High strength aerial insulated conductor
By adding reinforcing agents such as modified silica to the insulation layer, a dense physical support network is formed, which solves the problem of insufficient insulation strength of overhead insulated conductors and improves the conductor's durability and resistance to damage.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HEBEI TIANMA CABLE GRP CO LTD
- Filing Date
- 2026-05-21
- Publication Date
- 2026-06-30
AI Technical Summary
The insulation layer of existing overhead insulated conductors is not strong enough and is easily damaged by wind and temperature changes in outdoor environments, which may lead to tensile fracture or cracking of the insulation layer and cause short circuit faults.
Adding reinforcing agents such as modified silica to the insulation layer, and using silane coupling agents and polybutylene terephthalate-adipate to modify silica, forms a dense physical support network, thereby improving the tensile strength and hardness of the insulation layer.
It significantly improves the tensile strength and hardness of the insulation layer, enhances the durability of the conductor, and reduces the risk of insulation damage caused by outdoor environments.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of cable technology, and more specifically, to a high-strength overhead insulated conductor. Background Technology
[0002] Overhead insulated conductors are commonly used in urban power distribution networks, rural power grid upgrades, and in forested and densely built-up areas. Currently, most overhead insulated conductors use aluminum or aluminum alloys as the conductor, with an outer layer of polyvinyl chloride, polyethylene, or cross-linked polyethylene as insulation, manufactured by stranding the conductor and covering the insulation layer. This structure provides insulation protection while ensuring conductivity, meeting the needs of general overhead installations, and has the advantages of convenient installation and low maintenance costs. However, during long-term outdoor use, conductors are frequently subjected to wind pulling and temperature changes, which can easily lead to tensile fracture or cracking of the insulation layer. When the insulation layer is damaged, it not only loses its protective function but may also expose the conductor, causing short-circuit faults, making it difficult to meet the long-term use requirements of complex outdoor environments. Summary of the Invention
[0003] To address the above technical problems, this invention provides a high-strength overhead insulated conductor. The reinforcing agent provided by this invention not only has good dispersibility in the insulation layer material, but also improves the tensile strength of the insulation layer of the overhead insulated conductor when added to it, thus solving the problem of insufficient insulation layer strength of existing overhead insulated conductors.
[0004] The specific technical solution of the present invention is as follows: According to one aspect of the present invention, a high-strength overhead insulated conductor is provided, comprising a conductor and an insulation layer arranged sequentially from the inside out; the insulation layer comprises the following raw materials: polyethylene, ethylene-vinyl acetate copolymer, maleic anhydride-grafted polyethylene, reinforcing agent, antioxidant, ultraviolet absorber, and lubricant; The reinforcing agent includes modified silica; the modified silica is obtained by modifying silica with silane coupling agent and polybutylene terephthalate.
[0005] In the above technical solution, the preparation method of the modified silica includes the following steps: S1. Adjust the pH of the ethanol solution to 4-5, add silane coupling agent KH-560, stir, and obtain hydrolysate; add polybutylene terephthalate to dichloromethane, stir twice, and obtain polybutylene terephthalate solution. S2. Add the dried silica to the hydrolysate, stir, filter, wash, and dry to obtain pre-modified silica; add dichloromethane to the pre-modified silica to obtain wetted pre-modified silica; add the wetted pre-modified silica to the polybutylene terephthalate-adipate ester solution, mix, air dry, and then dry to obtain modified silica.
[0006] In the above technical solution, the mass-to-volume ratio of the silane coupling agent KH-560 to the ethanol solution is 1g:90~100mL.
[0007] In the above technical solution, the mass-volume ratio of polybutylene terephthalate (PET) to dichloromethane is 10g:100~110mL.
[0008] In the above technical solution, the mass-to-volume ratio of the dried silica to the hydrolysate is 10g:90~100mL.
[0009] In the above technical solution, the mass-to-volume ratio of the pre-modified silica and dichloromethane is 1g:5~10mL.
[0010] In the above technical solution, the mass ratio of the pre-modified silica to polybutylene terephthalate is 0.3~0.5:10.
[0011] In the above technical solution, the reinforcing agent also includes one or more of the following: sepiolite fiber, alumina, calcium silicate whiskers, calcium sulfate whiskers, silicon nitride whiskers, and brucite fiber.
[0012] In the above technical solution, when the reinforcing agent includes modified silica, sepiolite fiber and calcium silicate whiskers, the mass ratio of the modified silica, sepiolite fiber and calcium silicate whiskers is 5~6:2:2.
[0013] In the above technical solution, the raw materials of the insulating layer are as follows by weight: 80-90 parts of polyethylene, 6-12 parts of ethylene-vinyl acetate copolymer, 6-10 parts of maleic anhydride grafted polyethylene, 12-16 parts of reinforcing agent, 0.3-0.5 parts of antioxidant, 0.3-0.6 parts of ultraviolet absorber, and 0.2-0.4 parts of lubricant.
[0014] In the above technical solution, one or more of antioxidants 1010, antioxidant 1076, antioxidant 3114 and antioxidant 168 are used.
[0015] In the above technical solution, the ultraviolet absorber includes one or more of ultraviolet absorber UV-327, ultraviolet absorber UV-328, ultraviolet absorber UV-329 and ultraviolet absorber UV-531.
[0016] In the above technical solution, the lubricant includes one or more of stearic acid, zinc stearate, and oxidized polyethylene wax.
[0017] Compared with existing technologies, this invention provides a high-strength overhead insulated conductor. First, modified silica is added to the insulation layer of the overhead insulated conductor, improving the tensile strength of the insulation layer. Silica itself is a nano-sized rigid inorganic particle. After modification with silane coupling agent and polybutylene terephthalate (PET), it can be uniformly dispersed in the resin matrix, playing a rigid supporting role and effectively limiting the slippage of polymer chain segments. Furthermore, the modification enhances the interfacial bonding force between silica and the polyethylene and ethylene-vinyl acetate copolymer matrix, further improving the tensile strength of the insulation layer. Second, the uniformly dispersed silica also forms a dense physical support network in the matrix, thereby synergistically improving the hardness of the insulation layer. Detailed Implementation
[0018] To make the objectives, technical solutions, and advantages of this invention more apparent, the invention is described in detail below. It should be understood that the invention is not limited to the description herein.
[0019] polyethylene The polyethylene used in this invention is the type of polyethylene known in the art for use in overhead insulated conductor insulation layers. In the overhead insulated conductor insulation layer of this invention, the role of polyethylene is to provide basic insulation performance, mechanical protection, and weather resistance.
[0020] Ethylene-vinyl acetate copolymer The ethylene-vinyl acetate copolymer used in this invention is a known ethylene-vinyl acetate copolymer that can be used in the insulation layer of overhead insulated conductors. In the overhead insulated conductor insulation layer of this invention, the main function of the ethylene-vinyl acetate copolymer is to improve the flexibility of the insulation layer.
[0021] Maleic anhydride-grafted polyethylene The maleic anhydride-grafted polyethylene used in this invention is a type of maleic anhydride-grafted polyethylene known in the art for use in the insulation layer of overhead insulated conductors. In the overhead insulated conductor insulation layer of this invention, the maleic anhydride-grafted polyethylene serves to increase the compatibility, dispersibility, and interfacial bonding strength of polyethylene, ethylene-vinyl acetate copolymer, and other additives.
[0022] enhancer In this invention, the reinforcing agent can be modified silica, and may also include one or more of sepiolite fibers, alumina, calcium silicate whiskers, calcium sulfate whiskers, silicon nitride whiskers, and brucite fibers. In the overhead insulated conductor insulation layer of this invention, when modified silica, sepiolite fibers, and calcium silicate whiskers are used in combination as reinforcing agents, the synergistic effect on improving the tensile strength and hardness of the insulation layer is better. Specifically, modified silica fills the microscopic voids in the matrix, sepiolite fibers form an entangled skeleton, and calcium silicate whiskers have a stable structure that provides rigid support; the three form a reinforcing network that synergistically inhibits crack propagation and restricts resin molecular chain slippage. Furthermore, calcium silicate whiskers interact with sepiolite fibers and modified silica through a silane coupling agent. The mass ratio of modified silica, sepiolite fiber and calcium silicate whiskers is 5~6:2:2, preferably 5.5:2:2. When the proportion of modified silica is too high, it will weaken the overall support and the continuity of the skeleton; when the proportion of modified silica is too low, it will lead to insufficient filling and weaken the stress transmission function of the skeleton.
[0023] antioxidants The antioxidants used in this invention are known in the art for use in the insulation layers of overhead insulated conductors, and this invention is not limited to antioxidants 1010, 1076, 3114, and 168 listed below. As an example, the antioxidant may be one or more of antioxidants 1010, 1076, 3114, 264, 168, and DSTP. In the insulation layer of the overhead insulated conductor of this invention, the main function of the antioxidant is to inhibit the oxidative degradation process of the insulation material during long-term operation, effectively delaying the aging of the insulation layer, avoiding problems such as embrittlement, cracking, or pulverization of the material, thereby improving the overall durability and service life of the overhead insulated conductor.
[0024] UV absorber The ultraviolet absorber used in this invention is a known ultraviolet absorber in the art that can be used in the insulation layer of overhead insulated conductors, and this invention is not limited to ultraviolet absorbers UV-327, UV-328, UV-329, and UV-531 listed below. As an example, the ultraviolet absorber may be one or more of ultraviolet absorbers UV-327, UV-328, UV-329, UV-9, UV-531, and UV-400. In the insulation layer of the overhead insulated conductor of this invention, the ultraviolet absorber functions to inhibit photo-oxidative degradation and molecular chain breakage of the substrate under ultraviolet radiation, reduce aging, yellowing, and cracking of the insulation layer caused by long-term outdoor ultraviolet radiation, and ensure long-term stable operation of the conductor in outdoor environments.
[0025] lubricant The lubricant used in this invention is a known lubricant in the art for use in the insulation layer of overhead insulated conductors, and this invention is not limited to stearic acid, zinc stearate, and oxidized polyethylene wax listed below. As an example, the lubricant may be one or more of stearic acid, zinc stearate, calcium stearate, magnesium stearate, oxidized polyethylene wax, polyethylene wax, and microcrystalline wax. In the overhead insulated conductor insulation layer of this invention, the lubricant serves to reduce friction of the material during processing and improve flowability and dispersibility.
[0026] The high-strength overhead insulated conductor of the present invention comprises a conductor and an insulation layer arranged sequentially from the inside to the outside; the insulation layer comprises the following raw materials: polyethylene, ethylene-vinyl acetate copolymer, maleic anhydride grafted polyethylene, reinforcing agent, antioxidant, ultraviolet absorber, and lubricant.
[0027] In the raw materials of the insulation layer of high-strength overhead insulated conductors, the weight percentage of polyethylene is 80 to 90 parts, preferably 82 to 88 parts, and more preferably 84 to 86 parts.
[0028] In the raw materials for the insulation layer of high-strength overhead insulated conductors, the ethylene-vinyl acetate copolymer comprises 6 to 12 parts by weight, preferably 8 to 10 parts.
[0029] In the raw materials for the insulation layer of high-strength overhead insulated conductors, the weight percentage of maleic anhydride-grafted polyethylene is 6 to 10 parts, preferably 7 to 9 parts.
[0030] In the raw materials of the insulation layer of high-strength overhead insulated conductors, the weight of the reinforcing agent is 12 to 16 parts, preferably 13 to 15 parts.
[0031] In the raw materials of the insulation layer of high-strength overhead insulated conductors, the antioxidant is 0.3 to 0.5 parts by weight, preferably 0.35 to 0.45 parts.
[0032] In the raw materials of the insulation layer of high-strength overhead insulated conductors, the weight of ultraviolet absorber is 0.3 to 0.6 parts, preferably 0.4 to 0.5 parts.
[0033] In the raw materials of the insulation layer of high-strength overhead insulated conductors, the weight of lubricant is 0.2 to 0.4 parts, preferably 0.25 to 0.35 parts.
[0034] Preparation method of modified silica This invention also provides a method for preparing the modified silica as described above, comprising: S1. Adjust the pH of the ethanol solution to 4-5, add silane coupling agent KH-560, stir, and obtain hydrolysate; add polybutylene terephthalate to dichloromethane, stir twice, and obtain polybutylene terephthalate solution. S2. Add the dried silica to the hydrolysate, stir, filter, wash, and dry to obtain pre-modified silica; add dichloromethane to the pre-modified silica to obtain wetted pre-modified silica; add the wetted pre-modified silica to a polybutylene terephthalate-adipate solution, mix, air dry, and then bake to obtain modified silica.
[0035] In the preparation method of modified silica, the concentration of the ethanol solution is 80wt%~85wt%, preferably 82wt%~84wt%.
[0036] In the preparation method of modified silica, the mass-to-volume ratio of silane coupling agent KH-560 and ethanol solution is 1g:90~100mL, preferably 1g:92~98mL.
[0037] In the preparation method of modified silica, in step S1, the stirring speed is 300~500 rpm and the time is 10~15 min.
[0038] In the preparation method of modified silica, the mass-volume ratio of polybutylene terephthalate-adipate to dichloromethane is 10g:100~110mL, preferably 10g:102~106mL.
[0039] In the preparation method of modified silica, the stirring speed for the second stirring is 300~400 rpm and the time is 25~30 min.
[0040] In the preparation method of modified silica, the dried silica is obtained by drying silica at 80~100℃ for 4~5h.
[0041] In the preparation method of modified silica, the mass-volume ratio of dried silica to hydrolysate is 10g:90~100mL, preferably 10g:93~97mL.
[0042] In the preparation method of modified silica, in step S2, the stirring temperature is 60~65℃, the stirring speed is 400~500rpm, and the stirring time is 2~3h.
[0043] In the preparation method of modified silica, the drying temperature is 70~90℃ and the time is 10~12h.
[0044] In the preparation method of modified silica, the mass-to-volume ratio of pre-modified silica to dichloromethane is 1g:5~10mL.
[0045] In the preparation method of modified silica, the mass ratio of pre-modified silica to polybutylene terephthalate is 0.3~0.5:10, preferably 0.4:10. When there is a large amount of polybutylene terephthalate on the surface of modified silica, the silica tends to agglomerate, which weakens the dispersibility of modified silica. When the amount of pre-modified silica is too large, it is impossible to fully coat the silica, resulting in insufficient interfacial bonding. When added to the insulating resin matrix, the compatibility with polyethylene and ethylene-vinyl acetate copolymer is weakened.
[0046] In the preparation method of modified silica, the mixing speed is 20,000~25,000 rpm and the time is 1~2 min.
[0047] In the preparation method of modified silica, the drying temperature is 60~70℃ and the drying time is 1~2h.
[0048] To further illustrate the present invention, the following examples will provide a detailed description. All raw materials used in the following examples and comparative examples of the present invention are commercially available products. Specifically, the polyethylene is type 5000S; the ethylene-vinyl acetate copolymer is type 3176; the maleic anhydride-grafted polyethylene is type NE062E; the average particle size of the silica is 20 nm; the average diameter of the sepiolite fiber is 0.5 μm and the average length is 2 mm; the average particle size of the alumina is 50 nm; the average diameter of the calcium silicate whiskers is 1 μm and the average length is 20 μm; the average diameter of the calcium sulfate whiskers is 2 μm and the average length is 50 μm; the average diameter of the silicon nitride whiskers is 1 μm and the average length is 20 μm; the average diameter of the brucite fiber is 2 μm and the average length is 50 μm; and the oxidized polyethylene wax is type AC-629A.
[0049] Example 1 A method for preparing a high-strength overhead insulated conductor includes the following steps: mixing 80 parts of polyethylene, 6 parts of ethylene-vinyl acetate copolymer, 6 parts of maleic anhydride grafted polyethylene, 12 parts of modified silica, 0.2 parts of antioxidant 1010, 0.1 parts of antioxidant 168, 0.15 parts of ultraviolet absorber UV-327, 0.15 parts of ultraviolet absorber UV-531, and 0.2 parts of stearic acid, and extruding the mixture onto the surface of the conductor to obtain a high-strength overhead insulated conductor; The preparation method of modified silica includes the following steps: The pH of an 80wt% ethanol aqueous solution was adjusted to 4 using glacial acetic acid. Silane coupling agent KH-560 was added (the mass-to-volume ratio of KH-560 to the ethanol aqueous solution was 1 g:90 mL), and the mixture was stirred at 500 rpm for 10 min at room temperature to obtain a hydrolysate. Polybutylene terephthalate (PET) was added to dichloromethane (the mass-to-volume ratio of PET to dichloromethane was 10 g:100 mL), and the mixture was stirred at 300 rpm for 30 min at room temperature to obtain a PET solution. The dried silica was dried at 80℃ for 5 hours and then added to the hydrolysate (the mass-volume ratio of dried silica to hydrolysate was 10 g: 90 mL). The mixture was stirred at 60℃ and 500 rpm for 2 hours, filtered, washed, and then vacuum dried at 70℃ for 12 hours to obtain pre-modified silica. Dichloromethane was added to pre-modified silica (the mass-to-volume ratio of pre-modified silica to dichloromethane was 1 g:10 mL) to obtain wetted pre-modified silica. The wetted pre-modified silica was then added to a polybutylene terephthalate-adipate solution (the mass ratio of pre-modified silica to polybutylene terephthalate-adipate was 0.3:10). The mixture was stirred at 20,000 rpm for 2 min, dried at room temperature under ventilation for 24 h, and then dried at 70 °C for 1 h to obtain modified silica.
[0050] Example 2 A method for preparing a high-strength overhead insulated conductor includes the following steps: mixing 90 parts of polyethylene, 12 parts of ethylene-vinyl acetate copolymer, 10 parts of maleic anhydride grafted polyethylene, 16 parts of modified silica, 0.35 parts of antioxidant 1076, 0.15 parts of antioxidant 168, 0.4 parts of ultraviolet absorber UV-328, 0.2 parts of ultraviolet absorber UV-531, 0.2 parts of zinc stearate, and 0.2 parts of oxidized polyethylene wax, and extruding the mixture onto the surface of the conductor to obtain a high-strength overhead insulated conductor; The preparation method of modified silica includes the following steps: The pH of an 85wt% ethanol aqueous solution was adjusted to 4.5 using glacial acetic acid. Silane coupling agent KH-560 was added (the mass-to-volume ratio of KH-560 to the ethanol aqueous solution was 1 g:100 mL), and the mixture was stirred at 300 rpm for 15 min at room temperature to obtain a hydrolysate. Polybutylene terephthalate (PET) was added to dichloromethane (the mass-to-volume ratio of PET to dichloromethane was 10 g:110 mL), and the mixture was stirred at 400 rpm for 25 min at room temperature to obtain a PET solution. The dried silica was dried at 90℃ for 4 hours and then added to the hydrolysate (the mass-volume ratio of dried silica to hydrolysate was 10 g: 100 mL). The mixture was stirred at 65℃ and 400 rpm for 3 hours, filtered, washed, and then vacuum dried at 90℃ for 10 hours to obtain pre-modified silica. Dichloromethane was added to pre-modified silica (the mass-to-volume ratio of pre-modified silica to dichloromethane was 1 g:5 mL) to obtain wetted pre-modified silica. The wetted pre-modified silica was then added to a polybutylene terephthalate-adipate solution (the mass ratio of pre-modified silica to polybutylene terephthalate-adipate was 0.3:10). The mixture was stirred at 25,000 rpm for 1 min, dried at room temperature under ventilation for 24 h, and then dried at 60 °C for 2 h to obtain modified silica.
[0051] Example 3 A method for preparing a high-strength overhead insulated conductor includes the following steps: mixing 85 parts of polyethylene, 10 parts of ethylene-vinyl acetate copolymer, 8 parts of maleic anhydride grafted polyethylene, 15 parts of modified silica, 0.3 parts of antioxidant 3114, 0.1 parts of antioxidant 168, 0.2 parts of ultraviolet absorber UV-329, 0.3 parts of ultraviolet absorber UV-531, and 0.3 parts of zinc stearate, and extruding the mixture onto the surface of the conductor to obtain a high-strength overhead insulated conductor; The preparation method of modified silica includes the following steps: The pH of an 80wt% ethanol aqueous solution was adjusted to 5 using glacial acetic acid. Silane coupling agent KH-560 was added (the mass-to-volume ratio of silane coupling agent KH-560 to the ethanol aqueous solution was 1 g:100 mL). The mixture was stirred at 400 rpm for 12 min at room temperature to obtain a hydrolysate. Polybutylene terephthalate (PET) was added to dichloromethane (the mass-to-volume ratio of PET to dichloromethane was 10 g:100 mL). The mixture was stirred at 300 rpm for 30 min at room temperature to obtain a PET solution. The dried silica was dried at 100℃ for 4 hours and then added to the hydrolysate (the mass-volume ratio of dried silica to hydrolysate was 10 g: 100 mL). The mixture was stirred at 60℃ and 400 rpm for 3 hours, filtered, washed, and then vacuum dried at 80℃ for 12 hours to obtain pre-modified silica. Dichloromethane was added to pre-modified silica (the mass-to-volume ratio of pre-modified silica to dichloromethane was 1 g:8 mL) to obtain wetted pre-modified silica. The wetted pre-modified silica was then added to a polybutylene terephthalate-adipate solution (the mass ratio of pre-modified silica to polybutylene terephthalate-adipate was 0.3:10). The mixture was stirred at 20,000 rpm for 2 min, dried at room temperature under ventilation for 24 h, and then dried at 65 °C for 2 h to obtain modified silica.
[0052] Example 4 A method for preparing a high-strength overhead insulated conductor includes the following steps: mixing 85 parts of polyethylene, 10 parts of ethylene-vinyl acetate copolymer, 8 parts of maleic anhydride grafted polyethylene, 15 parts of modified silica, 0.3 parts of antioxidant 3114, 0.1 parts of antioxidant 168, 0.2 parts of ultraviolet absorber UV-329, 0.3 parts of ultraviolet absorber UV-531, and 0.3 parts of zinc stearate, and extruding the mixture onto the surface of the conductor to obtain a high-strength overhead insulated conductor; The preparation method of modified silica includes the following steps: The pH of an 80wt% ethanol aqueous solution was adjusted to 5 using glacial acetic acid. Silane coupling agent KH-560 was added (the mass-to-volume ratio of silane coupling agent KH-560 to the ethanol aqueous solution was 1 g:100 mL). The mixture was stirred at 400 rpm for 12 min at room temperature to obtain a hydrolysate. Polybutylene terephthalate (PET) was added to dichloromethane (the mass-to-volume ratio of PET to dichloromethane was 10 g:100 mL). The mixture was stirred at 300 rpm for 30 min at room temperature to obtain a PET solution. The dried silica was dried at 100℃ for 4 hours and then added to the hydrolysate (the mass-volume ratio of dried silica to hydrolysate was 10 g: 100 mL). The mixture was stirred at 60℃ and 400 rpm for 3 hours, filtered, washed, and then vacuum dried at 80℃ for 12 hours to obtain pre-modified silica. Dichloromethane was added to pre-modified silica (the mass-to-volume ratio of pre-modified silica to dichloromethane was 1 g:8 mL) to obtain wetted pre-modified silica. The wetted pre-modified silica was then added to a polybutylene terephthalate-adipate solution (the mass ratio of pre-modified silica to polybutylene terephthalate-adipate was 0.4:10). The mixture was stirred at 20,000 rpm for 2 min, dried at room temperature under ventilation for 24 h, and then dried at 65 °C for 2 h to obtain modified silica.
[0053] Example 5 A method for preparing a high-strength overhead insulated conductor includes the following steps: mixing 85 parts of polyethylene, 10 parts of ethylene-vinyl acetate copolymer, 8 parts of maleic anhydride grafted polyethylene, 15 parts of modified silica, 0.3 parts of antioxidant 3114, 0.1 parts of antioxidant 168, 0.2 parts of ultraviolet absorber UV-329, 0.3 parts of ultraviolet absorber UV-531, and 0.3 parts of zinc stearate, and extruding the mixture onto the surface of the conductor to obtain a high-strength overhead insulated conductor; The preparation method of modified silica includes the following steps: The pH of an 80wt% ethanol aqueous solution was adjusted to 5 using glacial acetic acid. Silane coupling agent KH-560 was added (the mass-to-volume ratio of silane coupling agent KH-560 to the ethanol aqueous solution was 1 g:100 mL). The mixture was stirred at 400 rpm for 12 min at room temperature to obtain a hydrolysate. Polybutylene terephthalate (PET) was added to dichloromethane (the mass-to-volume ratio of PET to dichloromethane was 10 g:100 mL). The mixture was stirred at 300 rpm for 30 min at room temperature to obtain a PET solution. The dried silica was dried at 100℃ for 4 hours and then added to the hydrolysate (the mass-volume ratio of dried silica to hydrolysate was 10 g: 100 mL). The mixture was stirred at 60℃ and 400 rpm for 3 hours, filtered, washed, and then vacuum dried at 80℃ for 12 hours to obtain pre-modified silica. Dichloromethane was added to pre-modified silica (the mass-to-volume ratio of pre-modified silica to dichloromethane was 1 g:8 mL) to obtain wetted pre-modified silica. The wetted pre-modified silica was then added to a polybutylene terephthalate-adipate solution (the mass ratio of pre-modified silica to polybutylene terephthalate-adipate was 0.5:10). The mixture was stirred at 20,000 rpm for 2 min, dried at room temperature under ventilation for 24 h, and then dried at 65 °C for 2 h to obtain modified silica.
[0054] Example 6 A method for preparing a high-strength overhead insulated conductor includes the following steps: mixing 85 parts of polyethylene, 10 parts of ethylene-vinyl acetate copolymer, 8 parts of maleic anhydride grafted polyethylene, 15 parts of reinforcing agent (modified silica, sepiolite fiber, and alumina in a mass ratio of 5:2:2), 0.3 parts of antioxidant 3114, 0.1 parts of antioxidant 168, 0.2 parts of ultraviolet absorber UV-329, 0.3 parts of ultraviolet absorber UV-531, and 0.3 parts of zinc stearate, and extruding the mixture onto the surface of the conductor to obtain a high-strength overhead insulated conductor; The preparation method of modified silica includes the following steps: The pH of an 80wt% ethanol aqueous solution was adjusted to 5 using glacial acetic acid. Silane coupling agent KH-560 was added (the mass-to-volume ratio of silane coupling agent KH-560 to the ethanol aqueous solution was 1 g:100 mL). The mixture was stirred at 400 rpm for 12 min at room temperature to obtain a hydrolysate. Polybutylene terephthalate (PET) was added to dichloromethane (the mass-to-volume ratio of PET to dichloromethane was 10 g:100 mL). The mixture was stirred at 300 rpm for 30 min at room temperature to obtain a PET solution. The dried silica was dried at 100℃ for 4 hours and then added to the hydrolysate (the mass-volume ratio of dried silica to hydrolysate was 10 g: 100 mL). The mixture was stirred at 60℃ and 400 rpm for 3 hours, filtered, washed, and then vacuum dried at 80℃ for 12 hours to obtain pre-modified silica. Dichloromethane was added to pre-modified silica (the mass-to-volume ratio of pre-modified silica to dichloromethane was 1 g:8 mL) to obtain wetted pre-modified silica. The wetted pre-modified silica was then added to a polybutylene terephthalate-adipate solution (the mass ratio of pre-modified silica to polybutylene terephthalate-adipate was 0.4:10). The mixture was stirred at 20,000 rpm for 2 min, dried at room temperature under ventilation for 24 h, and then dried at 65 °C for 2 h to obtain modified silica.
[0055] Example 7 A method for preparing a high-strength overhead insulated conductor includes the following steps: mixing 85 parts of polyethylene, 10 parts of ethylene-vinyl acetate copolymer, 8 parts of maleic anhydride grafted polyethylene, 15 parts of reinforcing agent (modified silica, sepiolite fiber, and calcium silicate whiskers in a mass ratio of 5:2:2), 0.3 parts of antioxidant 3114, 0.1 parts of antioxidant 168, 0.2 parts of ultraviolet absorber UV-329, 0.3 parts of ultraviolet absorber UV-531, and 0.3 parts of zinc stearate, and extruding the mixture onto the surface of the conductor to obtain a high-strength overhead insulated conductor; The preparation method of modified silica includes the following steps: The pH of an 80wt% ethanol aqueous solution was adjusted to 5 using glacial acetic acid. Silane coupling agent KH-560 was added (the mass-to-volume ratio of silane coupling agent KH-560 to the ethanol aqueous solution was 1 g:100 mL). The mixture was stirred at 400 rpm for 12 min at room temperature to obtain a hydrolysate. Polybutylene terephthalate (PET) was added to dichloromethane (the mass-to-volume ratio of PET to dichloromethane was 10 g:100 mL). The mixture was stirred at 300 rpm for 30 min at room temperature to obtain a PET solution. The dried silica was dried at 100℃ for 4 hours and then added to the hydrolysate (the mass-volume ratio of dried silica to hydrolysate was 10 g: 100 mL). The mixture was stirred at 60℃ and 400 rpm for 3 hours, filtered, washed, and then vacuum dried at 80℃ for 12 hours to obtain pre-modified silica. Dichloromethane was added to pre-modified silica (the mass-to-volume ratio of pre-modified silica to dichloromethane was 1 g:8 mL) to obtain wetted pre-modified silica. The wetted pre-modified silica was then added to a polybutylene terephthalate-adipate solution (the mass ratio of pre-modified silica to polybutylene terephthalate-adipate was 0.4:10). The mixture was stirred at 20,000 rpm for 2 min, dried at room temperature under ventilation for 24 h, and then dried at 65 °C for 2 h to obtain modified silica.
[0056] Example 8 A method for preparing a high-strength overhead insulated conductor includes the following steps: mixing 85 parts of polyethylene, 10 parts of ethylene-vinyl acetate copolymer, 8 parts of maleic anhydride grafted polyethylene, 15 parts of reinforcing agent (modified silica, sepiolite fiber, and calcium sulfate whiskers in a mass ratio of 5:2:2), 0.3 parts of antioxidant 3114, 0.1 parts of antioxidant 168, 0.2 parts of ultraviolet absorber UV-329, 0.3 parts of ultraviolet absorber UV-531, and 0.3 parts of zinc stearate, and extruding the mixture onto the surface of the conductor to obtain a high-strength overhead insulated conductor; The preparation method of modified silica includes the following steps: The pH of an 80wt% ethanol aqueous solution was adjusted to 5 using glacial acetic acid. Silane coupling agent KH-560 was added (the mass-to-volume ratio of silane coupling agent KH-560 to the ethanol aqueous solution was 1 g:100 mL). The mixture was stirred at 400 rpm for 12 min at room temperature to obtain a hydrolysate. Polybutylene terephthalate (PET) was added to dichloromethane (the mass-to-volume ratio of PET to dichloromethane was 10 g:100 mL). The mixture was stirred at 300 rpm for 30 min at room temperature to obtain a PET solution. The dried silica was dried at 100℃ for 4 hours and then added to the hydrolysate (the mass-volume ratio of dried silica to hydrolysate was 10 g: 100 mL). The mixture was stirred at 60℃ and 400 rpm for 3 hours, filtered, washed, and then vacuum dried at 80℃ for 12 hours to obtain pre-modified silica. Dichloromethane was added to pre-modified silica (the mass-to-volume ratio of pre-modified silica to dichloromethane was 1 g:8 mL) to obtain wetted pre-modified silica. The wetted pre-modified silica was then added to a polybutylene terephthalate-adipate solution (the mass ratio of pre-modified silica to polybutylene terephthalate-adipate was 0.4:10). The mixture was stirred at 20,000 rpm for 2 min, dried at room temperature under ventilation for 24 h, and then dried at 65 °C for 2 h to obtain modified silica.
[0057] Example 9 A method for preparing a high-strength overhead insulated conductor includes the following steps: mixing 85 parts of polyethylene, 10 parts of ethylene-vinyl acetate copolymer, 8 parts of maleic anhydride grafted polyethylene, 15 parts of reinforcing agent (modified silica, sepiolite fiber, and silicon nitride whiskers in a mass ratio of 5:2:2), 0.3 parts of antioxidant 3114, 0.1 parts of antioxidant 168, 0.2 parts of ultraviolet absorber UV-329, 0.3 parts of ultraviolet absorber UV-531, and 0.3 parts of zinc stearate, and extruding the mixture onto the surface of the conductor to obtain a high-strength overhead insulated conductor; The preparation method of modified silica includes the following steps: The pH of an 80wt% ethanol aqueous solution was adjusted to 5 using glacial acetic acid. Silane coupling agent KH-560 was added (the mass-to-volume ratio of silane coupling agent KH-560 to the ethanol aqueous solution was 1 g:100 mL). The mixture was stirred at 400 rpm for 12 min at room temperature to obtain a hydrolysate. Polybutylene terephthalate (PET) was added to dichloromethane (the mass-to-volume ratio of PET to dichloromethane was 10 g:100 mL). The mixture was stirred at 300 rpm for 30 min at room temperature to obtain a PET solution. The dried silica was dried at 100℃ for 4 hours and then added to the hydrolysate (the mass-volume ratio of dried silica to hydrolysate was 10 g: 100 mL). The mixture was stirred at 60℃ and 400 rpm for 3 hours, filtered, washed, and then vacuum dried at 80℃ for 12 hours to obtain pre-modified silica. Dichloromethane was added to pre-modified silica (the mass-to-volume ratio of pre-modified silica to dichloromethane was 1 g:8 mL) to obtain wetted pre-modified silica. The wetted pre-modified silica was then added to a polybutylene terephthalate-adipate solution (the mass ratio of pre-modified silica to polybutylene terephthalate-adipate was 0.4:10). The mixture was stirred at 20,000 rpm for 2 min, dried at room temperature under ventilation for 24 h, and then dried at 65 °C for 2 h to obtain modified silica.
[0058] Example 10 A method for preparing a high-strength overhead insulated conductor includes the following steps: mixing 85 parts of polyethylene, 10 parts of ethylene-vinyl acetate copolymer, 8 parts of maleic anhydride grafted polyethylene, 15 parts of reinforcing agent (modified silica, sepiolite fiber, and brucite fiber in a mass ratio of 5:2:2), 0.3 parts of antioxidant 3114, 0.1 parts of antioxidant 168, 0.2 parts of ultraviolet absorber UV-329, 0.3 parts of ultraviolet absorber UV-531, and 0.3 parts of zinc stearate, and extruding the mixture onto the surface of the conductor to obtain a high-strength overhead insulated conductor; The preparation method of modified silica includes the following steps: The pH of an 80wt% ethanol aqueous solution was adjusted to 5 using glacial acetic acid. Silane coupling agent KH-560 was added (the mass-to-volume ratio of silane coupling agent KH-560 to the ethanol aqueous solution was 1 g:100 mL). The mixture was stirred at 400 rpm for 12 min at room temperature to obtain a hydrolysate. Polybutylene terephthalate (PET) was added to dichloromethane (the mass-to-volume ratio of PET to dichloromethane was 10 g:100 mL). The mixture was stirred at 300 rpm for 30 min at room temperature to obtain a PET solution. The dried silica was dried at 100℃ for 4 hours and then added to the hydrolysate (the mass-volume ratio of dried silica to hydrolysate was 10 g: 100 mL). The mixture was stirred at 60℃ and 400 rpm for 3 hours, filtered, washed, and then vacuum dried at 80℃ for 12 hours to obtain pre-modified silica. Dichloromethane was added to pre-modified silica (the mass-to-volume ratio of pre-modified silica to dichloromethane was 1 g:8 mL) to obtain wetted pre-modified silica. The wetted pre-modified silica was then added to a polybutylene terephthalate-adipate solution (the mass ratio of pre-modified silica to polybutylene terephthalate-adipate was 0.4:10). The mixture was stirred at 20,000 rpm for 2 min, dried at room temperature under ventilation for 24 h, and then dried at 65 °C for 2 h to obtain modified silica.
[0059] Example 11 A method for preparing a high-strength overhead insulated conductor includes the following steps: mixing 85 parts of polyethylene, 10 parts of ethylene-vinyl acetate copolymer, 8 parts of maleic anhydride grafted polyethylene, 15 parts of reinforcing agent (modified silica, sepiolite fiber, and calcium silicate whiskers in a mass ratio of 5.5:2:2), 0.3 parts of antioxidant 3114, 0.1 parts of antioxidant 168, 0.2 parts of ultraviolet absorber UV-329, 0.3 parts of ultraviolet absorber UV-531, and 0.3 parts of zinc stearate, and extruding the mixture onto the surface of the conductor to obtain a high-strength overhead insulated conductor; The preparation method of modified silica includes the following steps: The pH of an 80wt% ethanol aqueous solution was adjusted to 5 using glacial acetic acid. Silane coupling agent KH-560 was added (the mass-to-volume ratio of silane coupling agent KH-560 to the ethanol aqueous solution was 1 g:100 mL). The mixture was stirred at 400 rpm for 12 min at room temperature to obtain a hydrolysate. Polybutylene terephthalate (PET) was added to dichloromethane (the mass-to-volume ratio of PET to dichloromethane was 10 g:100 mL). The mixture was stirred at 300 rpm for 30 min at room temperature to obtain a PET solution. The dried silica was dried at 100℃ for 4 hours and then added to the hydrolysate (the mass-volume ratio of dried silica to hydrolysate was 10 g: 100 mL). The mixture was stirred at 60℃ and 400 rpm for 3 hours, filtered, washed, and then vacuum dried at 80℃ for 12 hours to obtain pre-modified silica. Dichloromethane was added to pre-modified silica (the mass-to-volume ratio of pre-modified silica to dichloromethane was 1 g:8 mL) to obtain wetted pre-modified silica. The wetted pre-modified silica was then added to a polybutylene terephthalate-adipate solution (the mass ratio of pre-modified silica to polybutylene terephthalate-adipate was 0.4:10). The mixture was stirred at 20,000 rpm for 2 min, dried at room temperature under ventilation for 24 h, and then dried at 65 °C for 2 h to obtain modified silica.
[0060] Example 12 A method for preparing a high-strength overhead insulated conductor includes the following steps: mixing 85 parts of polyethylene, 10 parts of ethylene-vinyl acetate copolymer, 8 parts of maleic anhydride grafted polyethylene, 15 parts of reinforcing agent (modified silica, sepiolite fiber, and calcium silicate whiskers in a mass ratio of 6:2:2), 0.3 parts of antioxidant 3114, 0.1 parts of antioxidant 168, 0.2 parts of ultraviolet absorber UV-329, 0.3 parts of ultraviolet absorber UV-531, and 0.3 parts of zinc stearate, and extruding the mixture onto the surface of the conductor to obtain a high-strength overhead insulated conductor; The preparation method of modified silica includes the following steps: The pH of an 80wt% ethanol aqueous solution was adjusted to 5 using glacial acetic acid. Silane coupling agent KH-560 was added (the mass-to-volume ratio of silane coupling agent KH-560 to the ethanol aqueous solution was 1 g:100 mL). The mixture was stirred at 400 rpm for 12 min at room temperature to obtain a hydrolysate. Polybutylene terephthalate (PET) was added to dichloromethane (the mass-to-volume ratio of PET to dichloromethane was 10 g:100 mL). The mixture was stirred at 300 rpm for 30 min at room temperature to obtain a PET solution. The dried silica was dried at 100℃ for 4 hours and then added to the hydrolysate (the mass-volume ratio of dried silica to hydrolysate was 10 g: 100 mL). The mixture was stirred at 60℃ and 400 rpm for 3 hours, filtered, washed, and then vacuum dried at 80℃ for 12 hours to obtain pre-modified silica. Dichloromethane was added to pre-modified silica (the mass-to-volume ratio of pre-modified silica to dichloromethane was 1 g:8 mL) to obtain wetted pre-modified silica. The wetted pre-modified silica was then added to a polybutylene terephthalate-adipate solution (the mass ratio of pre-modified silica to polybutylene terephthalate-adipate was 0.4:10). The mixture was stirred at 20,000 rpm for 2 min, dried at room temperature under ventilation for 24 h, and then dried at 65 °C for 2 h to obtain modified silica.
[0061] Comparative Example 1 A method for preparing a high-strength overhead insulated conductor includes the following steps: mixing 85 parts of polyethylene, 10 parts of ethylene-vinyl acetate copolymer, 8 parts of maleic anhydride grafted polyethylene, 15 parts of coupling agent modified silica, 0.3 parts of antioxidant 3114, 0.1 parts of antioxidant 168, 0.2 parts of ultraviolet absorber UV-329, 0.3 parts of ultraviolet absorber UV-531, and 0.3 parts of zinc stearate, and extruding the mixture onto the surface of the conductor to obtain a high-strength overhead insulated conductor; The preparation method of coupling agent modified silica includes the following steps: The pH of an 80wt% ethanol aqueous solution was adjusted to 5 using glacial acetic acid. Silane coupling agent KH-560 (the mass-to-volume ratio of silane coupling agent KH-560 to the ethanol aqueous solution was 1g:100mL) was added, and the mixture was stirred at 400rpm for 12min at room temperature to obtain the hydrolysate. The dried silica was dried at 100℃ for 4 hours and then added to the hydrolysate (the mass-volume ratio of dried silica to hydrolysate was 10 g: 100 mL). The mixture was stirred at 60℃ and 400 rpm for 3 hours, filtered, washed, and then vacuum dried at 80℃ for 12 hours to obtain coupling agent modified silica.
[0062] Comparative Example 2 A method for preparing a high-strength overhead insulated conductor includes the following steps: mixing 85 parts of polyethylene, 10 parts of ethylene-vinyl acetate copolymer, 8 parts of maleic anhydride-grafted polyethylene, 15 parts of silica, 0.3 parts of antioxidant 3114, 0.1 parts of antioxidant 168, 0.2 parts of ultraviolet absorber UV-329, 0.3 parts of ultraviolet absorber UV-531, and 0.3 parts of zinc stearate, and extruding the mixture onto the surface of the conductor to obtain a high-strength overhead insulated conductor.
[0063] Performance testing The tensile strength was tested using the method specified in GB / T2951.11-2008 "General Test Methods for Insulation and Sheath Materials of Cables and Optical Cables - Part 11: General Test Methods - Measurement of Thickness and Dimensions - Mechanical Properties Test". The specimen was a dumbbell specimen, the test speed was 250 mm / s, and the specimen thickness was 1 mm. The Shore hardness was tested according to the method specified in GB / T 2411-2008 "Determination of indentation hardness (Shore hardness) of plastics and hard rubber using a hardness tester"; the performance of each example and comparative example after testing is shown in Table 1.
[0064] Table 1. Performance test results of the insulation layers of overhead insulated conductors prepared in Examples 1-12 and Comparative Examples 1-2
[0065] 1. The tensile strength of the insulation layer of the overhead insulated conductors prepared in Examples 1 to 12 reached 15.0 to 20.7 MPa, which was significantly higher than that of Comparative Examples 1 to 2, indicating that the addition of modified silica improved the tensile strength of the insulation layer of the overhead insulated conductors; and the Shore hardness A of the insulation layer prepared in Examples 1 to 12 was also higher than that of Comparative Examples 1 to 2, indicating that the addition of modified silica also improved the hardness of the insulation layer of the overhead insulated conductors.
[0066] 2. The tensile strength of the insulation layer of the overhead insulated conductor prepared in Example 4 is better than that in Examples 3 and 5, indicating that when the mass ratio of pre-modified silica to polybutylene terephthalate is 0.4:10, the tensile strength of the insulation layer is further improved.
[0067] 3. The tensile strength and Shore A of the insulation layer of the overhead insulated conductors prepared in Examples 6-12 are improved compared with those in Examples 1-5, indicating that the use of modified silica and sepiolite fiber, alumina, calcium silicate whiskers, calcium sulfate whiskers, silicon nitride whiskers and brucite fiber in combination can improve the tensile strength and hardness of the insulation layer.
[0068] 4. The tensile strength and Shore A of the insulation layer of the overhead insulated conductors prepared in Examples 7 and 11-12 are higher than those in Examples 6 and 8-10, indicating that the tensile strength and hardness of the insulation layer can be further improved when modified silica, sepiolite fiber and calcium silicate whiskers are used in combination. Among them, the tensile strength of the insulation layer of the overhead insulated conductor prepared in Example 11 reaches 20.7 MPa and the Shore A reaches 97, indicating that adjusting the mass ratio of modified silica, sepiolite fiber and calcium silicate whiskers to 5.5:2:2 results in even better tensile strength and hardness performance of the insulation layer.
[0069] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A high-strength overhead insulated conductor, characterized in that, It includes a conductor and an insulation layer arranged sequentially from the inside out; the insulation layer includes the following raw materials: polyethylene, ethylene-vinyl acetate copolymer, maleic anhydride grafted polyethylene, reinforcing agent, antioxidant, ultraviolet absorber, and lubricant; The reinforcing agent includes modified silica; The modified silica is obtained by modifying silica with silane coupling agent and polybutylene terephthalate-adipate.
2. The high-strength overhead insulated conductor according to claim 1, characterized in that, The method for preparing the modified silica includes the following steps: S1. Adjust the pH of the ethanol solution to 4-5, add silane coupling agent KH-560, stir, and obtain hydrolysate; add polybutylene terephthalate to dichloromethane, stir twice, and obtain polybutylene terephthalate solution. S2. Add the dried silica to the hydrolysate, stir, filter, wash, and dry to obtain pre-modified silica; add dichloromethane to the pre-modified silica to obtain wetted pre-modified silica; add the wetted pre-modified silica to the polybutylene terephthalate-adipate ester solution, mix, air dry, and then dry to obtain modified silica.
3. A high-strength overhead insulated conductor according to claim 2, characterized in that, The mass-to-volume ratio of the silane coupling agent KH-560 to the ethanol solution is 1g:90~100mL; The mass-to-volume ratio of polybutylene terephthalate (PET) to dichloromethane is 10 g: 100-110 mL.
4. A high-strength overhead insulated conductor according to claim 2, characterized in that, The mass-to-volume ratio of the dried silica to the hydrolysate is 10g:90~100mL; The mass-to-volume ratio of the pre-modified silica to dichloromethane is 1 g: 5~10 mL; The mass ratio of the pre-modified silica to polybutylene terephthalate (PET) is 0.3~0.5:
10.
5. A high-strength overhead insulated conductor according to claim 1, characterized in that, The reinforcing agent also includes one or more of the following: sepiolite fiber, alumina, calcium silicate whiskers, calcium sulfate whiskers, silicon nitride whiskers, and brucite fiber.
6. A high-strength overhead insulated conductor according to claim 5, characterized in that, When the reinforcing agent includes modified silica, sepiolite fiber and calcium silicate whiskers, the mass ratio of the modified silica, sepiolite fiber and calcium silicate whiskers is 5~6:2:
2.
7. A high-strength overhead insulated conductor according to claim 1, characterized in that, The raw materials of the insulating layer are as follows by weight: 80-90 parts of polyethylene, 6-12 parts of ethylene-vinyl acetate copolymer, 6-10 parts of maleic anhydride grafted polyethylene, 12-16 parts of reinforcing agent, 0.3-0.5 parts of antioxidant, 0.3-0.6 parts of ultraviolet absorber, and 0.2-0.4 parts of lubricant.
8. A high-strength overhead insulated conductor according to claim 1, characterized in that, One or more of antioxidants 1010, 1076, 3114 and 168 are mentioned.
9. A high-strength overhead insulated conductor according to claim 1, characterized in that, The ultraviolet absorber includes one or more of ultraviolet absorbers UV-327, UV-328, UV-329, and UV-531.
10. A high-strength overhead insulated conductor according to claim 1, characterized in that, The lubricant includes one or more of stearic acid, zinc stearate, and oxidized polyethylene wax.