Corrosion-resistant flame-retardant cable and method for manufacturing the same

Abstract

This invention relates to the field of cable technology and proposes a corrosion-resistant and flame-retardant cable and its preparation method. The corrosion-resistant and flame-retardant cable comprises, from the inside out, a conductor, an insulation layer, and a sheath layer. The raw materials of the sheath layer include the following components by weight: 100 parts polyethylene, 15-20 parts ethylene-vinyl acetate copolymer, 6-12 parts corrosion inhibitor, 6-10 parts compatibilizer, 8-12 parts plasticizer, 15-20 parts filler, and 25-35 parts flame retardant. The corrosion inhibitor includes ethylene-chlorotrifluoroethylene copolymer and octadecyl erucamide in a weight ratio of 1-19:1. By adding the corrosion inhibitors ethylene-chlorotrifluoroethylene copolymer and octadecyl erucamide to the cable sheath layer, the corrosion resistance of the cable sheath layer can be effectively improved.

Description

Technical Field

[0001] This invention relates to the field of cable technology, specifically to a corrosion-resistant and flame-retardant cable and its preparation method. Background Technology

[0002] Cables, as a crucial infrastructure for power transmission and information communication, are widely used in various fields such as industry, construction, transportation, and communications. With the continuous expansion of application scenarios, the environmental conditions faced by cables during use are becoming increasingly complex. Especially in highly corrosive environments such as chemical plants, coastal areas, underground pipe corridors, and sewage treatment plants, the cable sheath is exposed to acids, alkalis, salt spray, moisture, and various chemical solvents for extended periods, making it highly susceptible to aging, cracking, swelling, and even peeling.

[0003] The cable sheath is the first line of defense against external environmental damage, and its corrosion resistance directly affects the cable's service life and operational safety. Currently, commonly used cable sheath materials mainly include polyvinyl chloride (PVC), polyethylene (PE), and polyurethane (TPU). Among these, polyethylene is widely used due to its good electrical insulation, processing performance, and certain chemical stability. However, ordinary polyethylene materials still suffer from insufficient impermeability, swelling, or stress cracking when exposed to corrosive media such as strong acids, strong alkalis, or organic solvents for extended periods, making it difficult to meet the high corrosion resistance requirements of special environments.

[0004] Therefore, a cable with a sheath layer exhibiting excellent corrosion resistance is proposed, which is of great significance for broadening the application range of cables and improving their service life. Summary of the Invention

[0005] This invention proposes a corrosion-resistant and flame-retardant cable and its preparation method, which solves the problem of relatively poor corrosion resistance of cable sheaths in related technologies.

[0006] The technical solution of the present invention is as follows: This invention proposes a corrosion-resistant and flame-retardant cable, comprising, from the inside out, a conductor, an insulation layer, and a sheath layer. The raw material of the sheath layer comprises the following components in parts by weight: 100 parts polyethylene, 15-20 parts ethylene-vinyl acetate copolymer, 6-12 parts corrosion inhibitor, 6-10 parts compatibilizer, 8-12 parts plasticizer, 15-20 parts filler, and 25-35 parts flame retardant; The corrosion inhibitor comprises ethylene-trifluorochloroethylene copolymer and octadecyl erucamide in a weight ratio of 1 to 19:1.

[0007] Preferably, the weight ratio of the ethylene-trifluorochloroethylene copolymer to octadecyl erucamide is 1.5 to 9:1.

[0008] Preferably, the filler includes one or more of calcium carbonate, talc, mica powder, and serpentine powder.

[0009] Preferably, the flame retardant is a composite flame retardant, and the raw materials of the composite flame retardant include inorganic hydroxide, aluminum diethylphosphinate, and silane coupling agent.

[0010] Preferably, the weight ratio of the inorganic hydroxide and the aluminum diethylphosphonate to the silane coupling agent is 4~14:1.

[0011] Preferably, the preparation method of the composite flame retardant includes the following steps: The silane coupling agent was dissolved in an aqueous ethanol solution, the inorganic hydroxide was added, mixed, and dried to obtain the modified inorganic hydroxide. The aluminum diethylphosphonate was dispersed in acetone, the modified inorganic hydroxide was added, mixed, and dried to obtain the composite flame retardant.

[0012] Preferably, the silane coupling agent includes one or both of vinyltris(2-methoxyethoxy)silane and vinyltriethoxysilane.

[0013] Preferably, the raw material of the sheath layer further includes 1-3 parts of antioxidant; The antioxidant includes one or both of antioxidant 1010 and antioxidant 1076; The plasticizer includes one or more of tricresyl phosphate, diisodecyl phthalate, and trioctyl trimellitate. The compatibilizer includes one or more of EVA-g-MAH, LDPE-g-MAH, and POE-g-GMA.

[0014] Preferably, the conductor is made of either aluminum alloy or copper alloy; The insulation layer is a cross-linked polyethylene insulation layer.

[0015] This invention also proposes a method for preparing a corrosion-resistant and flame-retardant cable, comprising the following steps: The raw materials for the insulating layer are blended and extruded, then coated onto the outer layer of the conductor and cross-linked to obtain the insulating layer; The raw materials of the sheath layer are blended and then extruded to coat the outer layer of the insulation layer to obtain the corrosion-resistant and flame-retardant cable.

[0016] The beneficial effects of this invention are as follows: This invention relates to a corrosion-resistant and flame-retardant cable sheath layer. Polyethylene is used as the main base material, providing the sheath layer with basic mechanical strength and chemical stability. Combined with ethylene-vinyl acetate copolymer, corrosion inhibitors, compatibilizers, plasticizers, fillers, and flame retardants, a uniform and dense sheath layer with excellent corrosion resistance can be prepared. The corrosion inhibitors in the sheath layer include ethylene-chlorotrifluoroethylene copolymer and octadecyl erucamide. Ethylene-chlorotrifluoroethylene copolymer itself has good chemical stability, and its addition effectively prevents the intrusion of external corrosive substances. The addition of octadecyl erucamide improves the processing performance of the ethylene-chlorotrifluoroethylene copolymer, resulting in a denser sheath layer structure. Therefore, the combination of ethylene-chlorotrifluoroethylene copolymer and octadecyl erucamide in the sheath layer effectively improves the structural density and impermeability of the sheath layer, ultimately enhancing the corrosion resistance of the cable sheath layer. Detailed Implementation

[0017] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0018] To make the objectives, technical solutions, and advantages of the present invention clearer, the following will be described through embodiments.

[0019] A specific embodiment of the first aspect of the present invention provides a corrosion-resistant and flame-retardant cable, comprising, from the inside out, a conductor, an insulation layer, and a sheath layer, wherein the raw material of the sheath layer comprises the following components in parts by weight: 100 parts polyethylene, 15-20 parts ethylene-vinyl acetate copolymer, 6-12 parts corrosion inhibitor, 6-10 parts compatibilizer, 8-12 parts plasticizer, 15-20 parts filler, and 25-35 parts flame retardant; The corrosion inhibitors include ethylene-trifluorochloroethylene copolymer and octadecyl erucamide in a weight ratio of 1 to 19:1.

[0020] In this invention, polyethylene, as the base material of the sheath layer, imparts strength, flexibility, and chemical stability to the sheath layer, ensuring that the cable is not easily damaged during installation and use, and also resisting the erosion of external corrosive substances to a certain extent. In this invention, the polyethylene can be any polyethylene in the art, such as low-density polyethylene or high-density polyethylene, preferably low-density polyethylene.

[0021] In this invention, the ethylene-vinyl acetate copolymer can enhance the flexibility of the sheath layer. When used in conjunction with a plasticizer, the sheath layer can maintain good bending performance and is not prone to brittleness even at low temperatures.

[0022] In this invention, the ethylene-chlorotrifluoroethylene copolymer and polyethylene are directly blended in the sheath layer, resulting in relatively poor compatibility. Adding a compatibility agent to the sheath layer improves the compatibility between polyethylene, ethylene-vinyl acetate copolymer, and the corrosion inhibitor components, allowing each component to be uniformly dispersed in the system and forming a stable structure. In this invention, the compatibility agent can be any compatibility agent in the art that can improve the compatibility of polyethylene with other components, such as EVA-g-MAH, LDPE-g-MAH, POE-g-GMA, preferably LDPE-g-MAH.

[0023] In this invention, the addition of a plasticizer ensures that the interaction forces between the polymer chains in the sheath layer are in a moderate state, giving the sheath layer a certain degree of flexibility and plasticity. This ensures that the cable maintains good bending performance at different temperatures, facilitating installation and use. In this invention, the plasticizer can be any plasticizer in the art, such as tricresyl phosphate, diisodecyl phthalate, or trioctyl trimellitate, preferably tricresyl phosphate.

[0024] In this invention, the filler can be any filler in the art, such as calcium carbonate, talc, mica powder, or serpentine powder, preferably calcium carbonate. In this invention, the average particle size of the calcium carbonate is 10-60 μm, preferably 35-50 μm, and more preferably 45 μm. In this invention, the addition of calcium carbonate to the sheath layer can effectively enhance the mechanical properties and wear resistance of the sheath layer.

[0025] In this invention, the flame retardant is an essential additive for improving the flame retardant performance of the cable sheath. The flame retardant can be any flame retardant in the art, such as inorganic hydroxides, phosphorus-based flame retardants, or nitrogen-based flame retardants, preferably inorganic hydroxides. In this invention, the flame retardant used is an inorganic hydroxide. Compared with phosphorus-based and nitrogen-based flame retardants, inorganic hydroxides are inexpensive, non-toxic, halogen-free, and do not release harmful gases during use. When exercising its flame-retardant properties, the inorganic hydroxide decomposes upon heating, absorbing heat and thus lowering the temperature of the cable sheath, slowing the combustion rate. Simultaneously, during decomposition, the inorganic hydroxide releases water vapor, diluting the concentration of combustible gases produced during cable combustion, thereby inhibiting further combustion of the cable.

[0026] In one embodiment of the present invention, the weight ratio of ethylene-trifluorochloroethylene copolymer to octadecyl erucamide is 1.5 to 9:1.

[0027] In this invention, the corrosion-resistant additive includes ethylene-trifluorochloroethylene copolymer and octadecyl erucamide, which are used together, and the weight ratio of ethylene-trifluorochloroethylene copolymer to octadecyl erucamide is adjusted to 1~19:1, for example, it can be 1:1, 1.5:1, 2:1, 3:1, 4:1, 5:1, 6:1, 8:1, 9:1, 10:1, 12:1, 14:1, 15:1, 16:1, 18:1, 19:1, preferably 1.5~9:1. In this invention, when the weight ratio of ethylene-trifluorochloroethylene copolymer to octadecyl erucamide is 1.5~9:1, the corrosion resistance of the sheath layer can be further improved.

[0028] In one embodiment of the present invention, the flame retardant is a composite flame retardant, and the raw materials of the composite flame retardant include inorganic hydroxide, aluminum diethylphosphinate and silane coupling agent.

[0029] In this invention, to achieve good flame retardant effect, a high content of inorganic hydroxide needs to be added. However, adding too much will result in uneven dispersion, reduced flame retardant efficiency, and affect the physical and mechanical properties of the cable sheath. To improve this problem, the flame retardant of this invention uses a composite flame retardant, the raw materials of which include inorganic hydroxide, aluminum diethylphosphinate, and a silane coupling agent. The composite treatment of inorganic hydroxide with aluminum diethylphosphinate and a silane coupling agent can improve the dispersion of inorganic hydroxide in the sheath system and increase the flame retardant efficiency. At the same time, the addition of aluminum diethylphosphinate can reduce the amount of inorganic hydroxide used while still allowing the sheath to exhibit good flame retardant properties.

[0030] In one embodiment of the present invention, the weight ratio of the inorganic hydroxide and aluminum diethylphosphonate to the silane coupling agent is 4 to 14:1.

[0031] In one embodiment of the present invention, the weight ratio of inorganic hydroxide to aluminum diethylphosphinate is 4:1.

[0032] In this invention, the weight ratio of inorganic hydroxide and aluminum diethylphosphinate to silane coupling agent is adjusted. When the weight ratio of inorganic hydroxide and aluminum diethylphosphinate to silane coupling agent is 4~14:1, and the weight ratio of inorganic hydroxide and aluminum diethylphosphinate is 4:1, the flame retardant effect of the sheath layer is better.

[0033] In one embodiment of the present invention, the preparation method of the composite flame retardant includes the following steps: The silane coupling agent was dissolved in an aqueous ethanol solution, an inorganic hydroxide was added, the mixture was mixed, and the mixture was dried to obtain the modified inorganic hydroxide. Aluminum diethylphosphonate was dispersed in acetone, and a modified inorganic hydroxide was added. The mixture was then dried to obtain a composite flame retardant.

[0034] In this invention, the preparation of the composite flame retardant adopts a stepwise composite method. First, the inorganic hydroxide is modified by a silane coupling agent, and then the modified inorganic hydroxide is mixed with aluminum diethylphosphinate. The stepwise composite process helps to form a composite flame retardant with a relatively stable structure.

[0035] In one embodiment of the present invention, during the preparation of the modified inorganic hydroxide, the mixing is carried out by stirring at a speed of 400-700 rpm for a duration of 1.5-2.5 h.

[0036] In one embodiment of the present invention, during the preparation of the composite flame retardant, the mixing is carried out by stirring at a speed of 400-700 rpm for a duration of 1-2 hours.

[0037] In one embodiment of the present invention, the silane coupling agent includes one or both of vinyltris(2-methoxyethoxy)silane and vinyltriethoxysilane, preferably vinyltriethoxysilane.

[0038] In this invention, the silane coupling agent can be any silane coupling agent in the art, for example, it can be γ-silane coupling agent. aminopropyltriethoxysilane, γ Glycidyl etheroxypropyltrimethoxysilane, γ Mercaptopropyltrimethoxysilane, vinyltris(2-methoxyethoxy)silane, and vinyltriethoxysilane are preferred. In this invention, vinyltriethoxysilane is used as the silane coupling agent. Compared with other silane coupling agents, the resulting composite flame retardant exhibits superior flame retardant performance. The reason for this is likely that the modification of the inorganic hydroxide with vinyltriethoxysilane not only improves the dispersion of the inorganic hydroxide in the sheath matrix but also enhances the bonding between the composite flame retardant and the ethylene-chlorotrifluoroethylene copolymer in the system, further increasing the structural density of the sheath layer and thus further improving the flame retardant performance.

[0039] In one embodiment of the present invention, the raw material of the sheath layer further includes 1 to 3 parts of antioxidant; Antioxidants include one or both of antioxidant 1010 and antioxidant 1076.

[0040] In this invention, the raw material of the sheath layer also includes an antioxidant. The addition of the antioxidant can effectively inhibit the oxidative decomposition of the polymer in the sheath layer and improve the stability of the sheath layer. In this invention, the antioxidant can be any antioxidant in the art, such as antioxidant 1010, antioxidant 1076, antioxidant 1035, antioxidant 168, preferably antioxidant 1010 or antioxidant 1076, and more preferably antioxidant 1010.

[0041] In one embodiment of the present invention, the conductor is made of either aluminum alloy or copper alloy, preferably aluminum alloy; The insulation layer is a cross-linked polyethylene insulation layer.

[0042] A second aspect of the present invention provides a method for preparing a corrosion-resistant and flame-retardant cable, used to prepare the corrosion-resistant and flame-retardant cable provided in the first aspect of the present invention, comprising the following steps: The raw materials for the insulating layer are blended and extruded, then coated onto the outer layer of the conductor and cross-linked to obtain the insulating layer; The raw materials for the sheath layer are blended and then extruded and coated onto the outer layer of the insulation layer to obtain a corrosion-resistant and flame-retardant cable.

[0043] The present invention will now be described in detail with reference to preferred embodiments and comparative examples. The preferred embodiments of the invention described below can be modified in various ways, and therefore the scope of the invention should not be construed as limited to the preferred embodiments described in detail below. Preferred embodiments are provided to help those skilled in the art to more readily understand the invention.

[0044] Detailed information on some of the components used in the following examples and comparative examples is as follows: Polyethylene, specifically low-density polyethylene, model LDPE FD0274; ethylene-vinyl acetate copolymer, model EVA 18J3; ethylene-trifluorochloroethylene copolymer, model ECTFE 2408DA; LDPE-g-MAH, maleic anhydride grafted polyethylene, with a grafting rate of 1.0%~1.2%; calcium carbonate, with an average particle size of 45μm; magnesium hydroxide, with an average particle size of 20μm.

[0045] Example 1 A method for preparing a corrosion-resistant and flame-retardant cable includes the following steps: The raw materials for the insulation layer are blended and extruded, then coated onto the outer layer of an aluminum alloy conductor and cross-linked to obtain a cross-linked polyethylene insulation layer. 100 parts of polyethylene, 15 parts of ethylene-vinyl acetate copolymer, 6 parts of corrosion inhibitor, 6 parts of LDPE-g-MAH, 8 parts of tricresyl phosphate, 15 parts of calcium carbonate, 25 parts of magnesium hydroxide and 1 part of antioxidant 1010 are blended and then extruded and coated onto the outer layer of cross-linked polyethylene insulation to obtain a corrosion-resistant and flame-retardant cable. The corrosion inhibitor is composed of 3 parts ethylene-trifluorochloroethylene copolymer and 3 parts octadecyl erucamide.

[0046] Example 2 A method for preparing a corrosion-resistant and flame-retardant cable includes the following steps: The raw materials for the insulation layer are blended and extruded, then coated onto the outer layer of an aluminum alloy conductor and cross-linked to obtain a cross-linked polyethylene insulation layer. 100 parts of polyethylene, 18 parts of ethylene-vinyl acetate copolymer, 10 parts of corrosion inhibitor, 8 parts of LDPE-g-MAH, 10 parts of tricresyl phosphate, 18 parts of calcium carbonate, 30 parts of magnesium hydroxide and 2 parts of antioxidant 1010 are blended and then extruded and coated onto the outer layer of cross-linked polyethylene insulation to obtain a corrosion-resistant and flame-retardant cable. The corrosion inhibitor consists of 5 parts of ethylene-trifluorochloroethylene copolymer and 5 parts of octadecyl erucamide.

[0047] Example 3 A method for preparing a corrosion-resistant and flame-retardant cable includes the following steps: The raw materials for the insulation layer are blended and extruded, then coated onto the outer layer of an aluminum alloy conductor and cross-linked to obtain a cross-linked polyethylene insulation layer. 100 parts of polyethylene, 20 parts of ethylene-vinyl acetate copolymer, 12 parts of corrosion inhibitor, 10 parts of LDPE-g-MAH, 12 parts of tricresyl phosphate, 20 parts of calcium carbonate, 35 parts of magnesium hydroxide and 3 parts of antioxidant 1010 are blended and then extruded and coated onto the outer layer of cross-linked polyethylene insulation to obtain a corrosion-resistant and flame-retardant cable. The corrosion inhibitor is composed of 11.4 parts of ethylene-trifluorochloroethylene copolymer and 0.6 parts of octadecyl erucamide.

[0048] Example 4 The only difference between this embodiment and Embodiment 2 is that, in this embodiment, the corrosion inhibitor is composed of 9.5 parts of ethylene-trifluorochloroethylene copolymer and 0.5 parts of octadecyl erucamide.

[0049] Example 5 The only difference between this embodiment and Embodiment 2 is that, in this embodiment, the corrosion inhibitor is composed of 6 parts of ethylene-trifluorochloroethylene copolymer and 4 parts of octadecyl erucamide.

[0050] Example 6 The only difference between this embodiment and Embodiment 2 is that, in this embodiment, the corrosion inhibitor is composed of 9 parts of ethylene-trifluorochloroethylene copolymer and 1 part of octadecyl erucamide.

[0051] Example 7 A method for preparing a corrosion-resistant and flame-retardant cable includes the following steps: The raw materials for the insulation layer are blended and extruded, then coated onto the outer layer of an aluminum alloy conductor and cross-linked to obtain a cross-linked polyethylene insulation layer. 100 parts of polyethylene, 18 parts of ethylene-vinyl acetate copolymer, 10 parts of corrosion inhibitor, 8 parts of LDPE-g-MAH, 10 parts of tricresyl phosphate, 18 parts of calcium carbonate, 30 parts of composite flame retardant and 2 parts of antioxidant 1010 are blended and then extruded and coated onto the outer layer of cross-linked polyethylene insulation to obtain a corrosion-resistant and flame-retardant cable. The corrosion inhibitor is composed of 9 parts ethylene-trifluorochloroethylene copolymer and 1 part octadecyl erucamide; The preparation method of the composite flame retardant includes the following steps: A1. Dissolve 7.5 parts of vinyltriethoxysilane in 30 parts of aqueous ethanol (mass fraction of 85%), add 18 parts of magnesium hydroxide, stir at 500 rpm for 2 hours, and dry to obtain modified inorganic hydroxide. A2. Disperse 4.5 parts of aluminum diethylphosphonate in 50 parts of acetone, add the above modified inorganic hydroxide, stir at 500 rpm for 1.5 h, and dry to obtain a composite flame retardant.

[0052] Example 8 The only difference between this embodiment and Embodiment 7 is the preparation method of the composite flame retardant, which is as follows: A1. Dissolve 1 part of vinyltriethoxysilane in 30 parts of ethanol aqueous solution (mass fraction of 85%), add 23.2 parts of magnesium hydroxide, stir at 500 rpm for 2 h, and dry to obtain modified inorganic hydroxide; A2. Disperse 5.8 parts of aluminum diethylphosphonate in 50 parts of acetone, add the above-mentioned modified inorganic hydroxide, stir at 500 rpm for 1.5 h, and dry to obtain a composite flame retardant.

[0053] Example 9 The only difference between this embodiment and Embodiment 7 is the preparation method of the composite flame retardant, which is as follows: A1. Dissolve 6 parts of vinyltriethoxysilane in 30 parts of ethanol aqueous solution (mass fraction of 85%), add 19.2 parts of magnesium hydroxide, stir at 500 rpm for 2 h, and dry to obtain modified inorganic hydroxide; A2. Disperse 4.8 parts of aluminum diethylphosphonate in 50 parts of acetone, add the above-mentioned modified inorganic hydroxide, stir at 500 rpm for 1.5 h, and dry to obtain a composite flame retardant.

[0054] Example 10 The only difference between this embodiment and Embodiment 7 is the preparation method of the composite flame retardant, which is as follows: A1. Dissolve 2 parts of vinyltriethoxysilane in 30 parts of ethanol aqueous solution (mass fraction of 85%), add 22.4 parts of magnesium hydroxide, stir at 500 rpm for 2 h, and dry to obtain modified inorganic hydroxide; A2. Disperse 5.6 parts of aluminum diethylphosphonate in 50 parts of acetone, add the above-mentioned modified inorganic hydroxide, stir at 500 rpm for 1.5 h, and dry to obtain a composite flame retardant.

[0055] Example 11 The only difference between this embodiment and Embodiment 7 is the preparation method of the composite flame retardant, which is as follows: 7.5 parts of vinyltriethoxysilane were dissolved in 30 parts of an aqueous ethanol solution (mass fraction of 85%), and 22.5 parts of magnesium hydroxide were added. The mixture was stirred at 500 rpm for 2 hours and then dried to obtain a composite flame retardant.

[0056] Example 12 The only difference between this embodiment and Embodiment 7 is the preparation method of the composite flame retardant, which is as follows: Six parts of aluminum diethylphosphinic acid were dispersed in 50 parts of acetone, and 24 parts of magnesium hydroxide were added. The mixture was stirred at 500 rpm for 1.5 h and then dried to obtain a composite flame retardant.

[0057] Example 13 The only difference between this embodiment and Embodiment 7 is that, in the preparation method of the composite flame retardant in this embodiment, vinyltriethoxysilane is replaced with an equal amount of γ-ray dimethyl ether. Aminopropyltriethoxysilane.

[0058] Comparative Example 1 The only difference between this comparative example and Example 1 is that in this comparative example, the corrosion inhibitor includes only 6 parts of ethylene-chlorotrifluoroethylene copolymer.

[0059] Comparative Example 2 The only difference between this comparative example and Example 1 is that the preservative additive in this comparative example includes only 6 parts of octadecyl erucamide.

[0060] Comparative Example 3 The only difference between this comparative example and Example 1 is that no preservative additive was added in this comparative example.

[0061] Experimental Example 1 Three samples were cut from the sheath of the corrosion-resistant and flame-retardant cables prepared in Examples 1-6 and Comparative Examples 1-3. Dumbbell-shaped specimens with a thickness of 2 mm were prepared according to GB / T 2951.11-2008 "General Test Methods for Insulation and Sheath Materials of Cables and Optical Fibers - Part 11: General Test Methods for Thickness and Dimensional Measurement and Mechanical Properties Test" and their tensile strength was tested. After preparing dumbbell-shaped specimens with a thickness of 2 mm using the sheath layers of the corrosion-resistant and flame-retardant cables prepared in Examples 1-6 and Comparative Examples 1-3 according to the above method, the specimens were immersed in 20% hydrochloric acid for 72 hours, then cleaned and dried, and the tensile strength after corrosion was tested according to the above method. The test results are shown in Table 1.

[0062] Table 1. Corrosion resistance test results of Examples 1-6 and Comparative Examples 1-3

[0063] The tensile strength retention rate was calculated as follows: tensile strength retention rate = tensile strength after corrosion / tensile strength × 100%. Compared with Comparative Examples 1-3, the sheath layer of the corrosion-resistant and flame-retardant cable prepared in Examples 1-6 showed a lower decrease in tensile strength retention rate after corrosion resistance testing, still reaching 93.7%. This indicates that the addition of ethylene-trifluorochloroethylene copolymer and octadecyl erucamide as corrosion inhibitors to the sheath layer, through their combined use, can effectively improve the corrosion resistance of the cable sheath layer.

[0064] Experimental Example 2 Three samples were cut from the sheath of the corrosion-resistant and flame-retardant cables prepared in Examples 6-13 to form Type IV oxygen index samples. Based on GB / T 2406.2-2009 "Determination of Combustion Behavior by Oxygen Index Method for Plastics - Part 2: Room Temperature Test", the oxygen index was tested by diffusion ignition method. The test results are the average values ​​of the three samples, and the test results are shown in Table 2.

[0065] Table 2. Flame retardant performance test results of Examples 6-13

[0066] Compared with Examples 6 and 11-13, the oxygen index of the sheath layer prepared in Examples 7-10 is improved, indicating that the composite treatment of inorganic hydroxides with aluminum diethylphosphinate and vinyltriethoxysilane can effectively improve the flame retardant performance of the sheath layer.

[0067] Compared with Examples 7-8, the oxygen index of the sheath layer prepared in Examples 9-10 was further improved, indicating that the content ratio of inorganic hydroxide, aluminum diethylphosphonate, and vinyltriethoxysilane was optimized and adjusted. When the weight ratio of inorganic hydroxide and aluminum diethylphosphonate to silane coupling agent was 4-14:1, and the weight ratio of inorganic hydroxide and aluminum diethylphosphonate was 4:1, the flame retardant performance of the cable sheath layer could be further improved.

[0068] 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 corrosion-resistant and flame-retardant cable, comprising, from the inside out, a conductor, an insulation layer, and a sheath layer, characterized in that, The raw material of the sheath layer comprises the following components in parts by weight: 100 parts polyethylene, 15-20 parts ethylene-vinyl acetate copolymer, 6-12 parts corrosion inhibitor, 6-10 parts compatibilizer, 8-12 parts plasticizer, 15-20 parts filler, and 25-35 parts flame retardant; The corrosion inhibitor comprises ethylene-trifluorochloroethylene copolymer and octadecyl erucamide in a weight ratio of 1 to 19:

1.

2. The corrosion-resistant and flame-retardant cable according to claim 1, characterized in that, The weight ratio of the ethylene-trifluorochloroethylene copolymer to octadecyl erucamide is 1.5 to 9:

1.

3. The corrosion-resistant and flame-retardant cable according to claim 1, characterized in that, The filler includes one or more of calcium carbonate, talc, mica powder, and serpentine powder.

4. The corrosion-resistant and flame-retardant cable according to claim 1, characterized in that, The flame retardant is a composite flame retardant, and the raw materials of the composite flame retardant include inorganic hydroxide, aluminum diethylphosphinate, and silane coupling agent.

5. The corrosion-resistant and flame-retardant cable according to claim 4, characterized in that, The weight ratio of the inorganic hydroxide and the aluminum diethylphosphonate to the silane coupling agent is 4~14:

1.

6. The corrosion-resistant and flame-retardant cable according to claim 4, characterized in that, The preparation method of the composite flame retardant includes the following steps: The silane coupling agent was dissolved in an aqueous ethanol solution, the inorganic hydroxide was added, mixed, and dried to obtain the modified inorganic hydroxide. The aluminum diethylphosphonate was dispersed in acetone, the modified inorganic hydroxide was added, mixed, and dried to obtain the composite flame retardant.

7. The corrosion-resistant and flame-retardant cable according to claim 4, characterized in that, The silane coupling agent includes one or both of vinyltris(2-methoxyethoxy)silane and vinyltriethoxysilane.

8. The corrosion-resistant and flame-retardant cable according to claim 1, characterized in that, The raw material of the sheath layer also includes 1 to 3 parts of antioxidant; The antioxidant includes one or both of antioxidant 1010 and antioxidant 1076; The plasticizer includes one or more of tricresyl phosphate, diisodecyl phthalate, and trioctyl trimellitate. The compatibilizer includes one or more of EVA-g-MAH, LDPE-g-MAH, and POE-g-GMA.

9. A corrosion-resistant and flame-retardant cable according to claim 1, characterized in that, The conductor is made of either aluminum alloy or copper alloy. The insulation layer is a cross-linked polyethylene insulation layer.

10. A method for preparing a corrosion-resistant and flame-retardant cable, used to prepare a corrosion-resistant and flame-retardant cable as described in any one of claims 1 to 9, characterized in that, Includes the following steps: The raw materials for the insulating layer are blended and extruded, then coated onto the outer layer of the conductor and cross-linked to obtain the insulating layer; The raw materials of the sheath layer are blended and then extruded to coat the outer layer of the insulation layer to obtain the corrosion-resistant and flame-retardant cable.

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