A high voltage cable and a method for preparing the same

Abstract

The present invention relates to the field of cable technology, and a high-voltage cable and a preparation method thereof are proposed. The high-voltage cable includes a cable core, a shielding layer, an inner sheath layer, an armor layer, and an outer sheath layer from the inside to the outside. The cable core is formed by twisting a plurality of conductor cores, and the conductor core includes a conductor and an insulating layer. The outer sheath layer includes the following raw materials in parts by weight: 30 to 40 parts of polyethylene, 45 to 55 parts of ethylene-butyl acrylate copolymer, 3 to 6 parts of compatibilizer, 1 to 3 parts of antioxidant, 20 to 30 parts of flame retardant, 15 to 25 parts of filler, 0.5 to 1 part of lubricant, and 0.3 to 0.5 parts of heat stabilizer; the filler is sericite modified with potassium acetate and 3-amino-2-cinnamyl butenoate. Through the above technical scheme, the problem of poor flame retardancy and mechanical properties of high-voltage cables in related technologies is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of cables, and in particular to a high voltage cable and a preparation method thereof. Background Art

[0002] As a key equipment in the field of power transmission, high-voltage cables play a vital role in modern power systems. With the rapid development of the economy and the continuous growth of social demand for electricity, the distance and capacity requirements of power transmission are constantly increasing, which has led to extensive attention and in-depth research on high-voltage cable technology. In the process of power transmission, high-voltage cables need to operate stably in a high-voltage and high-current environment. With the acceleration of urbanization, the population in the central area of ​​the city is highly dense and buildings are everywhere. Traditional overhead lines have many problems in such an environment. In this case, high-voltage cables become an ideal choice. High-voltage cables can be laid in underground cable trenches and cable tunnels, effectively utilizing underground space without affecting the normal use and landscape of the city ground. For the power supply system in the central area of ​​the city, high-voltage cables need to meet the requirements of high reliability, because once a power failure occurs, the impact range will be extremely wide, which may lead to serious consequences such as stagnation of commercial activities, paralysis of traffic, and interruption of public services. This requires that high-voltage cables need to have higher flame retardant properties and mechanical properties to ensure that the cables can operate stably for a long time. Summary of the invention

[0003] The present invention provides a high-voltage cable and a preparation method thereof, which solves the problem of poor flame retardancy and mechanical properties of the high-voltage cable in the related art.

[0004] The technical solution of the present invention is as follows:

[0005] The present invention provides a high-voltage cable, which comprises a cable core, a shielding layer, an inner sheath layer, an armor layer, and an outer sheath layer in order from the inside to the outside. The cable core is formed by twisting a plurality of conductor cores. The conductor core comprises a conductor and an insulating layer. The outer sheath layer comprises the following raw materials in parts by weight: 30 to 40 parts of polyethylene, 45 to 55 parts of ethylene-butyl acrylate copolymer, 3 to 6 parts of a compatibilizer, 1 to 3 parts of an antioxidant, 20 to 30 parts of a flame retardant, 15 to 25 parts of a filler, 0.5 to 1 part of a lubricant, and 0.3 to 0.5 parts of a heat stabilizer; the filler is sericite modified by potassium acetate and cinnamyl 3-amino-2-butenoate.

[0006] As a further technical solution, the mass ratio of the sericite, potassium acetate and 3-amino-2-butenoic acid cinnamyl is 1:0.5:0.2~0.5.

[0007] In the present invention, the mass ratio of sericite, potassium acetate and cinnamyl 3-amino-2-butenoate is limited to 1:0.5:0.2-0.5, thereby further improving the flame retardant property and mechanical property of the high voltage cable.

[0008] As a further technical solution, the mass ratio of the sericite, potassium acetate and 3-amino-2-butenoic acid cinnamyl is 1:0.5:0.3.

[0009] As a further technical solution, the preparation method of the filler includes the following steps: adding sericite to a solvent and mixing, first adding potassium acetate for a first modification, then adding 3-amino-2-butenoic acid cinnamyl ester for a second modification, and obtaining the filler after drying.

[0010] As a further technical solution, the solvent is methanol.

[0011] In the present invention, the sericite is first modified by potassium acetate and 3-amino-2-butenoic acid cinnamyl is second modified, thereby further improving the flame retardant property and mechanical property of the high voltage cable.

[0012] As a further technical solution, the temperature of the first modification and the temperature of the second modification are independently 40-50° C., and the time of the first modification and the time of the second modification are independently 5-6 hours.

[0013] As a further technical solution, the ethylene-butyl acrylate copolymer includes a first ethylene-butyl acrylate copolymer and a second ethylene-butyl acrylate copolymer; the mass content of butyl acrylate in the first ethylene-butyl acrylate copolymer and the second ethylene-butyl acrylate copolymer is different.

[0014] As a further technical solution, the mass content of butyl acrylate in the first ethylene-butyl acrylate copolymer is 6%; the mass content of butyl acrylate in the second ethylene-butyl acrylate copolymer is 35%.

[0015] As a further technical solution, the mass ratio of the first ethylene-butyl acrylate copolymer to the second ethylene-butyl acrylate copolymer is 2-3:1.

[0016] In the present invention, the mechanical properties of the high-voltage cable are further improved by limiting the mass ratio of the first ethylene-butyl acrylate copolymer to the second ethylene-butyl acrylate copolymer to 2-3:1.

[0017] As a further technical solution, the antioxidant includes one or more of antioxidant 1010 , antioxidant 1035 , and antioxidant 1076 .

[0018] As a further technical solution, the flame retardant includes one or both of magnesium hydroxide and aluminum hydroxide.

[0019] As a further technical solution, the lubricant includes one or more of zinc stearate, stearic acid, and erucamide.

[0020] As a further technical solution, the heat stabilizer includes one or both of calcium zinc heat stabilizer CZ-113 and calcium zinc heat stabilizer CZ-116.

[0021] As a further technical solution, the compatibilizer includes one or two of POE-g-MAH and PP-g-MAH.

[0022] In the present invention, POE-g-MAH is maleic anhydride grafted polyethylene-octene copolymer; PP-g-MAH is maleic anhydride grafted polypropylene.

[0023] The present invention also provides a method for preparing a high voltage cable, comprising the following steps:

[0024] S1. Extruding an insulating layer on the outside of the conductor to obtain a conductor core, and twisting multiple conductor cores to obtain a cable core;

[0025] S2, weave tinned copper wire on the outside of the cable core to obtain a shielding layer;

[0026] S3, extruding a polyolefin material on the outer side of the shielding layer to obtain an inner sheath layer;

[0027] S4, wrapping a steel tape around the outer side of the inner sheath layer to obtain an armor layer, thereby obtaining a semi-finished high-voltage cable;

[0028] S5. Mix and knead the raw materials of the outer sheath layer, and extrude them onto the outside of the high-voltage cable semi-finished product to obtain the high-voltage cable.

[0029] The working principle and beneficial effects of the present invention are:

[0030] In the present invention, a shielding layer, an inner sheath layer, an armor layer and an outer sheath layer are arranged on the outer side of the cable core to form a multi-layer protection system, thereby ensuring the safe transmission of high voltage electricity; at the same time, polyethylene and ethylene-butyl acrylate copolymer are used as the main base materials of the outer sheath layer, and fillers composed of sericite, potassium acetate and 3-amino-2-cinnamyl butyl ester are added to improve the flame retardant property and mechanical property of the outer sheath layer, thereby solving the problem of poor flame retardant property and mechanical property of the high-voltage cable. DETAILED DESCRIPTION

[0031] 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.

[0032] In the following embodiments and comparative examples:

[0033] POE-g-MAH is POE-g-MAH Fusabond N416; PP-g-MAH, model: 18722; sericite, particle size: 800 mesh; polyethylene, model 5000S; ethylene-butyl acrylate copolymer with model 3210, the butyl acrylate content is 6wt%; ethylene-butyl acrylate copolymer with model 35BA40T, the butyl acrylate content is 35wt%.

[0034] Example 1

[0035] A method for preparing a high voltage cable comprises the following steps:

[0036] S1. Extruding an insulating layer on the outside of the conductor to obtain a conductor core, and twisting multiple conductor cores to obtain a cable core;

[0037] S2, weave tinned copper wire on the outside of the cable core to obtain a shielding layer;

[0038] S3, extruding a polyolefin material on the outer side of the shielding layer to obtain an inner sheath layer;

[0039] S4, wrapping a steel tape around the outer side of the inner sheath layer to obtain an armor layer, thereby obtaining a semi-finished high-voltage cable;

[0040] S5, 30 parts of polyethylene, 45 parts of ethylene-butyl acrylate copolymer 35BA40T, 3 parts of POE-g-MAH, 1 part of antioxidant 1035, 20 parts of magnesium hydroxide, 15 parts of filler, 0.5 parts of zinc stearate, and 0.3 parts of calcium zinc heat stabilizer CZ-113 are mixed and kneaded, and then extruded on the outside of the high-voltage cable semi-finished product to obtain a high-voltage cable;

[0041] The preparation method of the filler comprises the following steps: adding 50g of sericite into 1L of methanol, then adding 25g of potassium acetate and 40g of 3-amino-2-butenoic acid cinnamyl ester, heating to 50°C, stirring for 10h, and drying to obtain the filler.

[0042] Example 2

[0043] A method for preparing a high voltage cable comprises the following steps:

[0044] S1. Extruding an insulating layer on the outside of the conductor to obtain a conductor core, and twisting multiple conductor cores to obtain a cable core;

[0045] S2, weave tinned copper wire on the outside of the cable core to obtain a shielding layer;

[0046] S3, extruding a polyolefin material on the outer side of the shielding layer to obtain an inner sheath layer;

[0047] S4, wrapping a steel tape around the outer side of the inner sheath layer to obtain an armor layer, thereby obtaining a semi-finished high-voltage cable;

[0048] S5, 40 parts of polyethylene, 55 parts of ethylene-butyl acrylate copolymer 35BA40T, 6 parts of PP-g-MAH, 3 parts of antioxidant 1076, 30 parts of aluminum hydroxide, 25 parts of filler, 1 part of erucic acid amide, and 0.5 parts of calcium zinc heat stabilizer CZ-116 are mixed and kneaded, and then extruded on the outside of the high-voltage cable semi-finished product to obtain a high-voltage cable;

[0049] The preparation method of the filler comprises the following steps: adding 50g of sericite into 1L of methanol, then adding 25g of potassium acetate and 40g of 3-amino-2-butenoic acid cinnamyl ester, heating to 40°C, stirring for 12h, and drying to obtain the filler.

[0050] Example 3

[0051] The difference between this embodiment and embodiment 1 is that the added amount of cinnamyl 3-amino-2-butenoate is 5 g.

[0052] Example 4

[0053] The difference between this embodiment and embodiment 1 is that the addition amount of cinnamyl 3-amino-2-butenoate is 10 g.

[0054] Example 5

[0055] The difference between this embodiment and embodiment 1 is that the addition amount of cinnamyl 3-amino-2-butenoate is 15 g.

[0056] Example 6

[0057] The difference between this embodiment and embodiment 1 is that the addition amount of cinnamyl 3-amino-2-butenoate is 25 g.

[0058] Example 7

[0059] The present embodiment is different from the embodiment 5 in that the preparation method of the filler comprises the following steps: adding 50 g of sericite to 1 L of methanol, first adding 15 g of 3-amino-2-butenoic acid cinnamyl ester, heating to 50° C., stirring for 5 h, then adding 25 g of potassium acetate and continuing to stir for 5 h, and then drying to obtain the filler.

[0060] Example 8

[0061] The present embodiment is different from the embodiment 5 in that the preparation method of the filler comprises the following steps: adding 50 g of sericite to 1 L of methanol, first adding 25 g of potassium acetate, heating to 50° C., stirring for 5 h, then adding 15 g of 3-amino-2-butenoic acid cinnamyl ester, and continuing to stir for 5 h, and then drying to obtain the filler.

[0062] Example 9

[0063] The only difference between this embodiment and embodiment 8 is that the ethylene-butyl acrylate copolymer 35BA40T is replaced by an equal amount of ethylene-butyl acrylate copolymer 3210.

[0064] Example 10

[0065] The only difference between this embodiment and embodiment 8 is that the ethylene-butyl acrylate copolymer 35BA40T is replaced by equal amounts of ethylene-butyl acrylate copolymer 3210 and ethylene-butyl acrylate copolymer 35BA40T in a mass ratio of 1:1.

[0066] Embodiment 11

[0067] The only difference between this embodiment and embodiment 10 is that the mass ratio of ethylene-butyl acrylate copolymer 3210 and ethylene-butyl acrylate copolymer 35BA40T is 5:1.

[0068] Example 12

[0069] The only difference between this embodiment and Embodiment 10 is that the mass ratio of ethylene-butyl acrylate copolymer 3210 and ethylene-butyl acrylate copolymer 35BA40T is 2:1.

[0070] Embodiment 13

[0071] The only difference between this embodiment and embodiment 10 is that the mass ratio of ethylene-butyl acrylate copolymer 3210 and ethylene-butyl acrylate copolymer 35BA40T is 3:1.

[0072] Comparative Example 1

[0073] The only difference between this comparative example and Example 1 is that potassium acetate is replaced by an equal amount of cinnamyl 3-amino-2-butenoate.

[0074] Comparative Example 2

[0075] The only difference between this comparative example and Example 1 is that 3-amino-2-butenoic acid cinnamyl ester is replaced by an equal amount of potassium acetate.

[0076] Comparative Example 3

[0077] The only difference between this comparative example and Example 1 is that the filler is sericite.

[0078] The outer sheath layer of the high-voltage cables prepared in Examples 1 to 13 and Comparative Examples 1 to 3 was cut axially, and a narrow strip was taken to prepare a dumbbell test piece with a thickness of 3.5 mm. The test piece was tested for the tensile strength of the outer sheath layer according to the determination method in GB / T 2951.11-2008 "General test methods for insulation and sheath materials of electrical and optical cables Part 11: General test methods for thickness and dimensional measurement mechanical properties test", and the test results are shown in Table 1.

[0079] Table 1 Test results of tensile strength of outer sheath layer

[0080]

[0081] Compared with Comparative Examples 1 to 3, in Example 1, potassium acetate and 3-amino-2-butenoic acid cinnamyl are used to modify sericite. As a result, the tensile strength of the outer sheath layer in Example 1 is higher than that in Comparative Examples 1 to 3, indicating that modifying sericite with potassium acetate and 3-amino-2-butenoic acid cinnamyl can improve the mechanical properties of the outer sheath layer.

[0082] Compared with Example 1, the addition amount of cinnamyl 3-amino-2-butenoate was changed in Examples 3 to 6. As a result, the tensile strength of the outer sheath layer in Examples 4 to 6 was higher than that in Example 1 and Example 3, indicating that when the mass ratio of sericite, potassium acetate, and cinnamyl 3-amino-2-butenoate was 1:0.5:0.2 to 0.5, the mechanical properties of the outer sheath layer could be further improved; by comparing Examples 4 to 6, it was found that the tensile strength of the outer sheath layer in Example 5 was higher than that in Example 4 and Example 6, indicating that when the mass ratio of sericite, potassium acetate, and cinnamyl 3-amino-2-butenoate was 1:0.5:0.3, the mechanical properties of the obtained outer sheath layer were higher.

[0083] Compared with Example 5, in Example 7 and Example 8, the sericite was modified in two steps. As a result, the tensile strength of the outer sheath layer in Example 8 was higher than that in Example 5 and Example 7, indicating that the mechanical properties of the outer sheath layer can be further improved by first modifying the sericite with potassium acetate and then modifying it with 3-amino-2-butenoic acid cinnamyl ester for the second time.

[0084] Compared with Example 8, the composition of the ethylene-butyl acrylate copolymer was changed in Examples 9 to 13. As a result, the tensile strength of the outer sheath layer in Examples 12 to 13 was higher than that in Examples 8 to 11, indicating that when the ethylene-butyl acrylate copolymer is composed of ethylene-butyl acrylate copolymer 3210 and ethylene-butyl acrylate copolymer 35BA40T, and the mass ratio is 2 to 3:1, the mechanical properties of the outer sheath layer can be further improved.

[0085] The outer sheath layer of the high-voltage cables prepared in Examples 1 to 8 and Comparative Examples 1 to 3 was cut axially, and a narrow strip was taken to prepare an IV test specimen. The oxygen index of the outer sheath layer was tested according to the test method in GB / T 2406.2-2009 "Determination of Combustion Behavior of Plastics by Oxygen Index Method Part 2: Room Temperature Test". The test results are shown in Table 2.

[0086] Table 2 Test results of flame retardant properties of outer sheath layer

[0087]

[0088] Compared with Comparative Examples 1 to 3, in Example 1, potassium acetate and 3-amino-2-butenoic acid cinnamyl are used to modify sericite. As a result, the oxygen index of the outer sheath layer in Example 1 is higher than that in Comparative Examples 1 to 3, indicating that the flame retardant properties of the outer sheath layer can be improved by modifying sericite with potassium acetate and 3-amino-2-butenoic acid cinnamyl.

[0089] Compared with Example 1, the addition amount of cinnamyl 3-amino-2-butenoate was changed in Examples 3 to 6. As a result, the oxygen index of the outer sheath layer in Examples 4 to 6 was higher than that in Examples 1 and 3, indicating that when the mass ratio of sericite, potassium acetate, and cinnamyl 3-amino-2-butenoate was 1:0.5:0.2 to 0.5, the flame retardant properties of the outer sheath layer could be further improved; by comparing Examples 4 to 6, it was found that the oxygen index of the outer sheath layer in Example 5 was higher than that in Examples 4 and 6, indicating that when the mass ratio of sericite, potassium acetate, and cinnamyl 3-amino-2-butenoate was 1:0.5:0.3, the flame retardant properties of the obtained outer sheath layer were higher.

[0090] Compared with Example 5, in Example 7 and Example 8, the sericite was modified in two steps. As a result, the oxygen index of the outer sheath layer in Example 8 was higher than that in Example 5 and Example 7, indicating that the flame retardant properties of the outer sheath layer can be further improved by first modifying the sericite with potassium acetate and then modifying it with 3-amino-2-butenoic acid cinnamyl ester for the second time.

[0091] 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 voltage cable, characterized in that: The cable core comprises a cable core, a shielding layer, an inner sheath layer, an armor layer, and an outer sheath layer from the inside to the outside. The cable core is formed by twisting a plurality of conductor cores. The conductor core comprises a conductor and an insulating layer. The outer sheath layer comprises the following raw materials in parts by weight: 30-40 parts of polyethylene, 45-55 parts of ethylene-butyl acrylate copolymer, 3-6 parts of a compatibilizer, 1-3 parts of an antioxidant, 20-30 parts of a flame retardant, 15-25 parts of a filler, 0.5-1 parts of a lubricant, and 0.3-0.5 parts of a heat stabilizer; the filler is sericite modified by potassium acetate and 3-amino-2-butenoic acid cinnamyl ester; The mass ratio of the sericite, potassium acetate and 3-amino-2-butenoic acid cinnamyl is 1:0.5:0.2-0.

5.

2. A high voltage cable according to claim 1, characterized in that: The preparation method of the filler comprises the following steps: adding sericite to a solvent and mixing, first adding potassium acetate for a first modification, then adding 3-amino-2-butenoic acid cinnamyl for a second modification, and drying to obtain the filler.

3. A high voltage cable according to claim 1, characterized in that: The ethylene-butyl acrylate copolymer comprises a first ethylene-butyl acrylate copolymer and a second ethylene-butyl acrylate copolymer; the mass contents of butyl acrylate in the first ethylene-butyl acrylate copolymer and the second ethylene-butyl acrylate copolymer are different.

4. A high voltage cable according to claim 3, characterized in that: The mass content of butyl acrylate in the first ethylene-butyl acrylate copolymer is 6%; the mass content of butyl acrylate in the second ethylene-butyl acrylate copolymer is 35%.

5. A high voltage cable according to claim 3, characterized in that: The mass ratio of the first ethylene-butyl acrylate copolymer to the second ethylene-butyl acrylate copolymer is 2-3:

1.

6. A high voltage cable according to claim 1, characterized in that: The antioxidant includes one or more of antioxidant 1010 , antioxidant 1035 , and antioxidant 1076 .

7. A high voltage cable according to claim 1, characterized in that: The lubricant includes one or more of zinc stearate, stearic acid, and erucamide.

8. A high voltage cable according to claim 1, characterized in that: The heat stabilizer includes one or both of calcium zinc heat stabilizer CZ-113 and calcium zinc heat stabilizer CZ-116.

9. A method for preparing a high voltage cable according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Extruding an insulating layer on the outside of the conductor to obtain a conductor core, and twisting multiple conductor cores to obtain a cable core; S2, weave tinned copper wire on the outside of the cable core to obtain a shielding layer; S3, extruding a polyolefin material on the outer side of the shielding layer to obtain an inner sheath layer; S4, wrapping a steel tape around the outer side of the inner sheath layer to obtain an armor layer, thereby obtaining a semi-finished high-voltage cable; S5. Mix and knead the raw materials of the outer sheath layer, and extrude them onto the outside of the high-voltage cable semi-finished product to obtain the high-voltage cable.

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