Environment-friendly composite cable insulation protection sleeve raw material and preparation method thereof

Abstract

The invention relates to the technical field of cables, in particular to an environment-friendly composite cable insulation protective sleeve raw material and a preparation method thereof, and the raw material comprises the following components in parts by weight: 100 parts of PVC resin, 5-10 parts of a flame retardant, 20-25 parts of a plasticizer, 10-15 parts of modified basalt fiber, 2-4 parts of a lubricant, 4-6 parts of a calcium-zinc stabilizer and 5-8 parts of an anti-aging agent. The flame retardant comprises boron nitride, ammonium phosphomolybdate and magnesium hydroxide. Through scientific combination of the PVC resin, the composite flame retardant, the functional modified basalt fiber and other preferable auxiliaries, the comprehensive performance of the cable protection sleeve is remarkably improved, and the protection sleeve prepared from the raw materials has excellent mechanical strength and basic insulation performance; the cable is more excellent in wear resistance, rat and ant bite resistance and flame-retardant safety, meanwhile, the environment-friendly characteristic and long-term use stability of the material are considered, and the service life of the cable in a complex application environment is effectively prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cables, in particular to an environmentally friendly composite cable insulation protective sleeve raw material and a preparation method thereof. BACKGROUND

[0002] The cable insulation protective sleeve is an important component in power systems and communication systems to protect cables from external environmental influences, mainly serving the functions of electrical insulation, mechanical protection, waterproofing, moisture-proofing, and flame resistance. With the increasing demand for cable safety performance in the industrial and construction fields, cable insulation protective sleeves not only need to have basic insulation and flame resistance, but also need to meet various functional requirements such as wear resistance, anti-aging, and protection against gnawing animals (such as mice and ants) to extend the service life of the cable and ensure safe operation of the line. PVC resin has become one of the main base materials for cable insulation protective sleeves due to its good processing performance and low cost, but conventional PVC protective sleeves often need to add various additives to improve their performance.

[0003] The existing Chinese patent CN202311822033.X discloses an environmentally friendly anti-ultraviolet PVC cable sheath material, belonging to the technical field of cable sheaths, which comprises the following raw materials by weight: 100 parts of PVC resin, 35-45 parts of branched bio-based plasticizer, 3-5 parts of composite stabilizer, 6-8 parts of modified TiO2, 15-20 parts of inorganic filler, and 5 parts of lubricant. The preparation method of the above-mentioned environmentally friendly anti-ultraviolet PVC cable sheath material is also disclosed, which involves mixing the above-mentioned raw materials and then melt extruding to obtain the environmentally friendly anti-ultraviolet PVC cable sheath material. This technology avoids the use of small molecule plasticizers and traditional ultraviolet absorbers by introducing branched bio-based plasticizers and modified TiO2, reducing the harm to the environment and human body, and improving the mechanical properties, anti-ultraviolet properties, and flame resistance of PVC resin to some extent. However, this technology mainly focuses on anti-ultraviolet aging and environmental protection, and still has deficiencies in the wear resistance of the protective sleeve, especially in harsh working environments where it is easily damaged by friction and wear. In addition, this technology fails to solve the problem of damage to cable insulation protective sleeves by mice and ants in the wild or buildings, which is one of the important reasons for cable failure. The flame retardant system used in this technology is relatively simple, and the flame retardant effect under complex combustion conditions needs to be improved. SUMMARY

[0004] Therefore, the present application proposes an environmentally friendly composite cable insulation protective sleeve raw material and a preparation method thereof to solve the technical problems of insufficient wear resistance, easy damage by mice and ants, and poor synergistic effect of the flame retardant system of the cable protective sleeve in the prior art.

[0005] The technical solution of the present invention is achieved as follows: the present invention provides an environmentally friendly composite cable insulation protective cover raw material, which includes, by weight, 100 parts of PVC resin, 5-10 parts of flame retardant, 20-25 parts of plasticizer, 10-15 parts of modified basalt fiber, 2-4 parts of lubricant, 4-6 parts of calcium zinc stabilizer, and 5-8 parts of anti-aging agent; the flame retardant includes boron nitride, ammonium phosphomolybdate and magnesium hydroxide.

[0006] The environmentally friendly composite cable insulation protective sheath raw material provided by the present invention realizes the multifunctional synergistic enhancement effect of the material. This raw material not only maintains the good processing performance and basic insulation performance of the PVC material, but also significantly improves the wear resistance of the protective sheath and the protection against rats, ants, etc. by introducing multifunctional modified basalt fiber. At the same time, the composite flame retardant system gives the material efficient flame retardant properties, and the selection of environmentally friendly additives ensures the material's friendliness to the environment and the human body. Overall, the raw material provided by the present invention can effectively extend the service life of the cable and improve the operational reliability and safety of the cable in complex environments.

[0007] Based on the above technical solution, preferably, the mass ratio of boron nitride, ammonium phosphomolybdate and magnesium hydroxide is 1:1:2.5-3.

[0008] In the flame-retardant system of the present invention, boron nitride, ammonium phosphomolybdate, and magnesium hydroxide produce a significant synergistic flame-retardant effect through different mechanisms, thereby imparting excellent fire safety properties to the PVC composite material. Specifically, magnesium hydroxide undergoes an endothermic decomposition reaction upon heating, releasing a large amount of water vapor. The thermal decomposition products of ammonium phosphomolybdate (such as acidic substances such as polyphosphoric acid and metaphosphoric acid) promote dehydration and cross-linking carbonization of the PVC matrix, thereby achieving flame retardancy and smoke suppression. Boron nitride, with its thermal stability and high thermal conductivity, forms a more robust and continuous physical barrier with the magnesium oxide produced by the decomposition of magnesium hydroxide and the carbon layer formed by ammonium phosphomolybdate, further enhancing the flame retardant effect. The three components complement and promote each other, exerting flame retardant properties in both the gas and condensed phases, forming a multi-faceted synergistic flame-retardant mechanism of "endothermic decomposition, gas dilution, carbonization promotion, and insulation and coverage." This gives the composite cable insulation sheath material excellent flame retardancy, far superior to that achieved by a single flame retardant.

[0009] On the basis of the above technical solution, preferably, the preparation method of the modified basalt fiber includes: S1. Mixing basalt fiber and hydrogen peroxide, heating to 100-110° C. for 3-5 hours, filtering, and drying to obtain pretreated basalt fiber; S2. Prepare titanium dioxide sol, immerse the pretreated basalt fiber in the titanium dioxide sol, pull it at a speed of 2 cm / min, dry it, and then calcine it at high temperature to obtain functionalized basalt fiber; S3, dispersing the functionalized basalt fiber in an ethanol aqueous solution, adding an aminosilane coupling agent, and stirring to react to obtain an organized basalt fiber; S4. Dispersing the organized basalt fiber in DMF, adding azadirachtin and glutaraldehyde, and reacting at 40-60° C. for 4-6 hours to obtain modified basalt fiber.

[0010] Specifically, in step S1, the basalt fiber is surface-treated with hydrogen peroxide to further activate the surface and increase the density and reactivity of the hydroxyl groups. In step S2, a titanium dioxide sol is loaded onto the surface of the pretreated basalt fiber using a sol-gel method. This is then subjected to high-temperature calcination to firmly bond the titanium dioxide sol to the basalt fiber. The surface is then nitrided in an ammonia atmosphere to produce titanium nitride. The in-situ generation of titanium nitride on the basalt fiber surface significantly improves its surface hardness and wear resistance, thereby enhancing the composite material's ability to resist external friction and scratches, extending the service life of the cable sheath in harsh environments. The increased hardness and wear resistance also enhances its anti-bite properties. In step S3, an aminosilane coupling agent is introduced onto the surface of the functionalized basalt fiber to improve the interfacial compatibility between the inorganic filler and the organic polymer matrix (such as PVC). The introduction of amino functional groups provides chemical reaction sites. In step S4, glutaraldehyde is used as a cross-linking agent to chemically graft azadirachtin, which has rat and ant repellent properties, onto the surface of the organic basalt fiber. The chemical grafting method can greatly improve the durability and migration resistance of the rat and ant repellent, ensuring that it is not easily lost or ineffective during the long-term use of the cable sheath, thereby giving the composite material long-lasting and reliable rat and ant repellent properties, effectively protecting the cable from biological damage.

[0011] Based on the above technical solution, preferably, in step S1, the mass ratio of basalt fiber to hydrogen peroxide is 1:3-4.

[0012] Based on the above technical solution, preferably, in step S2, the titanium dioxide sol is prepared by mixing tetrabutyl titanate and anhydrous ethanol to obtain solution A; mixing glacial acetic acid, deionized water, and anhydrous ethanol to obtain solution B; and adding solution A dropwise to solution B, stirring for 1-2 hours to obtain the titanium dioxide sol. More preferably, in solution A, the volume ratio of tetrabutyl titanate to anhydrous ethanol is 10 ml:30-35 ml; in solution B, the volume ratio of glacial acetic acid, deionized water, and anhydrous ethanol is 4 ml:8-10 ml:30-35 ml. The viscosity of the titanium dioxide sol is 10-15 mPa·s (25°C). The mass ratio of the pretreated basalt fiber to the titanium dioxide sol is 1:5-8.

[0013] On the basis of the above technical solution, preferably, in step S2, the high-temperature calcination treatment includes: first heating to 300-350°C at 2-3°C / min under a nitrogen atmosphere, keeping warm for 1-1.2h, then heating to 450-500°C, keeping warm for 30-40min; then introducing ammonia, heating to 800-1000°C at 4-6°C / min, and keeping warm for 1.5-2.5h.

[0014] Through slow initial heating and segmented temperature control, the coating cracking, bubble formation or shedding caused by rapid temperature change of titanium dioxide sol is avoided, and the bonding strength and overall stability of titanium dioxide sol and basalt fiber are improved; further high-temperature ammonia treatment significantly improves the degree of nitriding reaction, so that titanium dioxide is converted into titanium nitride or titanium oxynitride structure with high nitrogen content, thereby improving the surface hardness and wear resistance of basalt fiber.

[0015] Based on the above technical solution, preferably, in step S3, the mass ratio of the functionalized basalt fiber to the aminosilane coupling agent is 1:0.1-0.3, the stirring reaction temperature is 50-80°C, and the reaction time is 3-5h; the aminosilane coupling agent is γ-aminopropyltrimethoxysilane or γ-aminopropyltriethoxysilane.

[0016] Based on the above technical solution, preferably, in step S4, the mass ratio of the organized basalt fiber, azadirachtin and glutaraldehyde is 10:1.3-1.7:0.8.

[0017] Based on the above technical solution, preferably, the lubricant is one or more of stearic acid, butyl stearate, and oleamide; the anti-aging agent is one or more of antioxidant 1076, antioxidant 1010, and antioxidant 264; and the plasticizer is epoxidized soybean oil or dioctyl phthalate.

[0018] The present invention also provides a method for preparing an environmentally friendly composite cable insulation protective sheath raw material. The preparation method is used to prepare the environmentally friendly composite cable insulation protective sheath raw material as described above. The preparation method comprises: weighing PVC resin, flame retardant, plasticizer, modified basalt fiber, lubricant, calcium zinc stabilizer and anti-aging agent in proportion, mixing at 100-110°C, transferring to a twin-screw extruder after stirring, and extruding and granulating at 170-190°C to obtain the environmentally friendly composite cable insulation protective sheath raw material.

[0019] The environmentally friendly composite cable insulation protective sheath raw material and preparation method thereof of the present invention have the following beneficial effects compared with the prior art: (1) The present application significantly improves the comprehensive performance of the cable protective sleeve by scientific combination of PVC resin, composite flame retardant, functional modified basalt fiber and other preferred additives. The protective sleeve made of the raw material not only has excellent mechanical strength and basic insulation performance, but also has outstanding performance in wear resistance, rat and termite bite prevention and flame retardant safety, while considering the environmental characteristics and long-term stability of the material, effectively prolonging the service life of the cable in complex application environment; (2) The present application adopts boron nitride, ammonium phosphomolybdate and magnesium hydroxide compounded flame retardant, which exhibits significant synergistic flame retardant effect. Magnesium hydroxide decomposes and absorbs heat and releases water vapor when heated, which plays a role in gas phase cooling and dilution and condensed phase covering; ammonium phosphomolybdate effectively promotes the formation of a dense carbon layer in the PVC matrix during combustion, which insulates heat and oxygen and suppresses smoke generation; boron nitride, with its high thermal stability and thermal conductivity, helps to dissipate heat and enhance the structural strength and insulation effect of the carbon layer, and the three work together in the gas phase and condensed phase to form a multi-mechanism, high-efficiency flame retardant network, thereby giving the composite excellent flame retardant performance.

[0020] (3) In the modified basalt fiber, first, the hydroxylation pretreatment provides an active basis for subsequent coating and grafting; then, through sol-gel method and high temperature calcination treatment, a titanium nitride functional layer is generated in situ on the surface of the basalt fiber, thereby significantly improving the wear resistance of the composite material; the functionalized basalt fiber is treated with amino silane coupling agent, which not only improves the interfacial compatibility and dispersibility of the basalt fiber with the PVC matrix, but also provides active sites for subsequent grafting of rat and termite repellent; neem oil is chemically grafted to the surface of the basalt fiber through glutaraldehyde, which gives the material a persistent and efficient ability to prevent rat and termite bites, and finally makes the environmentally friendly composite cable insulation protective sleeve material exhibit excellent comprehensive performance in wear resistance, biological damage prevention and compatibility with the matrix. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0022] It should be noted that in this embodiment, the PVC resin is purchased from Wuhan Jiyue Shenghua Chemical Co., Ltd., and the brand is SG-5; the particle size of boron nitride is 100 mesh, and the CAS number is 10043-11-5; the basalt fiber is purchased from Shandong Hengtai New Material Technology Co., Ltd., and the diameter is 7-25 μm; the calcium-zinc stabilizer is purchased from Jinan Xiangfeng Weiye Chemical Co., Ltd.

[0023] Example 1 This embodiment provides an environmentally friendly composite cable insulation protective sheath raw material and a preparation method thereof, comprising 100 parts of PVC resin, 8 parts of flame retardant, 23 parts of dioctyl phthalate, 13 parts of modified basalt fiber, 3 parts of stearic acid, 5 parts of calcium zinc stabilizer, and 6.5 parts of antioxidant 1010. The mass ratio of boron nitride, ammonium phosphomolybdate, and magnesium hydroxide in the flame retardant is 1:1:2.8. The preparation method of modified basalt fiber is as follows: S1. Mix 10 g of basalt fiber and 35 g of hydrogen peroxide (concentration: 30%), heat to 105° C. for 4 h, and after the reaction is complete, cool to room temperature, filter, and dry to obtain pretreated basalt fiber. S2. Mix 10 ml of tetrabutyl titanate and 33 ml of anhydrous ethanol and stir for 9 min to obtain solution A. Add 4 ml of glacial acetic acid and 9 ml of deionized water to 33 ml of anhydrous ethanol and stir vigorously to obtain solution B. Add hydrochloric acid dropwise to adjust the pH to ≤ 3. In a room temperature water bath, solution A was slowly added dropwise to solution B and stirred for 1.5 hours to obtain titanium dioxide sol. 10 g of pretreated basalt fiber was immersed in 65 g of titanium dioxide sol, soaked for 10 minutes, pulled at a speed of 2 cm / min, dried at 80°C for 30 minutes, and then subjected to high-temperature calcination treatment. First, the temperature was raised to 330°C at 2.5°C / min under a nitrogen atmosphere, kept warm for 1.1 hours, and then raised to 480°C and kept warm for 35 minutes; then ammonia was introduced at an ammonia flow rate of 150 ml / min, and the temperature was raised to 900°C at 5°C / min, kept warm for 2 hours, the ammonia was cut off, nitrogen was introduced, and the temperature was reduced to 500°C at a rate of 5°C / min, and then naturally cooled to room temperature to obtain functionalized basalt fiber; S3. Disperse 10 g of functionalized basalt fiber in 100 ml of ethanol-water solution (volume ratio of ethanol to water is 3:1), ultrasonically disperse for 15 min, add 2 g of γ-aminopropyltriethoxysilane, stir and react at 65°C for 4 h. After the reaction is complete, filter, wash and dry to obtain the organic basalt fiber. S4. Disperse 10 g of the organic basalt fiber in 100 ml of DMF, ultrasonically disperse for 10 min, add 1.5 g of azadirachtin, stir evenly, dropwise add 0.8 g of glutaraldehyde, heat to 50°C and react for 5 h. After the reaction is completed, filter, wash and dry to obtain modified basalt fiber.

[0024] The preparation method of the environmentally friendly composite cable insulation protective cover raw material comprises: weighing PVC resin, flame retardant, plasticizer, modified basalt fiber, lubricant, calcium zinc stabilizer and anti-aging agent in proportion, mixing at 95°C, transferring to a twin-screw extruder after stirring, and extruding and granulating at 170-190°C to obtain the environmentally friendly composite cable insulation protective cover raw material.

[0025] Example 2 This embodiment provides an environmentally friendly composite cable insulation protective sheath raw material and a preparation method thereof, comprising 100 parts of PVC resin, 5 parts of flame retardant, 20 parts of epoxy soybean oil, 10 parts of modified basalt fiber, 2 parts of butyl stearate, 4 parts of calcium zinc stabilizer, and 5 parts of antioxidant 264. The flame retardant comprises boron nitride, ammonium phosphomolybdate, and magnesium hydroxide in a mass ratio of 1:1:2.5; The preparation method of modified basalt fiber is as follows: S1. Mix 10 g of basalt fiber and 30 g of hydrogen peroxide (concentration: 30%), heat to 100°C for 5 h, and after the reaction is complete, cool to room temperature, filter, and dry to obtain pretreated basalt fiber; S2. Mix 10 ml of tetrabutyl titanate and 30 ml of anhydrous ethanol, and stir for 8 min to obtain solution A. Add 4 ml of glacial acetic acid and 8 ml of deionized water to 30 ml of anhydrous ethanol, and stir vigorously to obtain solution B. Add hydrochloric acid dropwise to adjust the pH to ≤ 3. In a room temperature water bath, solution A was slowly added dropwise to solution B and stirred for 1 hour to obtain titanium dioxide sol. 10 g of pretreated basalt fiber was immersed in 50 g of titanium dioxide sol, soaked for 10 minutes, pulled at a speed of 2 cm / min, dried at 80°C for 30 minutes, and then subjected to high-temperature calcination treatment. First, the temperature was raised to 300°C at 2°C / min under a nitrogen atmosphere, kept warm for 1.2 hours, then raised to 450°C and kept warm for 40 minutes; then ammonia was introduced at an ammonia flow rate of 150 ml / min, and the temperature was raised to 800°C at 4°C / min, kept warm for 2.5 hours, the ammonia was cut off, nitrogen was introduced, and the temperature was reduced to 500°C at a rate of 5°C / min, and then naturally cooled to room temperature to obtain functionalized basalt fiber; S3. Disperse 10 g of functionalized basalt fiber in 100 ml of ethanol-water solution (volume ratio of ethanol to water is 3:1), ultrasonically disperse for 15 min, add 1 g of γ-aminopropyltriethoxysilane, stir and react at 50° C. for 5 h. After the reaction is complete, filter, wash and dry to obtain the organic basalt fiber. S4. Disperse 10 g of the organic basalt fiber in 100 ml of DMF, ultrasonically disperse for 10 min, add 1.3 g of azadirachtin, stir evenly, dropwise add 0.8 g of glutaraldehyde, heat to 40°C and react for 6 h. After the reaction is completed, filter, wash and dry to obtain modified basalt fiber.

[0026] The preparation method of the environmentally friendly composite cable insulation protective cover raw material comprises: weighing PVC resin, flame retardant, plasticizer, modified basalt fiber, lubricant, calcium zinc stabilizer and anti-aging agent in proportion, mixing at 90°C, transferring to a twin-screw extruder after stirring, and extruding and granulating at 170-190°C to obtain the environmentally friendly composite cable insulation protective cover raw material.

[0027] Example 3 This embodiment provides an environmentally friendly composite cable insulation protective sheath raw material and a preparation method thereof, comprising 100 parts of PVC resin, 10 parts of flame retardant, 25 parts of epoxy soybean oil, 15 parts of modified basalt fiber, 4 parts of oleamide, 6 parts of calcium zinc stabilizer, and 8 parts of antioxidant 1076. The flame retardant comprises boron nitride, ammonium phosphomolybdate, and magnesium hydroxide in a mass ratio of 1:1:3. The preparation method of modified basalt fiber is as follows: S1. Mix 10 g of basalt fiber and 40 g of hydrogen peroxide (30% concentration), heat to 110° C. for 3 h, and after the reaction is complete, cool to room temperature, filter, and dry to obtain pretreated basalt fiber. S2. Mix 10 ml of tetrabutyl titanate and 35 ml of anhydrous ethanol, and stir for 10 min to obtain solution A. Add 4 ml of glacial acetic acid and 10 ml of deionized water to 35 ml of anhydrous ethanol, and stir vigorously to obtain solution B. Add hydrochloric acid dropwise to adjust the pH to ≤ 3. In a room temperature water bath, solution A was slowly added dropwise to solution B and stirred for 2 hours to obtain titanium dioxide sol. 10 g of pretreated basalt fiber was immersed in 80 g of titanium dioxide sol, soaked for 10 minutes, pulled at a speed of 2 cm / min, dried at 80°C for 30 minutes, and then subjected to high-temperature calcination treatment. First, the temperature was raised to 350°C at 3°C / min under a nitrogen atmosphere, kept warm for 1 hour, and then raised to 500°C and kept warm for 30 minutes; then ammonia was introduced at an ammonia flow rate of 150 ml / min, and the temperature was raised to 1000°C at 6°C / min, kept warm for 1.5 hours, the ammonia was cut off, nitrogen was introduced, and the temperature was reduced to 500°C at a rate of 5°C / min, and then naturally cooled to room temperature to obtain functionalized basalt fiber; S3. Disperse 10 g of functionalized basalt fiber in 100 ml of ethanol-water solution (volume ratio of ethanol to water is 3:1), ultrasonically disperse for 15 min, add 3 g of γ-aminopropyltriethoxysilane, stir and react at 80° C. for 3 h. After the reaction is complete, filter, wash and dry to obtain the organic basalt fiber. S4. Disperse 10 g of the organic basalt fiber in 100 ml of DMF, ultrasonically disperse for 10 min, add 1.7 g of azadirachtin, stir evenly, dropwise add 0.8 g of glutaraldehyde, heat to 60°C and react for 4 h. After the reaction is completed, filter, wash and dry to obtain modified basalt fiber.

[0028] The preparation method of the environmentally friendly composite cable insulation protective cover raw material comprises: weighing PVC resin, flame retardant, plasticizer, modified basalt fiber, lubricant, calcium zinc stabilizer and anti-aging agent in proportion, mixing at 100°C, transferring to a twin-screw extruder after stirring, and extruding and granulating at 170-190°C to obtain the environmentally friendly composite cable insulation protective cover raw material.

[0029] Comparative Example 1 This comparative example provides an environmentally friendly composite cable insulation protective sheath raw material and a preparation method thereof, which is the same as Example 1, except that the composition of the flame retardant is different. The flame retardant includes boron nitride and magnesium hydroxide, and the mass ratio of boron nitride to magnesium hydroxide is 2:2.8.

[0030] Comparative Example 2 This comparative example provides an environmentally friendly composite cable insulation protective sheath raw material and a preparation method thereof, which is the same as Example 1, except that the composition of the flame retardant is different. The flame retardant includes ammonium phosphomolybdate and magnesium hydroxide, and the mass ratio of ammonium phosphomolybdate to magnesium hydroxide is 2:2.8.

[0031] Comparative Example 3 This comparative example provides an environmentally friendly composite cable insulation protective sheath raw material and a preparation method thereof, which is the same as Example 1, except that the preparation method of the modified basalt fiber is different. The preparation method of the modified basalt fiber is as follows: S1. Mix 10 g of basalt fiber and 35 g of hydrogen peroxide (concentration: 30%), heat to 105° C. for 4 h, and after the reaction is complete, cool to room temperature, filter, and dry to obtain pretreated basalt fiber. S2. Mix 10 ml of tetrabutyl titanate and 33 ml of anhydrous ethanol and stir for 9 minutes to obtain solution A. Add 4 ml of glacial acetic acid and 9 ml of deionized water to 33 ml of anhydrous ethanol and stir vigorously to obtain solution B. Add hydrochloric acid dropwise to adjust the pH to ≤ 3. In a room temperature water bath, slowly add solution A dropwise to solution B and stir for 1.5 hours to obtain titanium dioxide sol. Immerse 10 g of pretreated basalt fiber in 65 g of titanium dioxide sol. After soaking for 10 minutes, pull at a speed of 2 cm / min and dry at 80°C for 30 minutes to obtain functionalized basalt fiber. S3. Disperse 10 g of functionalized basalt fiber in 100 ml of ethanol-water solution (volume ratio of ethanol to water is 3:1), ultrasonically disperse for 15 min, add 2 g of γ-aminopropyltriethoxysilane, stir and react at 65°C for 4 h. After the reaction is complete, filter, wash and dry to obtain the organic basalt fiber. S4. Disperse 10 g of the organic basalt fiber in 100 ml of DMF, ultrasonically disperse for 10 min, add 1.5 g of azadirachtin, stir evenly, dropwise add 0.8 g of glutaraldehyde, heat to 50°C and react for 5 h. After the reaction is completed, filter, wash and dry to obtain modified basalt fiber.

[0032] Comparative Example 4 This comparative example provides an environmentally friendly composite cable insulation protective sheath raw material and a preparation method thereof, which is the same as Example 1, except that the preparation method of the modified basalt fiber is different. The preparation method of the modified basalt fiber is as follows: S1. Mix 10 g of basalt fiber and 35 g of hydrogen peroxide (concentration: 30%), heat to 105° C. for 4 h, and after the reaction is complete, cool to room temperature, filter, and dry to obtain pretreated basalt fiber. S2. Mix 10 ml of tetrabutyl titanate and 33 ml of anhydrous ethanol and stir for 9 min to obtain solution A. Add 4 ml of glacial acetic acid and 9 ml of deionized water to 33 ml of anhydrous ethanol and stir vigorously to obtain solution B. Add hydrochloric acid dropwise to adjust the pH to ≤ 3. In a room temperature water bath, solution A was slowly added dropwise to solution B and stirred for 1.5 hours to obtain titanium dioxide sol. 10 g of pretreated basalt fiber was immersed in 65 g of titanium dioxide sol, soaked for 10 minutes, pulled at a speed of 2 cm / min, dried at 80°C for 30 minutes, and then subjected to high-temperature calcination treatment. First, the temperature was raised to 330°C at 2.5°C / min under a nitrogen atmosphere, kept warm for 1.1 hours, and then raised to 480°C and kept warm for 35 minutes; then ammonia was introduced at an ammonia flow rate of 150 ml / min, and the temperature was raised to 900°C at 5°C / min, kept warm for 2 hours, the ammonia was cut off, nitrogen was introduced, and the temperature was reduced to 500°C at a rate of 5°C / min, and then naturally cooled to room temperature to obtain functionalized basalt fiber; S3. Disperse 10 g of functionalized basalt fiber in 100 ml of ethanol-water solution (volume ratio of ethanol to water is 3:1), ultrasonically disperse for 15 min, add 2 g of γ-aminopropyltriethoxysilane, stir and react at 65 °C for 4 h. After the reaction is completed, filter, wash and dry to obtain organic basalt fiber, which is modified basalt fiber.

[0033] Comparative Example 5 This comparative example provides an environmentally friendly composite cable insulation protective sheath raw material and a preparation method thereof, which is the same as Example 1, except that the preparation method of the modified basalt fiber is different. The preparation method of the modified basalt fiber is as follows: The preparation method of modified basalt fiber is as follows: S1. Mix 10 g of basalt fiber and 35 g of hydrogen peroxide (concentration: 30%), heat to 105° C. for 4 h, and after the reaction is complete, cool to room temperature, filter, and dry to obtain pretreated basalt fiber. S2, 10 ml of tetrabutyl titanate and 33 ml of anhydrous ethanol were mixed, stirred for 9 min to obtain solution A; 4 ml of glacial acetic acid and 9 ml of deionized water were added to 33 ml of anhydrous ethanol, and stirred to obtain solution B, and hydrochloric acid was added dropwise to adjust pH≤3. Solution A was slowly added to solution B under room temperature water bath, stirred for 1.5 h to obtain titanium dioxide sol, 10 g of pretreated basalt fiber was immersed in 65 g of titanium dioxide sol, soaked for 10 min, then pulled up at a speed of 2 cm / min, dried at 80℃ for 30 min, then high temperature calcination treatment was carried out, first heated to 330℃ at a rate of 2.5℃ / min under nitrogen atmosphere, kept for 1.1 h, then heated to 480℃, kept for 35 min; then ammonia gas was introduced, the ammonia gas flow was 150 ml / min, heated to 900℃ at a rate of 5℃ / min, kept for 2 h, the ammonia gas was cut off, nitrogen was introduced, and the temperature was reduced to 500℃ at a rate of 5℃ / min, then naturally cooled to room temperature to obtain functionalized basalt fiber; S4, 10 g of functionalized basalt fiber was dispersed in 100 ml of DMF, ultrasonic dispersion for 10 min, 1.5 g of azadirachtin was added, stirred uniformly, then 0.8 g of glutaraldehyde was added dropwise, and the reaction was carried out at 50℃ for 5 h. After the reaction was completed, the modified basalt fiber was obtained by filtration, washing and drying.

[0034] Performance test The raw materials of the environmentally friendly composite cable insulation protective sleeve prepared by the examples and comparative examples were tested for performance. The performance was tested: the flame retardant performance was tested by LOI using an oxygen index tester with GB / T 2406.2 as the reference standard. The mechanical properties were tested by tensile properties of the sample with GB / T 1040 as the reference standard, the tensile rate was 200 mm / min, the tension was 500 N, and the tensile strength and elongation at break were detected. The wear resistance was tested according to GB / T 1689-2014 using an Akron abrasion tester. The rat and ant proof performance was tested as follows: the rats (250-300 g each) used for the test were randomly divided into groups of 5 per cage. During the test, the rats were allowed to drink water freely and were restricted to food. Two pieces of the same sample were placed in each cage and fixed at different positions in the cage. The positions in each cage were the same, and the weight of the sample was measured every 24 h, and the area of the sample bitten was recorded. The ant proof performance was tested according to GBT 2951.38-1986 "Termite Test Method for Wire and Cable", and the half knockdown time (Kt50) was used as the knockdown method.

[0035] The test results are shown in Tables 1 and 2.

[0036] Table 1 Flame retardant performance and mechanical properties Table 2 Wear resistance and rat and ant proof performance As can be seen from Tables 1 and 2, the environmentally friendly composite cable insulation sheath raw material prepared by the technical solution of the present invention achieves a comprehensive improvement in the flame retardancy, wear resistance and rat and ant resistance of the cable insulation sheath through the coordinated optimization of the multi-component synergistic effect of the flame retardant and the functional modification of the basalt fiber.

[0037] The above description is only a preferred embodiment of the present invention and is 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 scope of protection of the present invention.

Claims

1. An environmentally friendly composite cable insulation protective sheath raw material, characterized by: Calculated by weight, the composition includes 100 parts of PVC resin, 5-10 parts of flame retardant, 20-25 parts of plasticizer, 10-15 parts of modified basalt fiber, 2-4 parts of lubricant, 4-6 parts of calcium zinc stabilizer and 5-8 parts of anti-aging agent; the flame retardant includes boron nitride, ammonium phosphomolybdate and magnesium hydroxide.

2. The environmentally friendly composite cable insulation sheath material according to claim 1, characterized in that: The mass ratio of boron nitride, ammonium phosphomolybdate and magnesium hydroxide is 1:1:2.5-3.

3. The environmentally friendly composite cable insulation sheath material according to claim 1, characterized in that: The preparation method of the modified basalt fiber comprises: S1. Mixing basalt fiber and hydrogen peroxide, heating to 100-110° C. for 3-5 hours, filtering, and drying to obtain pretreated basalt fiber; S2. Prepare titanium dioxide sol, immerse the pretreated basalt fiber in the titanium dioxide sol, pull it at a speed of 2 cm / min, dry it, and then calcine it at high temperature to obtain functionalized basalt fiber; S3, dispersing the functionalized basalt fiber in an ethanol aqueous solution, adding an aminosilane coupling agent, and stirring to react to obtain an organized basalt fiber; S4. Dispersing the organized basalt fiber in DMF, adding azadirachtin and glutaraldehyde, and reacting at 40-60° C. for 4-6 hours to obtain modified basalt fiber.

4. The environmentally friendly composite cable insulation sheath material according to claim 1, characterized in that: In step S1, the mass ratio of basalt fiber to hydrogen peroxide is 1:3-4.

5. The environmentally friendly composite cable insulation sheath material according to claim 1, characterized in that: In step S2, the preparation of titanium dioxide sol includes: mixing tetrabutyl titanate and anhydrous ethanol to obtain solution A; mixing glacial acetic acid, deionized water and anhydrous ethanol to obtain solution B, adding solution A dropwise to solution B, and stirring for 1-2 hours to obtain titanium dioxide sol.

6. The environmentally friendly composite cable insulation sheath material according to claim 1, characterized in that: In step S2, the high-temperature calcination treatment includes: first heating to 300-350°C at 2-3°C / min under a nitrogen atmosphere, keeping warm for 1-1.2 hours, then heating to 450-500°C, keeping warm for 30-40 minutes; then introducing ammonia, heating to 800-1000°C at 4-6°C / min, and keeping warm for 1.5-2.5 hours.

7. The environmentally friendly composite cable insulation sheath material according to claim 1, characterized in that: In step S3, the mass ratio of the functionalized basalt fiber to the aminosilane coupling agent is 1:0.1-0.3, the stirring reaction temperature is 50-80° C., and the reaction time is 3-5 hours; the aminosilane coupling agent is γ-aminopropyltrimethoxysilane or γ-aminopropyltriethoxysilane.

8. The environmentally friendly composite cable insulation sheath material according to claim 1, characterized in that: In step S4, the mass ratio of the organized basalt fiber, azadirachtin and glutaraldehyde is 10:1.3-1.7:0.

8.

9. The environmentally friendly composite cable insulation sheath material according to claim 1, characterized in that: The lubricant is one or more of stearic acid, butyl stearate, and oleamide; the anti-aging agent is one or more of antioxidant 1076, antioxidant 1010, and antioxidant 264; and the plasticizer is epoxidized soybean oil or dioctyl phthalate.

10. A method for preparing an environmentally friendly composite cable insulation sheath raw material, characterized by: The preparation method is used to prepare the environmentally friendly composite cable insulation protective cover raw material according to any one of claims 1 to 9, and the preparation method comprises: weighing PVC resin, flame retardant, plasticizer, modified basalt fiber, lubricant, calcium zinc stabilizer and anti-aging agent in proportion, mixing at 100-110° C., transferring to a twin-screw extruder after stirring, and extruding and granulating at 170-190° C. to obtain the environmentally friendly composite cable insulation protective cover raw material.

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