A polyvinyl chloride insulation material for ultra-scratch-resistant cables and its preparation process

Abstract

This invention relates to the field of polyvinyl chloride (PVC) insulation material preparation technology, specifically to a PVC insulation material for ultra-scratch-resistant cables and its preparation process. By weight, it comprises 100 parts PVC resin, 10-15 parts chlorinated polyethylene, 5-7 parts calcium-zinc composite stabilizer, 30-45 parts plasticizer, 0.5-1.5 parts lubricant, 0.5-0.7 parts antioxidant, 10-15 parts flame retardant, 0.5-0.8 parts colorant, 3-8 parts wear-resistant fiber, and 5-15 parts composite repair filler. The composite repair filler is a composite structure obtained by coating a repair agent onto a nano-container. The wear-resistant fiber added to the PVC matrix forms a skeleton structure. During friction, the fiber skeleton initially bears wear, and the nano-container releases the repair agent when needed, filling and repairing micro-cracks, achieving high initial wear resistance and subsequent repairability, thus extending the service life of the cable under high-frequency, high-intensity scratching conditions.

Description

Technical Field

[0001] This invention relates to the field of polyvinyl chloride insulation material preparation technology, specifically to a polyvinyl chloride insulation material for ultra-scratch-resistant cables and its preparation process. Background Technology

[0002] Polyvinyl chloride, or PVC for short, can be processed into pipes, fittings, rods, profiles, films, sheets, wire and cable insulation materials, artificial leather, floor tiles, toys, shoes, bottles, records, foam materials, sealing materials, fibers and other products by extrusion, injection molding, calendering and blow molding. It is widely used in light industry, construction, agriculture, power and daily life.

[0003] In the preparation of wire and cable insulation materials, PVC is mainly used to prepare the insulation layer and sheath of cables. However, mining cables, drag chain cables, and elevator cables are subjected to repeated scraping and friction during actual use, leading to sheath wear, decreased insulation performance, and in severe cases, short circuits, leakage, and other safety accidents, affecting the cable's service life. To improve the wear resistance of PVC materials, existing technologies mainly reduce the coefficient of friction by adding inorganic fillers (such as calcium carbonate and talc), wear-resistant fibers (such as glass fiber and carbon fiber), or lubricants. These methods can indeed delay wear to a certain extent, but they are passive protection. Once wear accumulates to the point of micro-cracks, the material performance will gradually decline, and they cannot solve the irreversible degradation of sheath performance after wear accumulation.

[0004] Therefore, in addition to ensuring sufficient scratch and abrasion resistance in the initial stage to delay the occurrence of damage as much as possible, it is also necessary to actively repair cracks when micro-damage occurs in the sheath to prevent further expansion of defects and extend the maintenance time of high abrasion resistance throughout the entire life cycle of the cable sheath. Therefore, this invention provides a polyvinyl chloride insulation material for ultra-scratch and abrasion resistant cables and its preparation process. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a polyvinyl chloride insulation material for ultra-scratch-resistant cables, comprising the following components by weight: 100 parts PVC resin, 10-15 parts chlorinated polyethylene, 5-7 parts calcium-zinc composite stabilizer, 30-45 parts plasticizer, 0.5-1.5 parts lubricant, 0.5-0.7 parts antioxidant, 10-15 parts flame retardant, 0.5-0.8 parts colorant, 3-8 parts wear-resistant fiber, and 5-15 parts composite repair filler.

[0006] The composite repair filler is a composite structure obtained by coating a nanocontainer loaded with a repair agent. The nanocontainer is halloysite nanotube or mesoporous silica, and the repair agent is polyisobutylene or modified silicone oil. The modified silicone oil is one of methyl silicone oil or phenyl silicone oil.

[0007] Halloysite nanotubes, with their unique hollow tubular structure, effectively hinder the propagation of microcracks during friction by pinning and deflecting cracks through the tube walls.

[0008] Preferably, the plasticizer includes a primary plasticizer and a secondary plasticizer. The primary plasticizer is one of dioctyl terephthalate and trioctyl trimellitate, and the secondary plasticizer is one of epoxidized soybean oil, chlorinated paraffin, and dioctyl adipate. The secondary plasticizer accounts for 10%-30% of the total mass of the plasticizer, and the primary plasticizer accounts for 70%-90%. The lubricant is selected from 0.3-0.9 parts of polyethylene wax compounded with 0.2-0.6 parts of stearic acid. The flame retardant is selected from antimony trioxide and zinc borate.

[0009] Preferably, the viscosity of the liquid polyisobutylene at 25°C is 1000–2000 mPa·s, the viscosity of the methyl silicone oil is 350–500 mPa·s, and the viscosity of the phenyl silicone oil is 350–500 mPa·s.

[0010] Preferably, the wear-resistant fiber is one of silicon carbide whiskers, calcium carbonate whiskers, calcium titanate whiskers, carbon fiber, glass fiber, aramid fiber, and polyester fiber.

[0011] Preferably, the whiskers have an average diameter of 1-5 μm and a length of 10-100 μm; the chopped fibers have an average length of 1-5 mm; and the composite repair filler has a particle size of 50-200 nm.

[0012] Wear-resistant fibers form a micron-level skeleton network that preferentially withstands external scratching forces, reducing matrix wear. The nanoparticles of the composite repair filler fill the gaps in the skeleton, reducing matrix defects and increasing density, forming a micron-nano multi-level wear-resistant structure that synergistically enhances scratch resistance.

[0013] The present invention also provides a preparation process for polyvinyl chloride insulation material for ultra-scratch-resistant cables, including the following steps: S1, preparation of composite repair filler.

[0014] S11. Nanocontainer activation treatment: Depending on the type of nanocontainer, acid washing activation or high-temperature activation treatment is performed.

[0015] S12. Repair agent loading: The nanocontainer is stirred and dispersed in the repair agent solution. It is ultrasonically dispersed for 30 minutes at an ultrasonic power of 100-200W and a frequency of 40kHz to obtain a mixture. The mixture is then subjected to vacuum-assisted impregnation at a vacuum degree of 0.08-0.1MPa and repeated negative pressure-normal pressure cycles 2-3 times. After filtration, washing, and drying, the nanocontainer loaded with the repair agent is obtained.

[0016] S13. Coating treatment: Add the nano-container loaded with the repair agent to a chitosan solution with a concentration of 1%-2% and stir for 30 min. Then slowly add the crosslinking agent and continue stirring for 1-3 h to coat the surface of the nano-container with a chitosan membrane. Centrifuge at 8000-10000 r / min for 5-15 min, wash and dry to obtain the coated composite repair filler.

[0017] S14. Surface modification treatment: Add the coated composite repair filler to the coupling agent hydrolysate, ultrasonically disperse for 20 min, then stir at 60-80℃ for 1-2 h, filter, wash, and vacuum dry at 80-100℃.

[0018] S2. Preparation of Insulation Material: Add 100 parts of PVC resin, 10-15 parts of chlorinated polyethylene, and 5-7 parts of calcium-zinc composite stabilizer to a high-speed mixer for mixing; heat to 80-90℃ and add 30-45 parts of plasticizer and 0.5-1.5 parts of lubricant and continue mixing; then heat to 100-120℃ and add 10-15 parts of flame retardant, 0.5-0.7 parts of antioxidant, 0.5-0.8 parts of colorant, 3-8 parts of wear-resistant fiber, and 5-15 parts of composite repair filler. After stirring, put the mixture into a BUSS mixer for mixing, and then pressurize, extrude, and granulate it through a single-screw extruder to obtain PVC insulation material granules.

[0019] Preferably, when the nanocontainer is halloysite nanotubes, the activation treatment is acid washing activation, in which HNTs powder is dispersed in a 1 mol / L dilute hydrochloric acid solution, stirred at 60°C for 2 h, centrifuged, washed until neutral, and vacuum dried for later use; the solid-liquid mass ratio of the HNTs powder to the dilute hydrochloric acid is 1:(15-25).

[0020] Preferably, when the nanocontainer is mesoporous silica, the activation treatment is high-temperature activation, in which the mesoporous silica is placed in a muffle furnace and calcined at 300°C for 2 hours to obtain activated mesoporous silica.

[0021] Preferably, the repair agent solution is a polyisobutylene solution with a concentration of 20-30%. The polyisobutylene solution is prepared by completely dissolving liquid polyisobutylene in a low-boiling-point organic solvent, such as n-hexane or cyclohexane. The mass ratio of the nanocontainer to the liquid polyisobutylene is 1:(2-3).

[0022] Preferably, the repair agent solution is modified silicone oil, and the mass ratio of the nanocontainer to the modified silicone oil is 1:(3-5).

[0023] Preferably, the chitosan solution is prepared by dissolving chitosan in a 1% acetic acid solution, and the mass ratio of the nanocontainer to chitosan is 1:0.2; the crosslinking agent is a 0.5%-1% glutaraldehyde solution, and the glutaraldehyde is 2%-4% of the mass of chitosan.

[0024] Chitosan is used to coat the surface of nano-containers loaded with repair agents. The chitosan film effectively seals the ends of halloysite nanotubes or the pores of mesoporous silica within the coating, preventing premature leakage of the adsorbent during storage and processing. The chitosan film is reinforced by glutaraldehyde crosslinking, giving the chitosan coating a certain mechanical strength threshold. It does not crack under normal use or extrusion processing conditions. Only when microcracks appear on the surface of the cable sheath, stress concentration at the crack tip causes mechanical stress rupture of the chitosan coating. The ends of the halloysite nanotubes or the pores of the mesoporous silica open, and the repair agent automatically seeps out under capillary action and pressure, forming a lubricating and physical filling layer at the crack interface, bridging the microcracks and preventing crack propagation. At the same time, the repair agent reduces the interfacial friction coefficient, reducing further wear, and achieving stress-triggered, controllable release, and in-situ filling self-repair.

[0025] It should be noted that during the melt extrusion of the sheath, the temperature reaches 150-180℃, while the decomposition temperature of chitosan is above 250℃. Therefore, the temperature during the extrusion process is insufficient to cause the chitosan to crack. The melt shear stress at 150-180℃ is 0.3-0.6MPa, and the peak value of local stress concentration is close to 5MPa. The critical stress for the initiation of microcracks in the PVC sheath of the cable is 8-12MPa. Considering the stress concentration factor at the tip, the peak stress at the microcrack tip is 20-45MPa. The mechanical strength threshold of the chitosan coating is between the peak melt shear stress and the peak stress at the microcrack tip, which satisfies the requirement that the chitosan coating can withstand processing and crack at the microcrack tip. The technical solution controls the concentration, amount, and crosslinking time of the crosslinking agent to ensure that the mechanical strength of the chitosan film falls within this range.

[0026] Preferably, the pH of the ethanol-water mixed solution is adjusted to 4-5 with acetic acid, and after adding the silane coupling agent, the mixture is stirred and hydrolyzed for 30 minutes to obtain the coupling agent hydrolysate. The mass of the silane coupling agent is 2%-4% of the mass of the coated composite repair filler. The ethanol-water mixed solution is prepared by mixing ethanol and water in a 9:1 ratio. The concentration of the coupling agent hydrolysate is 0.4%-0.8%. The silane coupling agent can be KH-550 or KH-570, both of which can modify the surface of inorganic nanocontainers to improve the compatibility and dispersibility of the composite repair filler with the PVC matrix.

[0027] The present invention has at least one of the following technical effects: 1. By adding wear-resistant fibers to the PVC matrix to form a skeleton structure, and introducing nano-containers (halostone nanotubes or mesoporous silica) loaded with repair agents, and after coating treatment, during the friction process, the fiber skeleton bears the wear first, while the nano-containers release repair agents (polyisobutylene or modified silicone oil) when needed to fill and repair micro-cracks, achieving the effect of high wear resistance in the early stage and repairability in the later stage, thus extending the service life of the cable under high frequency and high intensity scraping conditions.

[0028] 2. The cable sheath made from the insulating material of the present invention not only does not affect the basic mechanical properties, insulation properties and aging resistance, but also improves the initial wear resistance and long-term wear resistance, and extends the service life of the sheath under high temperature conditions. Detailed Implementation

[0029] The present invention will now be described in detail through specific embodiments. However, these illustrative embodiments are for purposes and uses only to illustrate the invention and do not constitute any limitation on the actual scope of protection of the invention, nor are they intended to limit the scope of protection of the invention to these embodiments. All equivalent transformations or simple substitutions made based on the substantive content of this application should fall within the scope of protection of this application. For parameter ranges not mentioned, intermediate values ​​are selected. Furthermore, for mass percentages or weight percentages not explicitly stated or mentioned, they generally refer to the final concentration after addition.

[0030] The singular forms “for,” “or,” “a,” “any,” and “the” used in this application are intended to include the plural forms unless the context clearly indicates otherwise.

[0031] Example 1.

[0032] A process for preparing a polyvinyl chloride insulation material for ultra-scratch-resistant cables includes the following steps: S1, preparation of composite repair filler.

[0033] S11, Nanocontainer activation treatment.

[0034] Disperse 10g of HNTs powder in 200g of 1mol / L dilute hydrochloric acid solution, stir at 60℃ for 2h, centrifuge at 9000r / min for 10min, wash with deionized water until neutral, and vacuum dry for later use.

[0035] S12, Repair Agent Loading: 25g of liquid polyisobutylene was dissolved in n-hexane to prepare a 25% polyisobutylene solution; the activated HNTs powder from step S11 was stirred and dispersed in the 25% polyisobutylene solution, and ultrasonically dispersed for 30min at an ultrasonic power of 150W and a frequency of 40kHz to obtain a mixture. The mixture was then subjected to vacuum-assisted impregnation at a vacuum degree of 0.08-0.1MPa, with negative pressure maintained for 15min / cycle, and the negative pressure-normal pressure cycle was repeated 3 times. The mixture was then filtered, washed, and vacuum dried at 45℃ for 12h to obtain a nanocontainer loaded with the repair agent.

[0036] S13. Coating treatment: Add all the nano-containers loaded with the repair agent to 200g of a 1% chitosan solution and stir for 30min; dissolve 0.06g of glutaraldehyde in deionized water to prepare a 1% glutaraldehyde solution, then slowly add the 1% glutaraldehyde solution dropwise and continue stirring for 2h to coat the surface of the nano-containers with a chitosan membrane. Centrifuge at 9000r / min for 10min, wash, and vacuum dry at 50℃ to obtain the coated composite repair filler with a vacuum degree of 0.08-0.1MPa.

[0037] S14. Surface modification treatment: Prepare an ethanol-water mixed solution by mixing 45 mL of ethanol and 5 mL of deionized water. Adjust the pH of the system to 4-5 with acetic acid. Slowly add 0.2 g of KH-550 and stir at room temperature for 30 min until the coupling agent hydrolysate is transparent and does not separate into layers. Add 10 g of the coated composite repair filler to the above coupling agent hydrolysate, sonicate for 20 min, then stir at 70 °C for 1.5 h, filter, wash, and vacuum dry at 90 °C with a vacuum degree of 0.08-0.1 MPa.

[0038] S2. Preparation of Insulation Material: Add 100g of PVC resin, 13g of chlorinated polyethylene, and 6g of calcium-zinc composite stabilizer to a high-speed mixer for mixing; heat to 80-90℃ and add 32g of dioctyl terephthalate, 8g of epoxidized soybean oil, 0.6g of polyethylene wax, and 0.4g of stearic acid, and continue mixing for 10min; then heat to 100-120℃ and add 12g of antimony trioxide, 0.6g of antioxidant 1010, 0.7g of colorant, 5g of silicon carbide whiskers, and 10g of composite repair filler, and stir for 5min. Then, put the mixture into a BUSS mixer for mixing, and then pressurize, extrude, and granulate it through a single-screw extruder to obtain PVC insulation material granules.

[0039] The mixing temperature of the BUSS mixer is 150-180℃, and the temperatures of each section are as follows: feeding section 140-160℃, mixing section 160-175℃, and discharging section 170-180℃; the screw temperature of the single screw extruder is 150-175℃, and the die head temperature is 165-175℃.

[0040] Example 2.

[0041] The difference from Example 1 is that: 10g of mesoporous silica was used as the nanocontainer. 10g of mesoporous silica was placed in a muffle furnace and calcined at 300°C for 2 hours to remove the organic impurities and moisture adsorbed in the pores. It was then set aside for use. The remaining steps were the same as in Example 1.

[0042] Example 3.

[0043] The difference from Example 1 is that the repair agent solution in S12 is methyl silicone oil, and the amount of methyl silicone oil used is 30g. The remaining steps are the same as in Example 1.

[0044] Example 4.

[0045] The difference from Example 1 is that the repair agent solution in S12 is phenyl silicone oil, and the amount of phenyl silicone oil used is 50g. The remaining steps are the same as in Example 1.

[0046] Example 5.

[0047] The difference from Example 2 is that the repair agent solution in S12 is methyl silicone oil, and the amount of methyl silicone oil used is 40g.

[0048] Example 6.

[0049] The difference from Example 1 is that the amount of composite repair filler added is 5g.

[0050] Example 7.

[0051] The difference from Example 1 is that the amount of composite repair filler added is 15g.

[0052] Example 8.

[0053] The difference from Example 1 is that the wear-resistant fiber is 3g glass fiber.

[0054] Example 9.

[0055] The difference from Example 1 is that the wear-resistant fiber used is 8g of carbon fiber.

[0056] Comparative example.

[0057] Comparative Example 1.

[0058] The difference from Example 1 is that the HNTs powder is not activated, while the rest of the steps are the same as in Example 1.

[0059] Comparative Example 2.

[0060] The difference from Example 1 is that the HNTs powder does not carry a repair agent, while the rest of the steps are the same as in Example 1.

[0061] Comparative Example 3.

[0062] The difference from Example 1 is that the nanocontainer loaded with the repair agent is not coated, while the rest of the steps are the same as in Example 1.

[0063] Comparative Example 4.

[0064] The difference from Comparative Example 3 is that the composite repair filler does not undergo surface modification treatment, while the remaining steps are the same as those in Comparative Example 3.

[0065] Comparative Example 5.

[0066] The difference from Example 1 is that no wear-resistant fibers are added during the preparation of the insulating material.

[0067] Comparative Example 6.

[0068] The difference from Example 1 is that no composite repair filler is added during the preparation of the insulating material.

[0069] Comparative Example 7.

[0070] The difference from Example 1 is that the composite repair filler is replaced with an equal mass of calcium carbonate during the preparation of the insulating material.

[0071] Comparative Example 8.

[0072] The difference from Example 1 is that no wear-resistant fibers and composite repair fillers are added during the preparation of the insulating material.

[0073] The PVC insulation granules obtained in Examples 1-9 and Comparative Examples 1-8 were dried at 80°C for 3 hours to remove adsorbed moisture from the granule surface. The dried granules were then added to the hopper of a single-screw extruder. The preheating temperatures of the extruder sections were as follows: feeding section 130-145°C, melting section 145-165°C, metering section 160-175°C, die head 165-175°C, and die opening 165-175°C. A tube-type or semi-tube-type die was used, with the draw ratio (DDR) controlled at 1.2-1.8, the screw speed controlled at 20 r / min, and the traction speed and extrusion speed synchronized. After extrusion and coating the cable core surface, the granules were slowly cooled and shaped in a first-stage warm water bath (50°C), and then fully cooled and solidified in a second and subsequent room-temperature water bath (20°C). After traction and winding, the granules were formed into a cable sheath.

[0074] Cable sheath abrasion resistance test.

[0075] Abrasion test: An abrasion test was conducted according to Clause 11.5.7.6 of GB / T 33594-2017 "Cables for Electric Vehicle Charging". An 80cm long cable sample was taken, fixed, and scraped with an angle iron scraper at a speed of 200mm / s. The cumulative number of scraping cycles reached 2000. Observations were made every 100 cycles, and the results were recorded to determine whether the sheath surface was worn through and whether the internal insulation core or shielding layer was exposed. For sheaths that were not worn through after 2000 cycles, the abrasion test continued until the sheath was worn through, and the final number of cycles was recorded.

[0076] Friction coefficient: The friction coefficient was determined according to GB / T 3960-2016 "Test Method for Sliding Friction and Wear of Plastics". A pin-disc friction and wear tester was used. The wear material was 45# steel (surface roughness Ra 0.8μm), the load was 200N, the sliding speed was 0.5m / s, the sliding distance was 1000m, and the friction coefficient in the steady stage was recorded.

[0077] Taber wear: Refer to Method A (Taber method) of GB / T 5478-2008 "Test Method for Rolling Wear of Plastics", use CS-10 grinding wheel, apply an additional load of 500g, rotate at 60r / min, and weigh after running for 1000 revolutions to calculate the wear.

[0078] Friction coefficient after aging: The friction coefficient after aging was measured after aging in hot air at 100℃ for 168 hours.

[0079] Table 1. Test results of wear resistance of Examples 1-9 and Comparative Examples 1-8

[0080]

[0081] As shown in Table 1, all embodiments of the present invention did not wear through after 2000 scraping cycles, only showing slight to very light scratches. In contrast, most of the comparative examples 1-8 wore through within 2000 cycles, with only comparative example 3 showing localized thinning. This indicates that the present invention significantly improves the initial scratch resistance of the sheath through the synergistic effect of wear-resistant fibers and composite repair fillers. Furthermore, the number of repeated wear cycles in the embodiments was much higher than in comparative examples 2 and 6, indicating that the repair agent in the composite repair filler achieved in-situ self-repair during the scraping process, preventing the propagation of microcracks and extending the service life of the sheath.

[0082] The friction cycles of the embodiments were all below 0.5, while those of the comparative examples all exceeded 0.5. The friction coefficient of the embodiments after aging reached a maximum of 0.52, while that of the comparative examples was the lowest at 0.62. The lower friction coefficient reduces the scraping resistance when the sheath moves back and forth. In addition, compared with comparative example 8, the friction coefficient of embodiment 1 of this invention was reduced by 44%, and the Taber wear was reduced by 65%. Compared with comparative example 7, the friction coefficient was reduced by 40%, and the Taber wear was reduced by 62%. The number of wear-through cycles can indirectly evaluate the self-healing effect: under the same scraping conditions, the self-healing material can seal microcracks in time and delay the wear-through of the sheath. The number of wear-through cycles of embodiment 1 (9200 times) was much higher than that of comparative example 6 without repair filler (1600 times) and comparative example 2 without repair agent (2200 times), proving that the repair agent in the composite repair filler is released from the nano-container and does indeed achieve in-situ self-healing during the scraping process.

[0083] Comparative Example 1 (unactivated container) had 2600 wear cycles, Comparative Example 2 (no repair agent) had 2200 wear cycles, Comparative Example 3 (no coating) had 3200 wear cycles, and Comparative Example 4 (no surface modification) had 2900 wear cycles, all significantly lower than the examples. This indicates that each step of activation, loading, coating, and modification is crucial to achieving the self-healing effect.

[0084] Basic performance testing.

[0085] Tensile strength and elongation at break: Refer to GB / T 2951.21-2008, use dumbbell-shaped specimens, tensile speed of 250 mm / min, initial gauge length of 20 mm, and record the tensile strength and elongation at break of the cable.

[0086] Volume resistivity: Refer to GB / T 1410-2006 "Test methods for volume resistivity and surface resistivity of solid insulating materials", using a three-electrode system, test voltage 500V, charging time 60s, ambient temperature 23±2℃, relative humidity 50±5%.

[0087] Strength change rate after aging: Refer to GB / T 2951.12-2008 "General test methods for insulation and sheath materials of cables and optical cables - Part 12: Thermal aging test method", conduct the test in a forced ventilation aging chamber at a temperature of 100±2℃ for 168h. Measure the tensile strength after aging and calculate the strength change rate after aging based on the change in tensile strength before and after aging.

[0088] Table 2. Basic performance test results of Examples 1-9 and Comparative Examples 1-8

[0089]

[0090] As can be seen from Table 2, the tensile strength of the embodiment is between 15.9-18.3 MPa and the elongation at break is between 85%-220%, which is better than the comparative example. This indicates that the combination of wear-resistant fiber and composite repair filler plays a role in strengthening and toughening, and the mechanical properties of the sheath are not sacrificed due to changes in composition.

[0091] Secondly, the volume resistivity of the embodiments shows that the introduction of filler did not reduce the insulation performance of the sheath, and the strength retention rate of the embodiments after aging was ≥89%, which was better than that of the comparative examples. This indicates that the composite repair filler and the fiber skeleton synergistically suppressed the performance degradation caused by thermo-oxidative aging and extended the service life of the sheath under high temperature conditions.

[0092] The above results demonstrate and describe the basic principles and main features of this application, as well as its advantages.

[0093] Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this application. Various changes and modifications can be made to this application without departing from the spirit and scope thereof, and all such changes and modifications fall within the scope of this application as claimed. The scope of protection of this application is defined by the equivalents of the appended claims.

Claims

1. A polyvinyl chloride insulation material for super-scratch-resistant cables, characterized in that, By weight, it comprises the following components: 100 parts PVC resin, 10-15 parts chlorinated polyethylene, 5-7 parts calcium-zinc composite stabilizer, 30-45 parts plasticizer, 0.5-1.5 parts lubricant, 0.5-0.7 parts antioxidant, 10-15 parts flame retardant, 0.5-0.8 parts colorant, 3-8 parts wear-resistant fiber, and 5-15 parts composite repair filler; The composite repair filler is a composite structure obtained by coating a nanocontainer loaded with a repair agent. The nanocontainer is halloysite nanotube or mesoporous silica, and the repair agent is polyisobutylene or modified silicone oil. The modified silicone oil is one of methyl silicone oil or phenyl silicone oil.

2. The PVC insulation material for super scratch-resistant cable according to claim 1, characterized in that: The plasticizer includes a primary plasticizer and a secondary plasticizer. The primary plasticizer is one of dioctyl terephthalate and trioctyl trimellitate, and the secondary plasticizer is one of epoxidized soybean oil, chlorinated paraffin, and dioctyl adipate. The secondary plasticizer accounts for 10%-30% of the total mass of the plasticizer, and the primary plasticizer accounts for 70%-90%. The lubricant is selected from 0.3-0.9 parts of polyethylene wax and 0.2-0.6 parts of stearic acid; the flame retardant is selected from antimony trioxide and zinc borate.

3. The polyvinyl chloride insulation material for ultra-scratch-resistant cables according to claim 1, characterized in that: The wear-resistant fiber is one of silicon carbide whiskers, calcium carbonate whiskers, calcium titanate whiskers, carbon fiber, glass fiber, aramid fiber, and polyester fiber.

4. A preparation process for the polyvinyl chloride insulation material for ultra-scratch-resistant cables as described in claim 1, characterized in that: Includes the following steps: S1. Preparation of composite repair filler S11. Nanocontainer activation treatment: Depending on the type of nanocontainer, acid washing activation or high temperature activation treatment shall be performed. S12, Repair agent loading: The nanocontainer is stirred and dispersed in the repair agent solution. It is ultrasonically dispersed for 30 minutes at an ultrasonic power of 100-200W and a frequency of 40kHz to obtain a mixture. The mixture is then subjected to vacuum-assisted impregnation at a vacuum degree of 0.08-0.1MPa and repeated negative pressure-normal pressure cycles 2-3 times. After filtration, washing, and drying, the nanocontainer loaded with the repair agent is obtained. S13. Coating treatment: Add the nano-container loaded with the repair agent to a chitosan solution with a concentration of 1%-2%, stir for 30 min, then slowly add the cross-linking agent, continue stirring for 1-3 h, so that the surface of the nano-container is coated with a chitosan membrane, centrifuge at 8000-10000 r / min for 5-15 min, wash and dry to obtain the coated composite repair filler. S14. Surface modification treatment: Add the coated composite repair filler to the coupling agent hydrolysate, ultrasonically disperse for 20 min, then stir at 60-80℃ for 1-2 h, filter, wash, and vacuum dry at 80-100℃. S2. Preparation of Insulation Material: Add 100 parts of PVC resin, 10-15 parts of chlorinated polyethylene, and 5-7 parts of calcium-zinc composite stabilizer to a high-speed mixer for mixing; heat to 80-90℃ and add 30-45 parts of plasticizer and 0.5-1.5 parts of lubricant and continue mixing; then heat to 100-120℃ and add 10-15 parts of flame retardant, 0.5-0.7 parts of antioxidant, 0.5-0.8 parts of colorant, 3-8 parts of wear-resistant fiber, and 5-15 parts of composite repair filler. After stirring, put the mixture into a BUSS mixer for mixing, and then pressurize, extrude, and granulate it through a single-screw extruder to obtain PVC insulation material granules.

5. The preparation process of a polyvinyl chloride insulation material for ultra-scratch-resistant cables according to claim 4, characterized in that: When the nanocontainer is halloysite nanotubes, the activation treatment is acid washing activation. The HNTs powder is dispersed in a 1 mol / L dilute hydrochloric acid solution, stirred at 60°C for 2 hours, centrifuged, washed until neutral, and vacuum dried for later use. The solid-liquid mass ratio of the HNTs powder to the dilute hydrochloric acid is 1:(15-25).

6. The preparation process of a polyvinyl chloride insulation material for ultra-scratch-resistant cables according to claim 4, characterized in that: When the nanocontainer is mesoporous silica, the activation treatment is high-temperature activation. The mesoporous silica is placed in a muffle furnace and calcined at 300°C for 2 hours to obtain activated mesoporous silica.

7. The preparation process of a polyvinyl chloride insulation material for ultra-scratch-resistant cables according to any one of claims 5-6, characterized in that: The repair agent solution is a polyisobutylene solution with a concentration of 20-30%. The polyisobutylene solution is prepared by completely dissolving liquid polyisobutylene in a low-boiling-point organic solvent, such as n-hexane or cyclohexane. The mass ratio of the nanocontainer to the liquid polyisobutylene is 1:(2-3).

8. The preparation process of a polyvinyl chloride insulation material for ultra-scratch-resistant cables according to any one of claims 5-6, characterized in that: The repair agent solution is modified silicone oil, and the mass ratio of the nanocontainer to the modified silicone oil is 1:(3-5).

9. The preparation process of a polyvinyl chloride insulation material for ultra-scratch-resistant cables according to claim 4, characterized in that: The chitosan solution is prepared by dissolving chitosan in a 1% acetic acid solution, and the mass ratio of the nanocontainer to chitosan is 1:0.2; the crosslinking agent is a 0.5%-1% glutaraldehyde solution, and the glutaraldehyde is 2%-4% of the mass of chitosan.

10. The preparation process of a polyvinyl chloride insulation material for ultra-scratch-resistant cables according to claim 4, characterized in that: The mass of the silane coupling agent is 2%-4% of the coated composite repair filler, and the concentration of the coupling agent hydrolysate is 0.4%-0.8%.

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