Insulated power cable

Abstract

The invention relates to the technical field of cables, and provides an insulated power cable which is composed of three layers including a conductor, an insulating layer and a sheath layer from inside to outside in sequence. The sheath layer comprises the following raw materials in parts by weight: 60-70 parts of chlorinated polyethylene, 10-20 parts of calcium carbonate, 6-10 parts of glass fibers, 1-3 parts of carbon black, 10-12 parts of aluminum hydroxide, 2-10 parts of an organosilicon compound, 0.3-0.5 part of an antioxidant and 0.8-1.2 parts of a lubricant. According to the technical scheme, the problems of low mechanical strength and low insulating property of the power 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 insulated power cable. Background Art

[0002] Power cable is an electrical device used to transmit and distribute electrical energy. It consists of one or more insulated conductors with an insulating layer, an inner sheath, a metal sheath and an outer sheath. It is commonly used to transmit electrical energy from power plants to substations and to connect between substations. It is also used to supply power to industrial, commercial and residential buildings. Cables are often faced with changing mechanical stresses during use, such as underground burial, outdoor overhead and occasions that require mechanical protection. During installation and laying, they will be subjected to mechanical stresses such as stretching, extrusion and bending. If the cable itself lacks sufficient mechanical strength, it is easy to cause the attenuation of electrical characteristics and even the occurrence of wire core breakage. It is indispensable for the cable to have a certain insulation. Good insulation can effectively prevent current leakage and short circuit, thereby ensuring the safe operation of the power system and reducing the risk of insulation failure. Therefore, the development of a power cable with high mechanical strength and insulation is an urgent problem to be solved. Summary of the invention

[0003] The present invention provides an insulated power cable, which solves the problems of low mechanical strength and low insulation performance of the power cable in the related art.

[0004] The technical solution of the present invention is as follows: The present invention proposes an insulated power cable, which consists of three layers, which are, from inside to outside, a conductor, an insulating layer and a sheath layer, and the sheath layer includes the following raw materials in parts by weight: 60 to 70 parts of chlorinated polyethylene, 10 to 20 parts of calcium carbonate, 6 to 10 parts of glass fiber, 1 to 3 parts of carbon black, 10 to 12 parts of aluminum hydroxide, 2 to 10 parts of organic silicon compound, 0.3 to 0.5 parts of antioxidant, and 0.8 to 1.2 parts of lubricant.

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

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

[0007] As a further technical solution, the chlorinated polyethylene includes a first chlorinated polyethylene and a second chlorinated polyethylene, and the chlorine contents of the first chlorinated polyethylene and the second chlorinated polyethylene are different.

[0008] As a further technical solution, the chlorine content of the first chlorinated polyethylene is 40wt%, the chlorine content of the second chlorinated polyethylene is 65wt%, and the mass ratio of the first chlorinated polyethylene to the second chlorinated polyethylene is 2-4:1.

[0009] As a further technical solution, the mass ratio of the first chlorinated polyethylene to the second chlorinated polyethylene is 3:1.

[0010] When the chlorine content is low, the molecular chain structure of chlorinated polyethylene is shorter, the material is relatively soft, and the mechanical strength is relatively low. As the chlorine content increases, the molecular chain structure of chlorinated polyethylene becomes longer, and the intermolecular cross-linking effect is enhanced, so that the material becomes harder and more durable, and the mechanical strength is significantly improved; the degree of crystallization increases, and at the same time, its surface and volume resistivity will increase, thereby effectively preventing the leakage and conduction of current, and improving the insulation performance of chlorinated polyethylene materials. However, when the chlorine content continues to increase, the crystallinity of chlorinated polyethylene increases, the distance between molecular chains becomes shorter, and the molecular arrangement becomes closer, but too high a chlorine content will cause the chlorinated polyethylene to become too brittle, and the mechanical strength and insulation performance will decrease. In the present invention, by mixing the first chlorinated polyethylene and the second chlorinated polyethylene, a balance is found between insulation performance and material strength to obtain a power cable with optimal insulation performance and mechanical strength.

[0011] As a further technical solution, the organosilicon compound is an organosilicon compound containing phenyl groups and amine groups, and the mass ratio of the organosilicon compound to the chlorinated polyethylene is 1:10-20.

[0012] As a further technical solution, the mass ratio of the organosilicon compound to the chlorinated polyethylene is 1:15.

[0013] As a further technical solution, the organosilicon compound includes one or both of triphenylsilylamine and 4-(trimethylsilyl)aniline.

[0014] In addition to benzene rings, organosilicon compounds also contain amine groups. The presence of amine groups can not only increase the polarity of the molecule, improve the compatibility of chlorinated polyethylene with other polar substances, make them better mixed, and enhance insulation, but the hydrogen atoms in chlorinated polyethylene can also form hydrogen bonds with the nitrogen atoms in the amine groups, strengthening the bond between the two, thereby improving the mechanical strength of the power cable.

[0015] As a further technical solution, the antioxidant includes one or more of antioxidant 1010, antioxidant 1076, and antioxidant BHT.

[0016] As a further technical solution, the lubricant includes one or both of stearic acid and paraffin oil.

[0017] The present invention also provides a method for preparing an insulated power 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.

[0018] The working principle and beneficial effects of the present invention are: In the present invention, chlorinated polyethylene is used as the main insulating material. The presence of chlorine groups can prevent or slow down the movement of electric charges in the material, thereby improving the insulating properties of the material; since some hydrogen atoms in the chlorinated polyethylene are replaced by chlorine atoms, the polarity and bond crystallinity of the molecular chain are increased, the interaction force between molecules is increased, and the mechanical strength of the material is improved. Secondly, the present invention also adds an organosilicon compound, which forms an efficient insulating layer through its own high resistivity and electrical properties, effectively preventing current from passing through the insulating layer and leaking into the external environment, ensuring that the current is transmitted along the expected path, and providing more reliable insulation protection. 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 chlorinated polyethylene: chlorine content 40wt%, model CPE142C, manufacturer is Hangzhou Keli Chemical Co., Ltd.; The second chlorinated polyethylene: chlorine content 65wt%, model HCPE-1, manufacturer is Shandong Bangtai Petrochemical (Group) Co., Ltd.

[0021] Example 1 S1. Weigh 10 parts of calcium carbonate, 6 parts of glass fiber, and 1 part of carbon black, mix and stir for 5 minutes to obtain a mixture; S2, 30 parts of the first chlorinated polyethylene, 30 parts of the second chlorinated polyethylene, 10 parts of aluminum hydroxide, 12 parts of triphenylsilylamine, 0.3 parts of antioxidant 1010, 0.8 parts of stearic acid and the mixture are mixed, stirred at 110°C for 30 minutes, blended and extruded by a twin-screw extruder, granulated, and then sent to an extrusion molding machine for molding, sizing, pulling, and cutting to obtain a sheath layer; S3. Wrap the insulation layer and the sheath layer around the conductor in sequence to obtain a cable.

[0022] Example 2 S1. Weigh 15 parts of calcium carbonate, 8 parts of glass fiber, and 2 parts of carbon black, mix and stir for 10 minutes to obtain a mixture; S2, 32 parts of the first chlorinated polyethylene, 32 parts of the second chlorinated polyethylene, 11 parts of aluminum hydroxide, 12.8 parts of triphenylsilylamine, 0.3 parts of antioxidant 1076, 1 part of stearic acid and the mixture are mixed, stirred at 120°C for 25 minutes, blended and extruded through a twin-screw extruder, granulated, and then sent to an extrusion molding machine for molding, sizing, pulling, and cutting to obtain a sheath layer; S3. Wrap the insulation layer and the sheath layer around the conductor in sequence to obtain a cable.

[0023] Example 3 S1. Weigh 20 parts of calcium carbonate, 10 parts of glass fiber, and 3 parts of carbon black, mix and stir for 15 minutes to obtain a mixture; S2, 35 parts of the first chlorinated polyethylene, 35 parts of the second chlorinated polyethylene, 12 parts of aluminum hydroxide, 14 parts of 4-(trimethylsilyl)aniline, 0.5 parts of antioxidant BHT, 1.2 parts of stearic acid and the mixture are mixed, stirred at 130° C. for 20 min, blended and extruded through a twin-screw extruder, granulated, and then sent to an extrusion molding machine for molding, sizing, pulling, and cutting to obtain a sheath layer; S3. Wrap the insulation layer and the sheath layer around the conductor in sequence to obtain a cable.

[0024] Example 4 Compared with Example 1, Example 4 is different in that 30 parts of the first chlorinated polyethylene and 30 parts of the second chlorinated polyethylene are replaced by 40 parts of the first chlorinated polyethylene and 20 parts of the second chlorinated polyethylene.

[0025] Example 5 Compared with Example 1, Example 5 is different in that 30 parts of the first chlorinated polyethylene and 30 parts of the second chlorinated polyethylene are replaced by 45 parts of the first chlorinated polyethylene and 15 parts of the second chlorinated polyethylene.

[0026] Example 6 Compared with Example 1, Example 6 is different in that 30 parts of the first chlorinated polyethylene and 30 parts of the second chlorinated polyethylene are replaced by 48 parts of the first chlorinated polyethylene and 12 parts of the second chlorinated polyethylene.

[0027] Example 7 Compared with Example 1, Example 7 is different in that 30 parts of the first chlorinated polyethylene and 30 parts of the second chlorinated polyethylene are replaced by 50 parts of the first chlorinated polyethylene and 10 parts of the second chlorinated polyethylene.

[0028] Example 8 Compared with Example 1, Example 8 is different in that 30 parts of the first chlorinated polyethylene and 30 parts of the second chlorinated polyethylene are replaced with 60 parts of the first chlorinated polyethylene.

[0029] Example 9 Compared with Example 1, Example 9 is different in that 30 parts of the first chlorinated polyethylene and 30 parts of the second chlorinated polyethylene are replaced with 60 parts of the second chlorinated polyethylene.

[0030] Example 10 Compared with Example 5, Example 10 is different in that 12 parts of triphenylsilylamine are replaced by 6 parts of triphenylsilylamine.

[0031] Embodiment 11 Compared with Example 5, Example 11 is different in that 12 parts of triphenylsilylamine are replaced by 4 parts of triphenylsilylamine.

[0032] Example 12 Compared with Example 5, Example 12 is different in that 12 parts of triphenylsilylamine are replaced by 3 parts of triphenylsilylamine.

[0033] Embodiment 13 Compared with Example 5, Example 13 is different in that 12 parts of triphenylsilylamine are replaced by 2.4 parts of triphenylsilylamine.

[0034] Embodiment 14 Compared with Example 1, Example 14 is different in that triphenylsilylamine is replaced by an equal amount of diphenylmethylsilane.

[0035] Comparative Example 1 Compared with Example 1, the difference of Comparative Example 1 is that 30 parts of the first chlorinated polyethylene and 30 parts of the second chlorinated polyethylene are replaced by 60 parts of chlorinated polyethylene with a chlorine content of 25 wt %, model CPE645, and manufacturer Weifang Shuoyi Chemical Co., Ltd.

[0036] Comparative Example 2 Compared with Example 1, the difference of Comparative Example 2 is that 30 parts of the first chlorinated polyethylene and 30 parts of the second chlorinated polyethylene are replaced by 60 parts of chlorinated polyethylene, the chlorine content is 67wt%, the model is J-1000, and the manufacturer is Ruize Chemical Co., Ltd.

[0037] The insulated power cables prepared in Examples 1 to 14 and Comparative Examples 1 to 2 were tested according to the following method: 1. Dielectric constant: According to the test method specified in GB / T 3048.8-2007 "Electrical performance test methods for wires and cables Part 8: AC voltage test", the dielectric constant of the sample is tested.

[0038] 2. Flexural modulus: Test the flexural modulus of the sample according to the test method specified in GB / T 9341-2008 "Test for Flexural Properties of Plastics".

[0039] The test results are shown in the following table: Table 1 Performance test results of insulated power cables prepared in Examples 1 to 14 and Comparative Examples 1 to 2

[0040] Compared with Comparative Examples 1 and 2, the chlorine contents of chlorinated polyethylene added in Examples 8 and 9 are 40wt% and 65wt%, respectively. As a result, the dielectric constant and bending elastic modulus of Examples 8 and 9 are greater than those of Comparative Examples 1 and 2, indicating that chlorinated polyethylene with a chlorine content of 40-65wt% can improve the insulation and mechanical strength of power cables.

[0041] Compared with Examples 8 and 9, Examples 1 to 3 simultaneously added the first chlorinated polyethylene and the second chlorinated polyethylene. As a result, the dielectric constants and bending elastic moduli of Examples 1 to 3 were greater than those of Examples 8 and 9, indicating that when the first chlorinated polyethylene and the second chlorinated polyethylene were added simultaneously, the insulation and mechanical strength of the obtained power cable were better.

[0042] Compared with Example 1, Examples 4 to 7 added different proportions of the first chlorinated polyethylene and the second chlorinated polyethylene. As a result, the dielectric constants and bending elastic moduli of Examples 4 to 6 were greater than those of Examples 1 and 7, indicating that when the mass ratio of the first chlorinated polyethylene to the second chlorinated polyethylene was 2 to 4:1, and the preferred ratio was 3:1, the insulation and mechanical strength of the obtained power cable were better.

[0043] Compared with Example 14, the diphenylmethylsilane in Example 1 was replaced with an equal amount of triphenylsilylamine. As a result, the dielectric constant and bending modulus of Example 1 were greater than those of Example 14, indicating that the organosilicon compound containing amine groups can further enhance the mechanical strength of the insulation of the power cable.

[0044] Compared with Example 5, Examples 10 to 13 added different amounts of triphenylsilylamine, and the dielectric constants and bending elastic moduli of Examples 10 to 12 were greater than those of Examples 5 and 13, indicating that when the mass ratio of triphenylsilylamine to chlorinated polyethylene was 1:10 to 20, and the preferred mass ratio was 1:15, the insulation and mechanical strength of the obtained power cable were optimal.

[0045] 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 insulated power 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: 60-70 parts of chlorinated polyethylene, 10-20 parts of calcium carbonate, 6-10 parts of glass fiber, 1-3 parts of carbon black, 10-12 parts of aluminum hydroxide, 2-10 parts of organic silicon compound, 0.3-0.5 parts of antioxidant and 0.8-1.2 parts of lubricant.

2. An insulated power cable according to claim 1, characterized in that: The material of the conductor is copper.

3. An insulated power cable according to claim 1, characterized in that: The insulating layer is a cross-linked polyethylene insulating layer.

4. The insulated power cable according to claim 1, characterized in that: The chlorinated polyethylene includes a first chlorinated polyethylene and a second chlorinated polyethylene, and the first chlorinated polyethylene and the second chlorinated polyethylene have different chlorine contents.

5. An insulated power cable according to claim 4, characterized in that: The chlorine content of the first chlorinated polyethylene is 40wt%, the chlorine content of the second chlorinated polyethylene is 65wt%, and the mass ratio of the first chlorinated polyethylene to the second chlorinated polyethylene is 2-4:

1.

6. The insulated power cable according to claim 1, characterized in that: The organosilicon compound is an organosilicon compound containing phenyl and amine groups, and the mass ratio of the organosilicon compound to chlorinated polyethylene is 1:10-20.

7. An insulated power cable according to claim 6, characterized in that: The organic silicon compound includes one or both of triphenylsilylamine and 4-(trimethylsilyl)aniline.

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

9. The insulated power cable according to claim 1, characterized in that: The lubricant includes one or both of stearic acid and paraffin oil.

10. A method for preparing an insulated power cable according to any one of claims 1 to 9, characterized in that: The following steps are involved: 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.

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