polyphosphate particles; 130 parts of methylphenyl silicone rubber, 38 parts of white carbon black, 21 parts of hydrogen-terminated dimethyl (siloxane and polysiloxane), 1.4 parts of di-tert-butyl peroxide, 3 parts of acetylene black, 2 parts of KH570 silane coupling agent, and 4 parts of MQ methyl silicone resin.

[0035] The aminosilane-modified nickel-doped melamine polyphosphate particles of this embodiment are nickel-doped melamine polyphosphate particles modified by KH-550 aminosilane coupling agent; the aminosilane-modified nickel-doped melamine polyphosphate particles are core-shell particles, in which the nickel-doped melamine polyphosphate particles are the core, the KH-550 aminosilane modified layer is the shell, and the shell thickness is 6.8 nm; the nickel-doped melamine polyphosphate particles are composite particles with a synergistic flame retardant effect formed by doping nickel ions into the melamine polyphosphate lattice by a hydrothermal method.

[0036] The preparation method of the aminosilane-modified nickel-doped melamine polyphosphate particles of the present embodiment is as follows: in parts by weight, 12 parts of nickel-doped melamine polyphosphate particles are dispersed in 104 parts of anhydrous ethanol, and the mixture is dispersed for 48 min at a reaction temperature of 41.0°C and a stirring rate of 260 rpm under mechanical stirring to obtain a uniform suspension, and then 2 parts of KH-550 aminosilane coupling agent are mixed with 26 parts of anhydrous ethanol and stirred until completely dissolved, and then the aminosilane solution is slowly added dropwise to the nickel-doped melamine polyphosphate particle suspension at a dropping rate of 1.4 mL / min under a nitrogen protective atmosphere, the reaction temperature is controlled to 76.0°C during the dropping process, and the reaction time is continued under reflux conditions for 5 h after the dropping is completed, and then the reaction system is cooled to room temperature at a cooling rate of 4.0°C / min, and centrifuged at a speed of 4200 rpm for 13 The solid product was collected at 400 nm and washed three times with anhydrous ethanol to remove unreacted aminosilane. Finally, the product was dried in a vacuum drying oven at 72.0 °C for 10 h to obtain aminosilane-modified nickel-doped melamine polyphosphate particles.

[0037] The mass ratio of the KH-550 aminosilane coupling agent to the nickel-doped melamine polyphosphate particles in this embodiment is 1:15.0.

[0038] The preparation method of the nickel-doped melamine polyphosphate particles of the present embodiment is as follows: 15.0 parts of melamine polyphosphate and 250.0 parts of deionized water are added to a container by weight, and the temperature is raised to a reaction temperature of 45.0°C under mechanical stirring, and the stirring rate is 400.0 rpm for dispersion for 40.0 min to obtain a uniformly dispersed milky white suspension, and then 8.0 parts of nickel nitrate hexahydrate and 120.0 parts of deionized water are stirred in the container until they are completely dissolved to obtain a green transparent solution, and then the nickel nitrate solution is dropwise added to the melamine polyphosphate suspension at a drop rate of 3.0 mL / min with the help of a constant flow pump under vigorous mechanical stirring. The reaction temperature is continuously maintained at 45.0°C during the dropwise addition process. After the dropwise addition is completed, the stirring reaction time is continued for 6.0 h. Thereafter, the reaction system is transferred to a polytetrafluoroethylene reactor and sealed with stainless steel, and hydrothermally reacted in an oven at a reaction temperature of 65.0°C for 14.0 h. After the reaction, the reactor was naturally cooled to room temperature, and unreacted ions were removed by vacuum filtration and repeated rinsing with deionized water 5.0 times. Finally, the wet product was dried in a vacuum drying oven at 80.0°C for 14.0 h and ground several times to obtain light green nickel-doped melamine polyphosphate granular powder.

[0039] The average diameter of the aminosilane-modified nickel-doped melamine polyphosphate particles of this embodiment is 800.0 nm.

[0040] A method for preparing a high-heat-resistant silicone tube material in this embodiment includes the following steps: S1. The methylphenyl silicone rubber was placed in an open mill and masticated at 100.0 ° C, the roller speed was 25.0rpm, the roller pitch was 3.0 mm, the mastication time was 15.0 min, the compound temperature was controlled at 120.0 ° C, and after mastication, it was cooled to 25.0 ° C for standby; S2. Add silica, aminosilane-modified nickel-doped melamine polyphosphate particles, and acetylene black to a high-speed mixer and disperse at 1200 rpm at 60.0°C. Simultaneously, KH-570 silane coupling agent was added dropwise at a rate of 1.0 mL / min for a total mixing time of 20.0 min to obtain a composite modified filler system. S3. The base rubber obtained in step S1 was put into an internal mixer at a speed of 80.0 rpm, heated to 140.0 ° C, and the composite filler obtained in step S2 was added and mixed for 6.0 min. Subsequently, MQ methyl silicone resin and hydrogen-terminated dimethyl (siloxane and polysiloxane) were added and mixing was continued for 15.0 min. The discharge temperature was controlled at 150.0 ° C; the obtained internal rubber was transferred to an open mill, cooled to 60.0 ° C, and di-tert-butyl peroxide was added. The mixture was mixed at a roller speed of 40.0 rpm for 8.0 min, and the rubber temperature was controlled at 90.0 ° C to obtain a composite rubber. S4. The composite rubber was placed in an environment of 25.0 ° C and a relative humidity of 65.0% for 24.0h, and the surface was covered with a 0.10mm polyethylene film; S5. The matured rubber compound was extruded into a single-screw extruder with the body temperature set at 120.0°C, the die temperature at 130.0°C, the screw speed at 35.0 rpm, the extrusion speed at 8.0 m / min, and the ratio of the pulling speed to the extrusion speed controlled at 1.2. The extruded hose was subjected to a two-stage vulcanization to complete the preparation of a high-heat-resistant silicone hose. The two-stage vulcanization process included: initial vulcanization in a hot air environment at 200.0°C for 12.0 min at a pressure of 0.8 MPa; and secondary vulcanization in a hot air circulation oven at 250.0°C for an additional 6.0 h at a heating rate of 15.0°C / min.

[0041] Example 4: A high heat-resistant silicone tube material, comprising the following raw materials in parts by weight: 20.0 parts of aminosilane-modified nickel-doped melamine polyphosphate particles; 150.0 parts of methylphenyl silicone rubber, 50.0 parts of white carbon black, 25.0 parts of hydrogen-terminated dimethyl (siloxane and polysiloxane), 2.0 parts of di-tert-butyl peroxide, 5.0 parts of acetylene black, 3.0 parts of KH570 silane coupling agent, and 5.0 parts of MQ methyl silicone resin.

[0042] The aminosilane-modified nickel-doped melamine polyphosphate particles of this embodiment are nickel-doped melamine polyphosphate particles modified by KH-550 aminosilane coupling agent; the aminosilane-modified nickel-doped melamine polyphosphate particles are core-shell particles, in which the nickel-doped melamine polyphosphate particles are the core, the KH-550 aminosilane modified layer is the shell, and the shell thickness is 10.0 nm; the nickel-doped melamine polyphosphate particles are composite particles with a synergistic flame retardant effect formed by doping nickel ions into the melamine polyphosphate lattice by a hydrothermal method.

[0043] The preparation method of the aminosilane-modified nickel-doped melamine polyphosphate particles of the present embodiment is as follows: 15.0 parts by weight of nickel-doped melamine polyphosphate particles are dispersed in 120.0 parts of anhydrous ethanol, and the mixture is dispersed for 60.0 min at a reaction temperature of 45.0°C and a stirring rate of 300.0 rpm under mechanical stirring to obtain a uniform suspension, and then 3.0 parts of KH-550 aminosilane coupling agent and 30.0 parts of anhydrous ethanol are mixed and stirred until completely dissolved, and then the aminosilane solution is slowly added dropwise to the nickel-doped melamine polyphosphate particle suspension at a dropping rate of 2.0 mL / min under a nitrogen protective atmosphere, the reaction temperature is controlled to be 80.0°C during the dropping process, and the reaction time is continued under reflux conditions for 6.0 h after the dropping is completed, and then the reaction system is cooled to room temperature at a cooling rate of 5.0°C / min, and centrifuged at a speed of 5000.0 rpm for 15.0 min. The solid product was collected for 10 min, washed with anhydrous ethanol 3 times to remove unreacted aminosilane, and finally dried in a vacuum drying oven at 80.0°C for 12.0 h to obtain aminosilane-modified nickel-doped melamine polyphosphate particles.

[0044] The preparation method of the nickel-doped melamine polyphosphate particles of this embodiment is as follows: 13 parts by weight of melamine polyphosphate and 230 parts by weight of deionized water are added to a container, the temperature is raised to a reaction temperature of 41.0°C under mechanical stirring, the stirring rate is 320 rpm, and the dispersion is carried out for 36 min to obtain a uniformly dispersed milky white suspension, and then 7 parts of nickel nitrate hexahydrate and 112 parts of deionized water are stirred in the container until they are completely dissolved to obtain a green transparent solution, and then the nickel nitrate solution is added dropwise to the melamine polyphosphate suspension at a drop rate of 2 mL / min with the help of a constant flow pump under vigorous mechanical stirring. The reaction temperature is continuously maintained at 41.0°C during the dropwise addition process. After the dropwise addition is completed, the stirring reaction time is continued for 5 h. Thereafter, the reaction system is transferred to a polytetrafluoroethylene reactor and sealed with stainless steel, and hydrothermally reacted in an oven at a reaction temperature of 61.0°C for 12 h. After the reaction, the reactor was naturally cooled to room temperature, and unreacted ions were removed by vacuum filtration and repeated rinsing with deionized water four times. Finally, the wet product was dried in a vacuum drying oven at 76.0°C for 12 h and ground several times to obtain light green nickel-doped melamine polyphosphate granular powder.

[0045] The average diameter of the aminosilane-modified nickel-doped melamine polyphosphate particles of this embodiment is 560 nm.

[0046] A method for preparing a high-heat-resistant silicone tube material in this embodiment includes the following steps: S1. The methylphenyl silicone rubber was placed in an open mill and masticated at 92.0 ° C, the roller speed was 21 rpm, the roller pitch was 2 mm, the mastication time was 12 min, the compound temperature was controlled at 112 ° C, and after mastication, it was cooled to 23.0 ° C for standby; S2. Silica, aminosilane-modified nickel-doped melamine polyphosphate particles, and acetylene black were added to a high-speed mixer and dispersed at 1040 rpm at 52.0°C. KH-570 silane coupling agent was added dropwise at a rate of 0.8 mL / min for a total mixing time of 16 min to prepare a composite modified filler system. S3. The base rubber obtained in step S1 was put into an internal mixer at a speed of 64 rpm and heated to 128.0 ° C. The composite filler obtained in step S2 was added and mixed for 5 min. Then, MQ methyl silicone resin and hydrogen-terminated dimethyl (siloxane and polysiloxane) were added and mixed for 12 min. The discharge temperature was controlled at 138.0 ° C. The obtained internal mixer was transferred to an open mill, cooled to 56.0 ° C, and di-tert-butyl peroxide was added. The mixture was mixed at a roller speed of 32 rpm for 6 min. The temperature of the rubber was controlled at 86 ° C to obtain a composite rubber. S4. The composite rubber was placed in an environment of 23.0 ° C and a relative humidity of 59.0% for 19h, and the surface was covered with a 0.08mm polyethylene film; S5. The matured rubber compound was extruded into a single-screw extruder with the body temperature set at 108.0°C, the die temperature at 118.0°C, the screw speed at 27 rpm, the extrusion speed at 6 m / min, and the ratio of the pulling speed to the extrusion speed controlled at 1.1. The extruded hose was subjected to a two-stage vulcanization to complete the preparation of a high-heat-resistant silicone hose. The two-stage vulcanization process included: initial vulcanization in a hot air environment at 188.0°C, maintaining a pressure of 0.6 MPa for 9 minutes; secondary vulcanization: the initially vulcanized hose was placed in a hot air circulation oven at 230.0°C and vulcanized for another 4 hours at a heating rate of 11.0°C / min.

[0047] Comparative Example 1: basically the same as Example 1, except that aminosilane-modified nickel-doped melamine polyphosphate particles were not added, and the amounts of other components remained unchanged.

[0048] Comparative Example 2 is basically the same as Example 1, except that 10.0 parts of nickel-doped melamine polyphosphate particles that have not been modified with KH-550 aminosilane coupling agent are used instead of the aminosilane-modified nickel-doped melamine polyphosphate particles.

[0049] Comparative Example 3 is basically the same as Example 1, except that 10.0 parts of ordinary melamine polyphosphate particles are used instead of aminosilane-modified nickel-doped melamine polyphosphate particles, and nickel ion doping and aminosilane modification treatment are not performed.

[0050] Comparative Example 4: basically the same as Example 1, except that the amount of KH-550 aminosilane coupling agent added in the preparation of aminosilane-modified nickel-doped melamine polyphosphate particles is 0.5 parts, resulting in the nickel-doped melamine polyphosphate particles failing to be coated.

[0051] Comparative Example 5 is basically the same as Example 1, except that 100.0 parts of ordinary methyl silicone rubber is used instead of methyl phenyl silicone rubber, and the molecular chain does not contain a phenyl side group structure.

[0052] Comparative Example 6: basically the same as Example 1, except that the reaction temperature of the dropwise addition process during the preparation of aminosilane-modified nickel-doped melamine polyphosphate particles is 25.0°C.

[0053] Comparative Example 7: basically the same as Example 1, except that the reflux reaction time during the preparation of aminosilane-modified nickel-doped melamine polyphosphate particles is 1.0 h.

[0054] Comparative Example 8: basically the same as Example 1, except that the hydrothermal reaction temperature during the preparation of nickel-doped melamine polyphosphate particles is 45.0°C.

[0055] Comparative Example 9: basically the same as Example 1, except that the hydrothermal reaction time during the preparation of nickel-doped melamine polyphosphate particles is 6.0 h.

[0056] Comparative Example 10: basically the same as Example 1, except that 12 parts of melamine polyphosphate and 2 parts of nickel nitrate hexahydrate were added to prepare nickel-doped melamine polyphosphate particles.

[0057] Comparative Example 11: basically the same as Example 1, except that the plasticizing temperature in step S1 is 60.0°C.

[0058] Comparative Example 12: basically the same as Example 1, except that the secondary vulcanization temperature is 280.0°C.

[0059] Performance Testing: Tensile Strength Test: The high-heat-resistant silicone tubing materials prepared in the Examples and Comparative Examples were subjected to tensile strength testing in accordance with GB / T 528-2009. Dumbbell-shaped standard specimens with a thickness of 2.0 ± 0.2 mm were prepared. Tensile testing was performed at room temperature using a universal testing machine at a speed of 500 mm / min. The maximum tensile stress at break was recorded as the tensile strength value. Five parallel specimens were tested for each sample group, and the average result was taken as the final result.

[0060] Heat Aging Resistance Test: The silicone tubing materials prepared in the Examples and Comparative Examples were evaluated for heat aging resistance according to GB / T 3512-2014. The samples were placed in a hot air aging chamber and aged continuously at 200°C for 168 hours. Mechanical properties such as tensile strength, elongation at break, and hardness were measured before and after aging. The heat aging resistance of the materials was evaluated by calculating the performance retention rate (performance retention rate = (performance value after aging / performance value before aging) × 100%).

[0061] Flame Retardancy Test: The flame retardancy of the silicone tubing materials prepared in the Examples and Comparative Examples was evaluated using a vertical combustion test method in accordance with the UL-94 standard. Standard test strips of silicone tubing measuring 127 mm x 12.7 mm x 3.2 mm were prepared and clamped vertically in a combustion test apparatus. A Bunsen burner flame (flame height 20 mm) was applied to the bottom of the sample for 10 seconds before removal. The burning time, dripping behavior, and spread of the sample were recorded. The flame retardancy rating of the material was determined based on the burning behavior.

[0062] Thermal Stability Analysis: The thermal stability of the silicone tubing materials prepared in Examples 1-4 and Comparative Examples 1-15 was tested using a thermogravimetric analyzer (TGA) according to ASTM E1131. A 5-10 mg sample was placed in an alumina crucible and heated from room temperature to 800°C at a heating rate of 10°C / min under a nitrogen atmosphere. The thermogravimetric and differential thermogravimetric curves of the sample were recorded. The initial decomposition temperature (T5%, the temperature at which 5% weight loss occurs), the maximum decomposition rate temperature, and the carbon residue rate at 800°C were analyzed to evaluate the thermal stability of the material.

[0063] Dynamic Mechanical Properties: Dynamic mechanical properties of the silicone tubing materials prepared in the Examples and Comparative Examples were tested using a dynamic mechanical analyzer (DMA) according to ASTM D4065. Samples were prepared into rectangular bars (length × width × thickness = 35 mm × 10 mm × 2 mm) and tested in tension mode with a frequency of 1 Hz, a strain amplitude of 0.1%, a temperature range of -80°C to 250°C, and a heating rate of 3°C / min. The storage modulus (E'), loss modulus (E''), and dissipation factor (tan δ) were measured as a function of temperature, and the glass transition temperature and high-temperature mechanical properties of the materials were analyzed.

[0064] The effectiveness and superiority of the technical solution of the present invention were verified through a series of characterization analyses. Figure 1 The XRD phase analysis diagram clearly shows that the nickel-doped melamine polyphosphate particles prepared in Example 1 have a clear melamine polyphosphate crystal phase structure, proving the successful synthesis of the basic phase. Figure 2 The core-shell morphology and EDS elemental analysis further confirm that the aminosilane-modified nickel-doped melamine polyphosphate particles have indeed formed the expected core-shell structure, in which the successful doping of nickel elements and the effective coating of aminosilane are intuitively verified. The comparative test results of heat aging resistance further highlight the technical advantages of the present invention. Figure 3 As shown in FIG, the surface of the silicone tube prepared in Example 1 remains smooth and flat after the heat aging test, which fully proves its excellent heat aging resistance. Figure 4 The surface of the silicone tube prepared in Comparative Example 1 showed obvious blistering, indicating that the performance was degraded due to the lack of key flame retardant components. Figure 5 The morphology of the aminosilane-modified nickel-doped melamine polyphosphate particles in Comparative Example 4 shows that the particles failed to form an effective coating structure, further verifying the importance of preparation process parameters for obtaining an ideal core-shell structure. These characterization results together demonstrate the significant effect of the technical solution of the present invention in improving the heat resistance and flame retardancy of silicone tube materials.

[0065] The properties of the rubber tubes of Examples 1 to 4 and Comparative Examples 1 to 12 are summarized in Table 1. It can be seen from the table that in the comparative examples, the absence, unmodified or insufficient doping of the core flame retardant filler significantly weakened the flame retardant properties and thermal stability of the material, which was manifested in a decrease in flame retardant grade, a significant decrease in initial decomposition temperature and residual carbon rate; insufficient surface modification of the filler or deviation of the dropwise addition reaction conditions resulted in poor interface bonding with the silica gel matrix, resulting in poor filler dispersion, and further causing a decrease in tensile strength, an increase in tanδ, and a decrease in aging performance; and incomplete functional filler structure or unbalanced doping ratio limited the synergistic flame retardant effect, affecting the density and stability of the pyrolytic carbon layer; in addition, deviations in processing parameters such as plasticizing temperature or vulcanization temperature will result in insufficient or excessive cross-linking, affecting the mechanical property retention rate and microstructural stability of the material, ultimately leading to overall performance degradation, making it difficult to meet the requirements of high-temperature flame retardant applications.

[0066] Table 1 Performance summary of rubber tubes of Examples 1 to 4 and Comparative Examples 1 to 12:

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that any equivalent structural transformations made within the scope of the present invention using the contents of the present invention's description and drawings should be included within the scope of protection of the claims of the present invention.

Claims

1. A high heat-resistant silicone tube material, characterized in that: The invention comprises the following raw materials in parts by weight: 10.0-20.0 parts of aminosilane-modified nickel-doped melamine polyphosphate particles; 100.0-150.0 parts of methylphenyl silicone rubber, 20.0-50.0 parts of white carbon black, 15.0-25.0 parts of hydrogen-terminated dimethyl (siloxane and polysiloxane), 0.5-2.0 parts of di-tert-butyl peroxide, 1.0-5.0 parts of acetylene black, 1.0-3.0 parts of KH570 silane coupling agent, and 2.0-5.0 parts of MQ methyl silicone resin; The aminosilane-modified nickel-doped melamine polyphosphate particles are nickel-doped melamine polyphosphate particles modified with KH-550 aminosilane coupling agent; The aminosilane-modified nickel-doped melamine polyphosphate particles are core-shell particles, wherein the nickel-doped melamine polyphosphate particles are the core and the KH-550 aminosilane-modified layer is the shell, and the shell thickness is 2.0 to 10.0 nm; The nickel-doped melamine polyphosphate particles are composite particles with a synergistic flame retardant effect, which are formed by doping nickel ions into the melamine polyphosphate lattice through a hydrothermal method.

2. A high heat-resistant silicone tube material according to claim 1, characterized in that: The preparation method of the aminosilane-modified nickel-doped melamine polyphosphate particles is as follows: 8.0 to 15.0 parts by weight of nickel-doped melamine polyphosphate particles are dispersed in 80.0 to 120.0 parts of anhydrous ethanol, and the mixture is dispersed for 30.0 to 60.0 min under mechanical stirring at a reaction temperature of 35.0 to 45.0° C. and a stirring rate of 200.0 to 300.0 rpm to obtain a uniform suspension, and then 1.0 to 3.0 parts of KH-550 aminosilane coupling agent and 20.0 to 30.0 parts of anhydrous ethanol are mixed and stirred until completely dissolved, and then the aminosilane solution is slowly added dropwise to the nickel-doped melamine polyphosphate particle suspension at a dropwise rate of 0.5 to 2.0 mL / min under a nitrogen protective atmosphere, wherein the reaction temperature is controlled at 70.0 to 80.0° C. during the dropwise addition process, and the reaction is continued under reflux for 3.0 to 6.0 minutes after the dropwise addition is completed. h, then the reaction system was cooled to room temperature at a cooling rate of 3.0-5.0°C / min, and the solid product was collected by centrifugation at a speed of 3000.0-5000.0 rpm for 10.0-15.0 min. The solid product was washed with anhydrous ethanol 2.0-3.0 times to remove unreacted aminosilane, and finally the product was dried in a vacuum drying oven at 60.0-80.0°C for 8.0-12.0 h to obtain aminosilane-modified nickel-doped melamine polyphosphate particles.

3. A high heat-resistant silicone tube material according to claim 1, characterized in that: The mass ratio of the KH-550 aminosilane coupling agent to the nickel-doped melamine polyphosphate particles is 1:(5.0-8.0).

4. A high heat-resistant silicone tube material according to claim 1, characterized in that: The preparation method of the nickel-doped melamine polyphosphate particles is as follows: 10.0-15.0 parts of melamine polyphosphate and 200.0-250.0 parts of deionized water are added to a container by weight, and the temperature is raised to a reaction temperature of 35.0-45.0°C under mechanical stirring, and the stirring rate is 200.0-400.0 rpm for dispersion for 30.0-40.0 min to obtain a uniformly dispersed milky white suspension; then 4.5-8.0 parts of nickel nitrate hexahydrate and 100.0-120.0 parts of deionized water are stirred in the container until completely dissolved to obtain a green transparent solution; then, under vigorous mechanical stirring conditions, the nickel nitrate solution is dropwise added to the melamine polyphosphate suspension at a drop rate of 1.0-3.0 mL / min with the help of a constant flow pump; the reaction temperature is continuously maintained at 35.0-45.0°C during the dropwise addition process, and the stirring reaction time is continued for 4.0-6.0 minutes after the dropwise addition is completed. h, then the reaction system was transferred to a polytetrafluoroethylene reactor and sealed with stainless steel. The reaction was hydrothermally reacted in an oven at a reaction temperature of 55.0-65.0°C for 10.0-14.0 h. After the reaction, the reactor was naturally cooled to room temperature, and unreacted ions were removed by vacuum filtration and repeated rinsing with deionized water for 3.0-5.0 times. Finally, the wet product was dried in a vacuum drying oven at 70.0-80.0°C for 10.0-14.0 h and ground multiple times to obtain light green nickel-doped melamine polyphosphate granular powder.

5. A high heat-resistant silicone tube material according to claim 4, characterized in that: The mass ratio of the melamine polyphosphate to nickel nitrate hexahydrate is (10.0-15.0):(4.5-8.0).

6. A high heat-resistant silicone tube material according to claim 1, characterized in that: The average diameter of the aminosilane-modified nickel-doped melamine polyphosphate particles is 200.0-800.0 nm.

7. The method for preparing a high heat-resistant silicone tube material according to any one of claims 1 to 6, wherein: The following steps are involved: S1. The methylphenyl silicone rubber was placed in an open mill and masticated at 80.0~100.0 ° C, the roller speed was 15.0~25.0 rpm, the roller pitch was 1.0~3.0 mm, the mastication time was 8.0~15.0 min, the compound temperature was controlled at 100~120.0 ° C, and after mastication, it was cooled to 21.0~25.0 ° C for standby; S2. Add silica, aminosilane-modified nickel-doped melamine polyphosphate particles, and acetylene black to a high-speed mixer and disperse at 40.0-60.0°C at 800.0-1200.0 rpm. Simultaneously, add KH-570 silane coupling agent dropwise at a rate of 0.5-1.0 mL / min for a total mixing time of 10.0-20.0 min to obtain a composite modified filler system. S3. The base rubber obtained in step S1 was put into an internal mixer at a speed of 40.0~80.0 rpm, heated to 110.0~140.0 ° C, the composite filler obtained in step S2 was added and mixed for 3.0~6.0 min, followed by the addition of MQ methyl silicone resin and hydrogen-terminated dimethyl (siloxane and polysiloxane), and mixing was continued for 8.0~15.0 min. The discharge temperature was controlled at 120.0~150.0 ° C; the obtained internal rubber was transferred to an open mill, cooled to 50.0~60.0 ° C, di-tert-butyl peroxide was added, and the mixture was mixed at a roller speed of 20.0~40.0 rpm for 3.0~8.0 min. The rubber temperature was controlled at 80~90.0 ° C to obtain a composite rubber; S4. The composite rubber was placed in an environment of 21.0~25.0 ° C and a relative humidity of 50.0~65.0% for 12.0~24.0 h, and the surface was covered with a 0.05~0.10 mm polyethylene film; S5. The matured rubber compound is extruded into a single-screw extruder with the body temperature set between 90.0°C and 120.0°C, the die temperature between 100.0°C and 130.0°C, the screw speed between 15.0 and 35.0 rpm, the extrusion speed between 2.0 and 8.0 m / min, and the ratio of the pulling speed to the extrusion speed between 1.0 and 1.

2. The extruded hose is sequentially vulcanized in two stages to complete the preparation of the high-heat-resistant silicone hose.

8. The method for preparing a high heat-resistant silicone tube material according to claim 7, characterized in that: The two-stage vulcanization includes: primary vulcanization: in a hot air environment at 170.0-200.0°C, continuously vulcanize for 5.0-12.0 min under a pressure of 0.3-0.8 MPa; secondary vulcanization: placing the primary vulcanized hose in a hot air circulation oven at 200.0-250.0°C and continuing to vulcanize for 2.0-6.0 h, with the heating rate controlled at 5.0-15.0°C / min.

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