A High-Temperature-Resistant and Low-Loss RF Cable for Intelligent Connected Vehicles and Its Preparation Process

Abstract

This application relates to the technical field of polymer materials, and specifically discloses a high-temperature resistant and low-loss radio frequency cable for intelligent connected vehicles and its preparation process. A high-temperature resistant and low-loss radio frequency cable for intelligent connected vehicles includes a sheath layer. By weight, the raw materials used for the sheath layer include the following components: 100 parts of polyvinyl chloride; 30-35 parts of acrylate copolymer; 15-20 parts of heat stabilizer and 15-20 parts of refractory filler; the intrinsic viscosity of the acrylate copolymer < 5.8 dL / g, and the heat stabilizer includes a phosphorus-based compound modified magnesium-aluminum hydrotalcite, zinc borate, and lanthanum-modified St-MAH-AN terpolymer with a weight ratio of 25:5:(5-8). The high-temperature resistant and low-loss radio frequency cable of this application has a maximum fire supply temperature of above 850 °C, and the possibility of sheath layer aging, cracking, or melting at high temperatures is relatively low.

Description

Technical Field

[0001] The present application relates to the technical field of polymer materials, and in particular to a high temperature resistant and low loss radio frequency cable for intelligent networked vehicles and a preparation process thereof. Background Art

[0002] The wireless charging and discharging system for new energy vehicles is a system that uses the principle of electromagnetic induction or magnetic resonance to transmit electrical energy between the transmitting coil of the charging station and the receiving coil on the electric vehicle. It can charge or discharge electric vehicles without physical contact, and is currently a very advanced technology. The system consists of a transmitting end (usually installed at a charging station or parking space, containing a transmitting coil and a control circuit), a receiving end (installed on the electric vehicle, containing a receiving coil and a rectifier circuit, used to convert the received AC power into DC power for battery charging), and a radio frequency cable (a cable that transmits electromagnetic energy in the radio frequency range) used to connect the transmitting end and the receiving end. The system generates current in the receiving coil through a changing magnetic field, and uses the same resonant frequency of the two coils to achieve efficient wireless transmission of electrical energy.

[0003] Since the wireless charging and discharging system does not require physical plugging and unplugging, it can greatly improve the convenience of charging and user experience. At the same time, it avoids the risk of electric sparks and electric shock caused by contact charging. Therefore, it is very suitable for use in severe weather conditions and has a high safety factor. However, although this system has many advantages, it also has many problems that need to be solved. There is energy loss in the wireless transmission process, and technicians need to optimize the system design, such as using low-loss RF cables to improve transmission efficiency. However, with the development of low-loss RF cables, people have discovered a more difficult problem, that is, the wireless charging and discharging system will generate a lot of heat when charging at high power. The existing low-loss RF cables are prone to aging, cracking or melting of the sheath layer at high temperatures, and the possibility of safety hazards such as short circuits and leakage is very high. This requires the cable, a key connection component, to have good high temperature resistance to ensure system stability and safety. Therefore, in order to ensure the safe operation of the charging and discharging system and the personal safety of users, how to improve the high temperature resistance of low-loss RF cables used in wireless charging and discharging systems for new energy vehicles has become a current research hotspot. Summary of the invention

[0004] In order to solve the above technical problems, the present application provides a high temperature resistant and low loss radio frequency cable for intelligent connected vehicles and a preparation process thereof.

[0005] In the first aspect, the present application provides a high-temperature resistant and low-loss radio frequency cable for intelligent connected vehicles, comprising a twisted core, a winding layer, a shielding layer and a sheath layer sequentially coated on the outside of the twisted core, wherein the raw materials used for the sheath layer include the following components by weight: 100 parts of polyvinyl chloride; 30-35 parts of acrylic copolymer; 15-20 parts of thermal stabilizer and 15-20 parts of refractory filler; the intrinsic viscosity of the acrylic copolymer is less than 5.8 dL / g, and the thermal stabilizer includes a phosphorus-modified magnesium-aluminum hydrotalcite, zinc borate and lanthanum-modified St-MAH-AN ternary copolymer in a weight ratio of 25:5:(5-8).

[0006] Preferably, the raw materials used for the sheath layer include the following components in parts by weight: 100 parts of polyvinyl chloride; 32 parts of acrylic copolymer; 18 parts of heat stabilizer and 18 parts of refractory filler.

[0007] Optionally, the refractory filler includes at least two of mica, calcium carbonate, magnesium oxide and antimony trioxide.

[0008] By adopting the above technical scheme, the present application utilizes a heat stabilizer obtained by mixing a phosphorus-modified magnesium-aluminum hydrotalcite, zinc borate and a lanthanum-modified St-MAH-AN ternary copolymer and a refractory filler to work together to improve the thermal stability of the sheath layer, wherein the phosphorus-modified magnesium-aluminum hydrotalcite contains a variety of phosphorus-modified compounds, and the layered structure of the magnesium-aluminum hydrotalcite can play a hydrogen bond and electrostatic attraction role. When heated, the layer hydroxyl groups and the anions between the layers and the structural water will escape, reducing the ambient oxygen concentration and the ambient temperature. Therefore, the phosphorus-modified magnesium-aluminum hydrotalcite has good flame retardancy and heat resistance; zinc borate has a flame retardant mechanism and excellent heat resistance similar to those of phosphorus compounds, and also has a synergistic ability far exceeding other heat stabilizers, which can optimize the effects of other blended heat stabilizers, and the lanthanum-modified St-MAH-AN ternary copolymer has the characteristics of non-toxicity, environmental protection and excellent thermal stability. After the three are blended, they can give full play to the good synergistic effect and greatly improve the thermal stability of the sheath layer. At the same time, the present application also adds an acrylic copolymer to improve the compatibility of various substances in the system, and controls its intrinsic viscosity to be less than 5.8 dL / g. The acrylic copolymer with the intrinsic viscosity is dispersed in the system, which can effectively entangle with the molecular chain of polyvinyl chloride, ensuring that the refractory filler and the thermal stabilizer are fully interspersed in the polyvinyl chloride matrix, so that the internal compatibility of the sheath layer is significantly optimized, thereby simultaneously improving the thermal stability and mechanical stability of the sheath layer.

[0009] In summary, the present application fully exploits the heat stabilizer and refractory filler to enhance the thermal stability of the sheath layer, and also uses the acrylate copolymer with an intrinsic viscosity < 5.8 dL / g to improve the compatibility between various substances in the system. By blending and extruding the above substances with polyvinyl chloride, a sheath layer with good thermal stability and mechanical strength can be obtained, which plays a good protective role for the overall cable. Therefore, the high-temperature resistant and low-loss radio frequency cable for intelligent networked vehicles of the present application has a maximum fire supply temperature of over 850 °C (the highest temperature at which a 2A fuse does not blow and the conductor does not blow), a friction (50N friction force) mass loss rate of less than 1.5%, and a mass retention rate of not less than 97.5% at a temperature of 150 °C. The possibility of the sheath layer aging, cracking or melting at high temperatures is greatly reduced, and the possibility of safety hazards such as short circuits and electric leakage is almost reduced to zero, fully ensuring the safe operation of the charging and discharging system and the personal safety of users, and having high application value.

[0010] Preferably, the heat stabilizer comprises a phosphorus-based compound modified magnesium-aluminum hydrotalcite, zinc borate and a lanthanum-modified St-MAH-AN terpolymer with a weight ratio of 25:5:7.5.

[0011] By adopting the above technical solution, the present application strictly controls the weight ratio of the phosphorus-based compound modified magnesium-aluminum hydrotalcite, zinc borate and the lanthanum-modified St-MAH-AN terpolymer in the heat stabilizer to 25:5:7.5. This specific ratio can maximize the synergistic effect of each component. Specifically, the phosphorus-based compound modified magnesium-aluminum hydrotalcite has good flame retardant and heat resistance properties, can decompose and absorb heat at high temperatures, and reduce the oxygen concentration; zinc borate further enhances the flame retardant effect and optimizes the effects of other heat stabilizers; the lanthanum-modified St-MAH-AN terpolymer improves the mechanical strength and weather resistance of the material. The combined action of these components in the optimal ratio significantly improves the overall thermal stability and mechanical properties of the sheath layer, effectively preventing the aging, cracking or melting of the insulating layer at high temperatures, thereby reducing the occurrence probability of safety hazards such as short circuits and electric leakage, and ensuring the safe and reliable operation of the charging and discharging system. Experimental data shows that the maximum fire supply temperature of the high-temperature resistant and low-loss radio frequency cable for intelligent networked vehicles is significantly improved at this time.

[0012] Preferably, the acrylate copolymer is prepared by the following method: methyl methacrylate, isobornyl acrylate and tert-dodecyl mercaptan with a weight ratio of 120:10:(0.5 - 2.0) are mixed and dispersed in water containing initiator a and emulsifier, stirred and reacted, demulsified, and dried to obtain an acrylate copolymer with an intrinsic viscosity < 5.8 dL / g.

[0013] By adopting the above technical solutions, the present application uses a blend of methyl methacrylate, isobornyl acrylate, and tert-dodecyl mercaptan in a certain proportion, where tert-dodecyl mercaptan functions as a chain transfer agent, and the reaction is carried out in an aqueous medium containing initiator a and emulsifier. Finally, the obtained acrylate copolymer has a low intrinsic viscosity (<5.8 dL / g), which not only improves the compatibility of various substances in the sheath layer but also further enhances the mechanical stability and thermal stability of the sheath layer, thereby effectively improving the overall high-temperature resistance of the cable, reducing the risk of aging, cracking, or melting of the sheath layer in a high-temperature environment, and ensuring the safe and reliable operation of the charging and discharging system. Compared with acrylic monomers such as butyl acrylate, methyl acrylate, and isooctyl acrylate, isobornyl acrylate in the present application has better thermal stability, durability, lower viscosity, and toxicity, and has both good performance and environmental protection characteristics. Adding it to the acrylate copolymer can further improve the compatibility within the sheath layer, thereby enhancing the overall thermal stability and mechanical stability of the cable. The initiator a in the present application is potassium persulfate, and the emulsifier is sodium dodecyl sulfate. Those skilled in the art can reasonably replace the above two substances according to actual situations. Therefore, the specific selection of initiator a and emulsifier in the embodiments of the present application does not limit the protection scope of the present application.

[0014] Preferably, the weight ratio of methyl methacrylate, isobornyl acrylate, and tert-dodecyl mercaptan is 120:10:1.3.

[0015] By adopting the above technical solutions, the present application strictly controls the weight ratio of methyl methacrylate, isobornyl acrylate, and tert-dodecyl mercaptan, making the intrinsic viscosity of the acrylate copolymer at the most suitable size, further improving the compatibility of various substances in the sheath layer and the overall mechanical strength and thermal stability of the sheath layer. If the amount of tert-dodecyl mercaptan is too large, the conversion rate of methyl methacrylate will be greatly reduced (unable to reach more than 98%), resulting in an excessive amount of methyl methacrylate and isobornyl acrylate monomers in the system, and unable to effectively improve the compatibility of the system; if the amount of tert-dodecyl mercaptan is too small, the intrinsic viscosity of the acrylate copolymer will increase sharply, and it will also be unable to effectively improve the compatibility of the system. Experimental data prove that when the present application controls the weight ratio of the three at 120:10:1.3, the maximum fire supply temperature of the high-temperature resistant and low-loss radio frequency cable for intelligent connected vehicles will be significantly increased, and the mass loss rate will also be reduced.

[0016] Preferably, the phosphorus-based compounds in the phosphorus-based compound modified magnesium-aluminum type hydrotalcite include ammonium polyphosphate, resorcinol bis(diphenyl phosphate), and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide with a weight ratio of 1:(0.5 - 1):(1 - 1.5).

[0017] By adopting the above technical solution, the present application blends ammonium polyphosphate, resorcinol bis(diphenyl phosphate), and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to modify magnesium-aluminum layered double hydroxide, and strictly controls the weight ratio of the three, so that the phosphorus-based compound-modified magnesium-aluminum layered double hydroxide can form a stable protective film in the sheath layer system when the cable is heated, effectively inhibiting the decomposition and combustion of the sheath layer, reducing smoke generation, and improving the overall flame retardancy and heat resistance stability of the sheath layer. Specifically, ammonium polyphosphate, as the main charring agent, promotes charring at high temperatures, enhancing the heat insulation and oxygen isolation ability of the carbon layer; resorcinol bis(diphenyl phosphate) has excellent antioxidant properties, delaying the aging process of the material; 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide further improves the thermal stability and flame retardancy of the material. The synergistic effect of the three significantly enhances the comprehensive protection performance of the sheath layer under high-temperature conditions.

[0018] Preferably, the lanthanum-modified St-MAH-AN terpolymer is prepared by the following method: Blend styrene, acrylonitrile, maleic anhydride, and initiator b, raise the temperature for reaction, wash, and dry to obtain the terpolymer. Subsequently, disperse the terpolymer in an alkali solution, raise the temperature and stir until the system is completely clear, then keep it warm, and then add a lanthanum chloride solution to ensure that the weight ratio of the terpolymer to lanthanum ions in the system is 10:(0.5-1). Stir for reaction, cool, let stand, filter to obtain the filter residue, wash, and dry to obtain the lanthanum-modified St-MAH-AN terpolymer. The initiator b in the present application is benzoyl peroxide, and those skilled in the art can reasonably replace the above substances according to the actual situation. Therefore, the specific selection of the initiator b in the embodiments of the present application cannot limit the protection scope of the present application.

[0019] By adopting the above technical solution, the present application first generates a terpolymer from styrene, acrylonitrile, and maleic anhydride, and then introduces lanthanum ions through its reaction with lanthanum chloride to form a lanthanum-modified St-MAH-AN terpolymer with excellent thermal stability. This substance has excellent compatibility with polyvinyl chloride and good processing and molding properties. At the same time, the anhydride groups inside have good derivatization ability, and the cyano group can provide high hardness and low friction coefficient. Therefore, the lanthanum-modified St-MAH-AN terpolymer of the present application significantly enhances the overall thermal stability and mechanical strength of the sheath layer. This helps prevent the aging, cracking, or melting of the cable insulation layer in a high-temperature environment, effectively reducing the occurrence probability of safety hazards such as short circuits and electric leakage, greatly improving the wear resistance of the cable, further ensuring the integrity of the cable appearance, and ensuring the safe operation of the wireless charging and discharging system of new energy vehicles and the personal safety of users.

[0020] Preferably, after adding the lanthanum chloride solution, the weight ratio of the terpolymer to lanthanum ions in the system is 10:0.8.

[0021] By adopting the above technical solution, the present application strictly controls the weight ratio of the terpolymer to lanthanum ions. Without incurring additional costs, the doping rate of lanthanum is optimized to the maximum extent, the heat resistance of the sheath layer is increased to the highest level, effectively preventing the sheath layer from aging, cracking or melting due to high temperature, reducing the risks of short circuit and electric leakage, and ensuring the safe and reliable operation of the cable.

[0022] In a second aspect, the present application provides a preparation process for a high-temperature resistant and low-loss radio frequency cable for intelligent networked vehicles, comprising the following steps:

[0023] S1. Mixing materials: Stir the polyvinyl chloride, heat stabilizer and refractory filler at a rotation speed of 800 - 1000 r / min, then add the acrylate copolymer at a rotation speed of 600 - 800 r / min. After the addition is complete, homogenize the materials at a rotation speed of 1200 - 1400 r / min until there is no powder accumulation on the liquid surface, and then continue to homogenize at a rotation speed of 1200 - 1400 r / min to obtain a mixed material;

[0024] S2. Preparing a crude cable: Coating an insulating layer on the surface of the conductor to obtain a stranded core, and then sequentially coating a wrapping layer and a shielding layer outside the stranded core to obtain a crude cable;

[0025] S3. Preparing a high-temperature resistant and low-loss radio frequency cable: Extruding the mixed material obtained in step S1 outside the crude cable obtained in step S2 to form a sheath layer, thereby obtaining a high-temperature resistant and low-loss radio frequency cable.

[0026] By adopting the above technical solution, the preparation process for the high-temperature resistant and low-loss radio frequency cable for intelligent networked vehicles provided by the present application can effectively improve the thermal stability and mechanical strength of the sheath layer. Specifically, by uniformly stirring polyvinyl chloride, heat stabilizer and refractory filler at a specific rotation speed and then gradually adding the acrylate copolymer, the raw materials used for the final sheath have excellent thermal stability and compatibility, can maintain good physical properties in a high-temperature environment, and prevent the sheath layer from aging, cracking or melting due to high temperature, thereby significantly reducing safety hazards such as short circuit and electric leakage. In addition, this preparation process also ensures the stranding quality of the conductor and the tight fit of the insulating layer, wrapping layer and shielding layer, further improving the overall performance and reliability of the cable.

[0027] The raw material used for the conductor of this application is tinned copper wire with a cross-sectional area of 0.16 ± 0.01 mm² (this cross-sectional area and material improve the current-carrying capacity of the conductor and reduce the resistance value, which means lower energy loss, which is particularly important during high-current transmission. And the tin plating treatment effectively enhances the antioxidant and corrosion resistance of the copper wire, further extending the service life of the conductor and ensuring the reliability and stability during long-term use). The raw material used for the insulating layer is foamed polypropylene, the raw material used for the wrapping layer is double-sided non-self-adhesive aluminum foil, and the raw material used for the shielding layer is braided tinned copper wire with a specification of 16 × 6 × 0.10 ± 0.01 mm. Those skilled in the art can reasonably replace the above substances according to the actual situation. Therefore, the specific selection of the raw materials used for the insulating layer, wrapping layer, and shielding layer in the embodiments of this application cannot limit the protection scope of this application.

[0028] In summary, this application has the following beneficial technical effects:

[0029] 1. By using a phosphorous compound-modified magnesium-aluminum hydrotalcite, zinc borate, and lanthanum-modified St-MAH-AN terpolymer with specific ratios as heat stabilizers, this application significantly improves the high-temperature resistance of the sheath layer, enabling it to remain unfused at a maximum fire supply temperature above 850 °C, effectively preventing the sheath layer of the cable from aging, cracking, or melting in a high-temperature environment, and reducing the risks of short circuits and electric leakage.

[0030] 2. By adding an acrylate copolymer and controlling its intrinsic viscosity to be less than 5.8 dL / g, this application enhances the compatibility and mechanical stability among various substances inside the sheath layer, further improving the overall durability and reliability of the cable.

[0031] 3. The sheath layer of this application has excellent thermal stability and mechanical strength, ensuring the stability and safety of the cable during high-power charging, and fully guaranteeing the normal operation of the wireless charging and discharging system and the user's safety in use. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a cross-sectional view of the high-temperature resistant and low-loss radio frequency cable for intelligent networked vehicles of this application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] The following further elaborates on the cable structure of this application in conjunction with the attached Figure 1 drawings.

[0034] As Figure 1As shown, the conductor is composed of seven tinned copper wires with a cross-sectional area of 0.16 ± 0.01 mm², and the overall outer diameter is 0.48 mm. Expandable polypropylene is extruded outside the conductor to form a tightly wrapped insulating layer. After wrapping the insulating layer, the overall outer diameter is 1.25 ± 0.05 mm. The conductor and the insulating layer form a stranded core. Each cable contains two groups of the same stranded cores, and they are stranded into a cable in a right-handed back-twist manner according to a stranding pitch of 20 ± 2 mm. Outside the two groups of stranded cores after stranding, a double-sided non-self-adhesive aluminum foil is wrapped to form a wrapping layer, making the overall outer diameter reach 2.60 ± 0.1 mm. Outside the wrapping layer, a braided tinned copper wire with a specification of 16 × 6 × 0.10 ± 0.01 mm is wrapped to form a shielding layer, making the overall outer diameter reach 2.70 ± 0.1 mm, thus forming a semi-finished cable.

[0035] To further verify the relevant performance of the sheath layer of this application, the applicant uses the following examples and comparative examples for detailed description.

[0036] Material source

[0037] Unless otherwise specified, the raw materials used in this application are all commercially available products, specifically:

[0038] Methyl methacrylate is purchased from Jilin Chemical Industry Company;

[0039] Isobornyl acrylate is purchased from Jilin Chemical Industry Company;

[0040] Butyl acrylate is purchased from Jilin Chemical Industry Company;

[0041] Methyl acrylate is purchased from Jilin Chemical Industry Company;

[0042] 2-Ethylhexyl acrylate is purchased from Jilin Chemical Industry Company;

[0043] tert-Dodecyl mercaptan is purchased from Shandong Yukang Chemical Co., Ltd.;

[0044] Magnesium-aluminum hydrotalcite is purchased from Shanghai Macklin Biochemical Co., Ltd.;

[0045] Ammonium polyphosphate is purchased from Shanghai Macklin Biochemical Co., Ltd.;

[0046] Resorcinol bis(diphenyl phosphate) is purchased from Shanghai Macklin Biochemical Co., Ltd., CAS No. 57583-54-7;

[0047] 9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is purchased from Shanghai Macklin Biochemical Co., Ltd., CAS No. 35948-25-5;

[0048] Bisphenol A-bis(diphenyl phosphate) is purchased from Shanghai Macklin Biochemical Co., Ltd., CAS No. 5945-33-5;

[0049] Ammonium dihydrogen phosphate was purchased from Shanghai Macklin Biochemical Co., Ltd.;

[0050] Polyvinyl chloride was purchased from Hanwha Chemical (Ningbo) Co., Ltd.;

[0051] Zinc borate was purchased from Shandong Jiuchong Chemical Co., Ltd.;

[0052] Mica was purchased from Shandong Yuanbang New Materials Co., Ltd.;

[0053] Antimony trioxide was purchased from Shandong Yuanbang New Materials Co., Ltd.;

[0054] Magnesium oxide was purchased from Shandong Yuanbang New Materials Co., Ltd.;

[0055] Calcium carbonate was purchased from Shandong Yuanbang New Materials Co., Ltd.;

[0056] Dioctyl phthalate was purchased from Shandong Jichuang Chemical Co., Ltd.

[0057] The present application will be further described in detail below in conjunction with Preparation Examples, Examples and Comparative Examples.

[0058] Method for measuring intrinsic viscosity: Place the acrylate copolymer in an incubator at 65 °C for 10 h. After cooling, accurately weigh 0.75 g of the sample using an analytical balance and transfer it to a 250 ml volumetric flask. Subsequently, add 150 mL of chloroform to the volumetric flask and place it in a constant temperature water bath at (35 ± 0.1) °C for 12 h to completely dissolve the sample. After dissolution is complete, dilute the solution to 250 ml with chloroform. Finally, use an Ubbelohde viscometer to measure the viscosities of the solution and chloroform respectively. The formula for calculating the intrinsic viscosity is as follows:

[0059] η r = t / t0;

[0060] η sp = η r - 1;

[0061] η = 1 / c * (η sp - ln η r ); -2 ;

[0062] t: Time for the modifier solution to flow through the capillary / s, t0: Time for the solvent chloroform to flow through the same capillary / s, c: Mass concentration of the solution / g per 100 mL, η r : Relative viscosity, η sp : Specific viscosity, η: Intrinsic viscosity.

[0063] Preparation Example 1.1

[0064] Preparation method of acrylate copolymer, comprising the following steps:

[0065] Disperse 0.8 kg of potassium persulfate and 4 kg of sodium dodecyl sulfate in 200 L of water, and introduce nitrogen for protection. Continuously stir at a temperature of 60 °C for 5 min, then add 12 kg of methyl methacrylate, 1 kg of isobornyl acrylate, and 50 g of tert-dodecyl mercaptan. Carry out heat preservation reaction for 6 h under the condition that the stirring rate is 230 r / min. Detect the conversion rate of methyl methacrylate. After reaching 98%, take the material for demulsification and drying to obtain an acrylate copolymer with an intrinsic viscosity of 5.78 dL / g.

[0066] Preparation Example 1.2

[0067] Preparation method of acrylate copolymer, comprising the following steps:

[0068] Disperse 0.8 kg of potassium persulfate and 4 kg of sodium dodecyl sulfate in 200 L of water, and introduce nitrogen for protection. Continuously stir at a temperature of 60 °C for 5 min, then add 12 kg of methyl methacrylate, 1 kg of isobornyl acrylate, and 200 g of tert-dodecyl mercaptan. Carry out heat preservation reaction for 6 h under the condition that the stirring rate is 230 r / min. Detect the conversion rate of methyl methacrylate. After reaching 98%, take the material for demulsification and drying to obtain an acrylate copolymer with an intrinsic viscosity of 1.03 dL / g.

[0069] Preparation Example 2.1

[0070] The preparation method of acrylate copolymer is different from that of Preparation Example 1.1 in that: the dosage of tert-dodecyl mercaptan is 90 g, and the rest are the same as those of Preparation Example 1.1, and an acrylate copolymer with an intrinsic viscosity of 4.86 dL / g is obtained.

[0071] Preparation Example 2.2

[0072] The preparation method of acrylate copolymer is different from that of Preparation Example 1.1 in that: the dosage of tert-dodecyl mercaptan is 130 g, and the rest are the same as those of Preparation Example 1.1, and an acrylate copolymer with an intrinsic viscosity of 3.24 dL / g is obtained.

[0073] Preparation Example 2.3

[0074] The preparation method of acrylate copolymer is different from that of Preparation Example 1.1 in that: the dosage of tert-dodecyl mercaptan is 170 g, and the rest are the same as those of Preparation Example 1.1, and an acrylate copolymer with an intrinsic viscosity of 2.19 dL / g is obtained.

[0075] Preparation Example 3.1

[0076] The preparation method of the acrylate copolymer is different from Preparation Example 2.2 in that isobornyl acrylate is replaced by butyl acrylate, and the rest is the same as Preparation Example 2.2, obtaining an acrylate copolymer with an intrinsic viscosity of 4.10 dL / g.

[0077] Preparation Example 3.2

[0078] The preparation method of the acrylate copolymer is different from Preparation Example 2.2 in that isobornyl acrylate is replaced by methyl acrylate, and the rest is the same as Preparation Example 2.2, obtaining an acrylate copolymer with an intrinsic viscosity of 3.86 dL / g.

[0079] Preparation Example 3.3

[0080] The preparation method of the acrylate copolymer is different from Preparation Example 2.2 in that isobornyl acrylate is replaced by isooctyl acrylate, and the rest is the same as Preparation Example 2.2, obtaining an acrylate copolymer with an intrinsic viscosity of 4.02 dL / g.

[0081] Preparation Example 4.1

[0082] The preparation method of the phosphorus-based compound modified magnesium-aluminum hydrotalcite includes the following steps:

[0083] A total of 6 kg of the phosphorus-based compound is continuously stirred at a temperature of 120 °C until completely melted, then 1.2 kg of magnesium-aluminum hydrotalcite is added, stirring is stopped after 6 h, the solid substance is filtered by suction, washed, then placed in a drying oven and dried at 60 °C for 30 min, and after drying, it is ground to 500 meshes to obtain the phosphorus-based compound modified magnesium-aluminum hydrotalcite, wherein the phosphorus-based compound is obtained by mixing 2 kg of ammonium polyphosphate, 1 kg of resorcinol bis(diphenyl phosphate), and 3 kg of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

[0084] Preparation Example 4.2

[0085] The preparation method of the phosphorus-based compound modified magnesium-aluminum hydrotalcite includes the following steps:

[0086] A total of 6 kg of the phosphorus-based compound is continuously stirred at a temperature of 120 °C until completely melted, then 1.2 kg of magnesium-aluminum hydrotalcite is added, stirring is stopped after 6 h, the solid substance is filtered by suction, washed, then placed in a drying oven and dried at 60 °C for 30 min, and after drying, it is ground to 500 meshes to obtain the phosphorus-based compound modified magnesium-aluminum hydrotalcite, wherein the phosphorus-based compound is obtained by mixing 2 kg of ammonium polyphosphate, 2 kg of resorcinol bis(diphenyl phosphate), and 2 kg of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

[0087] Preparation Example 4.3

[0088] Preparation method of phosphorus-based compound modified magnesium-aluminum layered double hydroxide, comprising the following steps:

[0089] A total of 6 kg of phosphorus-based compound is continuously stirred at a temperature of 120 °C until completely melted, then 1.2 kg of magnesium-aluminum layered double hydroxide is added. After stirring for 6 h, stirring is stopped, and the solid substance is filtered by suction, washed, then placed in a drying oven and dried at 60 °C for 30 min. After drying, it is ground to 500 meshes to obtain phosphorus-based compound modified magnesium-aluminum layered double hydroxide, wherein the phosphorus-based compound is obtained by mixing 2 kg of ammonium polyphosphate, 0.5 kg of resorcinol bis(diphenyl phosphate), and 3.5 kg of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

[0090] Preparation Example 4.4

[0091] Preparation method of phosphorus-based compound modified magnesium-aluminum layered double hydroxide, comprising the following steps:

[0092] A total of 6 kg of phosphorus-based compound is continuously stirred at a temperature of 120 °C until completely melted, then 1.2 kg of magnesium-aluminum layered double hydroxide is added. After stirring for 6 h, stirring is stopped, and the solid substance is filtered by suction, washed, then placed in a drying oven and dried at 60 °C for 30 min. After drying, it is ground to 500 meshes to obtain phosphorus-based compound modified magnesium-aluminum layered double hydroxide, wherein the phosphorus-based compound is obtained by mixing 2 kg of ammonium polyphosphate, 3.5 kg of resorcinol bis(diphenyl phosphate), and 0.5 kg of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

[0093] Preparation Example 5.1

[0094] The preparation method of phosphorus-based compound modified magnesium-aluminum layered double hydroxide is different from that of Preparation Example 4.1 in that: resorcinol bis(diphenyl phosphate) is replaced by triphenyl phosphate, and the rest are the same as those in Preparation Example 4.1.

[0095] Preparation Example 5.2

[0096] The preparation method of phosphorus-based compound modified magnesium-aluminum layered double hydroxide is different from that of Preparation Example 4.1 in that: 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is replaced by bisphenol A-bis(diphenyl phosphate), and the rest are the same as those in Preparation Example 4.1.

[0097] Preparation Example 5.3

[0098] The preparation method of phosphorus-based compound modified magnesium-aluminum layered double hydroxide is different from that of Preparation Example 4.1 in that: ammonium polyphosphate is replaced by ammonium dihydrogen phosphate, and the rest are the same as those in Preparation Example 4.1.

[0099] Preparation Example 6.1

[0100] Preparation method of lanthanum-modified St-MAH-AN terpolymer, comprising the following steps:

[0101] Blend 3 kg of styrene, 2 kg of acrylonitrile, 8 kg of maleic anhydride and 30 g of dibenzoyl peroxide, react at a temperature of 70 °C for 2 h. At this time, the polymerization liquid becomes viscous. Wash with a 3 wt% ethanol solution and dry to obtain a terpolymer. Subsequently, disperse 10 kg of the terpolymer in 64 L of a sodium hydroxide solution with a concentration of 0.1 mol / L, then heat and stir at a temperature of 80 °C until the system becomes completely clear. While maintaining the temperature, add 36 L of a lanthanum chloride solution with a concentration of 0.1 mol / L, continue to stir and react for 30 min, cool, stand still, filter to obtain a filter residue, wash it several times with deionized water, and then vacuum dry at a temperature of 50 °C for 24 h to obtain the lanthanum-modified St-MAH-AN terpolymer.

[0102] Preparation Example 6.2

[0103] Preparation method of lanthanum-modified St-MAH-AN terpolymer, comprising the following steps:

[0104] Blend 3 kg of styrene, 2 kg of acrylonitrile, 8 kg of maleic anhydride and 30 g of dibenzoyl peroxide, react at a temperature of 70 °C for 2 h. At this time, the polymerization liquid becomes viscous. Wash with a 3 wt% ethanol solution and dry to obtain a terpolymer. Subsequently, disperse 10 kg of the terpolymer in 64 L of a sodium hydroxide solution with a concentration of 0.1 mol / L, then heat and stir at a temperature of 80 °C until the system becomes completely clear. While maintaining the temperature, add 72 L of a lanthanum chloride solution with a concentration of 0.1 mol / L, continue to stir and react for 30 min, cool, stand still, filter to obtain a filter residue, wash it several times with deionized water, and then vacuum dry at a temperature of 50 °C for 24 h to obtain the lanthanum-modified St-MAH-AN terpolymer.

[0105] Preparation Example 7.1

[0106] The preparation method of the lanthanum-modified St-MAH-AN terpolymer is different from that of Preparation Example 6.1 in that: the concentration of the lanthanum chloride solution remains unchanged, the amount used is 46 L, and the rest are the same as those in Preparation Example 6.1.

[0107] Preparation Example 7.2

[0108] The preparation method of the lanthanum-modified St-MAH-AN terpolymer is different from that of Preparation Example 6.1 in that: the concentration of the lanthanum chloride solution remains unchanged, the amount used is 57.6 L, and the rest are the same as those in Preparation Example 6.1.

[0109] Preparation Example 7.3

[0110] Preparation method of lanthanum-modified St-MAH-AN terpolymer, different from Preparation Example 6.1 in that: the concentration of lanthanum chloride solution remains unchanged, the dosage is 64 L, and the rest are the same as Preparation Example 6.1.

[0111] Comparative Preparation Example 1

[0112] Preparation method of acrylate copolymer, different from Preparation Example 1.1 in that: the dosage of tert-dodecyl mercaptan is 25 g, and the rest are the same as Preparation Example 1.1, obtaining an acrylate copolymer with an intrinsic viscosity of 6.11 dL / g.

[0113] Comparative Preparation Example 2

[0114] Preparation method of St-MAH-AN terpolymer, comprising the following steps:

[0115] Blend 6 kg of styrene, 4 kg of acrylonitrile, 16 kg of maleic anhydride and 60 g of dibenzoyl peroxide, react at a temperature of 70 °C for 2 h. At this time, the polymerization liquid becomes viscous. Wash with a 3 wt% ethanol solution and dry to obtain the St-MAH-AN terpolymer.

[0116] Example 1.1

[0117] Preparation process of a high-temperature resistant and low-loss radio frequency cable for intelligent networked vehicles, comprising the following steps:

[0118] S1. Mixing: Stir polyvinyl chloride, heat stabilizer and refractory filler at a speed of 800 r / min for 5 min, then at a speed of 800 r / min, feed the acrylate copolymer at a feeding speed of 5 kg / min. After feeding, homogenize at a speed of 1200 r / min for 5 min until there is no powder accumulation on the liquid surface, and finally homogenize at a speed of 1400 r / min for 25 min to obtain a mixed material. The specific material dosages are shown in Table 1, wherein the acrylate copolymer is prepared from Preparation Example 1.1, the phosphorus-based compound-modified magnesium-aluminum hydrotalcite is prepared from Preparation Example 4.1, the lanthanum-modified St-MAH-AN terpolymer is prepared from Preparation Example 6.1, the refractory filler A is mica, and the refractory filler B is antimony trioxide;

[0119] S2. Prepare the crude cable;

[0120] S3. Preparation of high-temperature resistant and low-loss RF cable: Feed the mixture obtained in step S1 into an extruder and perform extrusion on the outer layer of the semi-finished cable. The temperatures of the 1st - 8th zones of the extruder are 125°C, 140°C, 160°C, 160°C, 170°C, 170°C, 180°C, and 180°C respectively. The extrusion current of the extruder is 130 A, the screw speed of the extruder is not more than 30 r / min, and the production speed is 35 m / min to form a sheath layer, and finally obtain a high-temperature resistant and low-loss RF cable.

[0121] Example 1.2

[0122] A preparation process of a high-temperature resistant and low-loss RF cable for intelligent connected vehicles includes the following steps:

[0123] S1. Mixing: Stir polyvinyl chloride, heat stabilizer, and refractory filler at a speed of 1000 r / min for 5 min, then at a speed of 600 r / min, feed acrylate copolymer at a feeding speed of 5 kg / min. After feeding, homogenize at a speed of 1400 r / min for 5 min until there is no powder accumulation on the liquid surface, and finally homogenize at a speed of 1200 r / min for 25 min to obtain the raw materials for the sheath. The specific material dosages are shown in Table 1. Among them, the acrylate copolymer is prepared from Preparation Example 1.2, the phosphorus-based compound modified magnesium-aluminum hydrotalcite is prepared from Preparation Example 4.2, the lanthanum-modified St-MAH-AN terpolymer is prepared from Preparation Example 6.2, the refractory filler A is calcium carbonate, and the refractory filler B is magnesium oxide;

[0124] S2. Preparation of semi-finished cable;

[0125] S3. Preparation of high-temperature resistant and low-loss RF cable: Feed the mixture obtained in step S1 into an extruder and perform extrusion on the outer layer of the semi-finished cable. The temperatures of the 1st - 8th zones of the extruder are 125°C, 140°C, 160°C, 160°C, 170°C, 170°C, 180°C, and 180°C respectively. The extrusion current of the extruder is 130 A, the screw speed of the extruder is not more than 30 r / min, and the production speed is 35 m / min to form a sheath layer, and finally obtain a high-temperature resistant and low-loss RF cable.

[0126] Example 1.3

[0127] A preparation process of a high-temperature resistant and low-loss RF cable for intelligent connected vehicles includes the following steps:

[0128] S1. Mixing: Polyvinyl chloride, heat stabilizer, and refractory filler are stirred at a speed of 800 r / min for 5 min. Subsequently, at a speed of 800 r / min, acrylate copolymer is fed at a rate of 5 kg / min. After feeding, the mixture is homogenized at a speed of 1200 r / min for 5 min until there is no powder accumulation on the liquid surface. Finally, it is homogenized at a speed of 1400 r / min for 25 min to obtain the raw materials for the sheath. The specific amounts of substances are shown in Table 1. Among them, the acrylate copolymer is prepared from Preparation Example 1.1, the phosphorus-based compound-modified magnesium-aluminum layered double hydroxide is prepared from Preparation Example 4.1, the lanthanum-modified St-MAH-AN terpolymer is prepared from Preparation Example 6.1, refractory filler A is mica, and refractory filler B is antimony trioxide;

[0129] S2. Prepare the crude cable;

[0130] S3. Prepare the high-temperature resistant and low-loss radio frequency cable: Feed the mixture obtained in step S1 into an extruder and perform extrusion on the outer layer of the crude cable. The temperatures of the 1st - 8th zones of the extruder are 125°C, 140°C, 160°C, 160°C, 170°C, 170°C, 180°C, and 180°C respectively. The extrusion current of the extruder is 130 A, the screw speed of the extruder is not more than 30 r / min, and the production speed is 35 m / min to form a sheath layer, and finally obtain the high-temperature resistant and low-loss radio frequency cable.

[0131] Table 1 Dosages of each substance in step S1 in Examples 1.1 - 1.2 (kg)

[0132]

[0133] Example 1.4

[0134] A preparation process for a high-temperature resistant and low-loss radio frequency cable for intelligent connected vehicles, which is different from Example 1.3 in that: in step S1, the dosage of the phosphorus-based compound-modified magnesium-aluminum layered double hydroxide prepared from Preparation Example 1.1 is 12 kg, the dosage of zinc borate is 2.4 kg, and the dosage of the lanthanum-modified St-MAH-AN terpolymer prepared from Preparation Example 6.1 is 3.6 kg, and the rest are the same as in Example 1.3.

[0135] Example 1.5

[0136] A preparation process for a high-temperature resistant and low-loss radio frequency cable for intelligent connected vehicles, which is different from Example 1.3 in that: in step S1, the dosage of the phosphorus-based compound-modified magnesium-aluminum layered double hydroxide prepared from Preparation Example 1.1 is 12.5 kg, the dosage of zinc borate is 2.5 kg, and the dosage of the lanthanum-modified St-MAH-AN terpolymer prepared from Preparation Example 6.1 is 3 kg, and the rest are the same as in Example 1.3.

[0137] Examples 2.1 - 2.3

[0138] The preparation process of a high-temperature resistant and low-loss radio frequency cable for intelligent connected vehicles is different from that of Example 1.4 in that: in step S1, the acrylate copolymer prepared in Preparation Example 1.1 is respectively replaced with the acrylate copolymers prepared in Preparation Examples 2.1-2.3, and the rest are the same as those in Example 1.4.

[0139] Examples 3.1-3.3

[0140] The preparation process of a high-temperature resistant and low-loss radio frequency cable for intelligent connected vehicles is different from that of Example 2.2 in that: in step S1, the acrylate copolymer prepared in Preparation Example 2.2 is respectively replaced with the acrylate copolymers prepared in Preparation Examples 3.1-3.3, and the rest are the same as those in Example 2.2.

[0141] Examples 4.1-4.2

[0142] The preparation process of a high-temperature resistant and low-loss radio frequency cable for intelligent connected vehicles is different from that of Example 1.4 in that: in step S1, the phosphorus-based compound modified magnesium-aluminum hydrotalcite prepared in Preparation Example 4.1 is respectively replaced with the phosphorus-based compound modified magnesium-aluminum hydrotalcites prepared in Preparation Examples 4.3-4.4, and the rest are the same as those in Example 1.4.

[0143] Examples 5.1-5.3

[0144] The preparation process of a high-temperature resistant and low-loss radio frequency cable for intelligent connected vehicles is different from that of Example 1.4 in that: in step S1, the phosphorus-based compound modified magnesium-aluminum hydrotalcite prepared in Preparation Example 4.1 is respectively replaced with the phosphorus-based compound modified magnesium-aluminum hydrotalcites prepared in Preparation Examples 5.1-5.3, and the rest are the same as those in Example 1.4.

[0145] Examples 6.1-6.3

[0146] The preparation process of a high-temperature resistant and low-loss radio frequency cable for intelligent connected vehicles is different from that of Example 1.4 in that: in step S1, the lanthanum-modified St-MAH-AN terpolymer prepared in Preparation Example 6.1 is respectively replaced with the lanthanum-modified St-MAH-AN terpolymers prepared in Preparation Examples 7.1-7.3, and the rest are the same as those in Example 1.4.

[0147] Comparative Example 1.1

[0148] It is different from Example 1.4 in that: in step S1, the acrylate copolymer prepared in Preparation Example 1.1 is replaced with dioctyl phthalate, and the rest are the same as those in Example 1.4.

[0149] Comparative Example 1.2

[0150] It is different from Example 1.4 in that: in step S1, the phosphorus-based compound-modified magnesium-aluminum hydrotalcite prepared in Preparation Example 4.1 is removed, the dosage of zinc borate is 7.2 kg, and the dosage of the lanthanum-modified St-MAH-AN terpolymer prepared in Preparation Example 6.1 is 10.8 kg, and the rest are the same as in Example 1.4.

[0151] Comparative Example 1.3

[0152] It is different from Example 1.4 in that: in step S1, zinc borate is removed, the dosage of the phosphorus-based compound-modified magnesium-aluminum hydrotalcite prepared in Preparation Example 4.1 is 13.8 kg, and the dosage of the lanthanum-modified St-MAH-AN terpolymer prepared in Preparation Example 6.1 is 4.2 kg, and the rest are the same as in Example 1.4.

[0153] Comparative Example 1.4

[0154] It is different from Example 1.4 in that: in step S1, the lanthanum-modified St-MAH-AN terpolymer prepared in Preparation Example 6.1 is removed, the dosage of zinc borate is 5 kg, and the dosage of the phosphorus-based compound-modified magnesium-aluminum hydrotalcite prepared in Preparation Example 4.1 is 15 kg, and the rest are the same as in Example 1.4.

[0155] Comparative Example 2.1

[0156] It is different from Example 1.4 in that: in step S1, the acrylate copolymer prepared in Preparation Example 1.1 is replaced with the acrylate copolymer prepared in Comparative Preparation Example 1, and the rest are the same as in Example 1.4.

[0157] Comparative Example 2.2

[0158] It is different from Example 1.4 in that: in step S1, the phosphorus-based compound-modified magnesium-aluminum hydrotalcite prepared in Preparation Example 4.1 is replaced with magnesium-aluminum hydrotalcite, and the rest are the same as in Example 1.4.

[0159] Comparative Example 2.3

[0160] It is different from Example 1.4 in that: in step S1, the lanthanum-modified St-MAH-AN terpolymer prepared in Preparation Example 6.1 is replaced with the St-MAH-AN terpolymer prepared in Comparative Preparation Example 1, and the rest are the same as in Example 1.4.

[0161] Performance Testing

[0162] 1. Place the cables prepared in the examples and comparative examples under a N2 atmosphere and heat them from 25 °C to 150 °C at a heating rate of 10 °C / min, and record the mass retention rate (%) of each group of cables in Table 2;

[0163] 2. The high-temperature power supply stability of the cables prepared in the examples and comparative examples was determined with reference to the standard of GB / T 19216.21-2003. A voltage of 1000 V was applied, and the firing time was 180 min. The highest firing temperature / °C at which no short circuit (the 2 A fuse did not blow) and the conductor did not melt (the indicator light did not go out) were maintained during the test, and were recorded in Table 2;

[0164] 3. 5 g of the sheath layer of the cables prepared in the examples and comparative examples was taken respectively and pressed into a 3-mm thin sheet. The thin sheet was fixed on an abrasion tester and subjected to the same number of scratches under a frictional force of 50 N. The thin sheet was taken off and weighed, and the worn mass was used as a parameter to evaluate the abrasion resistance of the material. The mass loss rate (%) was recorded in Table 2.

[0165] Table 2 Performance Detection Table

[0166]

[0167] Data Analysis:

[0168] As can be seen from Table 2, the high-temperature resistant and low-loss radio frequency cables for intelligent networked vehicles obtained in Examples 1.1-1.3 had a high-temperature mass retention rate of 98.3-98.9% at 150 °C, a frictional mass loss rate of 1.40-1.41% under a frictional force of 50 N, and a highest firing temperature of 920-935 °C. It was proved that by using the substances within the defined ratio range in this application, the synergistic effect between the heat stabilizer and the fire-resistant filler was fully exerted, the thermal stability of the sheath layer was improved, and the compatibility between the substances in the system was improved by using an acrylate copolymer with an intrinsic viscosity < 5.8 dL / g. By blending and extruding the above substances with polyvinyl chloride, a sheath layer with good thermal stability and mechanical strength could be obtained, which played a good protective role for the overall cable.

[0169] Examples 1.4 - 1.5 are different from Example 1.3 in the weight ratios of the phosphorus - based compound - modified magnesium - aluminum layered double hydroxide, zinc borate, and lanthanum - modified St - MAH - AN terpolymer in the heat stabilizer. Among them, the cable in Example 1.4 has the highest high - temperature mass retention rate and maximum fire - supply temperature, and the lowest friction mass loss rate, which proves that the specific ratio in this application can maximize the synergistic effect of each component. The phosphorus - based compound - modified magnesium - aluminum layered double hydroxide has good flame - retardant and heat - resistant properties, can decompose and absorb heat at high temperatures, and reduce the oxygen concentration; zinc borate further enhances the flame - retardant effect and optimizes the effects of other heat stabilizers; the lanthanum - modified St - MAH - AN terpolymer improves the mechanical strength and weather resistance of the material. The combined action of these components in the optimal ratio significantly improves the overall thermal stability and mechanical properties of the sheath layer, effectively preventing the aging, cracking, or melting of the insulating layer at high temperatures, thereby reducing the probability of safety hazards such as short - circuit and leakage, and ensuring the safe and reliable operation of the charging and discharging system.

[0170] Examples 2.1 - 2.3 are different from Example 1.4 in that the intrinsic viscosity of the acrylate copolymer used is different. Among them, the cable in Example 2.2 has the highest high - temperature mass retention rate and maximum fire - supply temperature, and the lowest friction mass loss rate, which proves that by controlling the amount of tert - dodecyl mercaptan in the preparation of the acrylate copolymer in this application, the intrinsic viscosity of the acrylate copolymer is at the most suitable size, enabling more effective entanglement with the molecular chain of polyvinyl chloride, ensuring that itself, the refractory filler, and the heat stabilizer are all uniformly interspersed in the polyvinyl chloride matrix, thereby further improving the compatibility of various substances in the sheath layer and the overall mechanical strength and thermal stability of the sheath layer.

[0171] Examples 3.1 - 3.3 are different from Example 1.4 in that the types of monomers in the acrylate copolymer used are different, and the high - temperature mass retention rate and maximum fire - supply temperature of the cables in Examples 3.1 - 3.3 are lower than those in Example 1.4, and the friction mass loss rate is also higher than that in Example 1.4, which proves that using isobornyl acrylate in this application can achieve a more excellent effect of improving thermal stability than other acrylic monomers, and its compatibility with the polyvinyl chloride system is also better, thereby improving the overall thermal stability and mechanical stability of the cable.

[0172] Examples 4.1 - 4.2 are different from Example 1.4 in that the proportions of various substances in the phosphorus - based compound in the phosphorus - based compound - modified magnesium - aluminum layered double hydroxide are different, and the high - temperature mass retention rate and maximum fire - supply temperature of the cables in Examples 4.1 - 4.2 are lower than those in Example 1.4, which proves that there is a sufficient synergistic effect among the phosphorus - based compounds in this application, and only when they are combined in a certain proportion can an unexpected effect of improving heat resistance be achieved.

[0173] Examples 5.1 - 5.3 are different from Example 1.4 in that the phosphorus-based compounds used to modify the magnesium-aluminum layered double hydroxide are different. Moreover, the high-temperature mass retention rate and the maximum fire supply temperature of the cables in Examples 5.1 - 5.3 are lower than those in Example 1.4, which proves that there is a sufficient synergistic effect among the phosphorus-based compounds of the present application. When the cable is heated, a stable protective film can be formed within the sheath layer system, effectively inhibiting the decomposition and combustion of the sheath layer, reducing smoke generation, and improving the overall flame retardancy and heat resistance stability of the sheath layer.

[0174] Examples 6.1 - 6.3 are different from Example 1.4 in that the lanthanum-modified St-MAH-AN terpolymer used is different. Among them, the cable in Example 6.2 has the highest high-temperature mass retention rate and the maximum fire supply temperature, and the lowest friction mass loss rate, which proves that by strictly controlling the weight ratio of the terpolymer to lanthanum ions, the present application optimizes the doping rate of lanthanum to the greatest extent without incurring additional costs, raises the heat resistance of the sheath layer to the highest level, effectively prevents the aging, cracking or melting of the sheath layer caused by high temperature, reduces the risks of short circuit and electric leakage, and ensures the safe and reliable operation of the cable.

[0175] Comparative Example 1.1 is different from Example 1.4 in that the acrylate copolymer prepared in Preparation Example 1.1 is replaced with dioctyl phthalate. The data shows that the high-temperature mass retention rate and the maximum fire supply temperature of the cable in Comparative Example 1.1 are lower than those in Example 1.4, and the friction mass loss rate is also higher than that in Example 1.4, which proves that the acrylate copolymer of the present application improves the compatibility of various substances in the system, significantly optimizes the internal compatibility degree of the sheath layer, and thus not only improves the thermal stability of the sheath layer but also improves the mechanical stability of the sheath layer.

[0176] Comparative Examples 1.2 - 1.4 are different from Example 1.4 in that the phosphorus-based compound-modified magnesium-aluminum layered double hydroxide, zinc borate, and lanthanum-modified St-MAH-AN terpolymer in the heat stabilizer are removed respectively. The data shows that the high-temperature mass retention rate and the maximum fire supply temperature of the cables in Comparative Examples 1.2 - 1.4 are lower than those in Example 1.4, which proves that the phosphorus-based compound-modified magnesium-aluminum layered double hydroxide, zinc borate, and lanthanum-modified St-MAH-AN terpolymer can fully exert a good synergistic effect after blending, greatly improving the thermal stability of the sheath layer.

[0177] Comparative Example 2.1 is different from Example 1.4 in that the intrinsic viscosity of the acrylate copolymer is different. The data shows that the high-temperature mass retention rate and the maximum fire supply temperature of the cable in Comparative Example 2.1 are lower than those in Example 1.4, and the frictional mass loss rate is also much higher than that in Example 1.4, proving that the acrylate copolymer of the present application improves the compatibility of various substances in the system, and strictly controls the intrinsic viscosity of the acrylate copolymer to be <5.8 dL / g, so that the internal compatibility degree of the sheath layer is significantly optimized, thereby not only improving the thermal stability of the sheath layer, but also improving the mechanical stability of the sheath layer.

[0178] Comparative Examples 2.2 - 2.3 are different from Example 1.4 in that the phosphorus compound-modified magnesium-aluminum type hydrotalcite and the lanthanum-modified St-MAH-AN terpolymer are respectively replaced. The data shows that the high-temperature mass retention rate and the maximum fire supply temperature of the cables in Comparative Examples 2.2 - 2.3 are lower than those in Example 1.4, proving that both the phosphorus compound-modified magnesium-aluminum type hydrotalcite and the lanthanum-modified St-MAH-AN terpolymer of the present application have extremely high thermal stability, and at the same time, compared with their unmodified substances, the synergistic effect between the two and zinc borate is better.

[0179] The examples of the specific implementation manners are all preferred examples of the present application, and do not limit the protection scope of the present application accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A high temperature resistant and low loss radio frequency cable for intelligent networked vehicles, comprising a twisted wire core, a wrapping layer, a shielding layer and a sheath layer sequentially coated on the outer side of the twisted wire core, characterized in that: The raw materials used for the sheath layer include the following components by weight: 100 parts of polyvinyl chloride; 30-35 parts of acrylic copolymer; 15-20 parts of heat stabilizer and 15-20 parts of refractory filler; The intrinsic viscosity of the acrylic copolymer is less than 5.8 dL / g, and the thermal stabilizer includes a phosphorus compound-modified magnesium-aluminum hydrotalcite, zinc borate and a lanthanum-modified St-MAH-AN ternary copolymer in a weight ratio of 25:5:(5-8); the acrylic copolymer is prepared by the following method: methyl methacrylate, isobornyl acrylate and tert-dodecyl mercaptan in a weight ratio of 120:10:(0.5-2.0) are mixed and dispersed in water containing an initiator a and an emulsifier, stirred for reaction, demulsified and dried; the phosphorus compound in the phosphorus compound-modified magnesium-aluminum hydrotalcite includes a polyphosphorus compound in a weight ratio of 1:(0.5-1):(1-1.5) The lanthanum modified St-MAH-AN terpolymer is prepared by the following method: styrene, acrylonitrile, maleic anhydride and initiator b are blended, heated to react, washed, dried to obtain a terpolymer, then the terpolymer is dispersed in an alkaline solution, heated and stirred until the system is completely clarified and then kept warm, and then lanthanum chloride solution is added to ensure that the weight ratio of the terpolymer to lanthanum ions in the system is 10: (0.5-1), stirred to react, cooled, allowed to stand, filtered to obtain a filter residue, and washed.

2. The high temperature resistant and low loss radio frequency cable for intelligent networked vehicles according to claim 1, characterized in that: The raw materials used for the sheath layer include the following components by weight: 100 parts of polyvinyl chloride; 32 parts of acrylic copolymer; 18 parts of heat stabilizer and 18 parts of refractory filler.

3. The high temperature resistant and low loss radio frequency cable for intelligent networked vehicles according to claim 2, characterized in that: The thermal stabilizer comprises a weight ratio of 25:5: 7.5 phosphorus compound modified magnesium aluminum type hydrotalcite, zinc borate and lanthanum modified St-MAH-AN terpolymer.

4. The high temperature resistant and low loss radio frequency cable for intelligent networked vehicles according to claim 1, characterized in that: The weight ratio of the methyl methacrylate, isobornyl acrylate and tert-dodecyl mercaptan is 120:10:1.

3.

5. The high temperature resistant and low loss radio frequency cable for intelligent connected vehicles according to claim 1, characterized in that: After adding the lanthanum chloride solution, the weight ratio of the terpolymer to the lanthanum ions in the system is 10:0.

8.

6. A process for preparing a high temperature resistant and low loss radio frequency cable for an intelligent connected vehicle according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1, mixing: the polyvinyl chloride, heat stabilizer and refractory filler are stirred at a speed of 800-1000 r / min, and then the acrylic copolymer is added at a speed of 600-800 r / min, and after the addition is completed, the material is mixed at a speed of 1200-1400 r / min until there is no powder accumulation on the liquid surface, and then the material is further mixed at a speed of 1200-1400 r / min to obtain a mixture; S2. Preparing a crude cable: coating an insulating layer on the surface of a conductor to obtain a twisted wire core, and then sequentially coating a sheath layer and a shielding layer on the outer side of the twisted wire core to obtain a crude cable; S3. Preparation of high temperature resistant and low loss radio frequency cable: Extruding the mixture obtained in step S1 onto the outside of the crude cable obtained in step S2 to form a sheath layer, thereby obtaining a high temperature resistant and low loss radio frequency cable.

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