A PVC cable and its preparation method

Abstract

The present invention relates to the technical field of cables, and discloses a PVC cable and a preparation method thereof. The PVC cable sequentially includes a cable core, an insulating layer, and a sheath layer from inside to outside. The sheath layer is formed by extruding polyvinyl chloride sheath material, which is made by blending polyvinyl chloride as the main raw material with other additives such as flame retardant additives and functional fillers and granulating, on the outside of the insulating layer. By adding flame retardant additives and functional fillers and utilizing the synergistic effect of the flame retardant additives and functional fillers, the prepared polyvinyl chloride can have good flame retardant and fire resistance effects, anti-ultraviolet aging performance, and heat resistance performance, and has higher safety and a longer service life.

Description

Technical Field

[0001] The present invention relates to the technical field of cables, and particularly relates to a PVC cable and a preparation method thereof. Background Art

[0002] In recent years, the fields of energy transmission, transportation, etc. have developed rapidly, resulting in an increasing annual demand for cables. Cables have become inseparable from daily life. Generally, the outer side of a cable needs to be coated with a sheath layer mainly made of a polymer material to protect the cable and prevent interference to the cable core. Since polyvinyl chloride (PVC) is inexpensive, has high softness, and is easy to process into various shapes, it is often used as the sheath layer material of cables. However, a large amount of additives such as plasticizers and heat stabilizers are often required for the processing of polyvinyl chloride, which has a negative effect on the flame retardancy of polyvinyl chloride and is not conducive to the further development of polyvinyl chloride in the cable field. In addition, some cables need to work outdoors for a long time, and the anti-ultraviolet aging performance of polyvinyl chloride is poor. After long-term exposure to sunlight, obvious aging phenomena will occur, which will affect the normal operation of the cable. Therefore, it is particularly necessary to improve polyvinyl chloride.

[0003] The invention patent with the publication number of CN110760139B discloses a high-resistivity flame-retardant polyvinyl chloride cable compound, which uses a bromine-containing ester liquid as a flame-retardant plasticizer and is combined with chlorinated rubber to achieve the flame-retardant modification of polyvinyl chloride cable compound. However, halogen-based flame-retardant modifiers produce a large amount of smoke and toxic and corrosive gases during combustion, which are very harmful and have been gradually phased out. In addition, the flame-retardant performance of polyvinyl chloride can also be effectively improved by adding inorganic flame retardants. However, the flame-retardant effect of a single inorganic flame retardant is not good, and a large amount needs to be added to achieve an obvious effect, which will affect the mechanical properties of polyvinyl chloride.

[0004] Based on this, the present invention provides a polyvinyl chloride sheath material with good comprehensive properties such as anti-aging and flame retardancy, which can be directly used to manufacture polyvinyl chloride cables. Summary of the Invention

[0005] The purpose of the present invention is to provide a PVC cable and a preparation method thereof, which solve the problems that polyvinyl chloride is easy to burn and has poor ultraviolet light aging resistance when used as a cable sheath material.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A PVC cable, which sequentially includes a cable core, an insulating layer, and a sheath layer from inside to outside; the insulating layer is formed by extruding an insulating material outside the cable core; the sheath layer is formed by extruding a polyvinyl chloride sheath material outside the insulating layer; the insulating material includes the following components in parts by weight: 20-35 parts of low-density polyethylene, 15-25 parts of ethylene-vinyl acetate copolymer, 5-15 parts of SBS elastomer, 1-3 parts of lubricant, 0.5-1 part of antioxidant, 10-15 parts of plasticizer, and 10-20 parts of filler; the polyvinyl chloride sheath material includes the following components in parts by weight: 45-65 parts of polyvinyl chloride, 5-10 parts of powdered chloroprene rubber, 3-6 parts of flame retardant additive, 2-5 parts of functionalized filler, 6-8 parts of stabilizer, 20-30 parts of plasticizer, 0.5-2 parts of antioxidant, and 1-3 parts of lubricant;

[0008] The flame retardant additive is magnesium hydroxide with an organic monomolecular coating layer on its surface; the monomolecular layer structure contains ternary flame retardant elements of nitrogen, phosphorus, and silicon;

[0009] The functionalized filler is a benzophenone-based macromolecular ultraviolet absorber.

[0010] Further preferably, the lubricant is any one of calcium stearate, magnesium stearate, or zinc stearate; the antioxidant is any one of antioxidant 168, antioxidant RD, or antioxidant 1010; the plasticizer is any one of dioctyl phthalate, dioctyl sebacate, or epoxidized soybean oil; the filler is any one of calcium carbonate, talcum powder, or white carbon black; the stabilizer is a calcium-zinc stabilizer or a barium-zinc stabilizer.

[0011] A preparation method of a PVC cable, comprising the following steps:

[0012] First step, preparing the insulating material

[0013] Pour low-density polyethylene, ethylene-vinyl acetate copolymer, SBS elastomer, lubricant, antioxidant, plasticizer, and filler into a high-speed mixer in sequence, raise the temperature in the mixer to 160-170 °C, stir and mix for 30-60 min, transfer the mixture to an extruder for extrusion granulation after mixing, and cut the masterbatch to obtain the insulating material;

[0014] Second step, preparing the polyvinyl chloride sheath material

[0015] Pour polyvinyl chloride, powdered chloroprene rubber, flame retardant additive, functionalized filler, stabilizer, plasticizer, antioxidant, and lubricant into a high-speed mixer in sequence, raise the temperature in the mixer to 160-170 °C, stir and mix for 30-60 min, transfer the mixture to an extruder for extrusion granulation after mixing, and cut the masterbatch to obtain the polyvinyl chloride sheath material;

[0016] Step 3: Prepare the cable

[0017] Using a double-layer co-extrusion extruder, extrude the insulating material on the surface of the conductor. After forming, an insulating layer can be formed. Then, extrude the PVC sheath material outside the insulating layer. After forming, through air cooling and winding operations, the cable can be obtained.

[0018] Further preferably, the flame retardant additive is prepared by the following method:

[0019] Add magnesium hydroxide and N,N-dimethylformamide to a reactor filled with nitrogen in sequence. Start stirring. After dispersing evenly, add the flame retardant DDP and the catalyst to the reactor, stir and dissolve. Start heating until the temperature reaches 100 - 120 °C, keep warm for 8 - 12 h. Then continue to add silatrane glycol to the system and continuously stir for 6 - 9 h. Stop heating and wait for the material to cool naturally. Separate the product, wash and remove impurities, and vacuum dry completely in a vacuum drying oven at 50 - 60 °C to obtain the flame retardant additive.

[0020] Further preferably, the average particle size of the magnesium hydroxide is 50 nm.

[0021] Further preferably, the catalyst is p-toluenesulfonic acid.

[0022] In the above technical solution, the possible mechanism is as follows: Magnesium hydroxide contains hydroxyl groups, which can cooperate with the catalyst and high-temperature conditions to undergo condensation with the carboxyl groups in the structure of the flame retardant DDP, graft the phosphorus-containing flame retardant DDP on the surface of magnesium hydroxide. Since there are two equivalents of active carboxyl groups in the structure of the flame retardant DDP, using the flame retardant DDP as a bridge and its bridging effect, further condensation occurs with the hydroxyl groups in the structure of silatrane glycol to modify the surface of magnesium hydroxide with silatrane containing two flame retardant elements of nitrogen and silicon, forming an organic monomolecular coating layer containing ternary flame retardant elements of nitrogen, phosphorus, and silicon on its surface to obtain the flame retardant additive.

[0023] Further preferably, the functionalized filler is prepared by the following method:

[0024] Add 2,2’,4,4’-tetrahydroxybenzophenone and toluene to a reactor filled with nitrogen in sequence. Start stirring. After forming a homogeneous solution, mix 1,2-bis(chlorodimethylsilyl)ethane with toluene to form a reaction solution. Control the dropping rate and drop the reaction solution into the homogeneous solution. After adding, start heating, raise the temperature to 60 - 70 °C, keep warm for 2 - 4 h, then add an acid-binding agent to the reactor, continue to stir for 6 - 8 h, evaporate the solvent under reduced pressure, cool and discharge to obtain the functionalized additive.

[0025] Further preferably, the molar ratio of 2,2’,4,4’-tetrahydroxybenzophenone to 1,2-bis(chlorodimethylsilyl)ethane is 1:1.

[0026] Further preferably, the dropping rate is 1-2 ml / min.

[0027] Further preferably, the acid-binding agent is triethylamine or pyridine.

[0028] In the above technical solution, the possible mechanism is as follows: the para-hydroxy group in the 2,2’,4,4’-tetrahydroxybenzophenone structure has relatively high activity and can undergo substitution with Si-Cl in the 1,2-bis(chlorodimethylsilyl)ethane structure. Under the action of the acid-binding agent, continuous substitution reactions can occur between them to form a long-chain polymer molecule with an alternating connection and a block structure, that is, a functional additive.

[0029] Advantages of the present invention:

[0030] 1) The present invention adopts a chemical grafting method to modify the surface of magnesium hydroxide with an organic monomolecular coating layer containing nitrogen, phosphorus, and silicon ternary flame retardant elements. After the monomolecular layer coating, the compatibility between magnesium hydroxide and polyvinyl chloride can be improved, promoting the uniform and stable dispersion of magnesium hydroxide in the polyvinyl chloride sheath material. By utilizing the inorganic flame retardant magnesium hydroxide and the nitrogen, phosphorus, and silicon ternary flame retardant elements grafted on its surface, a synergistic flame retardant effect can be formed, achieving a significant improvement in the flame resistance of the polyvinyl chloride sheath material with a small amount of flame retardant additives. After testing, the limiting oxygen index of this polyvinyl chloride sheath material can reach up to 34.2%, showing excellent flame retardant performance.

[0031] 2) The present invention prepares a long-chain polymer molecule with a block structure as a functional additive. Due to the presence of a benzophenone structure in its structure, it can effectively improve the anti-ultraviolet aging performance of the polyvinyl chloride sheath material. Moreover, compared with conventional small molecule ultraviolet absorbers, this long-chain polymer molecule is difficult to precipitate and has low volatility, and can exist in the polyvinyl chloride sheath material for a long time to achieve a long-term anti-ultraviolet aging effect. In addition, a large number of high bond energy Si-O bonds are generated during the substitution reaction, which can effectively improve the heat resistance of the polyvinyl chloride sheath material. Therefore, using the polyvinyl chloride sheath material prepared by the present invention to make the sheath layer of a cable can effectively improve the safety and service life of the cable.

[0032] Of course, it is not necessary for any product implementing the present invention to simultaneously achieve all the above-mentioned advantages. Description of the Drawings

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0034] Figure 1 It is the infrared absorption spectrogram of the functionalized filler prepared in Example 1 of the present invention.

[0035] Figure 2 It is the structural schematic diagram of the PVC cable;

[0036] Reference numerals: 1, cable core; 2, insulating layer; 3, sheath layer. Specific embodiments

[0037] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0038] Example 1

[0039] Preparation of polyvinyl chloride sheath material

[0040] 45 parts of polyvinyl chloride, 5 parts of powdered chloroprene rubber, 3 parts of flame retardant additive, 2 parts of functionalized filler, 6 parts of calcium-zinc stabilizer, 20 parts of plasticizer dioctyl phthalate, 0.5 part of antioxidant 168 and 1 part of lubricant calcium stearate are successively poured into a high-speed mixer. The temperature in the mixer is raised to 160 °C, and stirred and mixed for 30 min. After mixing, the material is transferred into an extruder for extrusion granulation. The masterbatch is chopped to obtain the polyvinyl chloride sheath material.

[0041] The flame retardant additive is prepared by the following method:

[0042] 2.5 g of magnesium hydroxide with an average particle size of 50 nm and 240 mL of N,N-dimethylformamide are successively added to a reactor filled with nitrogen. Stirring is started, and after being dispersed evenly, 3.8 g of flame retardant DDP and 1.4 g of p-toluenesulfonic acid are added to the reactor, stirred and dissolved. Heating is started until the temperature reaches 110 °C, and kept warm for 9 h. Then 2.6 g of silatrane glycol is continuously added to the system, and stirring is continued for 8 h. Then heating is stopped, and the material is allowed to cool naturally. The product is separated, washed to remove impurities, and vacuum dried completely in a vacuum drying oven at 50 °C to obtain the flame retardant additive.

[0043] Weigh 0.5 g of the flame retardant additive sample, and use the soap back titration method to test the ester group content in the flame retardant additive. The test results show that the ester group content of the sample is 12.87 mmol / g. It can be analyzed that the above reaction process uses the flame retardant DDP as a bridge and forms a large number of ester groups in the form of esterification condensation to bridge magnesium hydroxide and silatrane triol.

[0044] The functionalized filler is prepared by the following method:

[0045] 1.5 g of 2,2’,4,4’-tetrahydroxybenzophenone and 80 mL of toluene were successively added into a reactor filled with nitrogen. Stirring was started. After a uniform solution was formed, 1.31 g of 1,2-bis(chlorodimethylsilyl)ethane was mixed with 50 mL of toluene to form a reaction solution. The dropping rate was controlled at 1 ml / min. The reaction solution was dropped into the uniform solution. After addition, heating was started and the temperature was raised to 65 °C. After holding the temperature for 3 h, triethylamine was added into the reactor, and stirring was continued for 8 h. The solvent was evaporated under reduced pressure, and the temperature was lowered and the product was discharged to obtain the functionalized additive.

[0046] Using the KBr tablet pressing method, in the range of 500 - 4000 cm -1 the infrared absorption spectrum of the functionalized additive was measured, and the results are as Figure 1 shown. After analysis, the characteristic stretching vibration peak of the hydroxyl group is at 3442 cm -1 the characteristic stretching vibration peak of the carbon-hydrogen on the benzene ring is at 3000 - 3100 cm -1 the characteristic stretching vibration peak of the carbon-oxygen double bond is at 1694 cm -1 the characteristic stretching vibration peak of the silicon-oxygen is at 1058 cm -1

[0047] Example 2

[0048] Preparation of polyvinyl chloride sheathing compound

[0049] 60 parts of polyvinyl chloride, 8 parts of powdered chloroprene rubber, 5 parts of flame retardant additive, 4 parts of functionalized filler, 6 parts of barium-zinc stabilizer, 25 parts of plasticizer dioctyl sebacate, 1 part of antioxidant 1010 and 1.5 parts of lubricant zinc stearate were successively poured into a high-speed mixer. The temperature in the mixer was raised to 165 °C, and stirring and mixing were carried out for 40 min. After mixing, the material was transferred into an extruder for extrusion granulation, and the masterbatch was chopped to obtain the polyvinyl chloride sheathing compound.

[0050] The flame retardant additive and the functionalized filler were prepared by the preparation method in Example 1.

[0051] Example 3

[0052] Preparation of polyvinyl chloride sheathing compound

[0053] ​Pour 65 parts of polyvinyl chloride, 10 parts of powdered chloroprene rubber, 6 parts of flame retardant additive, 5 parts of functional filler, 8 parts of calcium-zinc stabilizer, 30 parts of plasticizer epoxidized soybean oil, 2 parts of antioxidant RD, and 3 parts of lubricant calcium stearate into a high-speed mixer in sequence. Raise the temperature in the mixer to 170 °C, stir and mix for 60 min. After mixing, transfer the material into an extruder for extrusion granulation, and cut the masterbatch into pieces to obtain the polyvinyl chloride sheath material.

[0054] The flame retardant additive and the functional filler are prepared by the preparation method in Example 1.

[0055] Comparative Example 1

[0056] Preparation of Polyvinyl Chloride Sheath Material

[0057] Pour 60 parts of polyvinyl chloride, 8 parts of powdered chloroprene rubber, 5 parts of magnesium hydroxide, 4 parts of functional filler, 6 parts of barium-zinc stabilizer, 25 parts of plasticizer dioctyl sebacate, 1 part of antioxidant 1010, and 1.5 parts of lubricant zinc stearate into a high-speed mixer in sequence. Raise the temperature in the mixer to 165 °C, stir and mix for 40 min. After mixing, transfer the material into an extruder for extrusion granulation, and cut the masterbatch into pieces to obtain the polyvinyl chloride sheath material.

[0058] The functional filler is prepared by the preparation method in Example 1.

[0059] Comparative Example 2

[0060] Preparation of Polyvinyl Chloride Sheath Material

[0061] Pour 60 parts of polyvinyl chloride, 8 parts of powdered chloroprene rubber, 4 parts of functional filler, 6 parts of barium-zinc stabilizer, 25 parts of plasticizer dioctyl sebacate, 1 part of antioxidant 1010, and 1.5 parts of lubricant zinc stearate into a high-speed mixer in sequence. Raise the temperature in the mixer to 165 °C, stir and mix for 40 min. After mixing, transfer the material into an extruder for extrusion granulation, and cut the masterbatch into pieces to obtain the polyvinyl chloride sheath material.

[0062] The functional filler is prepared by the preparation method in Example 1.

[0063] Comparative Example 3

[0064] Preparation of Polyvinyl Chloride Sheath Material

[0065] Pour 60 parts of polyvinyl chloride, 8 parts of powdered chloroprene rubber, 5 parts of flame retardant additive, 6 parts of barium-zinc stabilizer, 25 parts of plasticizer dioctyl sebacate, 1 part of antioxidant 1010, and 1.5 parts of lubricant zinc stearate into a high-speed mixer in sequence. Raise the temperature in the mixer to 165 °C, stir and mix for 40 min. After mixing, transfer the material into an extruder for extrusion granulation, and cut the masterbatch into pieces to obtain the polyvinyl chloride sheath material.

[0066] The flame retardant additive is prepared by the preparation method in Example 1.

[0067] The polyvinyl chloride sheath materials prepared in Examples 1-3 and Comparative Examples 1-3 of the present invention are made into test specimens of composite specifications and subjected to the following tests respectively:

[0068] A. Refer to GB / T 2406.2-2009, the limiting oxygen index, to evaluate the flame retardant effect of the polyvinyl chloride sheath material;

[0069] B. Take 10 specimens each, refer to GB / T 1040.2-2022, randomly select 5 of them for tensile strength test, and place the other 5 in an ultraviolet accelerated aging chamber. Set the power of the ultraviolet lamp to 40W, and after accelerating aging for 168h, test the tensile strength and calculate the tensile strength retention rate to evaluate the anti-ultraviolet aging performance of the polyvinyl chloride sheath material;

[0070] C. Place the specimens in an oven, set the oven temperature to 150 °C, take them out after heat treatment for 120h, and evaluate the heat resistance of the polyvinyl chloride sheath material by calculating the mass loss rate before and after the specimens. The test results are recorded in the following table:

[0071] Limiting oxygen index / % Retention rate of tensile strength / % Mass loss rate / % Example 1 33.9 93.3 2.9 Example 2 34.2 94.1 2.3 Example 3 34.0 93.8 2.4 Comparative example 1 26.8 92.5 3.6 Comparative example 2 24.6 92.0 3.3 Comparative example 3 32.8 66.7 7.9

[0072] By analyzing the data in the table, it can be clearly observed that the polyvinyl chloride sheath material prepared by adding both the flame retardant additive and the functional filler has a high oxygen index, a relatively high tensile strength retention rate, and a low mass loss rate. Therefore, it exhibits good flame retardant performance, anti-ultraviolet aging performance, and heat resistance.

[0073] On the contrary, for the polyvinyl chloride sheath material prepared by only adding the functional filler in Comparative Example 2, the flame retardant performance significantly decreases, and the heat resistance also decreases slightly. It is speculated that the presence of magnesium hydroxide has a positive effect on the heat resistance of the polyvinyl chloride sheath material. For the polyvinyl chloride sheath material prepared by only adding the flame retardant additive in Comparative Example 3, both the anti-aging performance and the heat resistance significantly decrease because without the functional filler, it is impossible to absorb ultraviolet rays by benzophenone and impossible to improve the heat resistance by the high bond energy silicon-oxygen bond.

[0074] In Comparative Example 1, unmodified magnesium hydroxide is added for filling, and the flame retardant performance significantly decreases, but the anti-ultraviolet aging performance and heat resistance are acceptable.

[0075] Use the polyvinyl chloride sheath material prepared in Example 2 of the present invention to prepare PVC cables. The method is as follows:

[0076] The first step is to prepare the insulating material

[0077] Pour 30 parts of low-density polyethylene, 20 parts of ethylene-vinyl acetate copolymer, 12 parts of SBS elastomer, 1.5 parts of lubricant zinc stearate, 0.5 part of antioxidant 1010, 12 parts of plasticizer dioctyl sebacate, and 15 parts of filler calcium carbonate into a high-speed mixer in sequence. Raise the temperature in the mixer to 170 °C and stir and mix for 60 min. After mixing, transfer the material into an extruder for extrusion granulation. Cut the masterbatch into pieces to obtain the insulating material.

[0078] Step 2: Prepare the cable

[0079] Use a double-layer co-extrusion extruder to extrude the insulating material on the surface of the copper conductor. After forming, an insulating layer can be formed. Then extrude the polyvinyl chloride sheath material outside the insulating layer. After forming, through air cooling and winding operations, the cable can be obtained.

[0080] Figure 2 As shown in the structural schematic diagram of the cable, the cable sequentially includes 1. Cable core; 2. Insulating layer; 3. Sheath layer from the inside to the outside.

[0081] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0082] The above content is only an example and illustration of the concept of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the described specific embodiments or use similar ways to replace them. As long as they do not deviate from the concept of the invention or exceed the scope defined by this claim book, they should all belong to the protection scope of the present invention.

Claims

1. A PVC cable, characterized in that, It successively includes a cable core, an insulating layer, and a sheath layer from the inside to the outside; the insulating layer is formed by extruding an insulating material outside the cable core; the sheath layer is formed by extruding a polyvinyl chloride sheath material outside the insulating layer; the insulating material includes the following components in parts by weight: 20-35 parts of low-density polyethylene, 15-25 parts of ethylene-vinyl acetate copolymer, 5-15 parts of SBS elastomer, 1-3 parts of lubricant, 0.5-1 part of antioxidant, 10-15 parts of plasticizer, and 10-20 parts of filler; the polyvinyl chloride sheath material includes the following components in parts by weight: 45-65 parts of polyvinyl chloride, 5-10 parts of powdered chloroprene rubber, 3-6 parts of flame retardant additive, 2-5 parts of functionalized filler, 6-8 parts of stabilizer, 20-30 parts of plasticizer, 0.5-2 parts of antioxidant, and 1-3 parts of lubricant; The flame retardant additive is prepared by the following method: Magnesium hydroxide and N,N-dimethylformamide are successively added to a reactor filled with nitrogen. After starting stirring and dispersing evenly, a flame retardant DDP and a catalyst are added to the reactor, stirred and dissolved, then heating is started until the temperature reaches 100-120 °C, and kept warm for 8-12 h. Then, silatrane glycol is added to the system, and stirring is continued for 6-9 h. After that, heating is stopped, and the material is allowed to cool naturally. The product is separated out, washed to remove impurities, and vacuum dried completely in a vacuum drying oven at 50-60 °C to obtain the flame retardant additive; The functionalized filler is prepared by the following method: 2,2’,4,4’-tetrahydroxybenzophenone and toluene are successively added to a reactor filled with nitrogen. After starting stirring, when a uniform solution is formed, 1,2-bis(chlorodimethylsilyl)ethane and toluene are mixed evenly to form a reaction solution. The dropping rate is controlled, and the reaction solution is dropped into the uniform solution. After adding, heating is started, and the temperature is raised to 60-70 °C. After keeping warm for 2-4 h, a deacidifying agent is added to the reactor, and stirring is continued for 6-8 h. The solvent is evaporated under reduced pressure, and the temperature is lowered to discharge the material to obtain the functionalized additive.

2. A PVC cable according to claim 1, characterized in that, The lubricant is any one of calcium stearate, magnesium stearate, or zinc stearate; the antioxidant is any one of antioxidant 168, antioxidant RD, or antioxidant 1010; the plasticizer is any one of dioctyl phthalate, dioctyl sebacate, or epoxidized soybean oil; the filler is any one of calcium carbonate, talcum powder, or white carbon black; the stabilizer is a calcium-zinc stabilizer or a barium-zinc stabilizer.

3. A PVC cable according to claim 1, characterized in that, The average particle size of the magnesium hydroxide is 50 nm.

4. A PVC cable according to claim 1, characterized in that, The catalyst is p-toluenesulfonic acid.

5. A PVC cable according to claim 1, characterized in that, The molar ratio of 2,2’,4,4’-tetrahydroxybenzophenone to 1,2-bis(chlorodimethylsilyl)ethane is 1:

1.

6. A PVC cable according to claim 1, characterized in that, The dropping rate is 1-2 mL / min.

7. A PVC cable according to claim 1, characterized in that, The deacidifying agent is triethylamine or pyridine.

8. The preparation method of a PVC cable according to claim 1, wherein, It includes the following steps: The first step is to prepare the insulating material Pour low-density polyethylene, ethylene-vinyl acetate copolymer, SBS elastomer, lubricant, antioxidant, plasticizer and filler into a high-speed mixer in sequence. Raise the temperature in the mixer to 160 - 170 °C, stir and mix for 30 - 60 min. After mixing, transfer the material into an extruder for extrusion granulation. Cut the masterbatch into pieces to obtain the insulating material; Step 2: Prepare the PVC sheath material Pour polyvinyl chloride, powdered chloroprene rubber, flame retardant additive, functionalized filler, stabilizer, plasticizer, antioxidant and lubricant into a high-speed mixer in sequence. Raise the temperature in the mixer to 160 - 170 °C, stir and mix for 30 - 60 min. After mixing, transfer the material into an extruder for extrusion granulation. Cut the masterbatch into pieces to obtain the PVC sheath material; Step 3: Prepare the cable Use a double-layer co-extrusion extruder to extrude the insulating material on the surface of the conductor. After forming, an insulating layer can be formed. Then extrude the PVC sheath material outside the insulating layer. After forming, through air cooling and winding operations, the cable can be obtained.

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