Aerial insulated cable

Abstract

The invention relates to the technical field of cables, and provides an aerial insulated cable which sequentially comprises a wire, an insulating layer and a protective layer from inside to outside, and the protective layer is prepared from the following raw materials in parts by mass: 50-60 parts of polypropylene, 10-20 parts of polyolefin elastomer, 10-20 parts of ethylene-vinyl acetate copolymer, 20-30 parts of flame retardant and 0.5-1 part of antioxidant. The flame retardant is graphite powder coated with (4-hydroxy-phenyl)-diethyl phosphate. According to the technical scheme, the problems of poor flame retardance and low mechanical strength of the overhead insulated cable in the prior art are solved.

Description

Technical Field

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

[0002] Overhead insulated cable is a new way of power transmission between overhead wires and underground cables, used in power distribution systems or telecommunication lines. Overhead insulated cable uses the wire as the core, and is usually equipped with a layered structure such as an insulation layer and a protective layer outside the wire to ensure the normal operation and safety performance of the wire. Overhead insulated cables are often used in urban streets and green areas. Because they are often suspended between electric poles or power towers and close to buildings, they are given higher expectations in terms of safety performance, especially flame retardancy and mechanical strength. Therefore, the flame retardancy and mechanical strength of the existing overhead insulated cables on the market need to be further improved. Summary of the invention

[0003] The invention provides an overhead insulated cable, which solves the problems of poor flame retardancy and low mechanical 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 an overhead insulated cable, which comprises a conductor, an insulating layer and a protective layer in order from the inside to the outside. The raw materials of the protective layer comprise the following components in parts by mass: 50-60 parts of polypropylene, 10-20 parts of polyolefin elastomer, 10-20 parts of ethylene-vinyl acetate copolymer, 20-30 parts of flame retardant, and 0.5-1 part of antioxidant. The flame retardant is (4-hydroxy-phenyl)-diethyl phosphate coated graphite powder.

[0005] As a further technical solution, the raw materials of the flame retardant include (4-hydroxy-phenyl)-diethyl phosphate and graphite powder in a mass ratio of 1 to 10:30.

[0006] As a further technical solution, the mass ratio of the (4-hydroxy-phenyl)-diethyl phosphate to the graphite powder is 1-2:10.

[0007] The invention further enhances the flame retardancy and mechanical strength of the overhead insulated cable by limiting the mass ratio of (4-hydroxy-phenyl)-diethyl phosphate to graphite powder to 1-2:10.

[0008] As a further technical solution, the graphite powder is modifier-modified graphite powder, and the modifier in the modifier-modified graphite powder is 1,4-cyclohexanedimethyl diisocyanate.

[0009] The invention uses 1,4-cyclohexanedimethyl diisocyanate as a modifier to modify graphite powder, thereby further enhancing the flame retardancy and mechanical strength of the overhead insulated cable.

[0010] As a further technical solution, the raw materials of the modifier-modified graphite powder include graphite powder and modifier in a mass ratio of 30:2~3.

[0011] The invention further enhances the flame retardancy and mechanical strength of the overhead insulated cable by limiting the raw materials of the modifier-modified graphite powder to include the graphite powder and the modifier in a mass ratio of 30:2-3.

[0012] As a further technical solution, the preparation process of the flame retardant comprises the following steps: Dissolve (4-hydroxy-phenyl)-diethyl phosphate in tetrahydrofuran, add graphite powder and mix evenly, filter, and dry to obtain a flame retardant.

[0013] As a further technical solution, the method for preparing the modifier-modified graphite powder comprises the following steps: The modifier is dissolved in acetone, graphite powder is added and mixed evenly, filtered, and dried to obtain modifier-modified graphite powder.

[0014] As a further technical solution, the antioxidant includes one or more of antioxidant 1010, antioxidant 1035, and antioxidant 1076.

[0015] As a further technical solution, the particle size of the graphite powder is 1 μm.

[0016] The present invention provides a method for preparing an overhead insulated cable, comprising the following steps: Polypropylene, polyolefin elastomer, ethylene-vinyl acetate copolymer, antioxidant and flame retardant are mixed evenly and extruded outside the insulation layer to obtain an overhead insulated cable.

[0017] The working principle and beneficial effects of the present invention are: In the present invention, (4-hydroxy-phenyl)-diethyl phosphate is selected to be coated on the surface of graphite powder as a flame retardant for the protective layer of the overhead insulated cable, which not only improves the flame retardancy of the protective layer, but also improves the mechanical strength, thereby improving the flame retardancy and mechanical strength of the overhead insulated cable, and solving the problems of poor flame retardancy and low mechanical strength of the overhead insulated cable in the related art. DETAILED DESCRIPTION

[0018] 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.

[0019] An overhead insulated cable comprises, from the inside to the outside, a conductor, an insulating layer, and a protective layer, wherein the protective layer is prepared by the following method: In the following examples and comparative examples, the parameters of the raw materials are as follows: Graphite powder: particle size 1μm; The grade of polypropylene is CNOOC Shell RP346R; The model of polyolefin elastomer is Exxon 6202; The type of ethylene-vinyl acetate copolymer is DuPont Elvax 265.

[0020] Example 1 S1. Dissolve 1 part of (4-hydroxy-phenyl)-diethyl phosphate in 50 parts of tetrahydrofuran, add 30 parts of graphite powder and mix well, filter, and dry to obtain a flame retardant; S2. Evenly mix 50 parts of polypropylene, 10 parts of polyolefin elastomer, 10 parts of ethylene-vinyl acetate copolymer, 10350.5 parts of antioxidant and 30 parts of flame retardant, extrude them on the outside of the insulating layer with a thickness of 3 mm using a twin-screw extruder, and cool them to obtain a protective layer.

[0021] Example 2 S1. Dissolve 1 part of (4-hydroxy-phenyl)-diethyl phosphate in 50 parts of tetrahydrofuran, add 30 parts of graphite powder and mix well, filter, and dry to obtain a flame retardant; S2. Mix 60 parts of polypropylene, 20 parts of polyolefin elastomer, 20 parts of ethylene-vinyl acetate copolymer, 10101 parts of antioxidant and 20 parts of flame retardant evenly, extrude them on the outside of the insulation layer with a thickness of 3 mm using a twin-screw extruder, and cool them to obtain a protective layer.

[0022] Example 3 The only difference from Example 1 is that: 10 parts of (4-hydroxy-phenyl)-diethyl phosphate.

[0023] Example 4 The only difference from Example 1 is that: 3 parts of diethyl (4-hydroxy-phenyl)-phosphate.

[0024] Example 5 The only difference from Example 1 is that: 6 parts of (4-hydroxy-phenyl)-diethyl phosphate.

[0025] Example 6 S1, dissolving 1 part of 1,4-cyclohexanedimethyl diisocyanate in 20 parts of acetone, adding 30 parts of graphite powder and mixing evenly, filtering, and drying to obtain modifier-modified graphite powder; S2, dissolving 6 parts of (4-hydroxy-phenyl)-diethyl phosphate in 50 parts of tetrahydrofuran, adding 30 parts of modifier-modified graphite powder, mixing evenly, filtering, and drying to obtain a flame retardant; S3. Evenly mix 50 parts of polypropylene, 10 parts of polyolefin elastomer, 10 parts of ethylene-vinyl acetate copolymer, 10350.5 parts of antioxidant and 30 parts of flame retardant, extrude them on the outside of the insulating layer with a thickness of 3 mm using a twin-screw extruder, and cool them to obtain a protective layer.

[0026] Example 7 The only difference from Example 6 is that 6 parts of 1,4-cyclohexanedimethyl diisocyanate are used.

[0027] Example 8 The only difference from Example 6 is that 2 parts of 1,4-cyclohexanedimethyl diisocyanate are used.

[0028] Example 9 The only difference from Example 6 is that 3 parts of 1,4-cyclohexanedimethyl diisocyanate are used.

[0029] Comparative Example 1 50 parts of polypropylene, 10 parts of polyolefin elastomer, 10 parts of ethylene-vinyl acetate copolymer, 10350.5 parts of antioxidant and 30 parts of graphite powder were mixed evenly, extruded on the outside of the insulating layer with a thickness of 3 mm using a twin-screw extruder, and cooled to obtain a protective layer.

[0030] Comparative Example 2 Mix 50 parts of polypropylene, 10 parts of polyolefin elastomer, 10 parts of ethylene-vinyl acetate copolymer, 10350.5 parts of antioxidant, 1 part of (4-hydroxy-phenyl)-diethyl phosphate, and 30 parts of graphite powder evenly, extrude 3 mm thick on the outside of the insulating layer using a twin-screw extruder, and cool to obtain a protective layer.

[0031] Test example The protective layer of the overhead insulated cables prepared in Examples 1 to 9 and Comparative Examples 1 to 2 was cut open along the cable axis according to the standard of GB / T 2951.11-2008, and a narrow strip was cut to make a small dumbbell specimen for tensile strength test; the limiting oxygen index test of the protective layer specimen was carried out according to the standard of GB / T2406.2-2009, and the results were shown in Table 1.

[0032] Table 1 Test results of flame retardancy and mechanical strength of Examples 1 to 9 and Comparative Examples 1 to 2

[0033] Compared with Comparative Examples 1 to 2, the flame retardant of the overhead insulated cables prepared in Example 1 and Examples 3 to 5 is (4-hydroxy-phenyl)-diethyl phosphate coated graphite powder. As a result, the limiting oxygen index and tensile strength of Example 1 and Examples 3 to 5 are greater than those of Comparative Examples 1 to 2, indicating that the flame retardancy and mechanical strength of the overhead insulated cables can be enhanced by using (4-hydroxy-phenyl)-diethyl phosphate coated graphite powder.

[0034] Compared with Example 1 and Example 3, the raw materials of the flame retardant in the overhead insulated cables prepared in Examples 4 to 5 are (4-hydroxy-phenyl)-diethyl phosphate and graphite powder in a mass ratio of 1 to 2:10. As a result, the limiting oxygen index and tensile strength of Examples 4 to 5 are greater than those of Examples 1 and 3, indicating that by limiting the mass ratio of (4-hydroxy-phenyl)-diethyl phosphate and graphite powder to 1 to 2:10, the flame retardancy and mechanical strength of the overhead insulated cables are further enhanced.

[0035] Compared with Example 5, the graphite powder of the overhead insulated cable prepared in Examples 6 to 9 is 1,4-cyclohexanedimethyl diisocyanate modified graphite powder. As a result, the limiting oxygen index and tensile strength of Examples 6 to 9 are greater than those of Example 5, indicating that the flame retardancy and mechanical strength of the overhead insulated cable are further enhanced by using 1,4-cyclohexanedimethyl diisocyanate modified graphite powder.

[0036] Compared with Examples 6 to 7, the raw materials of the modifier-modified graphite powder in the overhead insulated cables prepared in Examples 8 to 9 are graphite powder and modifier in a mass ratio of 30:2 to 3. As a result, the limiting oxygen index and tensile strength of Examples 8 to 9 are greater than those of Examples 6 to 7, indicating that the flame retardancy and mechanical strength of the overhead insulated cables are further enhanced by limiting the raw materials of the modifier-modified graphite powder to include graphite powder and modifier in a mass ratio of 30:2 to 3.

[0037] 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. An overhead insulated cable, comprising a conductor, an insulating layer, and a protective layer from the inside out, characterized in that: The raw materials of the protective layer include the following components in parts by mass: 50-60 parts of polypropylene, 10-20 parts of polyolefin elastomer, 10-20 parts of ethylene-vinyl acetate copolymer, 20-30 parts of flame retardant, and 0.5-1 part of antioxidant. The flame retardant is (4-hydroxy-phenyl)-diethyl phosphate coated graphite powder.

2. An overhead insulated cable according to claim 1, characterized in that: The raw materials of the flame retardant include (4-hydroxy-phenyl)-diethyl phosphate and graphite powder in a mass ratio of 1 to 10:

30.

3. An overhead insulated cable according to claim 2, characterized in that: The mass ratio of the (4-hydroxy-phenyl)-diethyl phosphate to the graphite powder is 1-2:

10.

4. An overhead insulated cable according to claim 3, characterized in that: The graphite powder is modifier-modified graphite powder, and the modifier in the modifier-modified graphite powder is 1,4-cyclohexanedimethyl diisocyanate.

5. An overhead insulated cable according to claim 4, characterized in that: The raw materials of the modifier-modified graphite powder include graphite powder and modifier in a mass ratio of 30:2-3.

6. An overhead insulated cable according to any one of claims 1 to 3, characterized in that: The preparation process of the flame retardant comprises the following steps: Dissolve (4-hydroxy-phenyl)-diethyl phosphate in tetrahydrofuran, add graphite powder and mix evenly, filter, and dry to obtain a flame retardant.

7. An overhead insulated cable according to claim 4 or 5, characterized in that: The method for preparing the modifier-modified graphite powder comprises the following steps: The modifier is dissolved in acetone, graphite powder is added and mixed evenly, filtered, and dried to obtain modifier-modified graphite powder.

8. An overhead insulated cable according to claim 1, characterized in that: The antioxidant includes one or more of antioxidant 1010, antioxidant 1035, and antioxidant 1076.

9. An overhead insulated cable according to claim 2, characterized in that: The particle size of the graphite powder is 1 μm.

10. A method for preparing an overhead insulated cable according to any one of claims 1 to 9, characterized in that: The following steps are involved: Polypropylene, polyolefin elastomer, ethylene-vinyl acetate copolymer, antioxidant and flame retardant are mixed evenly and extruded outside the insulation layer to obtain an overhead insulated cable.

Images