A high wear-resistant wire harness and a preparation method thereof

Abstract

The application discloses a kind of high wear-resistant wire harness and preparation method thereof, it is related to wire harness technical field.The method is first mixed with SiC, after modification with KH-570 coupling agent, with vinyl chloride monomer etc., and is polymerized, and PTC / nano composite resin granules are prepared.Then the surface of tinned copper wire core wire is cleaned and handled, and the above composite resin is coated, and the initial forming wire harness is obtained.Again, the wire harness is activated by argon plasma, and grafted with methyl methacrylate to improve surface properties.Finally, configure wear-resistant coating slurry mainly with PTFE micro powder and epoxy resin, and the surface of wire harness is electrostatically sprayed, and high wear-resistant coating is formed after solidification.The method is combined by nano composite reinforcement, surface grafting modification and functional coating, which significantly improves the wear resistance of wire harness.

Description

Technical Field

[0001] This invention relates to the field of wire harness technology, specifically to a high wear-resistant wire harness and its preparation method. Background Technology

[0002] Signal transmission harnesses, as the core integrated connection system in electronic and electrical equipment, are crucial for the stable transmission of various signals, including audio, video, digital, and control signals. By bundling multiple signal lines together according to design requirements and supplementing them with insulation protection structures, they effectively simplify wiring layout, save installation space, and improve the system's anti-interference capability and operational reliability. They are widely used in numerous fields such as automotive electronics, industrial automation, communication equipment, medical instruments, and home appliances. For example, in new energy vehicles, wiring harnesses are responsible for transmitting high-frequency signals from in-vehicle navigation and cameras; in industrial scenarios, they connect sensors and control systems to achieve real-time signal interaction. These applications place stringent requirements on the continuity and stability of signal transmission.

[0003] As terminal devices become smaller, more integrated, and more multifunctional, the operating environment for signal transmission harnesses is becoming increasingly complex, and the mechanical wear problem they face is becoming more prominent, becoming one of the main bottlenecks affecting the reliability of signal transmission. Currently, most mainstream harnesses adopt a single PVC insulation layer or an outer mesh tube protective structure. This design has exposed obvious wear resistance defects in practical applications. The outer mesh tube can only resist light sliding friction. When subjected to external forces such as squeezing or scratching, the impact force is directly transmitted to the internal signal lines, easily causing wear, deformation, or even breakage of the wires. This type of damage is more common, especially in the exposed harness areas of exercise equipment such as treadmills. Summary of the Invention

[0004] The purpose of this invention is to provide a highly wear-resistant wire harness and its preparation method, thereby solving the technical problems mentioned in the background section. The wire harness prepared by this invention exhibits excellent wear resistance.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A method for preparing a highly wear-resistant wire harness includes the following steps:

[0007] S1. Mix nano-SiO2 and nano-SiC to obtain mixed nanoparticles. Add coupling agent KH-570 and anhydrous ethanol to the mixed nanoparticles, disperse by ultrasonic vibration, keep the reaction at a temperature, remove the ethanol by evaporation, and obtain coupling agent modified mixed nanoparticles after drying, pulverizing and sieving.

[0008] S2. The coupling agent-modified mixed nanoparticles were added to an anhydrous ethanol solution containing hydroxyethyl acrylate and azobisisobutyronitrile, and the mixture was heated and stirred to carry out the reaction. After the reaction was completed, the reaction product was separated into solid and liquid phases. The obtained solid was washed with anhydrous ethanol and dried to obtain the modified coupling agent-modified mixed nanoparticles.

[0009] Add a modified coupling agent to deionized water containing polyvinyl alcohol to modify and mix nanoparticles, vinyl chloride monomer, and azobisisobutyronitrile. After nitrogen purging and polymerization, unreacted monomers are removed to obtain PVC / nano composite latex. Spray dry the PVC / nano composite latex, and then mix it with ACR-g-VC resin, dioctyl terephthalate, calcium-zinc composite stabilizer, and compatibilizer. Extrusion granulation is then performed to obtain PVC / nano composite resin granules.

[0010] S3. Twisting tin-plated copper wires into core wires, and then subjecting them to alkali washing, acid washing, water washing and drying to obtain clean core wires; PVC / nano composite resin granules are melt-extruded and coated onto the surface of the clean core wires to obtain a preliminary wire bundle.

[0011] S4. The initial wire bundle is subjected to argon plasma treatment to obtain an activated wire bundle. The activated wire bundle is immersed in an anhydrous ethanol solution containing methyl methacrylate and benzoyl peroxide and heated under a nitrogen atmosphere. After cleaning and drying, the grafted modified wire bundle is obtained.

[0012] S5. Mix and grind PTFE micro powder, epoxy resin E-51, crosslinking agent T31 and ethyl acetate to obtain wear-resistant coating slurry. Apply the wear-resistant coating slurry to the surface of the grafted modified wire harness by electrostatic spraying and cure to obtain a high wear-resistant wire harness.

[0013] In this invention, the wear resistance of PVC wire harnesses is improved synergistically from two aspects. Firstly, after pretreatment of nano-SiO2 and SiC with KH-570, the surface double bonds can be copolymerized in situ with vinyl chloride monomer, achieving molecular-level dispersion. This avoids the weak areas of particle agglomeration in traditional additive methods, forming continuous wear-resistant support points and directly improving the substrate's scratch and cutting resistance. ACR-g-VC resin improves the toughness of PVC through internal plasticization (avoiding brittle fracture during friction) and optimizes the interfacial bonding force between nanoparticles and the matrix, preventing particle peeling after long-term friction. At the same time, calcium-zinc composite stabilizers and compatibilizers ensure that PVC does not degrade during polymerization, and dioctyl terephthalate regulates the glass transition temperature of the substrate to maintain appropriate elasticity and reduce rigid wear.

[0014] On the other hand, plasma treatment first forms a micron-level rough structure on the substrate surface (increasing the contact area) and generates active groups, providing grafting sites. After methyl methacrylate is grafted via free radical polymerization, its ester groups and residual double bonds can form chemical crosslinks with the coating epoxy resin, solving the problem of easy detachment from traditional coatings due to physical adsorption, and ensuring long-term coating adhesion. PTFE micropowder in the coating can form a lubricating film, significantly reducing frictional resistance to decrease adhesion and abrasive wear. The dense crosslinked network formed by the epoxy resin and T31 curing has high scratch resistance and can also prevent impurities from entering, thus forming a low-friction, high-hardness, and strongly adhesive wear-resistant coating on its surface. This, combined with the internal substrate reinforcement, improves the wear resistance of the wire harness from both internal wear resistance and surface protection.

[0015] Preferably, in step S1, the mass ratio of nano-SiO2 to nano-SiC is 2:0.5 to 1.5.

[0016] Preferably, in step S2, the coupling agent-modified mixed nanoparticles undergo a modification treatment, including the following steps:

[0017] The coupling agent-modified mixed nanoparticles were added to an anhydrous ethanol solution containing hydroxyethyl acrylate and azobisisobutyronitrile, and the mixture was heated and stirred to carry out the reaction. After the reaction was completed, the reaction product was separated into solid and liquid phases. The obtained solid was washed with anhydrous ethanol and dried to obtain the modified coupling agent-modified mixed nanoparticles.

[0018] In the technical solution of this invention, the invention team discovered through in-depth research that the KH-570 organic segments on the surface of nanoparticles modified by KH-570 grafting have a significantly lower response to plasma activation than the PVC substrate. This results in uneven distribution of active groups (hydroxyl and carboxyl groups) on the substrate surface after plasma activation. The active groups are dense in the PVC area, the methyl methacrylate graft layer is uniform and has a strong bond with the subsequent coating, while the active groups are sparse in the exposed area of ​​the nanoparticles, the methyl methacrylate graft layer is thin and has a weak bond with the coating. As a result, the coating is easily peeled off from the weak area during friction, which affects the wear resistance of the wire harness. To further address this technical problem, this invention further modifies the mixed nanoparticles with a bonding agent. The KH-570 grafted onto the nanoparticle surface is copolymerized with hydroxyethyl acrylate via free radical polymerization, forming a composite structure of long-chain KH-570 and short-chain hydroxyethyl acrylate on the particle surface. The strong polar hydroxyl groups of hydroxyethyl acrylate significantly enhance the particle's responsiveness to plasma activation, improving its plasma responsiveness and reducing the density difference of active groups between the particle and the PVC substrate. Simultaneously, the particles retain unsaturated double bonds from the KH-570 segments after hydroxyethyl acrylate grafting, without affecting their in-situ copolymerization with vinyl chloride monomer. This ensures molecular-level dispersion of the particles in the PVC matrix, fundamentally solving the coating adhesion and wear resistance problems caused by uneven distribution of active groups.

[0019] Preferably, the mass ratio of the coupling agent-modified mixed nanoparticles to hydroxyethyl acrylate is 100:5 to 10.

[0020] Preferably, the amount of the modified coupling agent-modified mixed nanoparticles added is 3 to 6 wt% of the vinyl chloride monomer.

[0021] Preferably, in step S4, the amount of benzoyl peroxide added is 0.2 to 0.5 wt% of methyl methacrylate.

[0022] Preferably, in step S4, the reaction temperature is 65–70°C and the reaction time is 2–3 hours.

[0023] Preferably, in step S5, the mass ratio of PTFE micro powder to epoxy resin E-51 is 10:5 to 8.

[0024] Preferably, in step S5, the wear-resistant coating slurry is electrostatically sprayed onto the surface of the grafted modified wire harness to control the wet film thickness to 10 μm.

[0025] A method for preparing a high wear-resistant wire harness, which is prepared by the method described above.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] 1. By in-situ compositing specially modified nanoparticles with PVC at the molecular level and introducing ACR-g-VC resin into the matrix, a composite resin matrix with high rigidity, high toughness and strong interfacial bonding is constructed. This structure provides stable and durable wear-resistant support from the inside of the material, effectively resisting scratches and cutting.

[0028] 2. By plasma activation and grafting with methyl methacrylate, a chemically cross-linkable active layer is formed on the substrate surface, enabling the PTFE / epoxy resin wear-resistant coating to form a strong chemical bond with the substrate. This coating combines the low coefficient of friction of PTFE with the high hardness and density of epoxy resin, fundamentally solving the problem of easy coating peeling and achieving integrated surface protection with low friction and high adhesion. Attached Figure Description

[0029] Figure 1 The cross-sectional SEM image of the high wear-resistant wire harness prepared according to the present invention. Detailed Implementation

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. 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.

[0031] Example 1

[0032] A method for preparing a highly wear-resistant wire harness includes the following steps:

[0033] Step 1: Weigh 200g of nano-SiO2 and 130g of nano-SiC into a three-necked flask, add 15g of coupling agent KH-570 and 1500mL of anhydrous ethanol, fix the flask in an ultrasonic disperser, set the power to 400W and the frequency to 28kHz, and continue ultrasonic oscillation for 30min; then connect the reflux condenser, place it in a 75℃ constant temperature water bath, turn on the stirrer at 300rpm, and keep the reaction at this temperature for 2h; after the reaction is complete, transfer the material to a rotary evaporator (temperature 60℃, vacuum degree -0.085MPa) to remove the anhydrous ethanol, place the obtained solid in a vacuum drying oven (temperature 85℃, vacuum degree -0.095MPa) to dry for 5h, pulverize it with a high-speed pulverizer and pass it through a 200-mesh sieve to obtain coupling agent modified mixed nanoparticles.

[0034] Step 2: Take 300g of coupling agent-modified mixed nanoparticles and add them to 1800mL of anhydrous ethanol solution containing 25g of hydroxyethyl acrylate and 0.105g of AIBN. Place the solution in a 65℃ constant temperature water bath, turn on the stirring at 300rpm, and keep the temperature for 2.5h. After the reaction is completed, transfer the mixture to a high-speed centrifuge (8000rpm) and centrifuge for 15min. Collect the bottom solid, wash it repeatedly with anhydrous ethanol 3 times, and then place it in an 80℃ vacuum drying oven to dry for 4h to obtain modified coupling agent-modified mixed nanoparticles.

[0035] Add 30L of deionized water and 100g of polyvinyl alcohol to the polymerization reactor, start stirring at 250rpm, heat to 50℃ and keep at that temperature for 30min until the polyvinyl alcohol is completely dissolved; add 50g of modified coupling agent to modify the mixed nanoparticles and 1000g of vinyl chloride monomer, and continue stirring for 35min until the system is homogeneous; add 10g of AIBN, close the feed port of the polymerization reactor, and purge with high-purity nitrogen three times; then heat to 70℃, maintain the pressure inside the reactor at 0.7MPa, and keep the reaction at that temperature for 4h; when the pressure inside the reactor drops to 0.35MPa, stop heating and cool to 42℃, and purge with steam to remove unreacted vinyl chloride monomer for 2h to obtain PVC / nano composite latex;

[0036] The latex was fed into a spray dryer (inlet air temperature 160℃, outlet air temperature 80℃, atomization pressure 0.3MPa) and dried into powder. 180g of ACR-g-VC resin, 250g of DOTP, 20g of calcium-zinc composite stabilizer, and 30g of ethylene-octene copolymer grafted maleic anhydride compatibilizer were added to the powder and then transferred to a high-speed mixer (temperature 95℃, speed 1300rpm) and mixed for 5min. Finally, the mixture was fed into a twin-screw extruder (feed section temperature 135℃, compression section temperature 155℃, homogenization section temperature 165℃, screw speed 180rpm) for extrusion granulation to obtain PVC / nano composite resin granules.

[0037] Step 3: Take a tin-plated copper wire with a single wire diameter of 0.15 mm, twist it into 7 core wires (twisting pitch 10 mm) using a stranding machine, and cut it into 10 m lengths; immerse the core wires in a 5% sodium hydroxide solution (500 mL, temperature 55℃), and place them in an ultrasonic cleaner (power 250 W) for ultrasonic treatment for 15 min; after removal, rinse 3 times with 30℃ deionized water, then immerse in a 12% hydrochloric acid solution (500 mL, temperature 28℃), and stir at 150 rpm for 10 min; finally, rinse with 30℃ deionized water until pH=7, and transfer to a 75℃ hot air drying oven to dry for 1.5 h to obtain clean core wires.

[0038] PVC / nano composite resin granules are added to the hopper of a twin-screw extruder. Clean core wires are introduced into the die head of the extruder through the wire feeding frame (matching a coating layer thickness of 0.8mm). The extruder parameters are set as follows: feeding section 145℃, compression section 165℃, homogenization section 170℃, die head temperature 172℃, screw speed 40rpm, and traction speed 5m / min. The extruder is then started. After the resin melts, it is extruded through the die and coated onto the surface of the core wire to form a preliminary wire bundle.

[0039] Step 4: Wrap the initial shaped wire bundle around the porous frame, fix it to the sample holder of the plasma processor, close the chamber door and evacuate to 0.2 Pa, introduce high-purity argon gas (flow rate 12 sccm) to stabilize the pressure inside the chamber at 0.8 Pa, turn on the radio frequency power supply (power 180W), and simultaneously start the frame rotation device (speed 5 rpm) to process for 4 minutes to ensure uniform activation of the wire bundle surface and obtain the activated wire bundle.

[0040] Measure 900 mL of anhydrous ethanol and place it in a reaction vessel. Add 100 g of methyl methacrylate and 0.4 g of benzoyl peroxide and stir until completely dissolved. Suspend the activated wire bundle in the reaction vessel (completely immersed in the solution to avoid tangling). After purging with nitrogen three times, raise the temperature to 68 °C, turn on the stirring inside the vessel, and keep the reaction at this temperature for 2.5 h. After the reaction is complete, remove the wire bundle and ultrasonically clean it with anhydrous ethanol (power 200 W, time 10 min). Then place it in a 65 °C forced-air drying oven and dry for 2 h to obtain the grafted modified wire bundle.

[0041] Step 5: Weigh 100g PTFE micro powder, 70g epoxy resin E-51, 20g crosslinking agent T31, and 300g ethyl acetate, place them in a high-speed dispersion tank, set the rotation speed to 2200rpm, and disperse for 30min. Transfer the dispersed slurry to a three-roll mill and grind it twice to ensure that the slurry particle size is ≤5μm. Introduce the grafted modified wire harness into the electrostatic spraying chamber through the wire feeding device, using a ring nozzle, and set the spraying parameters as follows: voltage 70kV, spraying distance 25cm, wire harness traction speed 1m / min, to ensure that the slurry is uniformly coated on the wire harness surface (wet film thickness 10μm). The sprayed wire harness enters the hot air curing oven, and the curing program is set as follows: heat up from room temperature to 70℃ at a rate of 6℃ / min, hold for 30min; then heat up to 80℃, hold for 2h; after curing, allow it to cool naturally to 45℃, and take out a sample cut to 1m in length to obtain a high wear-resistant wire harness.

[0042] Example 2

[0043] A method for preparing a highly wear-resistant wire harness includes the following steps:

[0044] Step 1: Weigh 200g of nano-SiO2 and 80g of nano-SiC into a three-necked flask, add 15g of coupling agent KH-570 and 1500mL of anhydrous ethanol, fix the flask in an ultrasonic disperser, set the power to 400W and the frequency to 28kHz, and continue ultrasonic oscillation for 30min; then connect the reflux condenser, place it in a 75℃ constant temperature water bath, turn on the stirrer at 300rpm, and keep it at the temperature for 2h; after the reaction is completed, transfer the material to a rotary evaporator (temperature 60℃, vacuum degree -0.085MPa) to remove the anhydrous ethanol, place the obtained solid in a vacuum drying oven (temperature 85℃, vacuum degree -0.095MPa) to dry for 5h, pulverize it with a high-speed pulverizer and pass it through a 200-mesh sieve to obtain coupling agent modified mixed nanoparticles.

[0045] Step 2: Take 300g of coupling agent-modified mixed nanoparticles and add them to 1800mL of anhydrous ethanol solution containing 18g of hydroxyethyl acrylate and 0.105g of AIBN. Place the solution in a 65℃ constant temperature water bath, turn on the stirring at 300rpm, and keep the reaction at this temperature for 2.5h. After the reaction is complete, transfer the mixture to a high-speed centrifuge (8000rpm) and centrifuge for 15min. Collect the bottom solid, wash it repeatedly with anhydrous ethanol 3 times, and then place it in an 80℃ vacuum drying oven to dry for 4h to obtain modified coupling agent-modified mixed nanoparticles.

[0046] Add 30L of deionized water and 100g of polyvinyl alcohol to the polymerization reactor, start stirring at 250rpm, heat to 50℃ and keep at that temperature for 30min until the polyvinyl alcohol is completely dissolved; add 40g of modified coupling agent to modify the mixed nanoparticles and 1000g of vinyl chloride monomer, and continue stirring for 35min until the system is homogeneous; add 10g of AIBN, close the feed port of the polymerization reactor, and purge with high-purity nitrogen three times; then heat to 70℃, maintain the pressure inside the reactor at 0.7MPa, and keep the reaction at that temperature for 4h; when the pressure inside the reactor drops to 0.35MPa, stop heating and cool to 42℃, and purge with steam to remove unreacted vinyl chloride monomer for 2h to obtain PVC / nano composite latex;

[0047] The latex was fed into a spray dryer (inlet air temperature 160℃, outlet air temperature 80℃, atomization pressure 0.3MPa) and dried into powder. 180g of ACR-g-VC resin, 250g of DOTP, 20g of calcium-zinc composite stabilizer, and 30g of ethylene-octene copolymer grafted maleic anhydride compatibilizer were added to the powder and then transferred to a high-speed mixer (temperature 95℃, speed 1300rpm) and mixed for 5min. Finally, the mixture was fed into a twin-screw extruder (feed section temperature 135℃, compression section temperature 155℃, homogenization section temperature 165℃, screw speed 180rpm) for extrusion granulation to obtain PVC / nano composite resin granules.

[0048] Step 3: Take a tin-plated copper wire with a single wire diameter of 0.15 mm, twist it into 7 core wires (twisting pitch 10 mm) using a stranding machine, and cut it into 10 m lengths; immerse the core wires in a 5% sodium hydroxide solution (500 mL, temperature 55℃), and place them in an ultrasonic cleaner (power 250 W) for ultrasonic treatment for 15 min; after removal, rinse 3 times with 30℃ deionized water, then immerse in a 12% hydrochloric acid solution (500 mL, temperature 28℃), and stir at 150 rpm for 10 min; finally, rinse with 30℃ deionized water until pH=7, and transfer to a 75℃ hot air drying oven to dry for 1.5 h to obtain clean core wires.

[0049] PVC / nano composite resin granules are added to the hopper of a twin-screw extruder. Clean core wires are introduced into the die head of the extruder through the wire feeding frame (matching a coating layer thickness of 0.8mm). The extruder parameters are set as follows: feeding section 145℃, compression section 165℃, homogenization section 170℃, die head temperature 172℃, screw speed 40rpm, and traction speed 5m / min. The extruder is then started. After the resin melts, it is extruded through the die and coated onto the surface of the core wire to form a preliminary wire bundle.

[0050] Step 4: Wrap the initial shaped wire bundle around the porous frame, fix it to the sample holder of the plasma processor, close the chamber door and evacuate to 0.2 Pa, introduce high-purity argon gas (flow rate 12 sccm) to stabilize the pressure inside the chamber at 0.8 Pa, turn on the radio frequency power supply (power 180W), and simultaneously start the frame rotation device (speed 5 rpm) to process for 4 minutes to ensure uniform activation of the wire bundle surface and obtain the activated wire bundle.

[0051] Measure 900 mL of anhydrous ethanol and place it in a reaction vessel. Add 100 g of methyl methacrylate and 0.3 g of benzoyl peroxide and stir until completely dissolved. Suspend the activated wire bundle in the reaction vessel (completely immersed in the solution to avoid tangling). After purging with nitrogen three times, raise the temperature to 68 °C, turn on the stirring inside the vessel, and keep the reaction at this temperature for 2.5 h. After the reaction is complete, remove the wire bundle and ultrasonically clean it with anhydrous ethanol (power 200 W, time 10 min). Then place it in a 65 °C forced-air drying oven and dry for 2 h to obtain the grafted modified wire bundle.

[0052] Step 5: Weigh 100g PTFE micro powder, 60g epoxy resin E-51, 20g crosslinking agent T31, and 300g ethyl acetate, place them in a high-speed dispersion tank, set the rotation speed to 2200rpm, and disperse for 30min. Transfer the dispersed slurry to a three-roll mill and grind it twice to ensure that the slurry particle size is ≤5μm. Introduce the grafted modified wire harness into the electrostatic spraying chamber through the wire feeding device, using a ring nozzle, and set the spraying parameters: voltage 70kV, spraying distance 25cm, wire harness traction speed 1m / min, to ensure that the slurry is uniformly coated on the wire harness surface (wet film thickness 10μm). The sprayed wire harness enters the hot air curing oven, and the curing program is set as follows: heat up from room temperature to 70℃ at a rate of 6℃ / min, hold for 30min; then heat up to 80℃, hold for 2h; after curing, allow it to cool naturally to 45℃, and take out a sample cut to 1m in length to obtain a high wear-resistant wire harness.

[0053] Example 3

[0054] A method for preparing a highly wear-resistant wire harness includes the following steps:

[0055] Step 1: Weigh 200g of nano-SiO2 and 100g of nano-SiC into a three-necked flask, add 15g of coupling agent KH-570 and 1500mL of anhydrous ethanol, fix the flask in an ultrasonic disperser, set the power to 400W and the frequency to 28kHz, and continue ultrasonic oscillation for 30min; then connect the reflux condenser, place it in a 75℃ constant temperature water bath, turn on the stirrer at 300rpm, and keep the reaction at this temperature for 2h; after the reaction is complete, transfer the material to a rotary evaporator (temperature 60℃, vacuum degree -0.085MPa) to remove the anhydrous ethanol, place the obtained solid in a vacuum drying oven (temperature 85℃, vacuum degree -0.095MPa) to dry for 5h, pulverize it with a high-speed pulverizer and pass it through a 200-mesh sieve to obtain coupling agent modified mixed nanoparticles.

[0056] Step 2: Take 300g of coupling agent-modified mixed nanoparticles and add them to 1800mL of anhydrous ethanol solution containing 20g of hydroxyethyl acrylate and 0.105g of AIBN. Place the solution in a 65℃ constant temperature water bath, turn on the stirring at 300rpm, and keep it at this temperature for 2.5h. After the reaction is complete, transfer the mixture to a high-speed centrifuge (8000rpm) and centrifuge for 15min. Collect the bottom solid, wash it repeatedly with anhydrous ethanol 3 times, and then place it in an 80℃ vacuum drying oven to dry for 4h to obtain modified coupling agent-modified mixed nanoparticles.

[0057] Add 30L of deionized water and 100g of polyvinyl alcohol to the polymerization reactor, start stirring at 250rpm, heat to 50℃ and keep at that temperature for 30min until the polyvinyl alcohol is completely dissolved; add 45g of modified coupling agent to modify the mixed nanoparticles and 1000g of vinyl chloride monomer, and continue stirring for 35min until the system is homogeneous; add 10g of AIBN, close the feed port of the polymerization reactor, and purge with high-purity nitrogen three times; then heat to 70℃, maintain the pressure inside the reactor at 0.7MPa, and keep the reaction at that temperature for 4h; when the pressure inside the reactor drops to 0.35MPa, stop heating and cool to 42℃, and purge with steam to remove unreacted vinyl chloride monomer for 2h to obtain PVC / nano composite latex;

[0058] The latex was fed into a spray dryer (inlet air temperature 160℃, outlet air temperature 80℃, atomization pressure 0.3MPa) and dried into powder. 180g of ACR-g-VC resin, 250g of DOTP, 20g of calcium-zinc composite stabilizer, and 30g of ethylene-octene copolymer grafted maleic anhydride compatibilizer were added to the powder and then transferred to a high-speed mixer (temperature 95℃, speed 1300rpm) and mixed for 5min. Finally, the mixture was fed into a twin-screw extruder (feed section temperature 135℃, compression section temperature 155℃, homogenization section temperature 165℃, screw speed 180rpm) for extrusion granulation to obtain PVC / nano composite resin granules.

[0059] Step 3: Take a tin-plated copper wire with a single wire diameter of 0.15 mm, twist it into 7 core wires (twisting pitch 10 mm) using a stranding machine, and cut it into 10 m lengths; immerse the core wires in a 5% sodium hydroxide solution (500 mL, temperature 55℃), and place them in an ultrasonic cleaner (power 250 W) for ultrasonic treatment for 15 min; after removal, rinse 3 times with 30℃ deionized water, then immerse in a 12% hydrochloric acid solution (500 mL, temperature 28℃), and stir at 150 rpm for 10 min; finally, rinse with 30℃ deionized water until pH=7, and transfer to a 75℃ hot air drying oven to dry for 1.5 h to obtain clean core wires.

[0060] PVC / nano composite resin granules are added to the hopper of a twin-screw extruder. Clean core wires are introduced into the die head of the extruder through the wire feeding frame (matching a coating layer thickness of 0.8mm). The extruder parameters are set as follows: feeding section 145℃, compression section 165℃, homogenization section 170℃, die head temperature 172℃, screw speed 40rpm, and traction speed 5m / min. The extruder is then started. After the resin melts, it is extruded through the die and coated onto the surface of the core wire to form a preliminary wire bundle.

[0061] Step 4: Wrap the initial shaped wire bundle around the porous frame, fix it to the sample holder of the plasma processor, close the chamber door and evacuate to 0.2 Pa, introduce high-purity argon gas (flow rate 12 sccm) to stabilize the pressure inside the chamber at 0.8 Pa, turn on the radio frequency power supply (power 180W), and simultaneously start the frame rotation device (speed 5 rpm) to process for 4 minutes to ensure uniform activation of the wire bundle surface and obtain the activated wire bundle.

[0062] Measure 900 mL of anhydrous ethanol and place it in a reaction vessel. Add 100 g of methyl methacrylate and 0.35 g of benzoyl peroxide and stir until completely dissolved. Suspend the activated wire bundle in the reaction vessel (completely immersed in the solution to avoid tangling). After purging with nitrogen three times, raise the temperature to 68 °C, turn on the stirring inside the vessel, and keep the reaction at this temperature for 2.5 h. After the reaction is complete, remove the wire bundle and ultrasonically clean it with anhydrous ethanol (power 200 W, time 10 min). Then place it in a 65 °C forced-air drying oven and dry for 2 h to obtain the grafted modified wire bundle.

[0063] Step 5: Weigh 100g PTFE micro powder, 65g epoxy resin E-51, 20g crosslinking agent T31, and 300g ethyl acetate, place them in a high-speed dispersion tank, set the rotation speed to 2200rpm, and disperse for 30min. Transfer the dispersed slurry to a three-roll mill and grind it twice to ensure that the slurry particle size is ≤5μm. Introduce the grafted modified wire harness into the electrostatic spraying chamber through the wire feeding device, using a ring nozzle, and set the spraying parameters as follows: voltage 70kV, spraying distance 25cm, wire harness traction speed 1m / min, to ensure that the slurry is uniformly coated on the surface of the wire harness (wet film thickness 10μm). The sprayed wire harness enters the hot air curing oven, and the curing program is set as follows: heat up from room temperature to 70℃ at a rate of 6℃ / min, hold for 30min; then heat up to 80℃, hold for 2h; after curing, allow it to cool naturally to 45℃, and take out a sample cut to 1m in length to obtain a high wear-resistant wire harness.

[0064] Example 4

[0065] A method for preparing a highly wear-resistant wire harness includes the following steps:

[0066] Step 1: Weigh 200g of nano-SiO2 and 150g of nano-SiC into a three-necked flask, add 15g of coupling agent KH-570 and 1500mL of anhydrous ethanol, fix the flask in an ultrasonic disperser, set the power to 400W and the frequency to 28kHz, and continue ultrasonic oscillation for 30min; then connect the reflux condenser, place it in a 75℃ constant temperature water bath, turn on the stirrer at 300rpm, and keep the reaction at this temperature for 2h; after the reaction is complete, transfer the material to a rotary evaporator (temperature 60℃, vacuum degree -0.085MPa) to remove the anhydrous ethanol, place the obtained solid in a vacuum drying oven (temperature 85℃, vacuum degree -0.095MPa) to dry for 5h, pulverize it with a high-speed pulverizer and pass it through a 200-mesh sieve to obtain coupling agent modified mixed nanoparticles.

[0067] Step 2: Take 300g of coupling agent-modified mixed nanoparticles and add them to 1800mL of anhydrous ethanol solution containing 30g of hydroxyethyl acrylate and 0.105g of AIBN. Place the solution in a 65℃ constant temperature water bath, turn on the stirring at 300rpm, and keep it at this temperature for 2.5h. After the reaction is complete, transfer the mixture to a high-speed centrifuge (8000rpm) and centrifuge for 15min. Collect the bottom solid, wash it repeatedly with anhydrous ethanol 3 times, and then place it in an 80℃ vacuum drying oven to dry for 4h to obtain modified coupling agent-modified mixed nanoparticles.

[0068] Add 30L of deionized water and 100g of polyvinyl alcohol to the polymerization reactor, start stirring at 250rpm, heat to 50℃ and keep at that temperature for 30min until the polyvinyl alcohol is completely dissolved; add 60g of modified coupling agent to modify the mixed nanoparticles and 1000g of vinyl chloride monomer, and continue stirring for 35min until the system is homogeneous; add 10g of AIBN, close the feed port of the polymerization reactor, and purge with high-purity nitrogen three times; then heat to 70℃, maintain the pressure inside the reactor at 0.7MPa, and keep the reaction at that temperature for 4h; when the pressure inside the reactor drops to 0.35MPa, stop heating and cool to 42℃, and purge with steam to remove unreacted vinyl chloride monomer for 2h to obtain PVC / nano composite latex;

[0069] The latex was fed into a spray dryer (inlet air temperature 160℃, outlet air temperature 80℃, atomization pressure 0.3MPa) and dried into powder. 180g of ACR-g-VC resin, 250g of DOTP, 20g of calcium-zinc composite stabilizer, and 30g of ethylene-octene copolymer grafted maleic anhydride compatibilizer were added to the powder and then transferred to a high-speed mixer (temperature 95℃, speed 1300rpm) and mixed for 5min. Finally, the mixture was fed into a twin-screw extruder (feed section temperature 135℃, compression section temperature 155℃, homogenization section temperature 165℃, screw speed 180rpm) for extrusion granulation to obtain PVC / nano composite resin granules.

[0070] Step 3: Take a tin-plated copper wire with a single wire diameter of 0.15 mm, twist it into 7 core wires (twisting pitch 10 mm) using a stranding machine, and cut it into 10 m lengths; immerse the core wires in a 5% sodium hydroxide solution (500 mL, temperature 55℃), and place them in an ultrasonic cleaner (power 250 W) for ultrasonic treatment for 15 min; after removal, rinse 3 times with 30℃ deionized water, then immerse in a 12% hydrochloric acid solution (500 mL, temperature 28℃), and stir at 150 rpm for 10 min; finally, rinse with 30℃ deionized water until pH=7, and transfer to a 75℃ hot air drying oven to dry for 1.5 h to obtain clean core wires.

[0071] PVC / nano composite resin granules are added to the hopper of a twin-screw extruder. Clean core wires are introduced into the die head of the extruder through the wire feeding frame (matching a coating layer thickness of 0.8mm). The extruder parameters are set as follows: feeding section 145℃, compression section 165℃, homogenization section 170℃, die head temperature 172℃, screw speed 40rpm, and traction speed 5m / min. The extruder is then started. After the resin melts, it is extruded through the die and coated onto the surface of the core wire to form a preliminary wire bundle.

[0072] Step 4: Wrap the initial shaped wire bundle around the porous frame, fix it to the sample holder of the plasma processor, close the chamber door and evacuate to 0.2 Pa, introduce high-purity argon gas (flow rate 12 sccm) to stabilize the pressure inside the chamber at 0.8 Pa, turn on the radio frequency power supply (power 180W), and simultaneously start the frame rotation device (speed 5 rpm) to process for 4 minutes to ensure uniform activation of the wire bundle surface and obtain the activated wire bundle.

[0073] Measure 900 mL of anhydrous ethanol and place it in a reaction vessel. Add 100 g of methyl methacrylate and 0.5 g of benzoyl peroxide and stir until completely dissolved. Suspend the activated wire bundle in the reaction vessel (completely immersed in the solution to avoid tangling). After purging with nitrogen three times, raise the temperature to 70 °C, turn on the stirring inside the vessel, and keep the reaction at this temperature for 3 hours. After the reaction is complete, remove the wire bundle and ultrasonically clean it with anhydrous ethanol (power 200 W, time 10 min). Then place it in a 65 °C forced-air drying oven and dry for 2 hours to obtain the grafted modified wire bundle.

[0074] Step 5: Weigh 100g PTFE micro powder, 80g epoxy resin E-51, 20g crosslinking agent T31, and 300g ethyl acetate, place them in a high-speed dispersion tank, set the rotation speed to 2200rpm, and disperse for 30min. Transfer the dispersed slurry to a three-roll mill and grind it twice to ensure that the slurry particle size is ≤5μm. Introduce the grafted modified wire harness into the electrostatic spraying chamber through the wire feeding device, using a ring nozzle, and set the spraying parameters as follows: voltage 70kV, spraying distance 25cm, wire harness traction speed 1m / min, to ensure that the slurry is uniformly coated on the wire harness surface (wet film thickness 10μm). The sprayed wire harness enters the hot air curing oven, and the curing program is set as follows: heat up from room temperature to 70℃ at a rate of 6℃ / min, hold for 30min; then heat up to 80℃, hold for 2h; after curing, allow it to cool naturally to 45℃, and take out a sample cut to 1m in length to obtain a high wear-resistant wire harness.

[0075] Example 5

[0076] A method for preparing a highly wear-resistant wire harness includes the following steps:

[0077] Step 1: Weigh 200g of nano-SiO2 and 50g of nano-SiC into a three-necked flask, add 15g of coupling agent KH-570 and 1500mL of anhydrous ethanol, fix the flask in an ultrasonic disperser, set the power to 400W and the frequency to 28kHz, and continue ultrasonic oscillation for 30min; then connect the reflux condenser, place it in a 75℃ constant temperature water bath, turn on the stirrer at 300rpm, and keep the reaction at this temperature for 2h; after the reaction is completed, transfer the material to a rotary evaporator (temperature 60℃, vacuum degree -0.085MPa) to remove the anhydrous ethanol, place the obtained solid in a vacuum drying oven (temperature 85℃, vacuum degree -0.095MPa) to dry for 5h, pulverize it with a high-speed pulverizer and pass it through a 200-mesh sieve to obtain coupling agent modified mixed nanoparticles.

[0078] Step 2: Take 300g of coupling agent-modified mixed nanoparticles and add them to 1800mL of anhydrous ethanol solution containing 15g of hydroxyethyl acrylate and 0.105g of AIBN. Place the solution in a 65℃ constant temperature water bath, turn on the stirring at 300rpm, and keep it at this temperature for 2.5h. After the reaction is complete, transfer the mixture to a high-speed centrifuge (8000rpm) and centrifuge for 15min. Collect the bottom solid, wash it repeatedly with anhydrous ethanol 3 times, and then place it in an 80℃ vacuum drying oven to dry for 4h to obtain modified coupling agent-modified mixed nanoparticles.

[0079] Add 30L of deionized water and 100g of polyvinyl alcohol to the polymerization reactor, start stirring at 250rpm, heat to 50℃ and keep at that temperature for 30min until the polyvinyl alcohol is completely dissolved; add 30g of modified coupling agent to modify the mixed nanoparticles and 1000g of vinyl chloride monomer, and continue stirring for 35min until the system is homogeneous; add 10g of AIBN, close the feed port of the polymerization reactor, and purge with high-purity nitrogen three times; then heat to 70℃, maintain the pressure inside the reactor at 0.7MPa, and keep the reaction at that temperature for 4h; when the pressure inside the reactor drops to 0.35MPa, stop heating and cool to 42℃, and purge with steam to remove unreacted vinyl chloride monomer for 2h to obtain PVC / nano composite latex;

[0080] The latex was fed into a spray dryer (inlet air temperature 160℃, outlet air temperature 80℃, atomization pressure 0.3MPa) and dried into powder. 180g of ACR-g-VC resin, 250g of DOTP, 20g of calcium-zinc composite stabilizer, and 30g of ethylene-octene copolymer grafted maleic anhydride compatibilizer were added to the powder and then transferred to a high-speed mixer (temperature 95℃, speed 1300rpm) and mixed for 5min. Finally, the mixture was fed into a twin-screw extruder (feed section temperature 135℃, compression section temperature 155℃, homogenization section temperature 165℃, screw speed 180rpm) for extrusion granulation to obtain PVC / nano composite resin granules.

[0081] Step 3: Take a tin-plated copper wire with a single wire diameter of 0.15 mm, twist it into 7 core wires (twisting pitch 10 mm) using a stranding machine, and cut it into 10 m lengths; immerse the core wires in a 5% sodium hydroxide solution (500 mL, temperature 55℃), and place them in an ultrasonic cleaner (power 250 W) for ultrasonic treatment for 15 min; after removal, rinse 3 times with 30℃ deionized water, then immerse in a 12% hydrochloric acid solution (500 mL, temperature 28℃), and stir at 150 rpm for 10 min; finally, rinse with 30℃ deionized water until pH=7, and transfer to a 75℃ hot air drying oven to dry for 1.5 h to obtain clean core wires.

[0082] PVC / nano composite resin granules are added to the hopper of a twin-screw extruder. Clean core wires are introduced into the die head of the extruder through the wire feeding frame (matching a coating layer thickness of 0.8mm). The extruder parameters are set as follows: feeding section 145℃, compression section 165℃, homogenization section 170℃, die head temperature 172℃, screw speed 40rpm, and traction speed 5m / min. The extruder is then started. After the resin melts, it is extruded through the die and coated onto the surface of the core wire to form a preliminary wire bundle.

[0083] Step 4: Wrap the initial shaped wire bundle around the porous frame, fix it to the sample holder of the plasma processor, close the chamber door and evacuate to 0.2 Pa, introduce high-purity argon gas (flow rate 12 sccm) to stabilize the pressure inside the chamber at 0.8 Pa, turn on the radio frequency power supply (power 180W), and simultaneously start the frame rotation device (speed 5 rpm) to process for 4 minutes to ensure uniform activation of the wire bundle surface and obtain the activated wire bundle.

[0084] Measure 900 mL of anhydrous ethanol and place it in a reaction vessel. Add 100 g of methyl methacrylate and 0.2 g of benzoyl peroxide and stir until completely dissolved. Suspend the activated wire bundle in the reaction vessel (completely immersed in the solution to avoid tangling). After purging with nitrogen three times, raise the temperature to 65 °C, turn on the stirring inside the vessel, and keep the reaction at this temperature for 2 hours. After the reaction is complete, remove the wire bundle and ultrasonically clean it with anhydrous ethanol (power 200 W, time 10 min). Then place it in a 65 °C forced-air drying oven and dry for 2 hours to obtain the grafted modified wire bundle.

[0085] Step 5: Weigh 100g PTFE micro powder, 50g epoxy resin E-51, 20g crosslinking agent T31, and 300g ethyl acetate, place them in a high-speed dispersion tank, set the rotation speed to 2200rpm, and disperse for 30min. Transfer the dispersed slurry to a three-roll mill and grind it twice to ensure that the slurry particle size is ≤5μm. Introduce the grafted modified wire harness into the electrostatic spraying chamber through a wire feeding device, using a ring nozzle, and set the spraying parameters as follows: voltage 70kV, spraying distance 25cm, wire harness traction speed 1m / min, to ensure that the slurry is uniformly coated on the wire harness surface (wet film thickness 10μm). The sprayed wire harness enters the hot air curing oven, and the curing program is set as follows: heat up from room temperature to 70℃ at a rate of 6℃ / min, hold for 30min; then heat up to 80℃, hold for 2h; after curing, allow it to cool naturally to 45℃, and take out a sample cut to 1m in length to obtain a high wear-resistant wire harness.

[0086] Comparative Example 1: The difference between Comparative Example 1 and Example 1 is that step 1 is omitted in the wire harness preparation process, and no modified coupling agent is added to the polymerization reactor in step 2 to modify the mixed nanoparticles.

[0087] Comparative Example 2: The difference between Comparative Example 2 and Example 1 is that in step 2 of the wire harness preparation process, the modified coupling agent-modified mixed nanoparticles added in the polymerization reactor are replaced with coupling agent-modified mixed nanoparticles.

[0088] Comparative Example 3: The difference between Comparative Example 3 and Example 1 is that steps 4 and 5 are omitted in the wire harness preparation process.

[0089] Performance testing:

[0090] 1. Abrasion Resistance Test: Referring to GB / T 1768-2021 "Determination of Abrasion Resistance of Paints and Varnishes - Rotary Friction Method", a 10cm long wire harness sample was fixed on the sample stage of the Taber abrasion tester. An H-18 grinding wheel was selected, a load of 500g was applied, and the rotation speed was set to 60r / min. The test was performed continuously for 1000 revolutions before stopping. The mass of the sample before and after the test was measured using an electronic balance with an accuracy of 0.1mg. The mass loss was calculated (Δm = mass before test - mass after test). Each sample was tested in triplicate, and the average value was taken. The smaller the mass loss, the better the abrasion resistance. The test results are shown in Table 1.

[0091] 2. Tensile Strength Test: Referring to GB / T 1040.3-2006 "Determination of Tensile Properties of Plastics - Part 3: Test Conditions for Films and Sheets", the wire harness was cut into strip specimens with a width of 10 mm and a length of 100 mm along the axial direction. A tensile testing machine was used, with a gauge length of 50 mm and a tensile speed of 20 mm / min. The maximum tensile force at which the specimen broke was recorded. The tensile strength was determined based on the cross-sectional area of ​​the specimen (S = π × (total diameter of the wire harness / 2)). 2 -π×(core wire diameter / 2) 2 Calculate the tensile strength (σ = maximum tensile force / S). Each sample was tested in triplicate, and the average value was taken. Higher tensile strength indicates stronger resistance to breakage in the wire harness. Test results are shown in Table 1.

[0092] 3. Volume Resistivity Test: Referring to GB / T 1410-2006 "Test Methods for Volume Resistivity and Surface Resistivity of Solid Insulating Materials", a 20cm long wire harness sample was taken, and 1cm of the coating layer was peeled off at each end to expose the tin-plated copper core. The two ends of the copper core were connected to the positive and negative electrodes of the high resistance meter, and the contact points between the electrodes and the copper core were reinforced with conductive silver paste. The test environment was controlled at 23℃ and 50% relative humidity, with a 100V DC voltage applied. After standing for 1 minute, the resistance value (R) was read. The volume resistivity was calculated according to the volume resistivity formula (ρv = R×S / L, where S is the cross-sectional area of ​​the coating layer and L is the length of the coating layer between the two electrodes). Each sample was tested in parallel 3 times, and the average value was taken. The test results are shown in Table 1.

[0093] Table 1:

[0094]

[0095] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method of making a high abrasion string, characterized by, The method comprises the following steps: S1, mixing nano-SiO2 and nano-SiC to obtain mixed nanoparticles, adding coupling agent KH-570 and anhydrous ethanol to the mixed nanoparticles, ultrasonic oscillation dispersion, incubation reaction, evaporation of ethanol, drying, crushing and sieving to obtain coupling agent modified mixed nanoparticles; S2, adding the coupling agent modified mixed nanoparticles into an anhydrous ethanol solution containing hydroxyethyl acrylate and azobisisobutyronitrile, heating and stirring to perform reaction, after the reaction is completed, performing solid-liquid separation on the reaction product, drying the obtained solid after washing with anhydrous ethanol to obtain modified coupling agent modified mixed nanoparticles; adding the modified coupling agent modified mixed nanoparticles, vinyl chloride monomer and azobisisobutyronitrile into deionized water in which polyvinyl alcohol is dissolved, replacing with nitrogen, performing polymerization reaction, and removing unreacted monomers to obtain PVC / nano composite latex, spraying and drying the PVC / nano composite latex, then mixing the PVC / nano composite latex with ACR-g-VC resin, dioctyl terephthalate, calcium-zinc composite stabilizer and compatibilizer, and performing extrusion granulation to obtain PVC / nano composite resin granules; S3, twisting tinned copper wires into core wires, and sequentially performing alkali washing, acid washing, water washing and drying to obtain clean core wires; melting and extruding the PVC / nano composite resin granules to coat the clean core wires to obtain a primary formed wire bundle; S4, performing argon plasma treatment on the primary formed wire bundle to obtain an activated wire bundle, immersing the activated wire bundle into an anhydrous ethanol solution containing methyl methacrylate and benzoyl peroxide, heating and reacting in a nitrogen atmosphere, and performing cleaning and drying to obtain a graft modified wire bundle; S5, mixing PTFE micro powder, epoxy resin E-51 and crosslinking agent T31 with ethyl acetate to obtain wear-resistant coating slurry, and performing electrostatic spraying of the wear-resistant coating slurry on the surface of the graft modified wire bundle to obtain high wear-resistant wire bundle after solidification.

2. The method of claim 1, wherein the high abrasion resistant wire harness is prepared by the steps of: In the step S1, the mass ratio of nano-SiO2 to nano-SiC is 2:0.5-1.

5.

3. The method of claim 1, wherein the high abrasion resistant wire harness is prepared by the steps of: In the step S2, the mass ratio of the coupling agent modified mixed nanoparticles to hydroxyethyl acrylate is 100:5-10. ​ 4. The method of claim 1, wherein the high abrasion wire harness is prepared by the steps of: In the step S2, the addition amount of the modified coupling agent modified mixed nanoparticles is 3-6wt% of the vinyl chloride monomer.

5. The method of claim 1, wherein the high abrasion resistant wire harness is prepared by the steps of: In the step S4, the addition amount of benzoyl peroxide is 0.2-0.5wt% of the methyl methacrylate. ​ 6. The method of claim 1, wherein the high abrasion resistant wire harness is prepared by the steps of: In the step S4, the reaction temperature is 65-70℃, and the reaction time is 2-3h.

7. The method of claim 1, wherein the high abrasion resistant wire harness is prepared by the steps of: In the step S5, the mass ratio of PTFE micro powder to epoxy resin E-51 is 10:5-8. ​ 8. The method of claim 1, wherein the high abrasion resistant wire harness is prepared by the steps of: In the step S5, the wet film thickness of the wear-resistant coating slurry on the surface of the graft modified wire bundle is controlled to be 10μm. ​ 9. A high abrasion string characterized in that, The method is prepared according to any one of the above claims 1-8.

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