Heat insulation cable and preparation method thereof
By combining modified hollow glass microspheres and silicon-based aerogel particles, the problem of insufficient thermal insulation performance of traditional cables in high-temperature environments is solved, and the stable operation and improved flexibility of cables in high-temperature environments are achieved.
Patent Information
- Application Number
- CN202511491357.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-18
- Publication Date
- 2026-02-13
AI Technical Summary
Traditional cables have insufficient thermal insulation performance in high-temperature environments and poor flexibility. The insulation material is prone to falling off after long-term use, resulting in low efficiency in cable laying in confined spaces and a short service life.
Using EPDM rubber, butadiene rubber, and ethylene-vinyl acetate rubber as matrix materials, combined with modified hollow glass microspheres and silicon-based aerogel particles, the hollow glass microspheres are modified with aminosilane, polyethylene glycol, and N,N-succinimide carbonate to form a uniformly distributed protective layer, which reduces the thermal conductivity and enhances the mechanical properties.
It improves the thermal insulation and flexibility of the cable, avoids multi-layer composite structures, enhances the cable's stable operation in high-temperature environments, and extends its service life.
Abstract
Description
Technical Field
[0001] This application relates to the field of cable technology, and in particular to a heat-insulating cable and its manufacturing method. Background Technology
[0002] With the increasing high-temperature operation of industrial equipment and the growing demand for new energy power transmission, the stable operation of cables in high-temperature environments (such as metallurgical furnaces, nuclear power facilities, or photovoltaic power stations) faces severe challenges. Traditional cables mostly use inorganic materials such as ceramic fibers and mica tape as insulation layers, but their thermal conductivity is high, and multi-layer composite structures are required to meet insulation requirements, leading to increased cable outer diameter and decreased flexibility. In recent years, aerogels, due to their ultra-low thermal conductivity and lightweight properties, have been regarded as a direction for upgrading insulation materials.
[0003] Existing cables typically use a ceramic fiber layer to wrap the conductor, with an outer galvanized steel tape armor layer to improve mechanical strength. While this type of cable can withstand temperatures up to 800℃ for short periods, the ceramic fiber layer needs to be at least 5mm thick to provide effective insulation. This results in an excessively large bending radius and a significant increase in weight due to the armor structure, leading to low installation efficiency in confined spaces. Under prolonged high temperatures, the ceramic fiber layer is prone to detachment, causing a substantial decrease in the cable's thermal insulation performance. Summary of the Invention
[0004] In order to improve the thermal insulation performance of cables, enhance their flexibility, and ensure their long-term stable operation in high-temperature environments, this application provides a thermally insulated cable and its preparation method.
[0005] Firstly, the heat-insulating cable provided in this application adopts the following technical solution: A heat-insulating cable, wherein the cable comprises, from the inside out, a cable core, a composite shielding layer, a filling layer and a protective layer; The protective layer is made of raw materials comprising the following parts by weight: 40-50 parts of EPDM rubber, 25-35 parts of butadiene rubber, 12-15 parts of ethylene-vinyl acetate rubber, 12-14 parts of modified hollow glass microspheres, 7-9 parts of carbon black N347, 8-12 parts of silicone aerogel particles, 1-2 parts of stearic acid, 2-4 parts of vulcanizing agent, 1.1-1.5 parts of crosslinking aid, and 0.5-0.7 parts of antioxidant; The raw materials for preparing the modified hollow glass microspheres include hollow glass microspheres, aminosilane, polyethylene glycol, and N,N-succinimide carbonate, and the weight ratio of the hollow glass microspheres, aminosilane, polyethylene glycol, and N,N-succinimide carbonate is 1:(0.02-0.04):(0.4-0.6):(0.4-0.6).
[0006] By adopting the above technical solutions, this application uses EPDM rubber, butadiene rubber, and ethylene-vinyl acetate rubber as the matrix materials for the cable protective layer, enabling the cable to comprehensively utilize the excellent properties of the three types of rubber. Modified hollow glass microspheres and silicon-based aerogel particles can reduce the thermal conductivity of the protective layer and improve the cable's thermal insulation performance; the addition of carbon black N347 can enhance the rubber's abrasion resistance and anti-aging properties; stearic acid helps to disperse other raw materials evenly; vulcanizing agents can enable the rubber to undergo vulcanization reactions, enhancing the rubber's strength and elasticity; crosslinking aids can promote rubber crosslinking and improve the rubber's physical properties; and antioxidants can slow down the aging rate of the rubber and extend the cable's service life.
[0007] Specifically, this application employs aminosilane, polyethylene glycol, and N,N-succinimidyl carbonate to synergistically modify hollow glass microspheres. The silanol groups generated from the hydrolysis of aminosilane combine with the hydroxyl groups on the surface of the hollow glass microspheres, introducing amino groups onto the surface. Since the hydroxyl groups at the ends of the polyethylene glycol molecular chains have poor reactivity, N,N-succinimidyl carbonate is used to activate the polyethylene glycol. The activated polyethylene glycol combines with the amino groups, thereby grafting polyethylene glycol onto the surface of the hollow glass microspheres. This results in the uniform distribution of the hollow glass microspheres within the rubber matrix. The strong interaction between the hollow glass microsphere particles and the rubber matrix effectively improves the mechanical properties of the rubber. Simultaneously, the hollow structure and the presence of a certain amount of gas encapsulated within the spheres give the material excellent thermal insulation properties. Silicon-based aerogel particles have ultra-low thermal conductivity and lightweight properties. When combined with modified hollow glass microspheres, they further improve the thermal insulation performance of the cable, avoid the need to use multi-layer composite structures to meet thermal insulation requirements, reduce the outer diameter of the cable, enhance the flexibility of the cable, and ensure the long-term stable operation of the cable in high-temperature environments.
[0008] Preferably, the method for preparing the modified hollow glass microspheres includes the following steps: (1) Add hollow glass microspheres to NaOH solution, heat to 60-80℃, stir for 4-6 hours, filter and dry to obtain pretreated hollow glass microspheres; (2) Mix the pretreated hollow glass microspheres, aminosilane and solvent evenly, sonicate for 30-45 min, stir and react at 70-80℃ for 4-6 h, centrifuge after reaction, wash and dry to obtain silanized hollow glass microspheres. (3) Dissolve polyethylene glycol in a solvent, add N,N-succinimide carbonate and catalyst at 50-60℃, stir and react for 3-4h to obtain activated polyethylene glycol solution, add silanized hollow glass microspheres to activated polyethylene glycol solution, sonicate for 25-35min, stir and react for 3-4h at 40-60℃, filter, wash and dry to obtain modified hollow glass microspheres.
[0009] Preferably, the catalyst in step (3) is one or both of pyridine and triethylamine.
[0010] Preferably, the aminosilane is selected from one or two of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane and N-(2-aminoethyl)-3-aminopropyltriethoxysilane.
[0011] By adopting the above technical solution, and applying modified hollow glass microspheres to the protective layer of thermally insulated cables, the shortcomings caused by the use of high thermal conductivity inorganic thermal insulation materials in traditional cables can be compensated, the thermal insulation performance of the cables can be improved, and the problem of thermal insulation performance deterioration due to the protective layer falling off under long-term high temperature can be avoided.
[0012] Specifically, pretreatment of hollow glass microspheres with NaOH solution can clean surface impurities and give them active groups, which is beneficial for subsequent reactions. After aminosilanization treatment, aminosilanes are grafted onto the surface of hollow glass microspheres, which enhances their grafting rate with polymers. Polyethylene glycol is activated and grafted onto the surface of hollow glass microspheres, which effectively improves the dispersibility of hollow glass microspheres in rubber matrix and improves the thermal insulation performance of cables.
[0013] Preferably, the hollow glass microspheres have a particle size of 20-40 μm.
[0014] By adopting the above technical solution, the hollow glass microspheres with a particle size of 20-40μm used in this application can better cooperate with other raw materials to enhance the thermal insulation performance of the cable, while avoiding the impact of uneven dispersion caused by particle size issues on the overall performance of the cable.
[0015] Preferably, the vulcanizing agent is selected from one or both of di-tert-butyl peroxide and dicumyl peroxide.
[0016] By adopting the above technical solution, peroxide vulcanizing agents can enable the rubber molecular chains in the cable protective layer to form an effective cross-linked structure. On the one hand, this can enhance the stability and durability of the rubber material, allowing the cable protective layer to better resist external environmental erosion and damage during long-term use, thus extending the cable's service life; on the other hand, it helps to improve the mechanical properties of the cable protective layer, giving it better flexibility and bending resistance.
[0017] Preferably, the crosslinking aid is selected from one or more of TAIC, TAC, trimethylolpropane triacrylate, and ethylene glycol diacrylate.
[0018] By adopting the above technical solution, the crosslinking aid promotes the crosslinking reaction, significantly shortens the vulcanization time, and improves production efficiency.
[0019] Preferably, the antioxidant is selected from one or more of antioxidant RD, antioxidant SP, and antioxidant 445.
[0020] By adopting the above technical solutions, adding anti-aging agents can delay the aging of the cable protective layer and extend the service life of the cable.
[0021] Secondly, the method for manufacturing a heat-insulating cable provided in this application adopts the following technical solution: A method for manufacturing a heat-insulating cable includes the following steps: Ethylene propylene diene monomer (EPDM) rubber, butadiene rubber, ethylene-vinyl acetate rubber, modified hollow glass microspheres, carbon black N347, silicone aerogel particles, stearic acid, and antioxidant are mixed at 130-140℃ for 10-15 minutes to obtain a premix. The vulcanizing agent and crosslinking aid are mixed with the premix and vulcanized at 110-120℃ and 3-10 MPa for 7-10 minutes. The protective layer material is then extruded using an extruder to coat the outside of the cable filler layer, forming a protective layer.
[0022] By adopting the above technical solution, the raw materials are vulcanized under appropriate temperature and pressure conditions, which enables the materials to undergo a good cross-linking reaction. The resulting cable protective layer can improve the thermal insulation performance of the cable and reduce its weight.
[0023] In summary, this application includes at least one of the following beneficial technical effects: This application uses EPDM rubber, butadiene rubber, and ethylene-vinyl acetate rubber as the matrix materials for the cable protective layer, enabling the cable to comprehensively utilize the excellent properties of these three types of rubber. Modified hollow glass microspheres and silica-based aerogel particles can reduce the thermal conductivity of the protective layer and improve the cable's thermal insulation performance; the addition of carbon black N347 can enhance the rubber's abrasion resistance and anti-aging properties; stearic acid helps to disperse other raw materials evenly; vulcanizing agents enable the rubber to undergo vulcanization reactions, enhancing the rubber's strength and elasticity; crosslinking aids can promote rubber crosslinking and improve the rubber's physical properties; and antioxidants can slow down the aging rate of the rubber and extend the cable's service life.
[0024] This application employs aminosilane, polyethylene glycol, and N,N-succinimidyl carbonate to synergistically modify hollow glass microspheres. The silanol groups generated from the hydrolysis of aminosilane combine with the hydroxyl groups on the surface of the hollow glass microspheres, introducing amino groups into the surface. Since the hydroxyl groups at the ends of the polyethylene glycol molecular chains have poor reactivity, N,N-succinimidyl carbonate is used to activate the polyethylene glycol. The activated polyethylene glycol combines with the amino groups, thereby grafting polyethylene glycol onto the surface of the hollow glass microspheres. This results in the uniform distribution of the hollow glass microspheres within the rubber matrix. The strong interaction between the hollow glass microsphere particles and the rubber matrix effectively improves the mechanical properties of the rubber. Simultaneously, the hollow structure and the presence of a certain amount of gas encapsulated within the spheres give the material excellent thermal insulation properties. Silicon-based aerogel particles have ultra-low thermal conductivity and lightweight properties. When combined with modified hollow glass microspheres, they further improve the thermal insulation performance of the cable, avoid the need to use multi-layer composite structures to meet thermal insulation requirements, reduce the outer diameter of the cable, enhance the flexibility of the cable, and ensure the long-term stable operation of the cable in high-temperature environments. Detailed Implementation
[0025] The present application will be further described in detail below with reference to the embodiments.
[0026] Preparation Example 1 Preparation of modified hollow glass microspheres: (1) 120g of hollow glass microspheres (particle size 20μm) were added to 250mL of NaOH solution, heated to 60℃, stirred for 4h, filtered and dried to obtain pretreated hollow glass microspheres; (2) The pretreated hollow glass microspheres, 2.4g N-(2-aminoethyl)-3-aminopropyltrimethoxysilane and 250mL ethanol were mixed evenly, ultrasonically treated for 30min, and stirred at 70℃ for 4h. After the reaction was completed, the mixture was centrifuged, washed and dried to obtain silanized hollow glass microspheres. (3) Dissolve 48g of polyethylene glycol in 250mL of ethanol, add 48g of N,N-succinimide carbonate and 2g of triethylamine at 50℃, stir for 3h to obtain activated polyethylene glycol solution, add silanized hollow glass microspheres to activated polyethylene glycol solution, sonicate for 25min, stir for 3h at 40℃, filter, wash and dry to obtain modified hollow glass microspheres.
[0027] Preparation Example 2 Preparation of modified hollow glass microspheres: (1) 130g of hollow glass microspheres (30μm in diameter) were added to 250mL of NaOH solution, heated to 70℃, stirred for 5h, filtered and dried to obtain pretreated hollow glass microspheres; (2) The pretreated hollow glass microspheres, 3.9g N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and 250mL ethanol were mixed evenly, ultrasonically treated for 40min, and stirred at 75℃ for 5h. After the reaction was completed, the mixture was centrifuged, washed, and dried to obtain silanized hollow glass microspheres. (3) Dissolve 65g of polyethylene glycol in 400mL of ethanol, add 65g of N,N-succinimide carbonate and 3g of triethylamine at 55℃, stir and react for 3.5h to obtain activated polyethylene glycol solution, add silanized hollow glass microspheres to activated polyethylene glycol solution, sonicate for 30min, stir and react for 3.5h at 50℃, filter, wash and dry to obtain modified hollow glass microspheres.
[0028] Preparation Example 3 Preparation of modified hollow glass microspheres: (1) 140g of hollow glass microspheres (particle size 40μm) were added to 250mL of NaOH solution, heated to 80℃, stirred for 6h, filtered and dried to obtain pretreated hollow glass microspheres; (2) The pretreated hollow glass microspheres, 5.6g of N-(2-aminoethyl)-3-aminopropyltriethoxysilane and 250mL of ethanol were mixed evenly, ultrasonically treated for 45min, and stirred at 80℃ for 6h. After the reaction was completed, the mixture was centrifuged, washed and dried to obtain silanized hollow glass microspheres. (3) Dissolve 84g of polyethylene glycol in 500mL of ethanol, add 84g of N,N-succinimide carbonate and 4g of pyridine at 60℃, stir and react for 4h to obtain activated polyethylene glycol solution, add silanized hollow glass microspheres to activated polyethylene glycol solution, sonicate for 35min, stir and react for 4h at 60℃, filter, wash and dry to obtain modified hollow glass microspheres.
[0029] Preparation Example 4 The difference between this preparation example and Preparation Example 2 is that an equal amount of 3-aminopropyltriethoxysilane is used instead of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane.
[0030] Preparation Example 5 The difference between this preparation example and Preparation Example 2 is that N-(2-aminoethyl)-3-aminopropyltrimethoxysilane was not added, i.e., the preparation of modified hollow glass microspheres: (1) Add 130g of hollow glass microspheres to 250mL of NaOH solution, heat to 70℃, stir and react for 5h, filter and dry to obtain pretreated hollow glass microspheres; (2) Dissolve 65g of polyethylene glycol in 400mL of ethanol, add 65g of N,N-succinimide carbonate and 3g of triethylamine at 55℃, stir and react for 3.5h to obtain activated polyethylene glycol solution, add the treated hollow glass microspheres to the activated polyethylene glycol solution, sonicate for 30min, stir and react for 3.5h at 50℃, filter, wash and dry to obtain modified hollow glass microspheres.
[0031] Preparation Example 6 The difference between this preparation example and Preparation Example 2 is that polyethylene glycol was not added, i.e., the preparation of modified hollow glass microspheres: (1) Add 130g of hollow glass microspheres to 250mL of NaOH solution, heat to 70℃, stir and react for 5h, filter and dry to obtain pretreated hollow glass microspheres; (2) The pretreated hollow glass microspheres, 3.9g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane and 250mL of ethanol were mixed evenly, ultrasonically treated for 40min, and stirred at 75℃ for 5h. After the reaction was completed, the modified hollow glass microspheres were obtained by centrifugation, washing and drying.
[0032] Preparation Example 7 The difference between this preparation example and Preparation Example 2 is that N,N-succinimide carbonate was not added, i.e., the preparation of modified hollow glass microspheres was carried out without the addition of N,N-succinimide carbonate. (1) Add 130g of hollow glass microspheres to 250mL of NaOH solution, heat to 70℃, stir and react for 5h, filter and dry to obtain pretreated hollow glass microspheres; (2) The pretreated hollow glass microspheres, 3.9g N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and 250mL ethanol were mixed evenly, ultrasonically treated for 40min, and stirred at 75℃ for 5h. After the reaction was completed, the mixture was centrifuged, washed, and dried to obtain silanized hollow glass microspheres. (3) Dissolve 65g of polyethylene glycol in 400mL of ethanol, add silanized hollow glass microspheres to the polyethylene glycol solution, sonicate for 30min, and then stir at 50℃ for 3.5h. After filtration, washing and drying, modified hollow glass microspheres are obtained.
[0033] Example
[0034] Example 1 A heat-insulating cable, comprising the following raw materials: 400g EPDM rubber (Alan Newco 10660C), 250g butadiene rubber (Yanshan Petrochemical K4912), 120g ethylene-vinyl acetate rubber (Taiwan Polymer UE647-04), 120g modified hollow glass microspheres (prepared in Example 1), 70g carbon black N347 (Xinglongtai 1333-86-4), 80g silicone aerogel particles (Langmiao), 10g stearic acid, 20g di-tert-butyl peroxide, 11g TAIC, and 5g antioxidant 445.
[0035] The preparation methods for heat-insulated cables include the following: Ethylene propylene diene monomer (EPDM) rubber, butadiene rubber, ethylene-vinyl acetate rubber, modified hollow glass microspheres, carbon black N347, silicone aerogel particles, stearic acid, and antioxidant 445 were mixed at 130°C for 10 minutes to obtain a premix. Di-tert-butyl peroxide and TAIC were mixed with the premix and vulcanized at 110°C and 3 MPa for 7 minutes. The protective layer material was then extruded using an extruder to coat the outside of the cable filler layer to form a protective layer.
[0036] Example 2 A heat-insulating cable, comprising the following raw materials: 450g EPDM rubber (Alan Newco 10660C), 300g butadiene rubber (Yanshan Petrochemical K4912), 135g ethylene-vinyl acetate rubber (Taiwan Polymer UE647-04), 130g modified hollow glass microspheres (prepared in Preparation Example 2), 80g carbon black N347 (Xinglongtai 1333-86-4), 100g silicone aerogel particles (Langmiao), 15g stearic acid, 30g dicumyl peroxide, 13g trimethylolpropane triacrylate, and 6g antioxidant RD.
[0037] The preparation methods for heat-insulated cables include the following: Ethylene propylene diene monomer (EPDM) rubber, butadiene rubber, ethylene-vinyl acetate rubber, modified hollow glass microspheres, carbon black N347, silicone aerogel particles, stearic acid, and antioxidant RD were mixed at 135°C for 13 minutes to obtain a premix. Dicumyl peroxide and trimethylolpropane triacrylate were mixed with the premix and vulcanized at 115°C and 7 MPa for 8 minutes. The protective layer material was then extruded using an extruder to coat the outside of the cable filler layer to form a protective layer.
[0038] Example 3 A heat-insulating cable, comprising the following raw materials: 500g EPDM rubber (Alan Newco 10660C), 350g butadiene rubber (Yanshan Petrochemical K4912), 150g ethylene-vinyl acetate rubber (Taiwan Polymer UE647-04), 140g modified hollow glass microspheres (prepared in Example 3), 90g carbon black N347 (Xinglongtai 1333-86-4), 120g silicone aerogel particles (Langmiao), 20g stearic acid, 40g dicumyl peroxide, 15g ethylene glycol diacrylate, and 7g antioxidant SP.
[0039] The preparation methods for heat-insulated cables include the following: Ethylene propylene diene monomer (EPDM) rubber, butadiene rubber, ethylene-vinyl acetate rubber, modified hollow glass microspheres, carbon black N347, silicone aerogel particles, stearic acid, and antioxidant SP were mixed at 140°C for 15 minutes to obtain a premix. Dicumyl peroxide and ethylene glycol diacrylate were mixed with the premix and vulcanized at 120°C and 10 MPa for 10 minutes. The protective layer material was then extruded using an extruder to coat the outside of the cable filler layer, forming a protective layer.
[0040] Example 4 The difference between this embodiment and Example 2 is that the modified hollow glass microspheres prepared in Example 4 are used.
[0041] Comparative Example
[0042] Comparative Example 1 A heat-insulating cable, which differs from Example 2 in that it uses the modified hollow glass microspheres prepared in Preparation Example 5.
[0043] Comparative Example 2 A heat-insulating cable, which differs from Example 2 in that it uses the modified hollow glass microspheres prepared in Preparation Example 6.
[0044] Comparative Example 3 A heat-insulating cable, which differs from Example 2 in that it uses the modified hollow glass microspheres prepared in Preparation Example 7.
[0045] Comparative Example 4 A heat-insulating cable differs from Example 2 in that it uses an equal amount of unmodified hollow glass microspheres instead of modified hollow glass microspheres.
[0046] Comparative Example 5 A heat-insulating cable, which differs from Example 2 in that it does not contain modified hollow glass microspheres.
[0047] Comparative Example 6 An insulated cable, which differs from Example 2 in that it does not contain carbon black N347.
[0048] Comparative Example 7 A heat-insulating cable differs from Example 2 in that it uses an equal amount of carbon black N347 instead of silicon-based aerogel particles.
[0049] Performance testing
[0050] 1. Mechanical property testing: Tests were conducted according to GB / T528-1998, using a Shenzhen UTM4304X microcomputer-controlled electronic universal testing machine for tensile property testing. The obtained vulcanized samples were cut into dumbbell shapes using a type II cutter. The hardness and thickness of the specimens were tested. The specimens were then clamped between upper and lower grippers, ensuring they were perpendicular. The electronic universal testing machine was started, and the lower gripper was used to stretch the specimen at a speed of 500 mm / min. Finally, the tensile strength and elongation at break of the specimens were calculated.
[0051] 2. Thermal conductivity: The thermal conductivity of the sample was tested using a thermal conductivity meter (TC3000E) from Xi'an Xiaxi Electronic Technology Co., Ltd. with a test current of 0.08A. The lower the thermal conductivity, the better the thermal insulation performance of the prepared insulated cable.
[0052] 3. Thermal insulation performance test: The cables prepared in Examples 1-4 and Comparative Examples 1-7 were placed at a temperature of 300°C to test the temperature of the cable core.
[0053] Based on Examples 2 and Comparative Examples 1-3, it can be seen that: in Comparative Example 1, the hollow glass microspheres were not modified by coupling, and only polyethylene glycol was used for graft modification, resulting in unsatisfactory modification effects; in Comparative Example 2, only the hollow glass microspheres were modified by coupling, but due to the short carbon chains of aminosilane, the steric hindrance effect after surface modification of the hollow glass microspheres was not obvious, and the microsphere particles were likely to adsorb to each other and form aggregates again, ultimately affecting the material's performance; in Comparative Example 3, the polyethylene glycol was not activated, and due to the poor activity of the hydroxyl groups at the ends of the polyethylene glycol molecular chains, it was difficult to directly bind with the hollow glass microspheres. In contrast, this application uses aminosilane, polyethylene glycol, and N,N-succinimidyl carbonate to couple and graft modify the hollow glass microspheres, resulting in a uniform distribution of the hollow glass microspheres in the rubber matrix, effectively improving the material's mechanical and thermal insulation properties.
[0054] As shown in Examples 2 and Comparative Examples 4-5, the unmodified hollow glass microspheres in Comparative Example 4 exhibit poor dispersion in the matrix; and the matrix cross-section in Comparative Example 5 without modified hollow glass microspheres shows obvious voids, affecting the overall performance of the material. In contrast, this application, by adding modified hollow glass microspheres, fills the voids in the matrix, gradually reducing their size. These microspheres interact with the matrix, forming physical cross-links, increasing the cross-linking density. The uniformly distributed rigid particles are surrounded by an interface layer of a certain thickness, resulting in good interfacial bonding. This allows for the absorption of impact energy and the transfer of stress, thereby improving the mechanical properties of the rubber. Furthermore, the hollow structure of the hollow glass microspheres, with a certain amount of gas encapsulated within the spheres, gives the protective layer excellent thermal insulation properties.
[0055] As can be seen from Example 2 and Comparative Example 6, carbon black N347 can play a reinforcing role in the material. It can be uniformly dispersed in the rubber matrix. When the material is stretched by external force, a large number of physical and chemical bonding points are formed between the carbon black particles and the rubber molecules, which prevents the sliding and deformation of the rubber molecular chains. This allows the stress to be more evenly distributed throughout the material system, thereby significantly improving the tensile strength and elongation at break of the material. This makes the protective layer less prone to breakage during the stretching process, thus improving the service life and reliability of the cable.
[0056] As can be seen from Example 2 and Comparative Example 7, silicon-based aerogel particles have ultra-low thermal conductivity and lightweight properties, which can effectively reduce the overall thermal conductivity of the cable, improve the thermal insulation performance, and reduce the weight of the cable. Furthermore, the synergistic effect of silicon-based aerogel particles and modified hollow glass microspheres can further improve the thermal insulation performance of the cable.
[0057] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.
Claims
1. A heat-insulating cable, characterized in that, The cable comprises, from the inside out, a cable core, a composite shielding layer, a filling layer, and a protective layer. The protective layer is made of raw materials comprising the following parts by weight: 40-50 parts of EPDM rubber, 25-35 parts of butadiene rubber, 12-15 parts of ethylene-vinyl acetate rubber, 12-14 parts of modified hollow glass microspheres, 7-9 parts of carbon black N347, 8-12 parts of silicone aerogel particles, 1-2 parts of stearic acid, 2-4 parts of vulcanizing agent, 1.1-1.5 parts of crosslinking aid, and 0.5-0.7 parts of antioxidant; The raw materials for preparing the modified hollow glass microspheres include hollow glass microspheres, aminosilane, polyethylene glycol, and N,N-succinimide carbonate, and the weight ratio of the hollow glass microspheres, aminosilane, polyethylene glycol, and N,N-succinimide carbonate is 1:(0.02-0.04):(0.4-0.6):(0.4-0.6).
2. The heat-insulating cable according to claim 1, characterized in that, The method for preparing the modified hollow glass microspheres includes the following steps: (1) Add hollow glass microspheres to NaOH solution, heat to 60-80℃, stir for 4-6 hours, filter and dry to obtain pretreated hollow glass microspheres; (2) Mix the pretreated hollow glass microspheres, aminosilane and solvent evenly, sonicate for 30-45 min, stir and react at 70-80℃ for 4-6 h, centrifuge after reaction, wash and dry to obtain silanized hollow glass microspheres. (3) Dissolve polyethylene glycol in a solvent, add N,N-succinimide carbonate and catalyst at 50-60℃, stir and react for 3-4h to obtain activated polyethylene glycol solution, add silanized hollow glass microspheres to activated polyethylene glycol solution, sonicate for 25-35min, stir and react for 3-4h at 40-60℃, filter, wash and dry to obtain modified hollow glass microspheres.
3. The heat-insulating cable according to claim 2, characterized in that, The catalyst used in step (3) is one or both of pyridine and triethylamine.
4. The heat-insulating cable according to claim 1, characterized in that, The aminosilane is selected from one or two of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane and N-(2-aminoethyl)-3-aminopropyltriethoxysilane.
5. A heat-insulating cable according to claim 1, characterized in that, The hollow glass microspheres have a particle size of 20-40 μm.
6. A heat-insulating cable according to claim 1, characterized in that, The vulcanizing agent is selected from one or two of di-tert-butyl peroxide and dicumyl peroxide.
7. A heat-insulating cable according to claim 1, characterized in that, The crosslinking aid is selected from one or more of TAIC, TAC, trimethylolpropane triacrylate, and ethylene glycol diacrylate.
8. A heat-insulating cable according to claim 1, characterized in that, The antioxidant is selected from one or more of antioxidants RD, SP, and 445.
9. A method for preparing a heat-insulating cable as described in any one of claims 1-8, characterized in that, Includes the following steps: Ethylene propylene diene monomer (EPDM) rubber, butadiene rubber, ethylene-vinyl acetate rubber, modified hollow glass microspheres, carbon black N347, silicone aerogel particles, stearic acid, and antioxidant are mixed at 130-140℃ for 10-15 minutes to obtain a premix. The vulcanizing agent and crosslinking aid are mixed with the premix and vulcanized at 110-120℃ and 3-10 MPa for 7-10 minutes. The protective layer material is then extruded using an extruder to coat the outside of the cable filler layer, forming a protective layer.