Industrial high-temperature-resistant cable

Abstract

The invention discloses an industrial high-temperature-resistant cable, and belongs to the technical field of cables. The cable comprises a cable core and a sheath layer wrapping the cable core. The sheath layer comprises the following components in parts by weight: 32-38 parts of alkenyl polyvinyl chloride, 38-42 parts of methyl vinyl silicone rubber, 15-20 parts of modified basalt fibers, 1-2 parts of a vulcanizing agent, 6-10 parts of a plasticizer, 1-2 parts of a lubricant, 1-2 parts of a stabilizer and 0.3-0.8 part of an antioxidant. Functional modification is performed on the surface of the basalt fiber, so that the basalt fiber and a polymer matrix of the cable sheath can form a multi-layer and firm chemical structure, and the comprehensive performance of the sheath material is effectively improved.

Description

Technical Field

[0001] This invention belongs to the field of cable technology, specifically, it relates to a high-temperature resistant cable for industrial use. Background Technology

[0002] In industrial sectors such as metallurgy, chemical engineering, aerospace, and the manufacture of special equipment, cables capable of long-term stable operation in high-temperature environments are frequently required. The sheath of these cables is a crucial structure protecting the internal conductors, and its performance directly determines the cable's lifespan and safety. Currently, common high-temperature resistant cable sheaths are mostly made of polymer materials such as silicone rubber, fluororubber, or polyvinyl chloride. While these materials possess a certain degree of heat resistance, their mechanical strength, resistance to deformation, and long-term thermal aging performance are often difficult to maintain simultaneously. Especially under the combined effects of high temperature and mechanical stress, the sheath material is prone to softening, deformation, and even cracking, leading to cable failure.

[0003] To improve the performance of sheath materials, existing technologies often employ reinforcement modification by adding inorganic fibers (such as glass fibers and basalt fibers). However, this method has a fundamental drawback: the interfacial bonding between the fibers and the polymer matrix is ​​typically weak, relying mainly on physical anchoring and weak intermolecular forces. This simple physical blending results in stress that cannot be effectively transferred from the matrix to the fibers under high temperatures or sustained stress, easily leading to defects and debonding at the interface, becoming the starting point for material failure and thus limiting the full realization of the reinforcement effect. Although some studies have attempted to use silane coupling agents to treat the surface of fibers to improve compatibility, the improvement effect is limited, and the resulting chemical bond strength is insufficient, making it difficult to construct a multi-layered, robust interfacial structure, which cannot meet the increasingly stringent requirements of industrial application environments for the mechanical strength and durability of cables.

[0004] Therefore, developing a high-temperature resistant cable that can achieve a strong bond between the fiber and the matrix, thereby significantly improving the overall performance of the sheath material, especially its mechanical properties and stability at high temperatures, has become a pressing technical problem to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a high-temperature resistant cable for industrial use.

[0006] The objective of this invention can be achieved through the following technical solutions: An industrial high-temperature resistant cable includes a cable core and a sheath covering the outside of the cable core; the sheath comprises the following components: by weight, 32-38 parts of alkenylated polyvinyl chloride, 38-42 parts of methyl vinyl silicone rubber, 15-20 parts of modified basalt fiber, 1-2 parts of vulcanizing agent, 6-10 parts of plasticizer, 1-2 parts of lubricant, 1-2 parts of stabilizer, and 0.3-0.8 parts of antioxidant.

[0007] In the scheme, the preparation process of alkenylated polyvinyl chloride is as follows: after mixing polyvinyl chloride powder and sodium hydroxide solution, the mixture is kept at 140-150℃ for 4-5 hours, followed by post-treatment to obtain alkenylated polyvinyl chloride; wherein, the chlorine atoms on the polyvinyl chloride molecular chain are attacked by sodium hydroxide, and an alkaline-catalyzed dehydrohalogenation reaction occurs, forming olefin double bonds on the polyvinyl chloride molecular chain, thereby obtaining polyvinyl chloride modified with unsaturated olefin double bonds.

[0008] Furthermore, the preparation process of the modified basalt fiber is as follows: A1: Mix the modifier, tetraethyl orthosilicate, ammonia, and anhydrous ethanol, and stir until homogeneous to obtain the sizing agent; A2: Add the dried chopped basalt fibers to the sizing agent and impregnate at 60°C for 5-8 minutes. Then, place the impregnated fibers in a vacuum oven and dry at 120°C overnight to obtain modified basalt fibers.

[0009] In this method, anhydrous ethanol is used as a solvent and ammonia as a catalyst to induce a hydrolysis-condensation reaction of tetraethyl orthosilicate to form a siloxane skeleton. Simultaneously, a modifier containing allyl groups, phosphate esters, and silanol groups is chemically embedded through the condensation reaction of silanol groups with the siloxane skeleton to construct a functionalized sizing agent. Subsequently, dried chopped basalt fibers are impregnated in the sizing agent at 60°C. The condensation reaction between the hydroxyl groups on the fiber surface and the silanol groups in the sizing agent achieves a strong bond between the sizing agent and the fiber. Finally, the impregnated fibers are dried overnight in a vacuum oven at 120°C to remove the solvent from the system and promote further densification of the siloxane skeleton, while fully preserving the active groups in the modifier. Ultimately, modified basalt fibers that can improve compatibility with the polymer matrix of cable sheaths and enhance interfacial bonding are obtained.

[0010] Furthermore, the sizing agent comprises the following components: by weight, 4-5 parts modifier, 10-12 parts tetraethyl orthosilicate, 2-3 parts ammonia, and 70-90 parts anhydrous ethanol; wherein the concentration of ammonia is 28 wt%.

[0011] Furthermore, the mass ratio of the chopped basalt fiber to the sizing agent is 1:(3-5). Furthermore, the preparation process of the modifier is as follows: S1: Mix 3-allyl-2-hydroxybenzaldehyde, triethylamine, and dichloromethane, stir until homogeneous, cool to 0°C, then slowly add phenyl dichlorophosphate dropwise. After the addition is complete, maintain the reaction at 0°C for 30-40 minutes. Then raise the reaction system to room temperature and stir overnight. After the reaction is complete, perform post-processing to obtain intermediate A. S2: Mix intermediate A, γ-aminopropyltriethoxysilane, and anhydrous ethanol, seal the mixture, raise the temperature to 70-80℃, stir and react for 8-10 hours. After the reaction is complete, cool to room temperature, concentrate the mixture, let it stand for 24 hours, wash and dry it to obtain the modifier.

[0012] In this method, the phenolic hydroxyl group of 3-allyl-2-hydroxybenzaldehyde undergoes a nucleophilic substitution reaction with phenyl dichlorophosphate to generate intermediate A, which contains a phosphate ester structure. Subsequently, the aldehyde group of intermediate A undergoes a condensation reaction with the amino group of γ-aminopropyltriethoxysilane to form an imine structure, while retaining the triethoxysilane group. After post-treatment, a modifier containing siloxane groups is finally obtained. The specific synthetic process is shown below: Furthermore, the raw materials for preparing intermediate A include the following components: by weight, 10-12 parts of 3-allyl-2-hydroxybenzaldehyde, 6-8 parts of triethylamine, 80-100 parts of dichloromethane, and 6-8 parts of phenyl dichlorophosphate.

[0013] Furthermore, the raw materials for preparing the modifier include the following components: by weight, 10-12 parts of intermediate A, 9-10 parts of γ-aminopropyltriethoxysilane, and 60-80 parts of anhydrous ethanol.

[0014] Furthermore, the vulcanizing agent is dicumyl peroxide and accelerator TMTM in a mass ratio of 3:1.

[0015] Furthermore, the plasticizer is phthalate; the lubricant is polyethylene wax; the stabilizer is calcium-zinc stabilizer; and the antioxidant is antioxidant 1024.

[0016] The beneficial effects of this invention are: This invention functionalizes the surface of basalt fibers, enabling them to form a multi-layered, robust chemical structure with the polymer matrix of the cable sheath, thereby effectively improving the overall performance of the sheath material. Specifically: In existing technologies, the bonding between fibers and the matrix largely relies on physical anchoring or weak intermolecular forces, which are prone to failure under high temperatures and stress. This invention, through a designed modifier, successfully introduces active groups (such as allyl groups) that can chemically crosslink with the matrix polymer onto the surface of basalt fibers. During the sheath vulcanization process, these active groups can directly participate in the crosslinking network of the alkenylated polyvinyl chloride / methyl vinyl silicone rubber matrix, forming a robust "fiber-interface layer-matrix" chemical bond structure. This covalent bond connection method greatly enhances the interfacial bonding force, far exceeding the effects of traditional physical adsorption or simple coupling agent treatment, thereby significantly improving the mechanical strength and durability of the material.

[0017] Unlike single coupling agent modification, this invention utilizes a "sizing agent" process to construct a composite interface layer on the fiber surface, with a siloxane backbone and embedded special structural modifiers. This interface layer not only firmly bonds to the fiber matrix through silanol condensation, but its own modifier molecules also contain structures such as phosphate esters, benzene rings, and long-chain alkyl groups. These structures enable stronger molecular-level interactions with the polymer matrix through various mechanisms, including polar interactions and π-π stacking, achieving multi-level, synergistic interface reinforcement, resulting in higher effective stress transfer efficiency and superior overall material performance.

[0018] Meanwhile, the benzene rings and phosphate ester structures introduced into the modifier molecules themselves possess excellent heat resistance and flame retardant effects. These groups are fixed on the fiber surface and interface layer through chemical bonds, and are not easily migrated or volatilized at high temperatures, thus enabling them to continue to function. They produce a synergistic effect with the inorganic heat-resistant properties of basalt fibers themselves, jointly improving the thermal stability and oxygen index of the sheath material, and endowing the cable with superior long-term high-temperature resistance and fire safety performance. Detailed Implementation

[0019] 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.

[0020] Pre-preparation: The preparation process of alkenylated polyvinyl chloride is as follows: 1 part of polyvinyl chloride powder and 30 parts of sodium hydroxide solution (30wt%) are mixed and reacted at 140℃ for 4 hours. After post-treatment, alkenylated polyvinyl chloride is obtained.

[0021] Example 1: The manufacturing process of a high-temperature resistant cable for industrial use is as follows: 32 parts of alkenylated polyvinyl chloride, 38 parts of methyl vinyl silicone rubber, 15 parts of modified basalt fiber, 1 part of vulcanizing agent (dicumyl peroxide and accelerator TMTM in a mass ratio of 3:1), 6 parts of plasticizer (phthalate), 1 part of lubricant (polyethylene wax), 1 part of stabilizer (calcium zinc stabilizer), and 0.3 parts of antioxidant (antioxidant 1024) are mixed and added to a twin-screw extruder. The mixture is melt-extruded and coated onto the outside of the cable core. After cooling and curing, a sheath layer is formed to obtain a high-temperature resistant cable. The preparation process of modified basalt fiber is as follows: A1: Mix 4 parts modifier, 10 parts tetraethyl orthosilicate, 2 parts ammonia water, and 70 parts anhydrous ethanol, and stir evenly to obtain a sizing agent; A2: Add the dried chopped basalt fiber to the sizing agent and impregnate at 60°C for 5 minutes. Then, place the impregnated fiber in a vacuum oven and dry at 120°C overnight to obtain modified basalt fiber. The mass ratio of chopped basalt fiber to sizing agent is 1:3. The preparation process of the modifier is as follows: S1: Mix 10 parts of 3-allyl-2-hydroxybenzaldehyde, 6 parts of triethylamine, and 80 parts of dichloromethane. After stirring evenly, cool to 0°C. Then slowly add 6 parts of phenyl dichlorophosphate. After the addition is complete, keep the reaction at 0°C for 30 min. Then raise the reaction system to room temperature and stir overnight. After the reaction is complete, perform post-processing to obtain intermediate A. S2: Mix 10 parts of intermediate A, 9 parts of γ-aminopropyltriethoxysilane, and 60 parts of anhydrous ethanol. After sealing, raise the temperature to 70°C and stir for 8 hours. After the reaction is complete, cool to room temperature, concentrate, and let stand for 24 hours. After washing and drying, the modifier is obtained.

[0022] Example 2: The manufacturing process of an industrial high-temperature resistant cable is as follows: 38 parts of alkenylated polyvinyl chloride, 42 parts of methyl vinyl silicone rubber, 20 parts of modified basalt fiber, 2 parts of vulcanizing agent (dicumyl peroxide and accelerator TMTM in a mass ratio of 3:1), 10 parts of plasticizer (phthalate), 2 parts of lubricant (polyethylene wax), 2 parts of stabilizer (calcium zinc stabilizer), and 0.8 parts of antioxidant (antioxidant 1024) are mixed and added to a twin-screw extruder. The mixture is melt-extruded and coated onto the outside of the cable core. After cooling and curing, a sheath layer is formed to obtain a high-temperature resistant cable. The preparation process of modified basalt fiber is as follows: A1: Mix 5 parts modifier, 12 parts tetraethyl orthosilicate, 3 parts ammonia water, and 90 parts anhydrous ethanol, and stir evenly to obtain a sizing agent; A2: Add the dried chopped basalt fiber to the sizing agent and impregnate at 60°C for 8 minutes. Then, place the impregnated fiber in a vacuum oven and dry at 120°C overnight to obtain modified basalt fiber. The mass ratio of chopped basalt fiber to sizing agent is 1:5. The preparation process of the modifier is as follows: S1: Mix 12 parts of 3-allyl-2-hydroxybenzaldehyde, 8 parts of triethylamine, and 100 parts of dichloromethane. After stirring evenly, cool to 0°C. Then slowly add 8 parts of phenyl dichlorophosphate. After the addition is complete, keep the reaction at 0°C for 40 min. Then raise the reaction system to room temperature and stir overnight. After the reaction is complete, perform post-processing to obtain intermediate A. S2: Mix 12 parts of intermediate A, 10 parts of γ-aminopropyltriethoxysilane, and 80 parts of anhydrous ethanol, seal the mixture, raise the temperature to 80°C, stir and react for 10 hours. After the reaction is complete, cool to room temperature, concentrate the mixture, let it stand for 24 hours, wash and dry it to obtain the modifier.

[0023] Example 3: The manufacturing process of an industrial high-temperature resistant cable is as follows: 35 parts of alkenylated polyvinyl chloride, 40 parts of methyl vinyl silicone rubber, 17.5 parts of modified basalt fiber, 1.5 parts of vulcanizing agent (dicumyl peroxide and accelerator TMTM in a mass ratio of 3:1), 8 parts of plasticizer (phthalate), 1.5 parts of lubricant (polyethylene wax), 1.5 parts of stabilizer (calcium zinc stabilizer), and 0.55 parts of antioxidant (antioxidant 1024) are mixed and added to a twin-screw extruder. The mixture is melt-extruded and coated onto the outside of the cable core. After cooling and curing, a sheath layer is formed to obtain a high-temperature resistant cable. The preparation process of modified basalt fiber is as follows: A1: Mix 4.5 parts modifier, 11 parts tetraethyl orthosilicate, 2.5 parts ammonia water, and 80 parts anhydrous ethanol, and stir evenly to obtain a sizing agent; A2: Add the dried chopped basalt fiber to the sizing agent and impregnate at 60°C for 6.5 min. Then place the impregnated fiber in a vacuum oven and dry at 120°C overnight to obtain modified basalt fiber. The mass ratio of chopped basalt fiber to sizing agent is 1:4. The preparation process of the modifier is as follows: S1: Mix 11 parts of 3-allyl-2-hydroxybenzaldehyde, 7 parts of triethylamine, and 90 parts of dichloromethane. After stirring evenly, cool to 0°C. Then slowly add 7 parts of phenyl dichlorophosphate. After the addition is complete, keep the reaction at 0°C for 35 min. Then raise the reaction system to room temperature and stir overnight. After the reaction is complete, perform post-processing to obtain intermediate A. S2: Mix 11 parts of intermediate A, 9.5 parts of γ-aminopropyltriethoxysilane, and 70 parts of anhydrous ethanol, seal the mixture, raise the temperature to 75°C, stir and react for 9 hours. After the reaction is complete, cool to room temperature, concentrate the mixture, let it stand for 24 hours, wash and dry it to obtain the modifier.

[0024] Comparative Example 1: No modified basalt fiber was added, as detailed below: 35 parts of alkenylated polyvinyl chloride, 40 parts of methyl vinyl silicone rubber, 1.5 parts of vulcanizing agent (dicumyl peroxide and accelerator TMTM in a mass ratio of 3:1), 8 parts of plasticizer (phthalate), 1.5 parts of lubricant (polyethylene wax), 1.5 parts of stabilizer (calcium zinc stabilizer), and 0.55 parts of antioxidant (antioxidant 1024) are mixed and added to a twin-screw extruder. The mixture is melt-extruded and coated onto the outside of the cable core. After cooling and curing, a sheath layer is formed, resulting in a high-temperature resistant cable.

[0025] Comparative Example 2: Using γ-aminopropyltriethoxysilane as a substitute for the modifier, as detailed below: 35 parts of alkenylated polyvinyl chloride, 40 parts of methyl vinyl silicone rubber, 17.5 parts of modified basalt fiber, 1.5 parts of vulcanizing agent (dicumyl peroxide and accelerator TMTM in a mass ratio of 3:1), 8 parts of plasticizer (phthalate), 1.5 parts of lubricant (polyethylene wax), 1.5 parts of stabilizer (calcium zinc stabilizer), and 0.55 parts of antioxidant (antioxidant 1024) are mixed and added to a twin-screw extruder. The mixture is melt-extruded and coated onto the outside of the cable core. After cooling and curing, a sheath layer is formed to obtain a high-temperature resistant cable. The preparation process of modified basalt fiber is as follows: A1: Mix 4.5 parts of γ-aminopropyltriethoxysilane, 11 parts of tetraethyl orthosilicate, 2.5 parts of ammonia water, and 80 parts of anhydrous ethanol, and stir evenly to obtain a sizing agent; A2: Add the dried chopped basalt fiber to the sizing agent and impregnate at 60°C for 6.5 min. Then place the impregnated fiber in a vacuum oven and dry at 120°C overnight to obtain modified basalt fiber. The mass ratio of chopped basalt fiber to sizing agent is 1:4.

[0026] Testing experiments: The cable sheath layers of the examples and comparative examples were peeled off, and the following testing experiments were conducted: (1) Test the tensile strength of the material according to standard GB / T1040.3-2006; (2) The oxygen index of the material was tested according to standard GB / T2406.2-2009; (3) According to standard GB / T8815-2008, test the thermal deformation of the material and the thermal stability time at 200℃; The obtained data is shown in the table below: project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Tensile strength (MPa) 24.5 26.2 27.1 15.4 19.5 Heat distortion (%) 19.4 19.7 18.7 38.9 28.1 Oxygen index (%) 34.5 35.1 35.6 28.1 31.1 Thermal stability time at 200℃ (min) 147 152 158 62 120 Conclusion: Based on the technical solution and experimental data provided by this invention, it can be seen that the industrial high-temperature resistant cable prepared by using a sheath material composed of a specific ratio of alkenylated polyvinyl chloride, methyl vinyl silicone rubber, and functionalized modified basalt fiber exhibits significant advantages in several key performance aspects. The test results of Examples 1 to 3 show that the cable sheath material has high tensile strength (24.5–27.1 MPa), low heat distortion rate (18.7–19.7%), high oxygen index (34.5–35.6%), and excellent long-term thermal stability (thermal stability time of 147–158 minutes at 200℃). Compared with Comparative Example 1 without modified basalt fiber, all performance aspects are significantly improved; compared with Comparative Example 2 treated only with conventional silane coupling agents, the composite modifier and sizing agent process used in this invention further enhances the interfacial bonding force between the fiber and the matrix, resulting in superior mechanical properties, heat resistance, and flame retardancy.

[0027] In summary, this invention effectively improves the overall performance of cable sheaths through surface functionalization modification of basalt fibers, making them particularly suitable for harsh industrial environments such as high temperature and high stress.

[0028] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0029] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A high temperature resistant industrial cable, characterized in that, The cable comprises a cable core and a sheath layer wrapped outside the cable core; the sheath layer comprises the following components: 32-38 parts by weight of alkenyl polyvinyl chloride, 38-42 parts by weight of methyl vinyl silicone rubber, 15-20 parts by weight of modified basalt fiber, 1-2 parts by weight of vulcanizing agent, 6-10 parts by weight of plasticizer, 1-2 parts by weight of lubricant, 1-2 parts by weight of stabilizer, and 0.3-0.8 parts by weight of antioxidant.

2. A high temperature resistant industrial cable according to claim 1, characterized in that The preparation process of the modified basalt fiber is as follows: A1: mixing the modifier, tetraethyl orthosilicate, ammonia water and anhydrous ethanol, stirring uniformly, and obtaining a sizing agent; A2: adding the dried chopped basalt fiber into the sizing agent, impregnating at 60 DEG C for 5-8 min, and then placing the impregnated fiber into a vacuum oven and drying at 120 DEG C overnight to obtain the modified basalt fiber.

3. A high temperature resistant industrial cable according to claim 2, characterized in that The sizing agent comprises the following components: 4-5 parts by weight of modifier, 10-12 parts by weight of tetraethyl orthosilicate, 2-3 parts by weight of ammonia water, and 70-90 parts by weight of anhydrous ethanol; wherein the concentration of the ammonia water is 28wt%.

4. A high temperature resistant industrial cable according to claim 2, characterized in that The mass ratio of the chopped basalt fiber to the sizing agent is 1: (3-5).

5. A high temperature resistant industrial cable according to claim 2, characterized in that The preparation process of the modifier is as follows: S1: mixing 3-allyl-2-hydroxybenzaldehyde, triethylamine and dichloromethane, stirring uniformly, cooling to 0 DEG C, then slowly adding phenyldichlorophosphate, keeping 0 DEG C for 30-40 min after the addition is completed, then increasing the temperature to room temperature, stirring overnight, and after the reaction is completed, post-treatment to obtain intermediate A; S2: mixing intermediate A, gamma-aminopropyltriethoxysilane and anhydrous ethanol, sealing, increasing the temperature to 70-80 DEG C, stirring for 8-10 h, cooling to room temperature after the reaction is completed, concentrating and standing for 24 h, washing, and drying to obtain the modifier.

6. A high temperature resistant industrial cable according to claim 5, characterized in that The raw materials for preparing the intermediate A comprise the following components: 10-12 parts by weight of 3-allyl-2-hydroxybenzaldehyde, 6-8 parts by weight of triethylamine, 80-100 parts by weight of dichloromethane, and 6-8 parts by weight of phenyldichlorophosphate.

7. A high temperature resistant industrial cable according to claim 5, characterized in that The raw materials for preparing the modifier comprise the following components: 10-12 parts by weight of intermediate A, 9-10 parts by weight of gamma-aminopropyltriethoxysilane, and 60-80 parts by weight of anhydrous ethanol.

8. A high temperature resistant industrial cable according to claim 1, characterized in that The vulcanizing agent is dicumyl peroxide and accelerator TMTM with a mass ratio of 3:

1.

9. A high temperature resistant industrial cable according to claim 1, characterized in that, The plasticizer is phthalate ester; the lubricant is polyethylene wax; the stabilizer is calcium-zinc stabilizer; and the antioxidant is antioxidant 1024.

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