High-strength aging-resistant overhead insulated wire

Abstract

The invention relates to the technical field of insulated wires, and provides a high-strength aging-resistant overhead insulated wire. The high-strength aging-resistant overhead insulated wire sequentially comprises a conductor and an insulating layer from inside to outside, and the insulating layer is prepared from, by weight, 80 parts of polyethylene, 15-20 parts of butadiene styrene rubber, 10-18 parts of ethylene propylene diene monomer, 3-5 parts of zinc oxide, 1-2 parts of vulcanizing agent, 0.5-1 part of accelerant, 5-7 parts of compatilizer, 2-3 parts of zinc stearate and 8-12 parts of reinforcing additive; the reinforcing aid comprises the following raw materials in parts by weight: 20 parts of carbon black, 4-8 parts of silicone powder and 5-10 parts of zinc diacrylate. According to the technical scheme, the problem that the mechanical property of the insulating layer of the overhead insulated wire is relatively poor in the prior art is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of insulated conductors, in particular, relates to a high-strength and anti-aging overhead insulated conductor. BACKGROUND

[0002] Overhead insulated conductors are an important part of power transmission and distribution networks. By coating the conductor with an insulating layer, the safety hazards of short circuit and electric leakage of traditional bare conductors exposed directly to the environment are effectively avoided. At the same time, the space occupation of the line corridor is reduced, and the reliability and safety of power supply are improved. Therefore, overhead insulated conductors are widely used in power transmission in urban power grids, industrial and mining enterprises, and rural power grid reconstruction.

[0003] With the continuous growth of power demand, the performance of overhead insulated conductors is required to be higher by the power system. Especially during long-term outdoor operation, the insulated conductor needs to withstand mechanical stress, environmental temperature change, ultraviolet radiation and other complex factors. Therefore, the insulating layer material not only needs to have excellent initial electrical insulation performance, but also needs to have good mechanical strength and environmental aging resistance.

[0004] At present, the commonly used insulating layer materials of overhead insulated conductors mainly include polyethylene (PE), polyvinyl chloride (PVC) and rubber materials. Among them, ethylene-propylene-diene rubber has a relatively stable molecular structure due to its high main chain saturation, all carbon-carbon single bonds, and only a small amount of unsaturated carbon-carbon double bonds in the side chain. However, ethylene-propylene-diene rubber itself lacks self-reinforcing properties, and the mechanical properties of pure rubber are relatively low. Although it helps to improve the electrical insulation and aging resistance of the insulating layer, it limits the effective improvement of the mechanical properties.

[0005] In order to improve the mechanical properties of rubber insulating materials in the insulating layer, reinforcing fillers such as carbon black and white carbon black are usually added. Carbon black is the most commonly used reinforcing agent, but its dispersion uniformity in the rubber matrix and interface bonding strength with the rubber molecules are relatively poor, which easily forms stress concentration points in the material, which not only is not conducive to the improvement of mechanical strength, but also may accelerate the aging failure process of the material in the hot oxygen environment. Therefore, it is of great significance to propose an overhead insulated conductor with good mechanical properties to meet the demand of the power system for high reliability and long service life of overhead insulated conductors. SUMMARY

[0006] The present application proposes a high-strength and anti-aging overhead insulated conductor, which solves the problem of relatively poor mechanical properties of the insulating layer of the overhead insulated conductor in the related art.

[0007] The technical solution of the present application is as follows: The application provides a high-strength and aging-resistant overhead insulated conductor, which comprises a conductor and an insulation layer from inside to outside. Polyethylene 80 parts, styrene butadiene rubber 15-20 parts, ethylene propylene diene rubber 10-18 parts, zinc oxide 3-5 parts, vulcanizing agent 1-2 parts, accelerator 0.5-1 part, compatibilizer 5-7 parts, zinc stearate 2-3 parts, reinforcing aid 8-12 parts. The raw material of the reinforcing aid comprises the following components in parts by weight: Carbon black 20 parts, silicone powder 4-8 parts, zinc diacrylate 5-10 parts.

[0008] As a further technical solution, the conductor is one of an aluminum alloy conductor and a copper alloy conductor, and preferably is an aluminum alloy conductor.

[0009] As a further technical solution, the raw material of the reinforcing aid further comprises a silane coupling agent, and the silane coupling agent is added in an amount of 8% to 15% of the weight of the carbon black, for example, can be 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, and preferably is 8%, 12%, or 15%.

[0010] In the application, the raw material of the reinforcing aid further comprises a silane coupling agent, and the addition of the silane coupling agent can make the zinc diacrylate better combined with the carbon black and the silicone powder, improve the stability of the reinforcing aid, and better play the reinforcing role, wherein the silane coupling agent can be any conventional silane coupling agent in the field, for example, can be an amino silane coupling agent or a mercapto silane coupling agent; the amino silane coupling agent can be, for example, gamma-aminopropyl triethoxysilane or gamma-aminopropyl trimethoxysilane, and the mercapto silane coupling agent can be, for example, gamma-mercaptopropyl triethoxysilane, and preferably is gamma-aminopropyl triethoxysilane.

[0011] As a further technical solution, the preparation method of the reinforcing aid comprises the following steps: A1, adding the silane coupling agent into an ethanol aqueous solution, adding the carbon black and the silicone powder, uniformly mixing, concentrating, drying, and obtaining a pretreated mixture; A2, blending the zinc diacrylate and the pretreated mixture, and ball milling to obtain the reinforcing aid.

[0012] As a further technical solution, the mass fraction of ethanol in the ethanol aqueous solution is 75% to 85%, for example, can be 75%, 80%, or 85%, and preferably is 80%.

[0013] As a further technical solution, the vulcanizing agent comprises one or both of sulfur and dicumyl peroxide, and preferably is dicumyl peroxide. The accelerator comprises one or both of accelerator H and accelerator TMTD, preferably accelerator TMTD.

[0014] As a further technical solution, the compatibilizer comprises one or both of maleic anhydride grafted polyethylene and maleic anhydride grafted EPDM, preferably both.

[0015] In the insulating layer of the aerial insulated conductor, the addition of the compatibilizer can improve the compatibility of polyethylene, styrene-butadiene rubber and EPDM, and reduce the interfacial tension, thereby avoiding the phase separation of the blending system during processing and subsequent long-term use. The compatibilizer comprises one or both of maleic anhydride grafted polyethylene and maleic anhydride grafted EPDM, preferably both. When both maleic anhydride grafted polyethylene and maleic anhydride grafted EPDM are used, the weight ratio of the two is optimized to be 3:1, which can improve the compatibility of the three.

[0016] As a further technical solution, the raw materials of the insulating layer further comprise 1-3 parts of antioxidant and 2-5 parts of plasticizer.

[0017] As a further technical solution, the antioxidant comprises one or more of antioxidant 1010, antioxidant 1024 and antioxidant 264, preferably antioxidant 1024. The plasticizer comprises one or more of dinonyl phthalate, tricresyl phosphate and dioctyl phthalate, preferably dioctyl phthalate.

[0018] As a further technical solution, the raw materials of the reinforcing aid further comprise 2-6 parts of zinc acetylacetone, for example 2 parts, 3 parts, 4 parts, 5 parts or 6 parts, preferably 4-5 parts.

[0019] In the insulating layer of the aerial insulated conductor, the raw materials of the reinforcing aid further comprise zinc acetylacetone. The combined action of zinc acetylacetone, zinc diacrylate and silicone powder on carbon black can further reduce the agglomeration of carbon black in the rubber component. The presence of zinc acetylacetone can inhibit the oxidation reaction of the rubber component to some extent, thereby improving the stability of the rubber component. In addition, by adjusting the amount of zinc acetylacetone, when the amount of zinc acetylacetone in the reinforcing aid is 4-5 parts, the combined action with the remaining raw materials in the reinforcing aid is more optimal, and the effect of improving the aging resistance of the insulating layer is better.

[0020] As a further technical solution, the preparation method of the reinforcing aid comprises the following steps: B1, adding the silane coupling agent into an aqueous ethanol solution, adding the carbon black and the silicone powder, mixing uniformly, concentrating, drying, to obtain a first pretreatment mixture; B2, dispersing the acetylpropyl zinc in anhydrous ethanol, adding the first pretreatment mixture, mixing uniformly, concentrating, drying, to obtain a second pretreatment mixture; B3, blending the zinc diacrylate and the second pretreatment mixture, ball milling, to obtain the reinforcing aid.

[0021] As a further technical solution, in steps B1 and B2, the stirring speed for mixing uniformly is independently 400-600 rpm, and the time is independently 30-40 min.

[0022] As a further technical solution, in step B3, the ball milling speed is 200-300 rpm, and the time is 15-25 min.

[0023] The application also proposes a preparation method of the high-strength anti-aging overhead insulated conductor wire. After mixing the styrene-butadiene rubber, the ethylene-propylene-diene rubber and the reinforcing aid uniformly, the remaining components in the insulating layer are added, mixed, extruded to coat the outer layer of the conductor, vulcanized, to obtain the high-strength anti-aging overhead insulated conductor wire.

[0024] The working principle and beneficial effects of the application are as follows: In the insulating layer of the overhead insulated conductor wire, the reinforcing aid formed by carbon black, silicone powder and zinc diacrylate can effectively improve the mechanical properties of the insulating layer of the overhead insulated conductor wire. The ethylene-propylene-diene rubber main chain in the insulating layer has a high saturation degree, only the side chain contains a small amount of unsaturated carbon-carbon double bond, and the structure is relatively stable but lacks self-reinforcing property. In order to solve the problem that the mechanical properties of the ethylene-propylene-diene rubber in the insulating layer are relatively poor, thereby limiting the improvement of the overall mechanical properties of the insulating layer, the reinforcing aid formed by carbon black, silicone powder and zinc diacrylate is introduced into the insulating layer. The presence of zinc diacrylate and silicone powder can improve the dispersion degree of carbon black in the ethylene-propylene-diene rubber system and improve the processing properties of the rubber. At the same time, the high activity of the double acrylate groups in zinc diacrylate can improve the interface bonding of the reinforcing aid and the ethylene-propylene-diene rubber, improve the internal crosslinking degree of the ethylene-propylene-diene rubber, and make the entire reinforcing system more stable. When the insulating layer is stretched by the outside, the ethylene-propylene-diene rubber with enhanced crosslinking network structure in the system can also better transmit stress, thereby improving the overall mechanical properties of the insulating layer. Therefore, carbon black, silicone powder and zinc diacrylate are used together to form a reinforcing aid, which is added to the insulating layer of the overhead insulated conductor wire, which can effectively improve the mechanical properties thereof. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work, are within the scope of protection of the present application.

[0026] In the following examples and comparative examples, the polyethylene is low-density polyethylene, model LD163; Styrene butadiene rubber, model SBR1502; Ethylene propylene diene rubber, model EPDM 3640; Zinc oxide, average particle size 50 nm; Maleic anhydride grafted polyethylene, model ADMER NF408E; Maleic anhydride grafted ethylene propylene diene rubber, model K-7M; Carbon black, model N330, average particle size 200 nm; Silicone powder, model K6105; Zinc acetylacetonate, CAS No. 14024-63-6, active ingredient content 98%; Copper acetylacetonate, CAS No. 13395-16-9, active ingredient content 99%; Zinc diacrylate, CAS No. 14643-87-9, active ingredient content 99%; Zinc methacrylate, CAS No. 13189-00-9, active ingredient content 99%.

[0027] Example 1 The preparation method of the reinforcing aid includes the following steps: A1, 1.6 parts of γ-aminopropyl triethoxysilane is added to 50 parts of an ethanol aqueous solution (ethanol mass fraction 80%), 20 parts of carbon black and 4 parts of silicone powder are added, and stirring is carried out at a stirring speed of 500 rpm for 40 min, and then concentration, drying are carried out to obtain a pretreated mixture; A2, 5 parts of zinc diacrylate and the pretreated mixture are blended, and ball milling is carried out at a ball milling speed of 200 rpm for 25 min to obtain a reinforcing aid; A preparation method of a high-strength and aging-resistant overhead insulated conductor wire includes the following steps: After 15 parts of styrene butadiene rubber, 10 parts of ethylene propylene diene rubber and 8 parts of reinforcing aid are uniformly mixed, 80 parts of polyethylene, 3 parts of zinc oxide, 1 part of dicumyl peroxide, 0.5 part of accelerator TMTD, 3.75 parts of maleic anhydride grafted polyethylene, 1.25 parts of maleic anhydride grafted ethylene propylene diene rubber, 2 parts of zinc stearate, 1 part of antioxidant 1024 and 2 parts of dioctyl phthalate are added, mixed, extruded and coated on the outer layer of an aluminum alloy conductor, vulcanized to obtain a high-strength aging-resistant overhead insulated conductor.

[0028] Example 2 The preparation method of the reinforcing aid comprises the following steps: A1, 2.4 parts of γ-aminopropyl triethoxysilane are added to 50 parts of ethanol aqueous solution (ethanol mass fraction is 80%), 20 parts of carbon black and 5 parts of silicone powder are added, stirred at a stirring speed of 500 rpm for 40 min, concentrated, dried to obtain a pretreatment mixture; A2, 5 parts of zinc diacrylate and the above pretreatment mixture are blended, and ball milling is performed at a ball milling speed of 250 rpm for 20 min to obtain a reinforcing aid; A preparation method of a high-strength aging-resistant overhead insulated conductor comprises the following steps: After 18 parts of styrene butadiene rubber, 15 parts of ethylene propylene diene rubber and 10 parts of reinforcing aid are uniformly mixed, 80 parts of polyethylene, 4 parts of zinc oxide, 1.5 parts of dicumyl peroxide, 0.8 parts of accelerator TMTD, 4.5 parts of maleic anhydride grafted polyethylene, 1.5 parts of maleic anhydride grafted ethylene propylene diene rubber, 2.5 parts of zinc stearate, 2 parts of antioxidant 1024 and 4 parts of dioctyl phthalate are added, mixed, extruded and coated on the outer layer of an aluminum alloy conductor, vulcanized to obtain a high-strength aging-resistant overhead insulated conductor.

[0029] Example 3 The preparation method of the reinforcing aid comprises the following steps: A1, 3 parts of γ-aminopropyl triethoxysilane are added to 50 parts of ethanol aqueous solution (ethanol mass fraction is 80%), 20 parts of carbon black and 8 parts of silicone powder are added, stirred at a stirring speed of 500 rpm for 40 min, concentrated, dried to obtain a pretreatment mixture; A2, 5 parts of zinc diacrylate and the above pretreatment mixture are blended, and ball milling is performed at a ball milling speed of 300 rpm for 15 min to obtain a reinforcing aid; A preparation method of a high-strength aging-resistant overhead insulated conductor comprises the following steps: After 20 parts of styrene-butadiene rubber, 18 parts of ethylene-propylene-diene rubber and 12 parts of reinforcing aid are uniformly mixed, 80 parts of polyethylene, 5 parts of zinc oxide, 2 parts of dicumyl peroxide, 1 part of accelerator TMTD, 5.25 parts of maleic anhydride grafted polyethylene, 1.75 parts of maleic anhydride grafted ethylene-propylene-diene rubber, 3 parts of zinc stearate, 3 parts of antioxidant 1024 and 5 parts of dioctyl phthalate are added, mixed, extruded to coat the outer layer of an aluminum alloy conductor, and vulcanized to obtain a high-strength and aging-resistant overhead insulated conductor.

[0030] Example 4 The difference between this example and Example 2 is only that in the preparation method of the reinforcing aid of this example, 8 parts of zinc diacrylate are added.

[0031] Example 5 The difference between this example and Example 2 is only that in the preparation method of the reinforcing aid of this example, 10 parts of zinc diacrylate are added.

[0032] Example 6 The difference between this example and Example 4 is only that the preparation method of the reinforcing aid is different, specifically: B1, 2.4 parts of γ-aminopropyl triethoxysilane are added to 50 parts of an ethanol aqueous solution (80% by mass of ethanol), 20 parts of carbon black and 5 parts of silicone powder are added, and stirring is performed at a stirring speed of 500 rpm for 40 min, and then concentrated and dried to obtain a first pretreatment mixture; B2, 2 parts of acetyl tripeptide zinc are dispersed in 50 parts of anhydrous ethanol, and the first pretreatment mixture is added, and stirring is performed at a stirring speed of 500 rpm for 40 min, and then concentrated and dried to obtain a second pretreatment mixture; B3, 8 parts of zinc diacrylate and the second pretreatment mixture are blended, and ball milling is performed at a ball milling speed of 250 rpm for 20 min to obtain a reinforcing aid.

[0033] Example 7 The difference between this example and Example 6 is only that in the preparation method of the reinforcing aid of this example, 4 parts of acetyl tripeptide zinc are added.

[0034] Example 8 The difference between this example and Example 6 is only that in the preparation method of the reinforcing aid of this example, 5 parts of acetyl tripeptide zinc are added.

[0035] Example 9 The difference between this example and Example 6 is only that in the preparation method of the reinforcing aid of this example, 6 parts of acetyl tripeptide zinc are added.

[0036] Example 10 The only difference between this embodiment and Example 6 is that in the preparation method of the reinforcing agent in this embodiment, acetylacetonine zinc is replaced with an equal amount of acetylacetone copper.

[0037] Comparative Example 1 The only difference between this comparative example and Example 2 is that, in the preparation method of the reinforcing agent in this comparative example, zinc bisacrylate is replaced with an equal amount of zinc methacrylate.

[0038] Comparative Example 2 The only difference between this comparative example and Example 2 is that the preparation method of the reinforcing agent in this comparative example is different, specifically: 24 parts carbon black and 6 parts silicone powder were mixed and ball-milled at 250 rpm for 20 min to obtain a reinforcing agent.

[0039] Comparative Example 3 The only difference between this comparative example and Example 2 is that the preparation method of the reinforcing agent in this comparative example is different, specifically: A1. Add 2.4 parts of γ-aminopropyltriethoxysilane to 50 parts of ethanol aqueous solution (ethanol mass fraction is 80%), add 25 parts of carbon black, stir at 500 rpm for 40 min, concentrate, dry, and obtain pretreated mixture. A2. Mix 5 parts of zinc diacrylate with the above pretreated mixture and ball mill at 250 rpm for 20 min to obtain the reinforcing agent.

[0040] Experimental Example 1 Sufficiently long samples were cut from the insulation layers of the overhead insulated conductors prepared in Examples 1-5 and Comparative Examples 1-3, according to GB / T 2951.11. After preparing a dumbbell-shaped specimen with a thickness of 1.5 mm using the method in 2008 "General Test Methods for Insulation and Sheath Materials of Cables and Optical Fibers - Part 11: General Test Methods for Thickness and Dimensional Measurement and Mechanical Properties Test", tensile strength was tested at a test speed of 250 mm / min. The test results are shown in Table 1.

[0041] Table 1 Performance test results of Examples 1-5 and Comparative Examples 1-3

[0042] Compared with Comparative Examples 1-3, the tensile strength of the insulation layer of the overhead insulated conductors in Examples 1-5 is improved, indicating that the addition of carbon black, silicone powder and zinc diacrylate to the insulation layer of the overhead insulated conductor can effectively improve the mechanical properties of the insulation layer, so that its tensile strength can reach more than 24.9 MPa.

[0043] Experiment Example 2 A sample section with sufficient length was cut from the insulating layer of the overhead insulated conductor prepared in Example 4, 6-10, and after the tensile strength test according to the above test method, the aging resistance test was carried out according to the method in GB / T 2951.12-2008 "Cable and optical cable insulating and sheath materials - General test methods - Part 12: General test methods - Heat aging test methods", and the tensile strength test after aging was carried out according to the above method, wherein the aging resistance test method is air oven aging method, the temperature is 135℃, and the time is 240h, and the test results are shown in Table 2.

[0044] Table 2 Performance test results of Examples 4, 6-10

[0045] Compared with Example 4 and Example 10, the tensile strength of the overhead insulated conductor insulating layer of Examples 6-9 decreases after the aging resistance test, and the tensile strength retention rate = tensile strength after aging / tensile strength before aging x 100% is calculated, the tensile strength retention rate of the insulating layer of Examples 6-9 can reach 96.4% or more, indicating that after adding zinc acetylacetonate in the raw material of the reinforcing aid, the mechanical strength of the insulating layer is ensured, and the aging resistance performance is improved. In addition, compared with Example 6 and Example 9, the tensile strength retention rate of the overhead insulated conductor insulating layer of Examples 7-8 is further improved after the aging resistance test, which can reach 96.8% or more, indicating that by adjusting the amount of zinc acetylacetonate, when its amount is 4-5 parts in the reinforcing aid, it can work better with the remaining raw materials in the reinforcing aid, and the aging resistance performance of the insulating layer can be further improved.

[0046] The above is only a preferred embodiment of the present application, and is not intended to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A high-strength, aging-resistant overhead insulated conductor, comprising, from the inside out, a conductor and an insulation layer, characterized in that, The raw material of the insulating layer comprises the following components in parts by weight: 80 parts polyethylene, 15-20 parts styrene-butadiene rubber, 10-18 parts ethylene propylene diene monomer (EPDM) rubber, 3-5 parts zinc oxide, 1-2 parts vulcanizing agent, 0.5-1 part accelerator, 5-7 parts compatibilizer, 2-3 parts zinc stearate, and 8-12 parts reinforcing agent; The raw materials of the reinforcing agent include the following components in parts by weight: 20 parts carbon black, 4-8 parts silicone powder, and 5-10 parts zinc diacrylate.

2. The high-strength, aging-resistant overhead insulated conductor according to claim 1, characterized in that, The conductor is either an aluminum alloy conductor or a copper alloy conductor.

3. The high-strength, aging-resistant overhead insulated conductor according to claim 1, characterized in that, The reinforcing agent also includes a silane coupling agent, wherein the amount of the silane coupling agent added is 8% to 15% of the weight of the carbon black.

4. The high-strength, aging-resistant overhead insulated conductor according to claim 3, characterized in that, The preparation method of the reinforcing agent includes the following steps: A1. Add the silane coupling agent to an ethanol aqueous solution, add the carbon black and the silicone powder, mix evenly, concentrate, and dry to obtain a pretreated mixture; A2. The zinc diacrylate and the pretreated mixture are blended and ball-milled to obtain the reinforcing agent.

5. The high-strength, aging-resistant overhead insulated conductor according to claim 1, characterized in that, The vulcanizing agent includes one or both of sulfur and dicumyl peroxide. The accelerator includes one or both of accelerator H and accelerator TMTD.

6. The high-strength, aging-resistant overhead insulated conductor according to claim 1, characterized in that, The compatibilizer includes one or both of maleic anhydride-grafted polyethylene and maleic anhydride-grafted EPDM rubber.

7. The high-strength, aging-resistant overhead insulated conductor according to claim 1, characterized in that, The raw materials for the insulating layer also include 1-3 parts of antioxidant and 2-5 parts of plasticizer.

8. A high-strength, aging-resistant overhead insulated conductor according to claim 7, characterized in that, The antioxidant includes one or more of antioxidant 1010, antioxidant 1024, and antioxidant 264; The plasticizer includes one or more of dinonyl phthalate, tricresyl phosphate, and dioctyl phthalate.

9. A high-strength, aging-resistant overhead insulated conductor according to claim 3, characterized in that, The reinforcing agent also includes 2-6 parts of zinc acetylacetonate as a raw material.

10. A high-strength, aging-resistant overhead insulated conductor according to claim 9, characterized in that, The preparation method of the reinforcing agent includes the following steps: B1. Add the silane coupling agent to an ethanol aqueous solution, add the carbon black and the silicone powder, mix evenly, concentrate, and dry to obtain the first pretreatment mixture; B2. Disperse the acetylacetic copper zinc in anhydrous ethanol, add the first pretreatment mixture, mix evenly, concentrate, and dry to obtain the second pretreatment mixture; B3. The zinc diacrylate and the second pretreatment mixture are blended and ball-milled to obtain the reinforcing agent.

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