Polyvinyl chloride insulated cable material and preparation method thereof

Abstract

The invention belongs to the technical field of polyvinyl chloride preparation, and particularly relates to a polyvinyl chloride insulated cable material and a preparation method thereof. According to the polyvinyl chloride insulated cable material, PVC resin serves as matrix resin, a mixture of terephthalic acid di (2-ethylhexyl) ester, trioctyl trimellitate and epoxidized soybean oil serves as a plasticizer, a mixture of propoxylated (3) glycerol triacrylate and isocyanuric acid tri (2-acryloyloxyethyl) ester serves as a cross-linking agent, and in addition, the polyvinyl chloride insulated cable material has the advantages that the heat resistance of the cable material is improved, and the service life of the cable material is prolonged. And an antioxidant, a heat stabilizer, a flame retardant and a lubricant (di (propylene glycol) allyl ether acrylate and oxidized polyethlene wax) are also added, so that the prepared polyvinyl chloride insulated cable material has relatively good mechanical property, flame retardance, heat resistance and oxidation resistance.

Description

Technical Field

[0001] This invention belongs to the field of polyvinyl chloride preparation technology, specifically relating to a polyvinyl chloride insulated cable material and its preparation method. Background Technology

[0002] In core areas such as modern building wiring, power transmission and distribution networks, and communication signal transmission, cables are the fundamental carriers for achieving efficient and stable transmission of electrical energy and information. The performance of their insulation materials directly determines the system's operational reliability, service life, and safety level.

[0003] Polyvinyl chloride (PVC) is one of the most widely used base materials in the field of insulated cables due to its excellent electrical insulation properties, good machinability and formability, and relatively low cost. It is widely used in the preparation of insulation layers for medium and low voltage power cables, building wiring, and communication cables.

[0004] However, traditional PVC insulated cable materials have gradually revealed several shortcomings in practical applications, mainly in the following aspects: ① Insufficient compressive strength: In scenarios such as underground pre-embedded structures in buildings and around heavy-duty industrial equipment, traditional PVC insulation layers are prone to deformation and cracking due to external pressure, which can lead to electrical short circuit risks and make it difficult to meet the structural stability requirements of complex working conditions; ② Insufficient heat resistance: The long-term continuous working temperature of traditional PVC insulation materials is usually only around 70℃. In high-temperature environments such as outdoor exposure in summer and dense electrical equipment, the material is prone to accelerated aging and insulation performance degradation, which cannot meet the requirements of application scenarios with heat resistance levels of 105℃ and above; ③ Insufficient flame retardant performance: The flame retardant level of traditional formulations is mostly limited to UL94 V-2, which is prone to melting and dripping and flame spread when exposed to open flames, and cannot meet the safety requirements of B1 flame retardant for building cables and flame retardant for bundled power systems in the "Design Standard for Power Engineering Cables".

[0005] Therefore, it is necessary to explore a new type of polyvinyl chloride insulated cable material. Summary of the Invention

[0006] The purpose of this invention is to provide a polyvinyl chloride (PVC) insulated cable material, which has excellent mechanical properties, flame retardant properties, and heat resistance properties; in addition, this invention also provides its preparation method.

[0007] The polyvinyl chloride insulated cable material of the present invention is composed of the following raw materials in parts by weight: 100 parts of PVC resin, 30-32 parts of di(2-ethylhexyl) terephthalate, 5-7 parts of trioctyl trimellitate, 3-4 parts of epoxidized soybean oil, 3-3.3 parts of propoxylated (3) glycerol triacrylate, 1.0-1.1 parts of tri(2-acryloyloxyethyl) isocyanurate, 0.4-0.5 parts of antioxidant, 5-6 parts of heat stabilizer, 11-12 parts of flame retardant, 0.3-0.5 parts of di(propylene glycol) allyl ether acrylate, and 0.1-0.15 parts of oxidized polyethylene wax.

[0008] The PVC resin is SG-3 type resin.

[0009] The antioxidant is a mixture of antioxidant 1024 and antioxidant THP-24, with a mass ratio of antioxidant 1024 to antioxidant THP-24 of 3:2.

[0010] The heat stabilizer is a mixture of calcium-zinc stabilizer and hydrotalcite, with a mass ratio of calcium-zinc stabilizer to hydrotalcite of 4:1. The calcium-zinc stabilizer is BP MC 90224KA from Germany.

[0011] The flame retardant is a mixture of hexaphenoxycyclotriphosphazene and melamine borate, wherein the mass ratio of hexaphenoxycyclotriphosphazene to melamine borate is 9:1.

[0012] The method for preparing the polyvinyl chloride insulated cable material of the present invention comprises the following steps: (1) Add PVC resin to the reaction apparatus and stir. Heat the mixture to 58-60℃ and add heat stabilizer. Heat the mixture to 78-80℃ and add di(2-ethylhexyl) terephthalate, trioctyl trimellitate and epoxidized soybean oil in sequence. Heat the mixture to 93-95℃ and add pretreated flame retardant and antioxidant in sequence and stir evenly. Then add propoxylated (3) glyceryl triacrylate and tri(2-acryloyloxyethyl) isocyanurate in sequence. Finally, add oxidized polyethylene wax and di(propylene glycol) allyl ether acrylate in sequence and stir evenly. Cool the mixture to 35-38℃ and discharge to obtain the mixture. (2) The mixture is added to a twin-screw extruder for extrusion granulation. The extruded material is then water-cooled, traction-cut into pellets, and dried to obtain dried cable pellets. (3) The dried cable granules are fed into a single screw extruder and extruded into strips, and then subjected to radiation crosslinking; (4) The cross-linked irradiated sample was dried to prepare polyvinyl chloride insulated cable material.

[0013] In step (1), PVC resin is added and stirred at a speed of 300 r / min for 3-5 min; heat stabilizer is added and stirred at a speed of 600 r / min for 3-5 min; di(2-ethylhexyl) terephthalate, trioctyl trimellitate and epoxidized soybean oil are added and stirred at a speed of 600 r / min for 6-8 min; pretreated flame retardant and antioxidant are added and stirred at a speed of 600 r / min for 3-5 min; propoxylated (3) glyceryl triacrylate and tri(2-acryloyloxyethyl) isocyanurate are added and stirred at a speed of 600 r / min for 3-4 min; finally, oxidized polyethylene wax and di(propylene glycol) allyl ether acrylate are added and stirred at a speed of 600 r / min for 2-3 min.

[0014] In step (1), the pretreated flame retardant is prepared by mixing hexaphenoxycyclotriphosphazene and melamine borate, adding silane coupling agent KH-570 solution, ultrasonically dispersing for 20 min at an ultrasonic power of 300 W, then vacuum drying at 80 °C for 12 h at a vacuum degree of -0.08 MPa, and grinding through a 200-mesh sieve. The silane coupling agent solution is prepared by mixing silane coupling agent KH-570 with anhydrous ethanol, controlling the mass concentration to 10%, and the mass of silane coupling agent KH-570 accounts for 0.8% of the total mass of hexaphenoxycyclotriphosphazene and melamine borate.

[0015] In step (2), the screw speed of the twin-screw extruder is 220 r / min, the temperature of the feeding section is 117℃, the temperature of the compression section is 138℃, the temperature of the melting section is 148℃, the temperature of the homogenization section is 142℃, and the temperature of the die head section is 145℃.

[0016] In step (2), 3mm cable material particles are obtained by pelletizing. The cable material particles are dried with hot air at 80℃ for 1 hour, and then dried under vacuum at 65℃ for 45 minutes with a vacuum degree of -0.08MPa to obtain dried cable granules.

[0017] In step (3), the temperature of the feeding section of the single screw extruder is 117℃, the temperature of the compression section is 138℃, the temperature of the melting section is 148℃, the temperature of the homogenization section is 142℃, and the temperature of the die head section is 145℃.

[0018] In step (3), the irradiation dose for crosslinking is 85 kGy, the irradiation rate is 6 m / min, and the irradiation atmosphere is air.

[0019] The drying process described in step (4) is 60°C circulating air drying for 1 hour.

[0020] Compared with the prior art, the present invention has the following advantages: (1) The polyvinyl chloride insulated cable material of the present invention uses PVC resin as the base resin, a mixture of di(2-ethylhexyl) terephthalate, trioctyl trimellitate and epoxidized soybean oil as plasticizer, a mixture of propoxylated (3) glycerol triacrylate and tri(2-acryloyloxyethyl) isocyanurate as crosslinking agent, and antioxidants, heat stabilizers, flame retardants and lubricants (di(propylene glycol) allyl ether acrylate and oxidized polyethylene wax) are added to ensure that the prepared polyvinyl chloride insulated cable material has good mechanical properties, flame retardant properties, heat resistance properties and antioxidant properties.

[0021] (2) The polyvinyl chloride insulated cable material of the present invention uses a mixture of di(2-ethylhexyl) terephthalate, trioctyl trimellitate and epoxidized soybean oil as plasticizer. Di(2-ethylhexyl) terephthalate utilizes its linear short side chain structure to quickly insert into the PVC molecular chain, achieving efficient plasticization in the early stage. During the plasticization process, the epoxy groups of epoxidized soybean oil can effectively capture HCl generated by PVC degradation, interrupt the autocatalytic degradation reaction of PVC, and play a synergistic stabilizing role with calcium and zinc stabilizers. At the same time, it also plays an auxiliary role in plasticizing and reducing viscosity. In the later stage of processing and during use, trioctyl trimellitate, with its large molecular weight and heat-resistant structure, significantly reduces the volatilization loss of plasticizer in the high-temperature zone and forms a more stable entanglement network with PVC, thereby giving the cable material long-term heat resistance and low migration performance.

[0022] (3) The polyvinyl chloride (PVC) insulated cable material of the present invention uses propoxylated (3)glycerol triacrylate and tris(2-acryloyloxyethyl) isocyanurate as crosslinking agents, and prepares PVC insulated cables by irradiation crosslinking. The propoxylated (3)glycerol triacrylate molecule contains 3 acrylic double bonds, and the tris(2-acryloyloxyethyl) isocyanurate molecule contains 3 acrylic double bonds. The triazine ring serves as a rigid core, and both are trifunctional. Under irradiation conditions, they can participate in the reaction efficiently, which helps to form a three-dimensional network with high crosslinking density and more uniform distribution. This uniform network structure can reduce stress concentration, making the material more stable and reliable when subjected to thermal or mechanical stress. The rigid crosslinking points provided by the triazine ring and acrylic crosslinking structure improve the heat deformation resistance of the cable material, while the flexible segments of propoxylated (3)glycerol triacrylate ensure that the material will not become excessively brittle after crosslinking; thus, the heat resistance and mechanical properties of the prepared PVC insulation material are fundamentally ensured.

[0023] (4) The polyvinyl chloride insulated cable material of the present invention uses a mixture of antioxidant 1024 and antioxidant THP-24 as the antioxidant. Antioxidant 1024 is a phenol-oxime bifunctional antioxidant that can capture alkoxy free radicals at low temperatures and block PVC deHCl removal. At the same time, the hydrazide structure in its molecule gives it the ability to passivate metal ions. Antioxidant THP-24 is a high phosphorus phosphite that reduces hydroperoxides to alcohols at high temperatures, preventing "free radical chains" from entering the crosslinking network and avoiding oxidative embrittlement after irradiation. The combination of the two extends the antioxidant time.

[0024] (5) The polyvinyl chloride insulated cable material of the present invention uses a mixture of hexaphenoxycyclotriphosphazene and melamine borate as the flame retardant. Hexaphenoxycyclotriphosphazene decomposes upon heating to generate PO· and PO2· free radicals, which capture H· and OH· in the combustion chain reaction, thus providing gas-phase flame retardancy. Its unique P and N hybrid structure gives it high thermal stability, high limiting oxygen index and low smoke release performance. Melamine borate releases NH3 and H2O at high temperature to dilute oxygen. At the same time, the boric acid component is converted into a B2O3 glass layer, which covers the PVC surface and blocks the transfer of heat and oxygen to the interior. The two work together to improve the oxygen index.

[0025] (6) The method for preparing polyvinyl chloride insulated cable material according to the present invention has controllable process parameters, simple operation, and stable performance of the prepared polyvinyl chloride insulated cable material. Detailed Implementation

[0026] Example 1 The polyvinyl chloride insulated cable material described in Example 1 is composed of the following raw materials by weight: 100 parts PVC resin, 31 parts di(2-ethylhexyl) terephthalate, 6 parts trioctyl trimellitate, 3.5 parts epoxidized soybean oil, 3.3 parts propoxylated (3) glycerol triacrylate, 1.1 parts tri(2-acryloyloxyethyl) isocyanurate, 0.45 parts antioxidant, 5.5 parts heat stabilizer, 11.5 parts flame retardant, 0.4 parts di(propylene glycol) allyl ether acrylate, and 0.13 parts oxidized polyethylene wax.

[0027] The PVC resin is SG-3 type resin.

[0028] The antioxidant is a mixture of antioxidant 1024 and antioxidant THP-24, with a mass ratio of antioxidant 1024 to antioxidant THP-24 of 3:2.

[0029] The heat stabilizer is a mixture of calcium-zinc stabilizer and hydrotalcite, with a mass ratio of calcium-zinc stabilizer to hydrotalcite of 4:1. The calcium-zinc stabilizer is BP MC 90224KA from Germany.

[0030] The flame retardant is a mixture of hexaphenoxycyclotriphosphazene and melamine borate, wherein the mass ratio of hexaphenoxycyclotriphosphazene to melamine borate is 9:1.

[0031] The preparation method of the polyvinyl chloride insulated cable material described in Example 1 consists of the following steps: (1) Add PVC resin to the reaction apparatus and stir. Heat stabilizer is added at 59°C. Heat to 79°C and di(2-ethylhexyl) terephthalate, trioctyl trimellitate and epoxidized soybean oil are added in sequence. Heat to 94°C and pretreated flame retardant and antioxidant are added in sequence and stirred evenly. Then propoxylated (3) glycerol triacrylate and tri(2-acryloyloxyethyl) isocyanurate are added in sequence. Finally, oxidized polyethylene wax and di(propylene glycol) allyl ether acrylate are added in sequence and stirred evenly. The mixture is cooled to 37°C and discharged to obtain the mixture. (2) The mixture is added to a twin-screw extruder for extrusion granulation. The extruded material is then water-cooled, traction-cut into pellets, and dried to obtain dried cable pellets. (3) The dried cable granules are fed into a single screw extruder and extruded into strips, and then subjected to radiation crosslinking; (4) The cross-linked irradiated sample was dried to prepare polyvinyl chloride insulated cable material.

[0032] In step (1), PVC resin is added and stirred at a speed of 300 r / min for 4 min; heat stabilizer is added and stirred at a speed of 600 r / min for 4 min; di(2-ethylhexyl) terephthalate, trioctyl trimellitate and epoxidized soybean oil are added and stirred at a speed of 600 r / min for 7 min; pretreated flame retardant and antioxidant are added and stirred at a speed of 600 r / min for 4 min; propoxylated (3) glyceryl triacrylate and tri(2-acryloyloxyethyl) isocyanurate are added and stirred at a speed of 600 r / min for 4 min; finally, oxidized polyethylene wax and di(propylene glycol) allyl ether acrylate are added and stirred at a speed of 600 r / min for 3 min.

[0033] In step (1), the pretreated flame retardant is prepared by mixing hexaphenoxycyclotriphosphazene and melamine borate, adding silane coupling agent KH-570 solution, ultrasonically dispersing for 20 min at an ultrasonic power of 300 W, then vacuum drying at 80 °C for 12 h at a vacuum degree of -0.08 MPa, and grinding through a 200-mesh sieve. The silane coupling agent solution is prepared by mixing silane coupling agent KH-570 with anhydrous ethanol, controlling the mass concentration to 10%, and the mass of silane coupling agent KH-570 accounts for 0.8% of the total mass of hexaphenoxycyclotriphosphazene and melamine borate.

[0034] In step (2), the screw speed of the twin-screw extruder is 220 r / min, the temperature of the feeding section is 117℃, the temperature of the compression section is 138℃, the temperature of the melting section is 148℃, the temperature of the homogenization section is 142℃, and the temperature of the die head section is 145℃.

[0035] In step (2), 3mm cable material particles are obtained by pelletizing. The cable material particles are dried with hot air at 80℃ for 1 hour, and then vacuum dried at 65℃ for 45 minutes with a vacuum degree of -0.08MPa to obtain dried cable granules. In step (3), the temperature of the feeding section of the single screw extruder is 117℃, the temperature of the compression section is 138℃, the temperature of the melting section is 148℃, the temperature of the homogenization section is 142℃, and the temperature of the die head section is 145℃.

[0036] In step (3), the irradiation dose for crosslinking is 85 kGy, the irradiation rate is 6 m / min, and the irradiation atmosphere is air.

[0037] The drying process described in step (4) is 60°C circulating air drying for 1 hour.

[0038] Example 2 The polyvinyl chloride insulated cable material described in Example 2 is composed of the following raw materials by weight: 100 parts PVC resin, 30 parts di(2-ethylhexyl) terephthalate, 7 parts trioctyl trimellitate, 3 parts epoxidized soybean oil, 3 parts propoxylated (3) glycerol triacrylate, 1.0 part tri(2-acryloyloxyethyl) isocyanurate, 0.4 parts antioxidant, 6 parts heat stabilizer, 11 parts flame retardant, 0.3 parts di(propylene glycol) allyl ether acrylate, and 0.15 parts oxidized polyethylene wax.

[0039] The PVC resin is SG-3 type resin.

[0040] The antioxidant is a mixture of antioxidant 1024 and antioxidant THP-24, with a mass ratio of antioxidant 1024 to antioxidant THP-24 of 3:2.

[0041] The heat stabilizer is a mixture of calcium-zinc stabilizer and hydrotalcite, with a mass ratio of calcium-zinc stabilizer to hydrotalcite of 4:1. The calcium-zinc stabilizer is BP MC 90224KA from Germany.

[0042] The flame retardant is a mixture of hexaphenoxycyclotriphosphazene and melamine borate, wherein the mass ratio of hexaphenoxycyclotriphosphazene to melamine borate is 9:1.

[0043] The preparation method of the polyvinyl chloride insulated cable material described in Example 2 consists of the following steps: (1) Add PVC resin to the reaction apparatus and stir. Heat stabilizer is added at 60°C. Heat to 78°C and di(2-ethylhexyl) terephthalate, trioctyl trimellitate and epoxidized soybean oil are added in sequence. Heat to 93°C and pretreated flame retardant and antioxidant are added in sequence and stirred evenly. Then propoxylated (3) glycerol triacrylate and tri(2-acryloyloxyethyl) isocyanurate are added in sequence. Finally, oxidized polyethylene wax and di(propylene glycol) allyl ether acrylate are added in sequence and stirred evenly. The mixture is cooled to 35°C and discharged to obtain the mixture. (2) The mixture is added to a twin-screw extruder for extrusion granulation. The extruded material is then water-cooled, traction-cut into pellets, and dried to obtain dried cable pellets. (3) The dried cable granules are fed into a single screw extruder and extruded into strips, and then subjected to radiation crosslinking; (4) The cross-linked irradiated sample was dried to prepare polyvinyl chloride insulated cable material.

[0044] In step (1), PVC resin is added and stirred at a speed of 300 r / min for 3 min; heat stabilizer is added and stirred at a speed of 600 r / min for 5 min; di(2-ethylhexyl) terephthalate, trioctyl trimellitate and epoxidized soybean oil are added and stirred at a speed of 600 r / min for 6 min; pretreated flame retardant and antioxidant are added and stirred at a speed of 600 r / min for 3 min; propoxylated (3) glyceryl triacrylate and tri(2-acryloyloxyethyl) isocyanurate are added and stirred at a speed of 600 r / min for 3 min; finally, oxidized polyethylene wax and di(propylene glycol) allyl ether acrylate are added and stirred at a speed of 600 r / min for 2 min.

[0045] In step (1), the pretreated flame retardant is prepared by mixing hexaphenoxycyclotriphosphazene and melamine borate, adding silane coupling agent KH-570 solution, ultrasonically dispersing for 20 min at an ultrasonic power of 300 W, then vacuum drying at 80 °C for 12 h at a vacuum degree of -0.08 MPa, and grinding through a 200-mesh sieve. The silane coupling agent solution is prepared by mixing silane coupling agent KH-570 with anhydrous ethanol, controlling the mass concentration to 10%, and the mass of silane coupling agent KH-570 accounts for 0.8% of the total mass of hexaphenoxycyclotriphosphazene and melamine borate.

[0046] In step (2), the screw speed of the twin-screw extruder is 220 r / min, the temperature of the feeding section is 117℃, the temperature of the compression section is 138℃, the temperature of the melting section is 148℃, the temperature of the homogenization section is 142℃, and the temperature of the die head section is 145℃.

[0047] In step (2), 3mm cable material particles are obtained by pelletizing. The cable material particles are dried with hot air at 80℃ for 1 hour, and then vacuum dried at 65℃ for 45 minutes with a vacuum degree of -0.08MPa to obtain dried cable granules. In step (3), the temperature of the feeding section of the single screw extruder is 117℃, the temperature of the compression section is 138℃, the temperature of the melting section is 148℃, the temperature of the homogenization section is 142℃, and the temperature of the die head section is 145℃.

[0048] In step (3), the irradiation dose for crosslinking is 85 kGy, the irradiation rate is 6 m / min, and the irradiation atmosphere is air.

[0049] The drying process described in step (4) is 60°C circulating air drying for 1 hour.

[0050] Example 3 The polyvinyl chloride insulated cable material described in Example 3 is composed of the following raw materials by weight: 100 parts PVC resin, 32 parts di(2-ethylhexyl) terephthalate, 5 parts trioctyl trimellitate, 4 parts epoxidized soybean oil, 3.2 parts propoxylated (3) glycerol triacrylate, 1.05 parts tri(2-acryloyloxyethyl) isocyanurate, 0.5 parts antioxidant, 5 parts heat stabilizer, 12 parts flame retardant, 0.5 parts di(propylene glycol) allyl ether acrylate, and 0.1 parts oxidized polyethylene wax.

[0051] Among them, the PVC resin is SG-3 type resin.

[0052] The antioxidant is a mixture of antioxidant 1024 and antioxidant THP-24, with a mass ratio of antioxidant 1024 to antioxidant THP-24 of 3:2.

[0053] The heat stabilizer is a mixture of calcium-zinc stabilizer and hydrotalcite, with a mass ratio of calcium-zinc stabilizer to hydrotalcite of 4:1. The calcium-zinc stabilizer is BP MC 90224KA from Germany.

[0054] The flame retardant is a mixture of hexaphenoxycyclotriphosphazene and melamine borate, wherein the mass ratio of hexaphenoxycyclotriphosphazene to melamine borate is 9:1.

[0055] The preparation method of the polyvinyl chloride insulated cable material described in Example 3 consists of the following steps: (1) Add PVC resin to the reaction apparatus and stir. Heat stabilizer is added at 58°C. Heat to 80°C and di(2-ethylhexyl) terephthalate, trioctyl trimellitate and epoxidized soybean oil are added in sequence. Heat to 95°C and pretreated flame retardant and antioxidant are added in sequence and stirred evenly. Then propoxylated (3) glycerol triacrylate and tri(2-acryloyloxyethyl) isocyanurate are added in sequence. Finally, oxidized polyethylene wax and di(propylene glycol) allyl ether acrylate are added in sequence and stirred evenly. The mixture is cooled to 38°C and discharged to obtain the mixture. (2) The mixture is added to a twin-screw extruder for extrusion granulation. The extruded material is then water-cooled, traction-cut into pellets, and dried to obtain dried cable pellets. (3) The dried cable granules are fed into a single screw extruder and extruded into strips, and then subjected to radiation crosslinking; (4) The cross-linked irradiated sample was dried to prepare polyvinyl chloride insulated cable material.

[0056] In step (1), PVC resin is added and stirred at a speed of 300 r / min for 5 min; heat stabilizer is added and stirred at a speed of 600 r / min for 3 min; di(2-ethylhexyl) terephthalate, trioctyl trimellitate and epoxidized soybean oil are added and stirred at a speed of 600 r / min for 8 min; pretreated flame retardant and antioxidant are added and stirred at a speed of 600 r / min for 5 min; propoxylated (3) glyceryl triacrylate and tri(2-acryloyloxyethyl) isocyanurate are added and stirred at a speed of 600 r / min for 4 min; finally, oxidized polyethylene wax and di(propylene glycol) allyl ether acrylate are added and stirred at a speed of 600 r / min for 3 min.

[0057] In step (1), the pretreated flame retardant is prepared by mixing hexaphenoxycyclotriphosphazene and melamine borate, adding silane coupling agent KH-570 solution, ultrasonically dispersing for 20 min at an ultrasonic power of 300 W, then vacuum drying at 80 °C for 12 h at a vacuum degree of -0.08 MPa, and grinding through a 200-mesh sieve. The silane coupling agent solution is prepared by mixing silane coupling agent KH-570 with anhydrous ethanol, controlling the mass concentration to 10%, and the mass of silane coupling agent KH-570 accounts for 0.8% of the total mass of hexaphenoxycyclotriphosphazene and melamine borate.

[0058] In step (2), the screw speed of the twin-screw extruder is 220 r / min, the temperature of the feeding section is 117℃, the temperature of the compression section is 138℃, the temperature of the melting section is 148℃, the temperature of the homogenization section is 142℃, and the temperature of the die head section is 145℃.

[0059] In step (2), 3mm cable material particles are obtained by pelletizing. The cable material particles are dried with hot air at 80℃ for 1 hour, and then vacuum dried at 65℃ for 45 minutes with a vacuum degree of -0.08MPa to obtain dried cable granules. In step (3), the temperature of the feeding section of the single screw extruder is 117℃, the temperature of the compression section is 138℃, the temperature of the melting section is 148℃, the temperature of the homogenization section is 142℃, and the temperature of the die head section is 145℃.

[0060] In step (3), the irradiation dose for crosslinking is 85 kGy, the irradiation rate is 6 m / min, and the irradiation atmosphere is air.

[0061] The drying process described in step (4) is 60°C circulating air drying for 1 hour.

[0062] Comparative Example 1 The polyvinyl chloride insulated cable material described in Comparative Example 1 is composed of the following raw materials by weight: 100 parts PVC resin, 31 parts di(2-ethylhexyl) terephthalate, 6 parts trioctyl trimellitate, 3.5 parts epoxidized soybean oil, 0.45 parts antioxidant, 5.5 parts heat stabilizer, 11.5 parts flame retardant, 0.4 parts di(propylene glycol) allyl ether acrylate, and 0.13 parts oxidized polyethylene wax; its antioxidant, heat stabilizer, and flame retardant are the same as those in Example 1.

[0063] The preparation method of the polyvinyl chloride insulated cable material described in Comparative Example 1 is the same as that in Example 1, except that irradiation crosslinking is not performed in step (3).

[0064] Comparative Example 2 The preparation method of the polyvinyl chloride insulated cable material described in Comparative Example 2 is the same as that in Example 1, except that the raw material composition is different. The polyvinyl chloride insulated cable material described in Comparative Example 2, by weight, is composed of the following raw materials: 100 parts of PVC resin, 31 parts of di(2-ethylhexyl) terephthalate, 6 parts of trioctyl trimellitate, 3.5 parts of epoxidized soybean oil, 3.3 parts of propoxylated (3) glycerol triacrylate, 1.1 parts of tri(2-acryloyloxyethyl) isocyanurate, 0.45 parts of antioxidant, 5.5 parts of heat stabilizer, 0.4 parts of di(propylene glycol) allyl ether acrylate, and 0.13 parts of oxidized polyethylene wax; wherein the antioxidant and heat stabilizer are the same as in Example 1.

[0065] The performance of the polyvinyl chloride insulated cable materials prepared in Examples 1-3 and Comparative Examples 1-2 was tested according to GB / T 8815-2008, and the results are shown in Table 1 below: Table 1 Performance test results of polyvinyl chloride insulated cable material As can be seen from Table 1 above, the performance of the PVC insulated cable material prepared in this application is superior to that of Comparative Examples 1-2. Based on tensile strength, tensile strain at break, heat distortion, room temperature oxygen index, and elongation at break retention after aging, the PVC insulation materials prepared in Examples 1-3 exhibit excellent mechanical properties, heat resistance, and flame retardancy. Comparative Example 1 suffers from a decrease in overall performance due to lack of cross-linking, while Comparative Example 2 suffers from a decrease in flame retardancy due to the absence of flame retardant.

[0066] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A polyvinyl chloride insulated cable material, characterized in that: The product is composed of the following raw materials in parts by weight: 100 parts PVC resin, 30-32 parts di(2-ethylhexyl) terephthalate, 5-7 parts trioctyl trimellitate, 3-4 parts epoxidized soybean oil, 3-3.3 parts propoxylated (3) glycerol triacrylate, 1.0-1.1 parts tri(2-acryloyloxyethyl) isocyanurate, 0.4-0.5 parts antioxidant, 5-6 parts heat stabilizer, 11-12 parts flame retardant, 0.3-0.5 parts di(propylene glycol) allyl ether acrylate, and 0.1-0.15 parts oxidized polyethylene wax.

2. The polyvinyl chloride insulated cable material according to claim 1, characterized in that: The PVC resin is SG-3 type resin; The antioxidant is a mixture of antioxidant 1024 and antioxidant THP-24, with a mass ratio of antioxidant 1024 to antioxidant THP-24 of 3:

2.

3. The polyvinyl chloride insulated cable material according to claim 1, characterized in that: The heat stabilizer is a mixture of calcium-zinc stabilizer and hydrotalcite, with a mass ratio of calcium-zinc stabilizer to hydrotalcite of 4:

1. The flame retardant is a mixture of hexaphenoxycyclotriphosphazene and melamine borate, wherein the mass ratio of hexaphenoxycyclotriphosphazene to melamine borate is 9:

1.

4. A method for preparing the polyvinyl chloride insulated cable material according to claim 1, characterized in that: It consists of the following steps: (1) Add PVC resin to the reaction apparatus and stir. Heat the mixture to 58-60℃ and add heat stabilizer. Heat the mixture to 78-80℃ and add di(2-ethylhexyl) terephthalate, trioctyl trimellitate and epoxidized soybean oil in sequence. Heat the mixture to 93-95℃ and add pretreated flame retardant and antioxidant in sequence and stir evenly. Then add propoxylated (3) glyceryl triacrylate and tri(2-acryloyloxyethyl) isocyanurate in sequence. Finally, add oxidized polyethylene wax and di(propylene glycol) allyl ether acrylate in sequence and stir evenly. Cool the mixture to 35-38℃ and discharge to obtain the mixture. (2) The mixture is added to a twin-screw extruder for extrusion granulation. The extruded material is then water-cooled, traction-cut into pellets, and dried to obtain dried cable pellets. (3) The dried cable granules are fed into a single screw extruder and extruded into strips, and then subjected to radiation crosslinking; (4) The cross-linked irradiated sample was dried to prepare polyvinyl chloride insulated cable material.

5. The method for preparing polyvinyl chloride insulated cable material according to claim 4, characterized in that: In step (1), PVC resin is added and stirred at a speed of 300 r / min for 3-5 min; heat stabilizer is added and stirred at a speed of 600 r / min for 3-5 min; di(2-ethylhexyl) terephthalate, trioctyl trimellitate and epoxidized soybean oil are added and stirred at a speed of 600 r / min for 6-8 min; pretreated flame retardant and antioxidant are added and stirred at a speed of 600 r / min for 3-5 min; propoxylated (3) glyceryl triacrylate and tri(2-acryloyloxyethyl) isocyanurate are added and stirred at a speed of 600 r / min for 3-4 min; finally, oxidized polyethylene wax and di(propylene glycol) allyl ether acrylate are added and stirred at a speed of 600 r / min for 2-3 min.

6. The method for preparing polyvinyl chloride insulated cable material according to claim 4, characterized in that: In step (1), the pretreated flame retardant is prepared by mixing hexaphenoxycyclotriphosphazene and melamine borate, adding silane coupling agent KH-570 solution and ultrasonically dispersing for 20 min with an ultrasonic power of 300 W, then vacuum drying at 80 °C for 12 h with a vacuum degree of -0.08 MPa, and grinding through a 200-mesh sieve. The silane coupling agent solution is made by mixing silane coupling agent KH-570 with anhydrous ethanol, controlling the mass concentration to 10%, and the mass of silane coupling agent KH-570 accounts for 0.8% of the total mass of hexaphenoxycyclotriphosphazene and melamine borate.

7. The method for preparing polyvinyl chloride insulated cable material according to claim 4, characterized in that: In step (2), the screw speed of the twin-screw extruder is 220 r / min, the temperature of the feeding section is 117℃, the temperature of the compression section is 138℃, the temperature of the melting section is 148℃, the temperature of the homogenization section is 142℃, and the temperature of the die head section is 145℃. In step (2), 3mm cable material particles are obtained by pelletizing. The cable material particles are dried with hot air at 80℃ for 1 hour, and then dried under vacuum at 65℃ for 45 minutes with a vacuum degree of -0.08MPa to obtain dried cable granules.

8. The method for preparing polyvinyl chloride insulated cable material according to claim 4, characterized in that: In step (3), the temperature of the feeding section of the single screw extruder is 117℃, the temperature of the compression section is 138℃, the temperature of the melting section is 148℃, the temperature of the homogenization section is 142℃, and the temperature of the die head section is 145℃.

9. The method for preparing polyvinyl chloride insulated cable material according to claim 4, characterized in that: In step (3), the irradiation dose for crosslinking is 85 kGy, the irradiation rate is 6 m / min, and the irradiation atmosphere is air.

10. The method for preparing polyvinyl chloride insulated cable material according to claim 4, characterized in that: The drying process described in step (4) is 60°C circulating air drying for 1 hour.

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