High-flame-retardant power cable

Abstract

The invention relates to the technical field of power cables, and provides a high-flame-retardant power cable which comprises a conductor, an insulating layer, a shielding layer and an outer sheath layer. The insulating layer is arranged outside the conductor, the shielding layer is arranged outside the insulating layer, and the outer sheath layer is arranged outside the shielding layer; the conductor is an aluminum alloy conductor; the insulating layer is a crosslinked polyethylene insulating layer; the outer sheath layer comprises the following components in parts by mass: 60-70 parts of polyethylene, 10-20 parts of polypropylene, 10-20 parts of an ethylene-vinyl acetate copolymer and 40-50 parts of a flame retardant, and the flame retardant comprises the following raw materials: aluminum hydroxide, aluminum oxide and a hydroxy anthraquinone compound in a ratio of 10: 1: (0.05-1). According to the technical scheme, the problems of low mechanical property and poor flame retardance of the power cable in the prior art are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of power cables, and in particular to a highly flame-retardant power cable. Background Art

[0002] Cables used for power transmission and distribution are power cables, which are an important branch of the wire and cable industry. Power cables are mainly composed of conductors, insulation layers, and sheath layers. The conductor is the conductive part, generally made of metal, used to transmit electric energy. The insulation layer plays an isolation role and is generally made of cross-linked polyethylene materials to ensure safe and reliable transmission of electric energy. The sheath layer is used to protect the insulation layer and is generally made of polyolefin materials to prevent the insulation layer from being damaged during laying and operation, so that the power cable can operate stably for a long time.

[0003] As people's safety awareness increases, higher requirements are also put forward for the safety of power cables. The safety of power cables is largely determined by the performance of the sheath layer. When the mechanical properties of the sheath layer are high and the flame retardancy is good, the safety of the power cable is high. Among them, the flame retardancy of the sheath layer is the most concerned. When the flame retardancy of the power cable is poor, it is easy to cause fire, thus affecting property safety and personal safety. At present, in order to improve the flame retardancy of power cables, inorganic hydroxides are generally added, such as aluminum hydroxide. However, aluminum hydroxide has strong polarity and certain hydrophilicity, and it is very easy to form hydrogen bonds between particles, which in turn affects its dispersibility in the polymer matrix, resulting in unsatisfactory mechanical properties and flame retardancy of power cables. Summary of the invention

[0004] The present invention provides a highly flame-retardant power cable, which solves the problems of low mechanical properties and poor flame retardancy of power cables in the related art.

[0005] The technical solution of the present invention is as follows: A highly flame-retardant power cable comprises a conductor, an insulating layer, a shielding layer and an outer sheath layer; The insulating layer is arranged outside the conductor, the shielding layer is arranged outside the insulating layer, and the outer sheath layer is arranged outside the shielding layer; The conductor is an aluminum alloy conductor; The insulating layer is a cross-linked polyethylene insulating layer; The raw materials of the outer sheath layer include the following components in parts by mass: 60-70 parts of polyethylene, 10-20 parts of polypropylene, 10-20 parts of ethylene-vinyl acetate copolymer, and 40-50 parts of flame retardant. The raw materials of the flame retardant include aluminum hydroxide, aluminum oxide, and hydroxyanthraquinone compounds in a ratio of 10:1:0.05-1.

[0006] The hydroxyanthraquinone compound in the present invention may be any one or more hydroxyanthraquinone compounds, for example, it may be one or more of 1,2-dihydroxyanthraquinone, 1,2,3-trihydroxyanthraquinone, 1-amino-4-hydroxyanthraquinone, 1,2,7-trihydroxyanthraquinone, 1,2,4-trihydroxyanthraquinone, preferably one or more of 1-amino-4-hydroxyanthraquinone, 1,2,7-trihydroxyanthraquinone, 1,2,4-trihydroxyanthraquinone, more preferably one or two of 1-amino-4-hydroxyanthraquinone and 1,2,7-trihydroxyanthraquinone, and most preferably 1,2,7-trihydroxyanthraquinone.

[0007] As a further technical solution, the mass ratio of the aluminum hydroxide, aluminum oxide and hydroxyanthraquinone compounds is 10:1:0.3~0.5.

[0008] The present invention limits the mass ratio of aluminum hydroxide, aluminum oxide and hydroxyanthraquinone compounds to 10:1:0.3-0.5, thereby further improving the mechanical properties of the outer sheath layer, thereby further improving the mechanical properties of the power cable.

[0009] As a further technical solution, the hydroxyanthraquinone compound is 1,2,7-trihydroxyanthraquinone.

[0010] In the present invention, the hydroxyanthraquinone compound is limited to 1,2,7-trihydroxyanthraquinone, which further improves the mechanical properties of the outer sheath layer, thereby further improving the mechanical properties of the power cable.

[0011] As a further technical solution, the raw material of the outer sheath layer further includes the following components in parts by weight: 1 to 3 parts of antioxidant and 2 to 4 parts of lubricant.

[0012] In the present invention, antioxidants and lubricants are also added to the outer sheath layer, wherein the antioxidant can not only prevent material aging, but also maintain material stability under high temperature conditions and prevent polymer degradation reactions under thermal effects, thereby improving the heat resistance of the power cable; in addition, the lubricant can reduce the friction resistance between the power cable and mechanical equipment during the manufacturing and laying process, and can also form a protective film on the cable surface to prevent the intrusion of moisture, corrosive substances and other pollutants, which helps to improve the reliability and durability of the power cable, and can help maintain the smoothness and consistency of the surface of the power cable, thereby improving the quality of the final product.

[0013] As a further technical solution, the method for preparing the flame retardant comprises the following steps: S1, mixing aluminum hydroxide and aluminum oxide, and grinding them to obtain a mixed material; S2. Dissolve the hydroxyanthraquinone compound in a solvent, add the mixture into the solvent, mix evenly, and dry to obtain a flame retardant.

[0014] In the present invention, when preparing the flame retardant, aluminum hydroxide and aluminum oxide are first ground so that the surface of the aluminum hydroxide is coated with aluminum oxide, and then treated with hydroxyanthraquinone compounds. Free hydroxyanthraquinone compounds can form complexes with aluminum oxide, thereby being adsorbed on the surface of aluminum oxide to make the surface of aluminum hydroxide organic, thereby achieving the effect of improving the mechanical properties and flame retardancy of the power cable.

[0015] As a further technical solution, the particle size of the aluminum hydroxide is 5000-10000 mesh, and the aluminum oxide is nano aluminum oxide.

[0016] As a further technical solution, the ethylene-vinyl acetate copolymer includes one or more of EVA 2054, EVA 3128, and EVA3861.

[0017] As a further technical solution, the polyethylene includes low-density polyethylene and high-density polyethylene in a mass ratio of 2:4-5.

[0018] As a further technical solution, the antioxidant includes one or more of antioxidant 1010, antioxidant 2246, and antioxidant 1076.

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

[0020] The working principle and beneficial effects of the present invention are: The present invention provides a highly flame-retardant power cable, comprising a conductor, an insulating layer, a shielding layer and an outer sheath layer; by using polyethylene, polypropylene, ethylene-vinyl acetate copolymer and a flame retardant as raw materials for the outer sheath layer, and using aluminum hydroxide, aluminum oxide and hydroxyanthraquinone compounds as raw materials for the flame retardant, the mechanical properties of the outer sheath layer are improved, thereby improving the mechanical properties of the power cable, because: aluminum hydroxide has a reinforcing and toughening effect, and aluminum hydroxide, aluminum oxide and hydroxyanthraquinone compounds are used as raw materials for the flame retardant, and aluminum oxide and hydroxyanthraquinone compounds can promote the dispersion of aluminum hydroxide and the compatibility of aluminum hydroxide with a polymer matrix. In addition, the power cable prepared by the present invention is a flame-retardant Class A power cable with high flame retardancy. DETAILED DESCRIPTION

[0021] 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.

[0022] A highly flame-retardant power cable comprises, from the inside to the outside, an aluminum alloy conductor, a 2.6 mm thick cross-linked polyethylene insulation layer, a shielding layer, and a 2.8 mm thick outer sheath layer. The raw materials and preparation method of the outer sheath layer are as follows: In the following examples and comparative examples: The low-density polyethylene is LDPE Sinopec Maoming 2426H; High-density polyethylene is HDPE Dushanzi Petrochemical DMDA-8008H; Polypropylene is PP Yanshan Petrochemical K7760; The nano-alumina is γ-nano-alumina with an average particle size of 50 nm.

[0023] Example 1 S1, mixing 50 parts of 5000 mesh aluminum hydroxide and 5 parts of aluminum oxide, grinding to obtain a mixture; S2, dissolving 0.25 parts of 1,2-dihydroxyanthraquinone in 100 parts of ethanol, adding the above mixture to mix evenly, filtering, and drying to obtain a flame retardant; S3. Mix 20 parts of low-density polyethylene, 50 parts of high-density polyethylene, 10 parts of polypropylene, 20 parts of EVA 3861, 50 parts of flame retardant, 3 parts of antioxidant 2246, and 2 parts of polyethylene wax evenly, and extrude them outside the shielding layer to obtain an outer sheath layer.

[0024] Example 2 S1, mixing 50 parts of 10000 mesh aluminum hydroxide and 5 parts of aluminum oxide, grinding to obtain a mixture; S2, dissolving 0.25 parts of 1,2-dihydroxyanthraquinone in 100 parts of ethanol, adding the above mixture to mix evenly, filtering, and drying to obtain a flame retardant; S3. Mix 20 parts of low-density polyethylene, 40 parts of high-density polyethylene, 20 parts of polypropylene, 10 parts of EVA 3128, 40 parts of flame retardant, 1 part of antioxidant 1076, and 4 parts of calcium stearate, and extrude them outside the shielding layer to obtain an outer sheath layer.

[0025] Example 3 The only difference from Example 1 is that 1,2-dihydroxyanthraquinone is replaced by an equal amount of 1,2,3-trihydroxyanthraquinone.

[0026] Example 4 The only difference from Example 1 is that 1,2-dihydroxyanthraquinone is replaced by an equal amount of 1,2,7-trihydroxyanthraquinone.

[0027] Example 5 The only difference from Example 4 is that 1.5 parts of 1,2,7-trihydroxyanthraquinone are used.

[0028] Example 6 The only difference from Example 4 is that 2.5 parts of 1,2,7-trihydroxyanthraquinone are used.

[0029] Example 7 The only difference from Example 4 is that 5 parts of 1,2,7-trihydroxyanthraquinone are used.

[0030] Comparative Example 1 S1, mixing 50 parts of 5000 mesh aluminum hydroxide and 5 parts of aluminum oxide, grinding to obtain a flame retardant; S2. Mix 20 parts of low-density polyethylene, 50 parts of high-density polyethylene, 10 parts of polypropylene, 20 parts of EVA 3861, 50 parts of flame retardant, 3 parts of antioxidant 2246, and 2 parts of polyethylene wax evenly, and extrude the mixture outside the shielding layer to obtain an outer sheath layer.

[0031] Comparative Example 2 20 parts of low-density polyethylene, 50 parts of high-density polyethylene, 10 parts of polypropylene, 20 parts of EVA 3861, 50 parts of 5000 mesh aluminum hydroxide, 3 parts of antioxidant 2246, and 2 parts of polyethylene wax are mixed evenly, and then extruded outside the shielding layer to obtain an outer sheath layer.

[0032] The power cables obtained in Examples 1 to 7 and Comparative Examples 1 to 2 were tested for tensile strength and elongation at break of the outer sheath layer according to the method in GB / T 2951.11-2008. The specimens were tubular specimens. The test results are recorded in Table 1.

[0033] Table 1 Tensile strength and elongation at break of outer sheath layer

[0034] It can be seen from Table 1 that the tensile strength of the power cable provided by the present invention is 12.4N / mm 2 The elongation at break is above 200%, and it has good mechanical properties.

[0035] Compared with Comparative Examples 1-2, in Examples 1-7, aluminum hydroxide, aluminum oxide and hydroxyanthraquinone compounds are used as raw materials for flame retardants, the tensile strength and elongation at break of the outer sheath layer obtained are higher than those of Comparative Examples 1-2, indicating that using aluminum hydroxide, aluminum oxide and hydroxyanthraquinone compounds as flame retardants can improve the mechanical properties of the outer sheath layer, thereby improving the mechanical properties of the power cable.

[0036] The tensile strength and elongation at break of the outer sheath layer obtained in Example 4 are higher than those in Example 1 and Example 3, indicating that the hydroxyanthraquinone compound is 1,2,7-trihydroxyanthraquinone, which can further improve the mechanical properties of the outer sheath layer, thereby further improving the mechanical properties of the power cable.

[0037] The tensile strength and elongation at break of the outer sheath layer obtained in Examples 5 to 6 are higher than those in Example 4 and Example 7, indicating that the mass ratio of aluminum hydroxide, aluminum oxide and hydroxyanthraquinone compounds is 10:1:0.3 to 0.5, which can further improve the mechanical properties of the outer sheath layer, thereby further improving the mechanical properties of the power cable.

[0038] The outer sheath layer and the power cable obtained in Example 1 were tested for various performances, and the test results are recorded in Table 2.

[0039] Table 2 Various properties of the outer sheath layer and power cable of Example 1

[0040] It can be seen from Table 2 that the outer sheath layer and the power cable provided by the present invention have good comprehensive performance, especially good flame retardancy. The bundled flame retardancy test of the cable meets Class A and is a highly flame retardant power cable.

[0041] 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 highly flame-retardant power cable, characterized in that: It includes conductor, insulation layer, shielding layer and outer sheath layer; The insulating layer is arranged outside the conductor, the shielding layer is arranged outside the insulating layer, and the outer sheath layer is arranged outside the shielding layer; The conductor is an aluminum alloy conductor; The insulating layer is a cross-linked polyethylene insulating layer; The raw materials of the outer sheath layer include the following components in parts by mass: 60-70 parts of polyethylene, 10-20 parts of polypropylene, 10-20 parts of ethylene-vinyl acetate copolymer, and 40-50 parts of flame retardant. The raw materials of the flame retardant include aluminum hydroxide, aluminum oxide, and hydroxyanthraquinone compounds in a ratio of 10:1:0.05-1.

2. A highly flame-retardant power cable according to claim 1, characterized in that: The mass ratio of the aluminum hydroxide, aluminum oxide and hydroxyanthraquinone compound is 10:1:0.3-0.

5.

3. A highly flame-retardant power cable according to claim 1, characterized in that: The hydroxyanthraquinone compounds include one or more of 1,2-dihydroxyanthraquinone, 1,2,3-trihydroxyanthraquinone, 1-amino-4-hydroxyanthraquinone, 1,2,7-trihydroxyanthraquinone and 1,2,4-trihydroxyanthraquinone.

4. A highly flame-retardant power cable according to claim 1, characterized in that: The raw materials of the outer sheath layer also include the following components in parts by weight: 1 to 3 parts of antioxidant and 2 to 4 parts of lubricant.

5. A highly flame-retardant power cable according to claim 1, characterized in that: The preparation method of the flame retardant comprises the following steps: S1, mixing aluminum hydroxide and aluminum oxide, and grinding them to obtain a mixture; S2. Dissolve the hydroxyanthraquinone compound in a solvent, add the mixture into the solvent, mix evenly, and dry to obtain a flame retardant.

6. A highly flame-retardant power cable according to claim 1, characterized in that: The particle size of the aluminum hydroxide is 5000-10000 mesh, and the aluminum oxide is nano aluminum oxide.

7. A highly flame-retardant power cable according to claim 1, characterized in that: The ethylene-vinyl acetate copolymer includes one or more of EVA 2054, EVA 3128, and EVA 3861.

8. A highly flame-retardant power cable according to claim 1, characterized in that: The polyethylene includes low-density polyethylene and high-density polyethylene in a mass ratio of 2:4-5.

9. A highly flame-retardant power cable according to claim 4, characterized in that: The antioxidant includes one or more of antioxidant 1010 , antioxidant 2246 , and antioxidant 1076 .

10. A highly flame-retardant power cable according to claim 4, characterized in that: The lubricant includes one or more of stearic acid, stearate, and polyethylene wax.

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