Corrosion-resistant flame-retardant cable and preparation method thereof

Abstract

The invention relates to a corrosion-resistant flame-retardant cable and a preparation method thereof, and belongs to the technical field of special flame-retardant cables. The cable is composed of a bunched wire core and a protective sleeve on the surface, and the protective sleeve is prepared from, by weight, 100 parts of PVC resin, 10-15 parts of POE resin, 12-16 parts of insulating filler, 25-30 parts of flexibilizer, 4.8-5.5 parts of stabilizer, 9-13 parts of modified phosphorus-silicon flame retardant, 0.13-0.16 part of antioxidant and 4.5-5.8 parts of lubricant. The modified phosphorus-silicon flame retardant is substituted by hydroxyl single-terminated silicone oil and vinyl trichlorosilane to form a compound with multiple silicon chains and alkenyl, namely an intermediate, DOPO and the alkenyl on an intermediate molecule are subjected to addition, DOPO serving as a phosphorus flame-retardant material is grafted to the intermediate molecule, a large number of silicon chain-DOPO-PVC layered structures are formed in the near surface layer of the protective sleeve, and the flame-retardant protective sleeve is formed. And the shielding, corrosion-resistant and flame-retardant effects are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of special flame-retardant cables, and in particular relates to a corrosion-resistant flame-retardant cable and a preparation method thereof. Background Art

[0002] Wires and cables play a vital role in power transmission and signal transmission, which will directly determine the operating safety of the equipment. The cable sheath is the outermost layer of the cable, and its basic function is to protect the safety of the internal structure.

[0003] Existing cable sheath materials generally include polyvinyl chloride (PVC), polyethylene (PE) and rubber, etc. These materials show a good balance in terms of cost and mechanical properties. These traditional materials still have defects in chemical corrosion resistance and fire resistance, especially in extreme environmental conditions or special application scenarios, the limitations of traditional cable sheath materials are particularly obvious. In the prior art, through structural design, metal materials, inorganic insulating materials and the like are used to fill the cable to meet the flame retardant and anti-corrosion requirements, but the molding process of this type of cable is complicated, the cost is high, and the mass and volume are large, which makes construction difficult and is only used in special fields; in addition, various flame retardant materials, corrosion resistant materials and the like are added to the traditional sheath materials to improve the flame retardant and anti-corrosion properties of the sheath, but these materials are difficult to form a stable and continuous insulating layer, and the protection performance of the cable is insufficient. Summary of the invention

[0004] In order to solve the technical problems mentioned in the background technology, the object of the present invention is to provide a corrosion-resistant flame-retardant cable and a preparation method thereof.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A corrosion-resistant flame-retardant cable consists of a bundled wire core and a protective sheath on the surface, wherein the protective sheath comprises, by weight: 100 parts of PVC resin, 10-15 parts of POE resin, 12-16 parts of insulating filler, 25-30 parts of toughening agent, 4.8-5.5 parts of stabilizer, 9-13 parts of modified phosphorus silicon flame retardant, 0.13-0.16 parts of antioxidant and 4.5-5.8 parts of lubricant.

[0007] The modified phosphorus silicon flame retardant is prepared by the following method:

[0008] Step A1: Mix terminal hydroxyl silicone oil, triethylamine and anhydrous tetrahydrofuran, introduce dry nitrogen for protection, control the temperature of the water bath at 10-20°C, apply stirring at 120-150rpm, slowly add vinyltrichlorosilane to react for 2-3h, then continue to raise the temperature to 45-55°C to react for 1-1.5h, and after the reaction is completed, remove tetrahydrofuran by rotary evaporation to obtain an intermediate;

[0009] Furthermore, the terminal hydroxyl silicone oil is a hydroxyl mono-terminated silicone oil, and the obtained modified phosphorus silicon flame retardant has a small molecular weight and contains multiple silicon-containing chains, which is relatively easy to migrate to the surface of the protective sleeve to form an enriched layer.

[0010] Furthermore, the feed ratio of vinyltrichlorosilane, the hydroxyl content of the terminal hydroxyl silicone oil, triethylamine and anhydrous tetrahydrofuran is 10mmol:30mmol:3.5-5mL:30-40mL, and triethylamine is used as an acid binding agent to promote the substitution of the terminal hydroxyl silicone oil with vinyltrichlorosilane to form a compound with multi-branched silicon chains and alkenyl groups.

[0011] Step A2: premix DOPO, transition metal-based catalyst and dimethylformamide, add the intermediate and mix, preheat to 80-90°C, stir at 60-90 rpm to react for 1.5-2h, then heat to 120-130°C and continue to react for 2.2-2.8h, add water to wash after the reaction, remove the water phase and dry to obtain a modified phosphorus silicon flame retardant;

[0012] Furthermore, the transition metal-based catalyst is selected from an organic nickel-based catalyst, preferably bis(1,5-cyclooctadiene)nickel, which has good compatibility with the reaction system, has a good catalytic effect on the addition of DOPO, and has a relatively low cost, and has a higher application prospect in industrial production.

[0013] Furthermore, the feed ratio of the intermediate, DOPO, transition metal-based catalyst and dimethylformamide is 10g:2.8-3.5mmol:4-6mg:15-20mL. Under the catalytic action of the transition metal-based catalyst, DOPO is added to the olefin group on the intermediate molecule, and DOPO is grafted onto the intermediate molecule as a phosphorus-based flame retardant material.

[0014] A method for preparing a corrosion-resistant flame-retardant cable comprises the following steps:

[0015] Step S1: Mix the raw materials in a high-speed mixer, plasticize and blend at 170-180° C., and then cut into pellets to obtain functional masterbatch;

[0016] Step S2: plasticize and extrude the functional masterbatch using a twin-screw extruder, and the temperature zones are set as follows: zone 1 165-175°C, zone 2 180-190°C, zone 3 190-200°C, zone 4 180-190°C, and the head temperature is 190-200°C. The functional masterbatch is coated on the surface of the bundled wire core, cooled and rolled, and then baked and homogenized at 65-80°C for 1-1.5h to obtain a corrosion-resistant and flame-retardant cable.

[0017] Preferably, the PVC resin is SG-3 type resin, which has a high degree of polymerization, a dense structure, a certain degree of corrosion resistance, and excellent processing performance, and is compatible with the extrusion molding process of the cable.

[0018] Preferably, the lubricant is selected from high-density oxidized polyethylene wax, which has good internal and external lubrication for PVC, is beneficial to improving the surface density of the protective sleeve after extrusion, and promotes the corrosion resistance of the protective sleeve and the formation of a continuous ablation layer.

[0019] Beneficial effects of the present invention:

[0020] The cable disclosed by the invention only consists of a bundled wire core and a protective sheath, has a simple structure and a molding process, and is suitable for industrial production. The protective sheath takes PVC as a matrix, and is introduced into a self-developed modified phosphorus silicon flame retardant for blending and modification to impart good flame retardancy and corrosion resistance; the modified phosphorus silicon flame retardant is substituted by hydroxyl mono-terminated silicone oil and vinyl trichlorosilane to form a compound with multi-branched silicon chains and alkenyl groups, i.e., an intermediate, and then DOPO is added to the alkenyl groups on the intermediate molecules, and DOPO is grafted onto the intermediate molecules as a phosphorus-based flame retardant material; the multi-branched silicon chains on the modified phosphorus silicon flame retardant molecules are greatly different from the molecular structure of the PVC matrix, and the silicon chain ends migrate to the surface of the protective sheath during the thermoforming process. In comparison, DOPO The PO end has better compatibility with the PVC matrix and is close to the PVC matrix end during migration. As a result, a large number of silicon chain-DOPO-PVC layered structures are formed in the near-surface layer of the protective sleeve. These silicon-containing layered structures form a surface shielding effect, hindering the in-depth corrosion of the protective sleeve by external media, and show good corrosion resistance in the test; under high-temperature ignition conditions, the DOPO structure preferentially decomposes and promotes the carbonization of PVC to form an initial carbon layer. As the temperature rises, the silicon chain decomposes into small segment silicon chains and even inorganic silicon attached to the carbon layer, thereby constructing a large number of continuous silicon-carbon flame retardant layers, which effectively hinder the penetration of combustion and the release of smoke and heat, and show excellent flame retardancy in the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0022] Figure 1 It is a heat release rate variation curve diagram of the present invention;

[0023] Figure 2 It is a smoke release rate variation curve diagram of the present invention. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Example 1, preparing a corrosion-resistant flame-retardant cable, the specific implementation process is as follows:

[0026] (1) Preparation of modified phosphorus silicon flame retardant

[0027] Step A1: Take terminal hydroxyl silicone oil, triethylamine and anhydrous tetrahydrofuran, mix them, pass dry nitrogen for protection, control the temperature of the water bath at 20°C, apply stirring at 150rpm, slowly add vinyltrichlorosilane to react for 2h, and then continue to heat to 55°C to react for 1h, wherein the terminal hydroxyl silicone oil is selected from IOTA 8861 hydroxyl mono-terminated silicone oil of Anhui IOTA Silicone Oil Co., Ltd., with a hydroxyl value of 40.5KOHmg / g, and the hydroxyl content of vinyltrichlorosilane, terminal hydroxyl silicone oil, triethylamine and anhydrous tetrahydrofuran are 10mmol:30mmol:5mL:40mL. After the reaction, tetrahydrofuran is removed by rotary evaporation to obtain an intermediate.

[0028] Step A2: pre-mix DOPO, a transition metal-based catalyst and dimethylformamide, add the intermediate and mix, pre-heat to 90°C, stir at 90rpm for 1.5h, and then heat to 130°C for 2.2h, wherein the transition metal-based catalyst is selected from an organic nickel-based catalyst bis(1,5-cyclooctadiene)nickel, and the feed ratio of the intermediate, DOPO, the transition metal-based catalyst and dimethylformamide is 10g:3.5mmol:6mg:20mL. After the reaction is completed, water three times the mass of the reaction system is added for washing, the mixture is allowed to stand and the aqueous phase is removed, and the substrate is dried to obtain a modified phosphorus silicon flame retardant.

[0029] (2) Preparation of corrosion-resistant and flame-retardant cables

[0030] Ingredients: The raw materials are measured by weight: 100 parts of PVC resin, SG-3 type resin raw material from Xinjiang Tianye (Group) Co., Ltd.; 13 parts of POE resin, 8100 type resin raw material from Dow Chemical; 16 parts of insulating filler, GM-3 type plastic-grade mica powder selected from Anhui Ge Rui New Material Technology Co., Ltd.; 30 parts of toughening agent, selected from commercially available industrial-grade trioctyl trimellitate; 4.8 parts of stabilizer, selected from GP-283 type raw material from Qingdao Guangde New Materials Co., Ltd.; 9 parts of modified phosphosilicate flame retardant, prepared by this embodiment; 0.13 parts of antioxidant, selected from commercially available antioxidant 1010 and antioxidant 168, compounded in a weight ratio of 2: 1; 5.8 parts of lubricant, selected from ZC-316A type high-density oxidized polyethylene wax from Jiaxing Zhongcheng Environmental Protection Technology Co., Ltd.

[0031] Step S1: Add the above raw materials into a high-speed mixer according to the weight ratio, mix at 600 rpm for 10 minutes, and then transfer the mixture into a torque rheometer, control the temperature to 170°C, the stirring speed to 40 rpm, plasticize and blend the mixture for 19 minutes, the torque tends to be stable, and the material is discharged and pelletized to obtain a functional masterbatch.

[0032] Step S2: Add the functional masterbatch into the twin-screw extruder, set the barrel temperature of the twin-screw extruder to: 165°C for zone 1, 180°C for zone 2, 190°C for zone 3, 180°C for zone 4, and the head temperature to 190°C, coat the functional masterbatch on the surface of the bundled wire core, cool and reel it, and then bake and homogenize it at 65°C for 1.5 hours to obtain a corrosion-resistant and flame-retardant cable.

[0033] Example 2, preparing a corrosion-resistant flame-retardant cable, the specific implementation process is as follows:

[0034] (1) Preparation of modified phosphorus silicon flame retardant

[0035] Step A1: Take terminal hydroxyl silicone oil, triethylamine and anhydrous tetrahydrofuran, mix them, pass dry nitrogen for protection, control the temperature of the water bath at 10°C, apply stirring at 120rpm, slowly add vinyltrichlorosilane to react for 3h, and then continue to heat to 45°C to react for 1.5h, wherein the terminal hydroxyl silicone oil is selected from IOTA 8861 hydroxyl mono-terminated silicone oil of Anhui IOTA Silicone Oil Co., Ltd., with a hydroxyl value of 40.5KOHmg / g, and the hydroxyl content of vinyltrichlorosilane, terminal hydroxyl silicone oil, triethylamine and anhydrous tetrahydrofuran are 10mmol:30mmol:3.5mL:30mL. After the reaction, tetrahydrofuran is removed by rotary evaporation to obtain an intermediate.

[0036] Step A2: pre-mix DOPO, a transition metal-based catalyst and dimethylformamide, add the intermediate and mix, pre-heat to 80°C, stir at 60rpm for 2h, and then heat to 120°C for 2.8h, wherein the transition metal-based catalyst is selected from an organic nickel-based catalyst bis(1,5-cyclooctadiene)nickel, and the feed ratio of the intermediate, DOPO, the transition metal-based catalyst and dimethylformamide is 10g:2.8mmol:4mg:15mL. After the reaction is completed, water three times the mass of the reaction system is added for washing, the mixture is allowed to stand and the aqueous phase is removed, and the substrate is dried to obtain a modified phosphosilicate flame retardant.

[0037] (2) Preparation of corrosion-resistant and flame-retardant cables

[0038] Ingredients: The raw materials are measured by weight: 100 parts of PVC resin, SG-3 type resin raw material from Xinjiang Tianye (Group) Co., Ltd.; 10 parts of POE resin, 8100 type resin raw material from Dow Chemical; 14 parts of insulating filler, GM-3 type plastic-grade mica powder selected from Anhui Ge Rui New Material Technology Co., Ltd.; 25 parts of toughening agent, selected from commercially available industrial-grade trioctyl trimellitate; 5.5 parts of stabilizer, selected from GP-283 type raw material from Qingdao Guangde New Materials Co., Ltd.; 11 parts of modified phosphosilicate flame retardant, prepared by this embodiment; 0.16 parts of antioxidant, selected from commercially available antioxidant 1010 and antioxidant 168, compounded in a weight ratio of 2: 1; 4.5 parts of lubricant, selected from ZC-316A type high-density oxidized polyethylene wax from Jiaxing Zhongcheng Environmental Protection Technology Co., Ltd.

[0039] Step S1: Add the above raw materials into a high-speed mixer according to the weight ratio, mix at 600 rpm for 10 minutes, and then transfer the mixture into a torque rheometer, control the temperature to 180°C, the stirring speed to 40 rpm, plasticize and blend the mixture for 16 minutes, and when the torque tends to be stable, cut the material into pellets to obtain a functional masterbatch.

[0040] Step S2: Add the functional masterbatch into the twin-screw extruder, set the barrel temperature of the twin-screw extruder to: 175°C for zone 1, 190°C for zone 2, 200°C for zone 3, 190°C for zone 4, and 200°C for the head temperature, coat the functional masterbatch on the surface of the bundled wire core, cool and reel it, and then bake and homogenize it at 80°C for 1 hour to obtain a corrosion-resistant and flame-retardant cable.

[0041] Example 3, preparing a corrosion-resistant flame-retardant cable, the specific implementation process is as follows:

[0042] (1) Preparation of modified phosphorus silicon flame retardant

[0043] Step A1: Take terminal hydroxyl silicone oil, triethylamine and anhydrous tetrahydrofuran, mix them, pass dry nitrogen for protection, control the temperature of the water bath at 15°C, apply stirring at 150rpm, slowly add vinyltrichlorosilane to react for 2.2h, and then continue to heat to 50°C to react for 1.3h, wherein the terminal hydroxyl silicone oil is selected from IOTA 8861 hydroxyl mono-terminated silicone oil of Anhui IOTA Silicone Oil Co., Ltd., with a hydroxyl value of 40.5KOHmg / g, and the hydroxyl content of vinyltrichlorosilane, terminal hydroxyl silicone oil, triethylamine and anhydrous tetrahydrofuran are 10mmol:30mmol:4mL:40mL. After the reaction, tetrahydrofuran is removed by rotary evaporation to obtain an intermediate.

[0044] Step A2: pre-mix DOPO, a transition metal-based catalyst and dimethylformamide, add the intermediate and mix, pre-heat to 85°C, stir at 90rpm for 1.8h, and then heat to 120°C for 2.6h, wherein the transition metal-based catalyst is selected from an organic nickel-based catalyst bis(1,5-cyclooctadiene)nickel, and the feed ratio of the intermediate, DOPO, the transition metal-based catalyst and dimethylformamide is 10g:3.2mmol:5mg:20mL. After the reaction is completed, water three times the mass of the reaction system is added for washing, the mixture is allowed to stand and the aqueous phase is removed, and the substrate is dried to obtain a modified phosphorus silicon flame retardant.

[0045] (2) Preparation of corrosion-resistant and flame-retardant cables

[0046] Ingredients: The raw materials are measured by weight: 100 parts of PVC resin, SG-3 resin raw material from Xinjiang Tianye (Group) Co., Ltd.; 15 parts of POE resin, 8100 resin raw material from Dow Chemical; 12 parts of insulating filler, GM-3 plastic-grade mica powder selected from Anhui Ge Rui New Material Technology Co., Ltd.; 28 parts of toughening agent, selected from commercially available industrial-grade trioctyl trimellitate; 5.2 parts of stabilizer, selected from GP-283 raw material from Qingdao Guangde New Materials Co., Ltd.; 13 parts of modified phosphosilicate flame retardant, prepared by this embodiment; 0.15 parts of antioxidant, selected from commercially available antioxidant 1010 and antioxidant 168, compounded in a weight ratio of 2: 1; 5.5 parts of lubricant, selected from ZC-316A high-density oxidized polyethylene wax from Jiaxing Zhongcheng Environmental Protection Technology Co., Ltd.

[0047] Step S1: Add the above raw materials into a high-speed mixer according to the weight ratio, mix at 600 rpm for 10 minutes, and then transfer the mixture into a torque rheometer, control the temperature to 180°C, the stirring speed to 40 rpm, plasticize and blend the mixture for 17 minutes, and when the torque tends to be stable, cut the material into pellets to obtain a functional masterbatch.

[0048] Step S2: Add the functional masterbatch into the twin-screw extruder, set the barrel temperature of the twin-screw extruder to: 170°C for zone 1, 185°C for zone 2, 200°C for zone 3, 185°C for zone 4, and 200°C for the head temperature, coat the functional masterbatch on the surface of the bundled wire core, cool and reel it, and then bake and homogenize it at 70°C for 1.2 hours to obtain a corrosion-resistant and flame-retardant cable.

[0049] Comparative Example 1

[0050] This comparative example refers to Example 3, except that the modified phosphorus silicon flame retardant is replaced by 11 parts of IOTA 8861 hydroxyl mono-terminated silicone oil and 2 parts of DOPO, and the rest of the implementation process is exactly the same.

[0051] Comparative Example 2

[0052] This comparative example refers to Example 3, except that the modified phosphorus silicon flame retardant is replaced by 10 parts of GT-150P halogen-free cable organosilicon additive produced by Zhejiang Jiahua Fine Chemical Co., Ltd. and 3 parts of DOPO, and the rest of the implementation process is exactly the same.

[0053] In order to facilitate the detection of the protective effect of the protective sleeve on the cable, the functional masterbatch prepared as above was hot pressed into a sheet at 190°C and 5MPa using a flat vulcanizer, and baked and homogenized at 80°C for 1.5h. A 3mm thick sample was taken and tested according to the vertical burning test of GB / T2048-2021 standard and the limiting oxygen index test of ASTM D2683 standard. The specific test results are shown in Table 1:

[0054] Table 1

[0055] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Flame retardant grade V-0 V-0 V-0 V-1 V-1 Oxygen index / % 29.7 29.2 30.7 26.1 27.5

[0056] It can be seen from the test results in Table 1 that the flame retardant grade of the protective sheath of the cable prepared in the embodiment reaches V-0 level, and the oxygen index reaches more than 29%, which has excellent flame retardancy.

[0057] Take a sample from the above sheet, weigh the original weight and record it as M0, prepare a 5% sodium hydroxide aqueous solution, a 5% sulfuric acid aqueous solution and a 20% sodium chloride aqueous solution respectively, soak the sample at room temperature for 72 hours, and then use a scrubbing tester to scrub both sides of the sample, the scrubbing material is nylon cloth, the scrubbing load is 1.5kg, the scrubbing agent is water, the scrubbing time is 10min, rinse after scrubbing and dry under 50℃ hot air for 3h, weigh the weight after corrosion and record it as M1, calculate the corrosion weight loss rate L=(M0-M1) / M0×100%; the specific test results are shown in Table 2:

[0058] Table 2

[0059] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 L(NaOH) / % 3.74 3.52 3.19 3.05 5.53 <![CDATA[L(H2SO 4) / %]]> 5.53 5.49 5.07 5.32 8.44 L(NaCl) / % 0.71 0.69 0.76 1.02 0.81

[0060] It can be seen from the test results in Table 2 that the protective sheath of the cable prepared in the embodiment has good tolerance to common corrosive media such as acid, alkali and salt, and exhibits good corrosion resistance.

[0061] Based on the above test results, samples were taken from the sheets of Example 3, Comparative Example 1 and Comparative Example 2, and cone calorimetry tests were performed according to ISO 5660-1 standard. Table 3 shows the combustion heat and smoke release test data. Figure 1 and Figure 2 They are the changing curves of heat release rate and smoke release rate respectively;

[0062] Table 3

[0063]

[0064]

[0065] As shown in Table 3, the protective sheath of the cable prepared in Example 3 has lower heat release and smoke release under continuous ignition, and produces lower harmful effects in a fire environment. Figure 1 and Figure 2 The ignition time of Example 3 lags behind that of Comparative Examples 1 and 2. During the continuous ignition process, the heat release and smoke release rates slowly increase, indicating that a uniform ablation layer can be formed under the ignition state, and the ablation layer fails by slowly peeling off, inhibiting the long-distance release of smoke and heat.

[0066] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0067] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A corrosion-resistant flame-retardant cable, consisting of a bundled wire core and a protective sheath on the surface, characterized in that: The protective cover includes, by weight: 100 parts of PVC resin, 10-15 parts of POE resin, 12-16 parts of insulating filler, 25-30 parts of toughening agent, 4.8-5.5 parts of stabilizer, 9-13 parts of modified phosphorus silicon flame retardant, 0.13-0.16 parts of antioxidant and 4.5-5.8 parts of lubricant; The modified phosphorus silicon flame retardant is prepared by the following method: Step A1: Mix terminal hydroxyl silicone oil, triethylamine and anhydrous tetrahydrofuran, introduce dry nitrogen for protection, control the temperature of the water bath at 10-20°C, stir and slowly add vinyltrichlorosilane to react for 2-3h, then continue to raise the temperature to 45-55°C to react for 1-1.5h, and remove tetrahydrofuran by rotary evaporation after the reaction to obtain an intermediate; Step A2: premix DOPO, transition metal-based catalyst and dimethylformamide, then add the intermediate and mix, preheat to 80-90°C and stir to react for 1.5-2h, then heat to 120-130°C and continue to react for 2.2-2.8h, add water to wash after the reaction, remove the water phase and dry to obtain a modified phosphorus silicon flame retardant.

2. A corrosion-resistant flame-retardant cable according to claim 1, characterized in that: The feed ratio of vinyl trichlorosilane, the hydroxyl content of the terminal hydroxyl silicone oil, triethylamine and anhydrous tetrahydrofuran is 10mmol:30mmol:3.5-5mL:30-40mL.

3. A corrosion-resistant flame-retardant cable according to claim 2, characterized in that: Hydroxyl-terminated silicone oil is a hydroxyl-terminated silicone oil.

4. A corrosion-resistant flame-retardant cable according to claim 2, characterized in that: The feed ratio of the intermediate, DOPO, transition metal-based catalyst and dimethylformamide is 10 g: 2.8-3.5 mmol: 4-6 mg: 15-20 mL.

5. The corrosion-resistant flame-retardant cable according to claim 4, characterized in that: The transition metal-based catalyst is bis(1,5-cyclooctadiene)nickel.

6. The corrosion-resistant flame-retardant cable according to claim 1, characterized in that: The PVC resin is SG-3 type resin.

7. The corrosion-resistant flame-retardant cable according to claim 1, characterized in that: The lubricant is high-density oxidized polyethylene wax.

8. A method for preparing a corrosion-resistant flame-retardant cable according to any one of claims 1 to 7, characterized in that: The steps include: Step S1: Mix the raw materials in a high-speed mixer, plasticize and blend at 170-180° C., and then cut into pellets to obtain functional masterbatch; Step S2: plasticize and extrude the functional masterbatch using a twin-screw extruder, and the temperature zones are set as follows: zone 1 165-175°C, zone 2 180-190°C, zone 3 190-200°C, zone 4 180-190°C, and the head temperature is 190-200°C. The functional masterbatch is coated on the surface of the bundled wire core, cooled and rolled, and then baked and homogenized at 65-80°C for 1-1.5h to obtain a corrosion-resistant and flame-retardant cable.

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