High-temperature-resistant power cable and preparation method thereof

Abstract

The invention relates to the technical field of cables, and provides a high-temperature-resistant power cable and a preparation method thereof. The high-temperature-resistant power cable sequentially comprises a conductor, an insulating layer, a shielding layer and an outer sheath layer from inside to outside, and the outer sheath layer is prepared from the following raw materials in parts by weight: 90-100 parts of polyvinyl chloride, 15-20 parts of high-density polyethylene, 12-15 parts of polyacrylate rubber, 8-12 parts of high-temperature-resistant filler, 0.3-0.4 part of an antioxidant, 1-2 parts of a plasticizer, 1-3 parts of a heat stabilizer, 2-4 parts of a compatilizer, 0.2-0.5 part of a cross-linking agent and 0.1-0.3 part of an assistant cross-linking agent; the high-temperature-resistant filler comprises the following raw materials in parts by weight: 100 parts of graphite and 20-30 parts of an intercalator; the intercalator comprises stearic acid and lauryl gallate. According to the technical scheme, the problem of poor high-temperature resistance of the power cable in the prior art is solved.

Description

Technical Field

[0001] This invention relates to the field of cable technology, specifically to a high-temperature resistant power cable and its manufacturing method. Background Technology

[0002] Power cables, as the core carrier of power transmission and distribution, are widely used in various fields such as industrial production, energy extraction, transportation, and construction engineering. Especially in high-temperature applications such as metallurgy, chemical engineering, and thermal power generation, higher requirements are placed on the high-temperature resistance of cables. However, the outer sheath of existing power cables has poor high-temperature resistance. Under long-term high-temperature environments, the material is prone to aging, softening, cracking, and even decomposition, leading to decreased insulation performance and unstable conductivity. This not only reduces cable transmission efficiency and significantly shortens service life but also poses safety hazards. Therefore, there is a need to propose a power cable with excellent high-temperature resistance and its manufacturing method. Summary of the Invention

[0003] This invention proposes a high-temperature resistant power cable and its preparation method, which solves the problem of poor high-temperature resistance of power cables in related technologies.

[0004] The technical solution of the present invention is as follows: This invention proposes a high-temperature resistant power cable, comprising, from the inside out, a conductor, an insulation layer, a shielding layer, and an outer sheath layer. The outer sheath layer comprises the following raw materials in parts by weight: 90-100 parts of polyvinyl chloride, 15-20 parts of high-density polyethylene, 12-15 parts of polyacrylate rubber, 8-12 parts of high-temperature resistant filler, 0.3-0.4 parts of antioxidant, 1-2 parts of plasticizer, 1-3 parts of heat stabilizer, 2-4 parts of compatibilizer, 0.2-0.5 parts of crosslinking agent, and 0.1-0.3 parts of co-crosslinking agent. The high-temperature resistant filler comprises the following raw materials in parts by weight: 100 parts graphite and 20-30 parts intercalating agent, wherein the intercalating agent comprises stearic acid and lauryl gallate.

[0005] As a further technical solution, the mass ratio of stearic acid to lauryl gallate is 7~10:4, preferably 9:4.

[0006] As a further technical solution, the preparation method of the high-temperature resistant filler includes the following steps: A1. After mixing graphite with nitric acid aqueous solution, filter and wash until the filtrate is neutral, then dry and calcine to obtain pretreated graphite; A2. Disperse the pretreated graphite in a solvent, add an intercalating agent and mix, then filter, wash and dry to obtain a high-temperature resistant filler.

[0007] As a further technical solution, in step A1, the washing is done with water; in step A2, the washing is done with anhydrous ethanol.

[0008] As a further technical solution, in step A1, the mass fraction of the nitric acid aqueous solution is 65wt%, and the mass-volume ratio of the graphite to the nitric acid aqueous solution is 1g:8mL.

[0009] As a further technical solution, in step A1, the mixing temperature is 25~35℃ and the time is 2~3h.

[0010] As a further technical solution, in step A1, the calcination temperature is 380~400℃ and the time is 1~3h.

[0011] As a further technical solution, the mass-to-volume ratio of graphite to solvent is 1g:12mL.

[0012] As a further technical solution, in step A2, the solvent is anhydrous ethanol.

[0013] As a further technical solution, in step A2, the mixing temperature is 60~80℃ and the mixing time is 2~4h.

[0014] As a further technical solution, the plasticizer includes one or more of dioctyl adipate, diisononyl adipate, and trioctyl trimellitate.

[0015] As a further technical solution, the polyacrylate rubber includes a first polyacrylate rubber and a second polyacrylate rubber; the first polyacrylate rubber and the second polyacrylate rubber have different Mooney viscosities.

[0016] As a further technical solution, the Mooney viscosity ML of the first polyacrylate rubber at 100°C... 1+4 The Mooney viscosity ML of the second polyacrylate rubber at 100°C is 55. 1+4 It is 44.

[0017] This invention relates to a high-temperature resistant power cable that effectively improves the toughness of the outer sheath by incorporating a blend of polyacrylate rubbers with different Mooney viscosities into the outer sheath. The first polyacrylate rubber has a higher Mooney viscosity and greater entanglement, forming a supporting skeleton within the system and reducing deformation under impact, thus providing a good anti-deformation foundation for the outer sheath. The second polyacrylate rubber has a lower Mooney viscosity, better fluidity, and is easier to slip and stretch, which can buffer impact stress and release internal stress. The blending of two polyacrylate rubbers with different Mooney viscosities overcomes the shortcomings of using a single type of polyacrylate rubber, thereby improving the toughness of the outer sheath.

[0018] As a further technical solution, the mass ratio of the first polyacrylate rubber to the second polyacrylate rubber is 4~6:3, preferably 5:3.

[0019] As a further technical solution, the crosslinking agent includes dicumyl peroxide; the co-crosslinking agent includes trimethylolpropane trimethacrylate.

[0020] As a further technical solution, the heat stabilizer is a calcium-zinc composite stabilizer; the compatibilizer is maleic anhydride-grafted polyethylene.

[0021] As a further technical solution, the antioxidant includes one or more of antioxidant 1010, antioxidant 168 and antioxidant RD.

[0022] This invention also proposes a method for preparing a high-temperature resistant power cable, comprising the following steps: S1. Extruding the insulating material onto the outside of the conductor and cross-linking it to form an insulating layer; S2. The shielding layer material is woven into the outside of the insulation layer to form a shielding layer; S3. Mix the components of the outer sheath layer, extrude them onto the outside of the shielding layer, crosslink them to form the outer sheath layer, and obtain a high-temperature resistant power cable.

[0023] As a further technical solution, the conductor is a copper conductor; the insulating layer material is polyethylene material; and the shielding layer material is tin-plated copper wire.

[0024] The working principle and beneficial effects of this invention are as follows: This invention relates to a high-temperature resistant power cable, which further enhances the high-temperature resistance of the outer sheath by adding a high-temperature resistant filler obtained by intercalating graphite with an intercalating agent. Existing technologies often add graphite to the outer sheath to improve high-temperature resistance; however, graphite is prone to agglomeration. This invention uses stearic acid and lauryl gallate to intercalate and modify graphite, resulting in better dispersibility and further improving the high-temperature resistance of the cable's outer sheath. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] In the following examples and comparative examples, polyvinyl chloride (PVC-SG8), high-density polyethylene (DMDA-8008H), and first polyacrylate rubber (Mooney viscosity ML at 100°C) were used. 1+4 The viscosity is 55, model ACM-101X; second polyacrylate rubber, Mooney viscosity ML at 100°C 1+4 The material is 44, model ACM-2012; maleic anhydride-grafted polyethylene, grade ZJ-800E; graphite, particle size 20μm.

[0027] Example 1 A high-temperature resistant power cable comprises, from the inside out, a conductor, an insulation layer, a shielding layer, and an outer sheath layer. The outer sheath layer comprises the following raw materials in parts by weight: 90 parts polyvinyl chloride, 15 parts high-density polyethylene, 12 parts polyacrylate rubber, 8 parts high-temperature resistant filler, 0.3 parts antioxidant 1010, 1 part dioctyl adipate, 1 part calcium-zinc composite stabilizer, 2 parts maleic anhydride-grafted polyethylene, 0.2 parts dicumyl peroxide, and 0.1 parts trimethylolpropane trimethacrylate; the polyacrylate rubber is a first polyacrylate rubber. The high-temperature resistant filler is obtained by treating graphite with an intercalating agent. Its preparation method includes the following steps: A1. Add 100 parts of graphite to a 65wt% nitric acid aqueous solution, mix at 30℃ for 2 hours, filter, wash with water until the filtrate is neutral, dry, and calcine at 400℃ for 2 hours to obtain pretreated graphite; wherein the mass-volume ratio of graphite to nitric acid aqueous solution is 1g:8mL. A2. Disperse the pretreated graphite in anhydrous ethanol, add 20 parts of intercalating agent, mix at 60℃ for 4 hours, filter, wash with anhydrous ethanol, and dry to obtain a high-temperature resistant filler; the intercalating agent is composed of stearic acid and gallic acid lauryl ester in a mass ratio of 7:4; the mass-volume ratio of graphite to anhydrous ethanol is 1g:12mL. A method for preparing a high-temperature resistant power cable includes the following steps: S1. Polyethylene material is extruded onto the outside of a copper conductor and cross-linked to form an insulating layer; S2. Braid tin-plated copper wires onto the outside of the insulation layer to form a shielding layer; S3. Mix the components of the outer sheath layer, extrude them onto the outside of the shielding layer, crosslink them to form the outer sheath layer, and obtain a high-temperature resistant power cable.

[0028] Example 2 A high-temperature resistant power cable comprises, from the inside out, a conductor, an insulation layer, a shielding layer, and an outer sheath layer. The outer sheath layer comprises the following raw materials in parts by weight: 95 parts polyvinyl chloride, 18 parts high-density polyethylene, 14 parts polyacrylate rubber, 10 parts high-temperature resistant filler, 0.4 parts antioxidant 168, 1.5 parts diisononyl adipate, 2 parts calcium-zinc composite stabilizer, 3 parts maleic anhydride-grafted polyethylene, 0.4 parts dicumyl peroxide, and 0.2 parts trimethylolpropane trimethacrylate; the polyacrylate rubber is a first polyacrylate rubber. The high-temperature resistant filler is obtained by treating graphite with an intercalating agent. Its preparation method includes the following steps: A1. Add 100 parts of graphite to a 65wt% nitric acid aqueous solution, mix at 30℃ for 2 hours, filter, wash with water until the filtrate is neutral, dry, and calcine at 400℃ for 2 hours to obtain pretreated graphite; wherein the mass-volume ratio of graphite to nitric acid aqueous solution is 1g:8mL. A2. Disperse the pretreated graphite in anhydrous ethanol, add 24 parts of intercalating agent, mix at 70℃ for 3 hours, filter, wash with anhydrous ethanol, and dry to obtain a high-temperature resistant filler; the intercalating agent is composed of stearic acid and gallic acid lauryl ester in a mass ratio of 7:4; the mass-volume ratio of graphite to anhydrous ethanol is 1g:12mL. A method for preparing a high-temperature resistant power cable is the same as in Example 1.

[0029] Example 3 A high-temperature resistant power cable comprises, from the inside out, a conductor, an insulation layer, a shielding layer, and an outer sheath layer. The outer sheath layer comprises the following raw materials in parts by weight: 100 parts polyvinyl chloride, 20 parts high-density polyethylene, 15 parts polyacrylate rubber, 12 parts high-temperature resistant filler, 0.4 parts antioxidant RD, 2 parts trioctyl trimellitate, 3 parts calcium-zinc composite stabilizer, 4 parts maleic anhydride-grafted polyethylene, 0.5 parts dicumyl peroxide, and 0.3 parts trimethylolpropane trimethacrylate; the polyacrylate rubber is a first polyacrylate rubber. The high-temperature resistant filler is obtained by treating graphite with an intercalating agent. Its preparation method includes the following steps: A1. Add 100 parts of graphite to a 65wt% nitric acid aqueous solution, mix at 30℃ for 2 hours, filter, wash with water until the filtrate is neutral, dry, and calcine at 400℃ for 2 hours to obtain pretreated graphite; wherein the mass-volume ratio of graphite to nitric acid aqueous solution is 1g:8mL. A2. Disperse the pretreated graphite in anhydrous ethanol, add 30 parts of intercalating agent, mix at 80℃ for 2 hours, filter, wash with anhydrous ethanol, and dry to obtain a high-temperature resistant filler; the intercalating agent is composed of stearic acid and gallic acid lauryl ester in a mass ratio of 7:4; the mass-volume ratio of graphite to anhydrous ethanol is 1g:12mL. A method for preparing a high-temperature resistant power cable is the same as in Example 1.

[0030] Example 4 Compared with Example 1, the only difference in this example is that in the preparation method of the high-temperature resistant filler in this example, the intercalating agent is composed of stearic acid and lauryl gallate in a mass ratio of 9:4.

[0031] Example 5 Compared with Example 1, the only difference in this example is that in the preparation method of the high-temperature resistant filler in this example, the intercalating agent is composed of stearic acid and lauryl gallate in a mass ratio of 10:4.

[0032] Example 6 Compared with Example 1, the only difference in this example is that the polyacrylate rubber in this example includes a first polyacrylate rubber and a second polyacrylate rubber with a mass ratio of 4:3.

[0033] Example 7 Compared with Example 1, the only difference in this example is that the polyacrylate rubber in this example includes a first polyacrylate rubber and a second polyacrylate rubber with a mass ratio of 5:3.

[0034] Example 8 Compared with Example 1, the only difference in this example is that the polyacrylate rubber in this example includes a first polyacrylate rubber and a second polyacrylate rubber with a mass ratio of 2:1.

[0035] Example 9 Compared with Example 1, the only difference in this example is that the polyacrylate rubber in this example includes a first polyacrylate rubber and a second polyacrylate rubber with a mass ratio of 1:1.

[0036] Example 10 Compared with Example 1, the only difference in this example is that the polyacrylate rubber in this example includes a first polyacrylate rubber and a second polyacrylate rubber with a mass ratio of 7:3.

[0037] Example 11 Compared with Example 1, the only difference in this example is that the polyacrylate rubber in this example is a second polyacrylate rubber.

[0038] Comparative Example 1 Compared with Example 1, the only difference in this comparative example is that in the preparation method of the high-temperature resistant filler in this comparative example, gallic acid lauryl ester in the intercalating agent is replaced with an equal amount of stearic acid.

[0039] Comparative Example 2 Compared with Example 1, the only difference in this comparative example is that in the preparation method of the high-temperature resistant filler in this comparative example, stearic acid in the intercalating agent is replaced with an equal amount of lauryl gallate.

[0040] Comparative Example 3 Compared with Example 1, the only difference in this comparative example is that the high-temperature resistant filler is replaced with an equal amount of graphite.

[0041] Experimental Example 1 Three samples were cut from the outer sheath of each of the high-temperature resistant power cables prepared in Examples 1-5 and Comparative Examples 1-3. The samples were 30 mm long and 3 mm thick. The thermal stability time of the outer sheath samples at 200 °C was tested according to the method in GB / T 2951.32-2008 "General Test Methods for Insulation and Sheath Materials of Cables and Optical Fibers Part 32: Test Methods for Polyvinyl Chloride Mixtures - Weight Loss Test and Thermal Stability Test". The test results were taken as the average of the three samples, that is, the average time taken for each sample to change from pH=5 to pH=2~3 when the color of the general test paper changed. The test results are shown in Table 1. Table 1. Test results of high temperature resistance of the outer sheath layer

[0042] The data in Table 1 show that adding high-temperature resistant filler obtained by treating graphite with stearic acid and lauryl gallate as intercalating agents to the outer sheath can improve the high-temperature resistance of the outer sheath of power cables.

[0043] Experimental Example 2 Three samples were cut from the outer sheath of each of the high-temperature resistant power cables prepared in Examples 1, 6-11. The impact strength of the outer sheath was tested according to the test method specified in standard GB / T 1843-2008 "Determination of Impact Strength of Plastic Cantilever Beam". The sample size was 80×10×4mm; the sample type was unnotched. The test results are shown in Table 2. Table 2 Impact strength test results of outer sheath

[0044] The data in Table 2 show that blending first and second polyacrylate rubbers with different Mooney viscosities as polyacrylate rubber and adding them to the outer sheath layer can improve the toughness of the outer sheath layer.

[0045] The above are merely 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 within the protection scope of the present invention.

Claims

1. A high-temperature resistant power cable, comprising, from the inside out, a conductor, an insulation layer, a shielding layer, and an outer sheath layer, characterized in that, The outer sheath layer comprises the following raw materials in parts by weight: 90-100 parts polyvinyl chloride, 15-20 parts high-density polyethylene, 12-15 parts polyacrylate rubber, 8-12 parts high-temperature resistant filler, 0.3-0.4 parts antioxidant, 1-2 parts plasticizer, 1-3 parts heat stabilizer, 2-4 parts compatibilizer, 0.2-0.5 parts crosslinking agent, and 0.1-0.3 parts co-crosslinking agent; The high-temperature resistant filler comprises the following raw materials in parts by weight: 100 parts graphite and 20-30 parts intercalating agent; the intercalating agent comprises stearic acid and lauryl gallate.

2. The high-temperature resistant power cable according to claim 1, characterized in that, The mass ratio of stearic acid to gallic acid lauryl ester is 7~10:

4.

3. The high-temperature resistant power cable according to claim 1, characterized in that, The preparation method of the high-temperature resistant filler includes the following steps: A1. After mixing graphite with nitric acid aqueous solution, filter and wash until the filtrate is neutral, then dry and calcine to obtain pretreated graphite; A2. Disperse the pretreated graphite in a solvent, add an intercalating agent and mix, then filter, wash and dry to obtain a high-temperature resistant filler.

4. A high-temperature resistant power cable according to claim 3, characterized in that, In step A2, the mixing temperature is 60~80℃ and the mixing time is 2~4h.

5. A high-temperature resistant power cable according to claim 1, characterized in that, The plasticizer includes one or more of dioctyl adipate, diisononyl adipate, and trioctyl trimellitate.

6. A high-temperature resistant power cable according to claim 1, characterized in that, The polyacrylate rubber includes a first polyacrylate rubber and a second polyacrylate rubber; the first polyacrylate rubber and the second polyacrylate rubber have different Mooney viscosities.

7. A high-temperature resistant power cable according to claim 6, characterized in that, The Mooney viscosity ML of the first polyacrylate rubber at 100°C 1+4 The Mooney viscosity ML of the second polyacrylate rubber at 100°C is 55. 1+4 It is 44.

8. A high-temperature resistant power cable according to claim 7, characterized in that, The mass ratio of the first polyacrylate rubber to the second polyacrylate rubber is 4~6:

3.

9. A high-temperature resistant power cable according to claim 1, characterized in that, The crosslinking agent includes dicumyl peroxide; the co-crosslinking agent includes trimethylolpropane trimethacrylate.

10. A method for preparing a high-temperature resistant power cable, used to prepare a high-temperature resistant power cable as described in any one of claims 1 to 9, characterized in that, Includes the following steps: S1. Extruding the insulating material onto the outside of the conductor and cross-linking it to form an insulating layer; S2. The shielding layer material is woven into the outside of the insulation layer to form a shielding layer; S3. Mix the components of the outer sheath layer, extrude them onto the outside of the shielding layer, crosslink them to form the outer sheath layer, and obtain a high-temperature resistant power cable.

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