High-strength overhead insulated cable

Abstract

The invention relates to the technical field of cables, and provides a high-strength overhead insulated cable which is composed of three layers including a conductor, an insulating layer and a sheath layer from inside to outside in sequence, and the sheath layer is prepared from the following raw materials in parts by weight: 60-80 parts of ethylene-octylene copolymer, 6-10 parts of plasticizer, 15-20 parts of flame retardant, 0.5-1.5 parts of antioxidant, 0.2-0.8 part of lubricant and 12-15 parts of filler; the ethylene-octylene copolymer is composed of a first ethylene-octylene copolymer and a second ethylene-octylene copolymer, the crystallization temperature of the first ethylene-octylene copolymer is lower than that of the second ethylene-octylene copolymer, and the mass ratio of the first ethylene-octylene copolymer to the second ethylene-octylene copolymer is (1-5): (5-1). According to the technical scheme, the problem of low strength of the overhead insulated cable in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of cables, and in particular to a high-strength overhead insulated cable. Background Art

[0002] Overhead insulated cable is a kind of power transmission equipment installed in high-altitude power transmission lines. It consists of conductor, insulation layer and sheath layer, and is mainly used to transmit electric energy. With the continuous growth of demand for electricity in modern society, the use of overhead insulated cables is becoming more and more widespread. In practical applications, overhead insulated cables often face various complex environmental conditions and external forces. For example, natural disasters such as strong winds, ice and snow, and lightning strikes may cause serious mechanical damage to cables; at the same time, with the continuous expansion of the scale of the power grid and the increase of voltage levels, the load on the cables is also increasing. Therefore, it is particularly necessary to develop an overhead insulated cable with high strength. Summary of the invention

[0003] The invention provides a high-strength overhead insulated cable, which solves the problem of low strength of the overhead insulated cable in the related art.

[0004] The technical solution of the present invention is as follows: The present invention provides a high-strength overhead insulated cable, which is composed of three layers, from the inside to the outside, which are a conductor, an insulating layer and a sheath layer, wherein the sheath layer comprises the following raw materials in parts by weight: 60 to 80 parts of ethylene-octene copolymer, 6 to 10 parts of plasticizer, 15 to 20 parts of flame retardant, 0.5 to 1.5 parts of antioxidant, 0.2 to 0.8 parts of lubricant, and 12 to 15 parts of filler; The ethylene-octene copolymer consists of a first ethylene-octene copolymer and a second ethylene-octene copolymer, the crystallization temperature of the first ethylene-octene copolymer is lower than that of the second ethylene-octene copolymer, and the mass ratio of the first ethylene-octene copolymer to the second ethylene-octene copolymer is 1-5:5-1.

[0005] As a further technical solution, the conductor is made of copper.

[0006] As a further technical solution, the insulating layer is a cross-linked polyethylene insulating layer.

[0007] As a further technical solution, the crystallization temperature of the first ethylene-octene copolymer is 42°C, the crystallization temperature of the second ethylene-octene copolymer is 84°C, and the mass ratio of the first ethylene-octene copolymer to the second ethylene-octene copolymer is 2~3:2.

[0008] As a further technical solution, the filler includes one or more of glass fiber, carbon fiber, and silicon carbide fiber.

[0009] As a further technical solution, the silicon carbide fiber is a modified silicon carbide fiber, and the modifier of the modified silicon carbide fiber is N-decenyl succinic anhydride.

[0010] In the present invention, N-decenyl succinic anhydride is used to modify silicon carbide fibers, thereby improving the dispersibility and compatibility of silicon carbide fibers in a polymer matrix, reducing agglomeration, and thus improving the strength of the overhead insulated cable.

[0011] As a further technical solution, the mass ratio of the silicon carbide fiber to the N-decenyl succinic anhydride is 10:1-2; The preparation steps of the modified silicon carbide fiber include: dissolving N-decenyl succinic anhydride and then adding the silicon carbide fiber, dispersing and reacting uniformly, removing the solvent and drying to obtain the modified silicon carbide fiber.

[0012] In the present invention, the mass ratio of N-decenyl succinic anhydride and silicon carbide fiber is regulated so that the copolymer can be well coated on the surface of the silicon carbide fiber, thereby improving the interface bonding between the fiber and the matrix without agglomeration, effectively conducting the stress between the fiber and the matrix, and thus significantly improving the strength of the overhead insulated cable.

[0013] As a further technical solution, the plasticizer includes one or more of dioctyl phthalate, diisooctyl phthalate, and dioctyl terephthalate.

[0014] As a further technical solution, at least one of the following technical features is also included: The flame retardant includes one or more of aluminum hydroxide, magnesium hydroxide, and zinc borate; The antioxidant includes one or more of antioxidant 1010 , antioxidant 1076 , and antioxidant 168 .

[0015] As a further technical solution, the lubricant includes one or both of calcium stearate and zinc stearate.

[0016] The present invention also provides a method for preparing a high-strength overhead insulated cable, comprising the following steps: S1, mixing the raw materials of the sheath layer uniformly, and extruding to obtain a sheath layer; S2. Wrap the insulation layer and the sheath layer around the conductor in sequence to obtain a cable.

[0017] As a further technical solution, the extrusion temperature is 130-150°C.

[0018] The working principle and beneficial effects of the present invention are: In the present invention, ethylene-octene copolymers with different crystallization temperatures are added as raw materials to adjust the molecular structure and crystallization process of the polymer, enhance the compactness of the molecular chain arrangement sequence and the interaction force between molecules, enhance the connection between crystals, and improve the strength of the overhead insulated cable. DETAILED DESCRIPTION

[0019] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] In the following examples and comparative examples: The first ethylene-octene copolymer has a crystallization temperature of 42°C, a model of 8150, and is manufactured by Dow Chemical Company; The second ethylene-octene copolymer has a crystallization temperature of 84°C, a model of 8480, and is manufactured by The Dow Chemical Company; The insulation material is cross-linked polyethylene; The conductor material is copper.

[0021] Example 1 S1, weighing 60 parts of ethylene-octene copolymer, 6 parts of dioctyl phthalate, 15 parts of aluminum hydroxide, 0.5 parts of antioxidant 1010, 0.2 parts of calcium stearate, and 12 parts of glass fiber, mixing them evenly, and extruding at 130° C. to obtain a sheath layer, wherein the 60 parts of ethylene-octene copolymer include 12 parts of a first ethylene-octene copolymer and 48 parts of a second ethylene-octene copolymer; S2. Wrap the insulation layer and the sheath layer around the conductor in sequence to obtain a cable.

[0022] Example 2 S1, weigh 70 parts of ethylene-octene copolymer, 8 parts of di-2-ethylhexyl phthalate, 18 parts of magnesium hydroxide, 1 part of antioxidant 1076, 0.5 parts of calcium stearate, and 14 parts of carbon fiber, mix them evenly, and extrude them at 140° C. to obtain a sheath layer, wherein the 70 parts of ethylene-octene copolymer include 14 parts of a first ethylene-octene copolymer and 56 parts of a second ethylene-octene copolymer; S2. Wrap the insulation layer and the sheath layer around the conductor in sequence to obtain a cable.

[0023] Example 3 S1, weigh 80 parts of ethylene-octene copolymer, 10 parts of dioctyl terephthalate, 20 parts of zinc borate, 1.5 parts of antioxidant 168, 0.8 parts of zinc stearate, and 15 parts of silicon carbide fiber, mix them evenly, and extrude them at 150° C. to obtain a sheath layer, wherein the 80 parts of ethylene-octene copolymer include 16 parts of a first ethylene-octene copolymer and 64 parts of a second ethylene-octene copolymer; S2. Wrap the insulation layer and the sheath layer around the conductor in sequence to obtain a cable.

[0024] Example 4 Compared with Example 3, the difference of Example 4 is that 80 parts of the ethylene-octene copolymer includes 40 parts of the first ethylene-octene copolymer and 40 parts of the second ethylene-octene copolymer.

[0025] Example 5 Compared with Example 3, Example 5 is different in that 80 parts of the ethylene-octene copolymer includes 48 parts of the first ethylene-octene copolymer and 32 parts of the second ethylene-octene copolymer.

[0026] Example 6 Compared with Example 3, Example 6 is different in that 80 parts of the ethylene-octene copolymer includes 50 parts of the first ethylene-octene copolymer and 30 parts of the second ethylene-octene copolymer.

[0027] Example 7 Modified silicon carbide fiber: Weigh 1.5 parts of N-decenyl succinic anhydride and dissolve it in 15 parts of toluene, add 20 parts of silicon carbide fiber, heat to 60°C and disperse for 2 hours, cool to room temperature after the reaction is completed, filter and dry to obtain modified silicon carbide fiber; A method for preparing a high-strength overhead insulated cable comprises the following steps: S1, weigh 48 parts of the first ethylene-octene copolymer, 32 parts of the second ethylene-octene copolymer, 10 parts of dioctyl terephthalate, 20 parts of zinc borate, 1.5 parts of antioxidant 168, 0.8 parts of zinc stearate, and 15 parts of modified silicon carbide fiber, mix them evenly, and extrude them at 150° C. to obtain a sheath layer; S2. Wrap the insulation layer and the sheath layer around the conductor in sequence to obtain a cable.

[0028] Example 8 Compared with Example 7, the difference of Example 8 is that the modified silicon carbide fiber is prepared by the following method: weigh 2 parts of N-decenyl succinic anhydride and dissolve it in 20 parts of toluene, add 20 parts of silicon carbide fiber, heat to 60°C and disperse for 2 hours, cool to room temperature after the reaction is completed, filter and dry to obtain the modified silicon carbide fiber.

[0029] Example 9 Compared with Example 7, the difference of Example 9 is that the modified silicon carbide fiber is prepared by the following method: weigh 4 parts of N-decenyl succinic anhydride and dissolve it in 40 parts of toluene, add 20 parts of silicon carbide fiber, heat to 60°C and disperse for 2 hours, cool to room temperature after the reaction is completed, filter and dry to obtain the modified silicon carbide fiber.

[0030] Example 10 Compared with Example 7, the difference of Example 10 is that the modified silicon carbide fiber is prepared by the following method: weigh 6 parts of N-decenyl succinic anhydride and dissolve it in 60 parts of toluene, add 20 parts of silicon carbide fiber, heat to 60°C and disperse for 2 hours, cool to room temperature after the reaction is completed, filter and dry to obtain the modified silicon carbide fiber.

[0031] Comparative Example 1 Compared with Example 3, Comparative Example 1 is different in that 80 parts of the added ethylene-octene copolymer only include the first ethylene-octene copolymer.

[0032] Comparative Example 2 Compared with Example 3, Comparative Example 2 is different in that 80 parts of the added ethylene-octene copolymer only includes the second ethylene-octene copolymer.

[0033] The sheath layers prepared in Examples 1 to 10 and Comparative Examples 1 to 2 were tested according to the following method: 1. Tensile strength: Test the tensile strength of the sample according to the test method specified in GB / T 1040.1-2018 "Determination of tensile properties of plastics Part 1: General".

[0034] 2. Elongation at break: According to the test method specified in GB / T 2951.11-2008 "General test methods for insulation and sheath materials of electric and optical cables Part 11: General test methods for thickness and dimensional measurement - Mechanical properties test", the elongation at break of the test sample is tested.

[0035] The test results are shown in the following table: Table 1 Performance test results of high-strength overhead insulated cables prepared in Examples 1 to 10 and Comparative Examples 1 to 2

[0036] Compared with Comparative Examples 1 and 2, Example 3 simultaneously adds the first ethylene-octene copolymer and the second ethylene-octene copolymer. As a result, the tensile strength and elongation at break of Example 3 are better than those of Comparative Examples 1 and 2, indicating that the first ethylene-octene copolymer and the second ethylene-octene copolymer play a synergistic role and can improve the tensile strength and elongation at break of the overhead insulated cable. In Examples 3 to 6, the first ethylene-octene copolymer and the second ethylene-octene copolymer are added in different mass ratios. As a result, the tensile strength and elongation at break of Examples 4 and 5 are better than those of Examples 3 and 6, indicating that when the mass ratio of the first ethylene-octene copolymer to the second ethylene-octene copolymer is 2 to 3:2, the tensile strength and elongation at break of the obtained overhead insulated cable are better.

[0037] Compared with Example 5, Examples 7 to 10 replaced silicon carbide with an equal amount of modified silicon carbide. As a result, the tensile strength and elongation at break of Examples 7 to 10 were better than those of Example 5, indicating that the addition of modified silicon carbide can improve the tensile strength and elongation at break of the overhead insulated cable. In Examples 7 to 10, N-decenyl succinic anhydride modified silicon carbide was added in different mass ratios. As a result, the tensile strength and elongation at break of Examples 8 and 9 were better than those of Examples 7 and 10, indicating that when the mass ratio of silicon carbide to N-decenyl succinic anhydride was 10:1 to 2, the tensile strength and elongation at break of the obtained overhead insulated cable were better.

[0038] The above are only 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 in the protection scope of the present invention.

Claims

1. A high-strength overhead insulated cable, characterized in that: The invention is composed of three layers, which are, from the inside to the outside, a conductor, an insulating layer and a sheath layer. The sheath layer comprises the following raw materials in parts by weight: 60-80 parts of ethylene-octene copolymer, 6-10 parts of plasticizer, 15-20 parts of flame retardant, 0.5-1.5 parts of antioxidant, 0.2-0.8 parts of lubricant and 12-15 parts of filler. The ethylene-octene copolymer is composed of a first ethylene-octene copolymer and a second ethylene-octene copolymer, the crystallization temperature of the first ethylene-octene copolymer is lower than that of the second ethylene-octene copolymer, and the mass ratio of the first ethylene-octene copolymer to the second ethylene-octene copolymer is 1-5:5-1.

2. A high-strength overhead insulated cable according to claim 1, characterized in that: The material of the conductor is copper.

3. A high-strength overhead insulated cable according to claim 1, characterized in that: The insulating layer is a cross-linked polyethylene insulating layer.

4. A high-strength overhead insulated cable according to claim 1, characterized in that: The crystallization temperature of the first ethylene-octene copolymer is 42° C., the crystallization temperature of the second ethylene-octene copolymer is 84° C., and the mass ratio of the first ethylene-octene copolymer to the second ethylene-octene copolymer is 2-3:

2.

5. A high-strength overhead insulated cable according to claim 1, characterized in that: The filler includes one or more of glass fiber, carbon fiber, and silicon carbide fiber.

6. A high-strength overhead insulated cable according to claim 5, characterized in that: The silicon carbide fiber is a modified silicon carbide fiber, and the modifier of the modified silicon carbide fiber is N-decenyl succinic anhydride.

7. A high-strength overhead insulated cable according to claim 6, characterized in that: The mass ratio of the silicon carbide fiber to the N-decenyl succinic anhydride is 10:1-2; The preparation steps of the modified silicon carbide fiber include: dissolving N-decenyl succinic anhydride and then adding the silicon carbide fiber, dispersing and reacting uniformly, removing the solvent and drying to obtain the modified silicon carbide fiber.

8. A high-strength overhead insulated cable according to claim 1, characterized in that: The plasticizer includes one or more of dioctyl phthalate, diisooctyl phthalate, and dioctyl terephthalate.

9. A high-strength overhead insulated cable according to claim 1, characterized in that: It also includes at least one of the following technical features: The flame retardant includes one or more of aluminum hydroxide, magnesium hydroxide, and zinc borate; The antioxidant includes one or more of antioxidant 1010 , antioxidant 1076 , and antioxidant 168 .

10. A high-strength overhead insulated cable according to claim 1, characterized in that: The lubricant includes one or both of calcium stearate and zinc stearate.

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