Flame-retardant insulating cable material as well as preparation method and application thereof

Abstract

The invention relates to a flame-retardant insulated cable material as well as a preparation method and application thereof, the cable material takes polypropylene as a matrix, and by adding a styrene elastomer, fluororesin and PMV resin modified barium titanate in a specific ratio, the defects of the existing cable material in electrical performance and heat resistance are overcome. The cable material has high insulation resistance (not less than 1014 omega.m), low dielectric loss (tan delta is low) and high dielectric strength (the breakdown field strength is greater than 84.9 kV / mm), keeps good mechanical properties and aging resistance, has the tensile strength and elongation at break retention rate of 88% or above after thermal aging under the condition of 150 DEG C / 300 h, is suitable for the fields of robots, rail transit, high-rise buildings and the like, and has wide application prospects. Wide application prospects are realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of polymer cable materials, and particularly relates to a flame-retardant insulating cable material and a preparation method and application thereof, which has high breakdown field strength, high insulation resistance and low dielectric loss. BACKGROUND

[0002] With the rapid development of the wire and cable industry, its demand continues to grow, and its application fields are increasingly wide. High-voltage power transmission has become the main way of large-scale, long-distance, cross-regional power transmission due to its low loss and long transmission distance. Under this background, cross-linked polyethylene (XLPE) is widely used as the main insulation material of cables due to its excellent electrical insulation performance, thermal mechanical properties and extrusion processing performance. At present, the cables on the market are mostly based on polyvinyl chloride (PVC) as the matrix. However, this material has significant shortcomings: first, it has poor heat resistance, low long-term use temperature, and its performance is easily degraded at high temperatures. When the conductor current is too large or the environmental temperature is high, the insulation layer may soften, deform or even be damaged, affecting safe operation. Second, it has poor cold resistance and is easily brittle at low temperatures, such as cracking in cold regions, leading to insulation failure. Third, it has limited insulation performance, relatively low insulation resistance, high dielectric loss, high power consumption, heat generation, low power transmission efficiency, and is easily damaged by overheating. In addition, it has poor environmental performance, produces harmful substances during production and use, releases toxic gases during fire or aging, and harms health and the environment. Finally, it has a limited service life and a relatively short normal service life, which is much lower than that of high-performance insulation materials such as cross-linked polyethylene insulated cables.

[0003] Polypropylene (PP) has many advantages in the preparation of high-voltage cable insulation layers. First, it has excellent insulation properties, such as high insulation resistivity and low dielectric loss factor, can maintain stable electrical properties under high-voltage electric field, effectively reduce signal interference and noise. Second, PP is a thermoplastic material, without the need for crosslinking process like crosslinked polyethylene (XLPE); PP also has good heat resistance, can work at 90℃ for a long time, meet the requirements of large-capacity power transmission, and the long-term working temperature of modified PP cable insulation material can even reach 105℃. At the same time, PP has good mechanical properties, generally does not need crosslinking agent to obtain good mechanical properties, and has sufficient mechanical flexibility, which can meet the mechanical performance requirements of cable during laying and use. In addition, the thermoplastic properties of PP make it easy to recycle and reprocess, meet the environmental protection requirements, and help to reduce resource waste and environmental pollution. SEBS has excellent flexibility and resilience, making the cable not easy to become brittle in low temperature environment, can adapt to larger deformation without breaking, thereby enhancing the fatigue resistance and mechanical stability of the cable, especially suitable for occasions that need frequent bending; compared with polyvinyl chloride (PVC) and other materials, SEBS can still maintain good flexibility and mechanical properties at low temperature, ensuring the normal work of the cable in cold environment. SEBS has good flowability and processing stability during processing, can be molded by common processing techniques such as extrusion, injection molding, etc., which is beneficial to the production and manufacturing of cables. In PP composite materials, the addition of SEBS can improve the elongation at break and impact resistance of PP, while reducing its crystallinity, thereby improving the electrical properties and processing properties of PP.

[0004] The cable insulation layer needs to meet many performance requirements: in terms of electrical properties, it needs high insulation resistance (not less than 10 13 Ω·cm), low dielectric loss (tanδ low), high dielectric strength (high breakdown field strength), in terms of physical properties, it needs good flexibility, appropriate hardness and strength, low water absorption. In terms of chemical properties, it needs corrosion resistance and aging resistance. Adding inorganic nanoparticles to PP polymer materials can inhibit space charge injection, however, due to the incompatibility of most inorganic nanoparticles with the polymer matrix, they are prone to agglomeration in crosslinked polyethylene-based substrates, causing a significant reduction in the breakdown strength of the insulation material, limiting the application of the insulation material in high-voltage cables.

[0005] Barium titanate (BT) is an inorganic ceramic particle with high dielectric constant, which is widely used as a filler for preparing cable insulating material with high insulation and low dielectric loss due to its excellent dielectric and insulation properties. However, the dispersion effect of barium titanate in the polymer is poor, which makes it difficult for the material to have both high breakdown strength and low dielectric loss. Therefore, there is an urgent need to develop a cable material with high volume resistance and high breakdown strength, low dielectric loss, and without reducing the mechanical properties and aging resistance, so as to expand the application range of the cable material. SUMMARY

[0006] The present application aims to overcome the shortcomings of the prior art and provide a flame-retardant insulating cable material and a preparation method thereof. The flame-retardant insulating cable material provided by the present application has high breakdown field strength, high insulation resistance, low dielectric loss (low tan delta), and does not reduce the mechanical properties and aging resistance, which is beneficial to expand the application range of the cable material.

[0007] The present application provides a flame-retardant insulating cable material, which comprises the following raw materials by weight: 100 parts of polypropylene, 30-50 parts of styrene-based elastomer, 5-10 parts of fluororesin, 10-30 parts of PMV resin modified barium titanate, 30-50 parts of filling oil, 5-15 parts of compatibilizer, 10-20 parts of flame retardant, 2-5 parts of antioxidant, and 1-5 parts of lubricant.

[0008] Preferably, the styrene-based elastomer comprises SEBS elastomer and SBS elastomer, and the mass ratio of the SEBS elastomer to the SBS elastomer is (1.0-1.5):1.

[0009] Preferably, the average particle size of the barium titanate is 10-300 nm, and further preferably, the average particle size of the barium titanate is 50-100 nm.

[0010] Preferably, the PMV resin modified barium titanate comprises the following steps: reacting amino-modified barium titanate with PMV resin (vinyl acetate-maleic anhydride copolymer) at a mass ratio of 1:0.9-2.

[0011] The preparation method of the amino-modified barium titanate is not particularly limited, as long as the surface of the barium titanate has an amino functional group. For example, the barium titanate can be modified with an amino silane coupling agent, or by plasma amination. The reaction of the amino-modified barium titanate with the PMV resin (vinyl acetate-maleic anhydride copolymer) can be carried out in a solvent, such as DMF, toluene, or xylene organic solvent. Alternatively, the amino-modified barium titanate and the PMV resin can be extruded at high temperature to prepare the product, as long as the amino group in the amino-modified barium titanate reacts with the maleic anhydride in the PMV resin.

[0012] Preferably, the mass percentage of maleic anhydride in the PMV resin is 30-50%.

[0013] Preferably, the polypropylene is homopolymer polypropylene or propylene ethylene copolymer, and the melt index of the polypropylene resin is 10-100 g / 10 min under the test conditions of 230℃ and 2.16 kg.

[0014] Preferably, the mass fraction of styrene in the SEBS resin is 30-50%, and the mass fraction of styrene in the SBS resin is 25-45%.

[0015] Preferably, the fluorine resin is at least one of polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF), ethylene-tetrafluoroethylene copolymer (ETFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), and polyvinyl fluoride (PVF).

[0016] Preferably, the filling oil is at least one of industrial-grade white mineral oil, silicone oil, and naphthenic oil.

[0017] Preferably, the compatibilizer is at least one of maleic anhydride grafted polypropylene, maleic anhydride grafted polyethylene, and maleic anhydride grafted styrene-butadiene-styrene block copolymer.

[0018] Preferably, the flame retardant includes at least one of piperazine pyrophosphate, melamine polyphosphate, and ammonium polyphosphate. According to the requirements of the flame retardant grade, a carbonization agent can also be added, and the carbonization agent is at least one of expanded graphite, montmorillonite, and silicon dioxide.

[0019] Preferably, the antioxidant includes at least one of hindered phenolic antioxidants and phosphite antioxidants; and the lubricant includes one or more of erucic acid amide, oleic acid amide, EBS amide, PE wax, and stearate.

[0020] The present application also provides a preparation method of the flame-retardant insulating cable material, which comprises the following steps:

[0021] The components are mixed in proportion, uniformly extruded in a double-screw extruder, granulated, and dried to obtain the insulating material.

[0022] Preferably, the extrusion temperature of the double-screw extruder is 180-210℃, the drying temperature is 80-100℃, and the drying time is 2-3h.

[0023] Preferably, the present application also provides a preparation method of the flame-retardant insulating cable, which comprises the following steps:

[0024] (1) Preparation of the conductor core layer: after the conductor material is drawn into a wire, a conductor core layer is prepared.

[0025] (2) Preparation of the insulation layer: the insulation layer is coated on the surface of the conductor core in step (1) by using an extrusion die, to obtain the insulation layer; the insulation layer is prepared by using the flame-retardant insulation cable material of the application.

[0026] (3) Preparation of the shielding layer: the shielding layer is coated on the surface of the insulation layer in step (2), to obtain the shielding layer.

[0027] (4) Preparation of the outer sheath layer: the outer sheath layer is extruded on the surface of the shielding layer in step (3), to obtain the flame-retardant insulation cable.

[0028] Preferably, the application further provides the use of the above-mentioned flame-retardant insulation cable in robots, rail transit and high-rise buildings.

[0029] SEBS can improve the mechanical properties of polypropylene as a toughening agent, but with the increase of the content of SEBS, the crystallinity, DC volume resistivity and DC breakdown field strength of the composite material will decrease, and the dielectric loss factor will increase. In order to solve the above problems, the application selects a suitable ratio of SEBS and SBS to modify the polypropylene material. The polarity and distribution of the molecular chain structure of SEBS and SBS are different. The polarity of the polystyrene hard segment of SEBS is relatively low, while the polarity of the polystyrene hard segment of SBS is relatively high. When they are blended with polypropylene, the difference in polarity can complement each other, making the overall polarity of the material more uniform, reducing the electric field distortion and charge accumulation caused by too large polarity difference, and further reducing the dielectric loss, improving the breakdown field strength and insulation resistance. The combination of SEBS and SBS not only improves the electrical properties of polypropylene, but also improves its mechanical properties. Good mechanical properties can ensure that the material is not easy to deform and damage during use, thereby ensuring the stable play of its electrical properties.

[0030] In the technical scheme of the application, a specific content of fluororesin is further introduced into the composite matrix formed by polypropylene and styrene-based elastomer as a synergistic component. On the one hand, the high bond energy of C-F bond in fluororesin forms a strong polarity barrier, reduces the accumulation of space charge, and avoids local electric field distortion. At the same time, the high crystallinity of fluororesin (such as PTFE crystallinity ≥ 90%) fills the defects of the matrix, reduces air gap and micropores, and weakens electric field concentration, significantly improving the electrical properties (breakdown field strength, insulation resistance, dielectric loss). On the other hand, the strong polarity of fluororesin has a traction effect on the styrene-based elastomer particles, increasing the uniformity of the product composite resin and forming a high-dispersion sea-island structure. Under the combined action of the three, the breakdown field strength, insulation resistance and dielectric loss of the material are significantly improved.

[0031] Barium titanate (BT) is an inorganic ceramic particle with high dielectric constant, which is widely used as a filler to prepare cable insulation material with high insulation and low dielectric loss due to its excellent dielectric and insulation properties. However, the dispersibility of barium carbonate in polypropylene polymer material is poor. The present application uses PMV resin (vinyl acetate-maleic anhydride copolymer) to modify barium titanate, which is beneficial to promote the dispersion of barium titanate in the island structure of styrene elastomer. Moreover, the vinyl acetate in PMV resin can not only intertwine with the molecular chain of polypropylene, but also prevent the mutual contact between barium titanate particles, thereby improving the bonding force between barium titanate and polypropylene, inhibiting the injection of space charge, and making the material have higher breakdown strength and lower dielectric loss.

[0032] The advantages or beneficial effects of the flame-retardant insulated cable and the preparation method thereof of the present application at least include:

[0033] The cable insulation material of the present application promotes the dispersion of barium carbonate and prevents the mutual contact between barium titanate particles by grafting modification of barium titanate particles with PMV resin, thereby significantly improving the bonding force between barium titanate and polypropylene, and further improving the breakdown strength of the material. At the same time, the combination of SEBS and SBS effectively reduces the electric field distortion and charge accumulation caused by too large polarity difference. In addition, the addition of fluororesin forms a strong polarity barrier, further reducing the accumulation of space charge and forming a highly dispersed island structure. The optimization of this structure not only reduces the dielectric loss of the insulation layer material, but also improves the breakdown field strength and insulation resistance, which is beneficial to expand the application range of the cable material. DETAILED DESCRIPTION

[0034] In order to more clearly illustrate the purpose, technical scheme and advantages of the present application, the technical scheme of the present application will be described in detail through specific examples. It should be pointed out that these examples are only used to illustrate the present application, and the actual protection scope of the present application should be defined by the claims.

[0035] The materials, reagents and the like used in the following examples and comparative examples are commercially available reagents and materials unless otherwise specified. The amount of components in the following examples is 1 g per weight part or per part unless otherwise specified.

[0036] The main raw materials used in the examples and comparative examples are as follows:

[0037] PP-1: HJ4045, melt index 45 g / 10 min at 230℃, 2.16 Kg, Daehan Oil Chemical Co., Ltd.

[0038] PP-2: UT8012M, melt index 12 g / 10 min at 230℃, 2.16 Kg, Maoming Petrochemical Co., Ltd.

[0039] SEBS-1: SEBS, 6151, purchased from China Taiwan Co., Ltd., styrene mass fraction is 34%;

[0040] SEBS-2: ZL-Q5501 brand, purchased from Zhongli Science and Technology, styrene content is 49wt%.

[0041] SBS-1: SBS3741 brand, purchased from Li Changrong, styrene content is 30wt%.

[0042] SBS-2: SBS YH-792 brand, purchased from Yueyang Petrochemical, styrene content is 40wt%.

[0043] Polytetrafluoroethylene (PTFE), PTFE 6C, USA DuPont.

[0044] Polyvinylidene fluoride (PVDF): Zhonghua Blue Sky Group Co., Ltd.

[0045] PMV resin (vinyl acetate-maleic anhydride copolymer): PMV-50M, maleic anhydride content 50%, Huihong.

[0046] SMA resin (styrene-maleic anhydride copolymer): SMA-10M, maleic anhydride content 50%, Huihong.

[0047] The filling oil is white oil, and the kinematic viscosity is 90mm 2 / s, commercially available.

[0048] The compatibilizer is maleic anhydride grafted polypropylene, brand CA100, manufacturer Arkema.

[0049] Barium titanate: average particle size 100nm, purchased from Japan Sakai Chemical Industry Co., Ltd.

[0050] The flame retardant is a mixture of ammonium polyphosphate and expanded graphite in a mass ratio of 10:1, and ammonium polyphosphate and expanded graphite are commercially available.

[0051] The antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 2:1, and antioxidant 1010 and antioxidant 168 are commercially available.

[0052] The lubricant is commercially available.

[0053] I. Preparation of insulating flame-retardant cable material

[0054] 1. PMV resin modified barium titanate 1#, the preparation method comprises the following steps:

[0055] S1, BaTiO3 powder was dried at 120°C under vacuum for 2h to remove water, 2g KH-550 was added into 100ml ethanol / water mixed solution (volume ratio 90:10) and ultrasonic dispersed for 10min; 10g dried BaTiO3 was added into the hydrolysis solution, mechanically stirred at 60°C for 4h, centrifuged, washed with ethanol for 3 times, dried at 80°C under vacuum for 6h to obtain amino-modified BaTiO3.

[0056] S2, 10g PMV resin was dispersed in 100ml toluene, 10g amino-modified BaTiO3 of step S1 was added, refluxed at 110°C under nitrogen protection for 6h, centrifuged, washed with toluene for 3 times, dried at 70°C under vacuum for 10h to obtain PMV resin modified BaTiO3, which was recorded as modified BaTiO3 1#.

[0057] 2, PMV resin modified BaTiO3 2#, the preparation method comprising the following steps:

[0058] S1, BaTiO3 powder was dried at 110°C under vacuum for 3h to remove water, 5g KH-550 was added into 100ml ethanol / water mixed solution (volume ratio 90:10) and ultrasonic dispersed for 20min; 10g dried BaTiO3 was added into the hydrolysis solution, mechanically stirred at 60°C for 4h, centrifuged, washed with ethanol for 3 times, dried at 80°C under vacuum for 6h to obtain amino-modified BaTiO3.

[0059] S2, 10g PMV resin was dispersed in 100ml toluene, 15g amino-modified BaTiO3 of step S1 was added, refluxed at 110°C under nitrogen protection for 5h, centrifuged, washed with toluene for 3 times, dried at 70°C under vacuum for 10h to obtain PMV resin modified BaTiO3, which was recorded as modified BaTiO3 2#.

[0060] 3, PMV resin modified BaTiO3 3#, the preparation method comprising the following steps:

[0061] S1, BaTiO3 powder was dried at 120°C under vacuum for 2h to remove water, 2g KH-550 was added into 100ml ethanol / water mixed solution (volume ratio 90:10) and ultrasonic dispersed for 10min; 10g dried BaTiO3 was added into the hydrolysis solution, mechanically stirred at 60°C for 4h, centrifuged, washed with ethanol for 3 times, dried at 80°C under vacuum for 6h to obtain amino-modified BaTiO3, which was recorded as modified BaTiO3 3#.

[0062] 4, PMV resin modified BaTiO3 4#, the preparation method comprising the following steps:

[0063] The 10g PMV resin is dispersed in 100mL toluene, 10g BaTiO3 is added, and the reaction is carried out under reflux at 110°C for 6h under nitrogen protection, centrifuged, washed with toluene for 3 times, and dried at 70°C under vacuum for 10h to obtain the PMV resin modified barium titanate, which is recorded as PMV resin modified barium titanate 4#.

[0064] 5. PMV resin modified barium titanate 5#, the preparation method comprising the following steps:

[0065] The difference from PMV resin modified barium titanate 1# is that SMA-10M resin (styrene-maleic anhydride copolymer) is used instead of PMV resin, and other conditions are the same.

[0066] 2. The application also relates to a preparation method of the flame-retardant insulating cable material, and specifically comprises the following steps:

[0067] The materials are mixed according to the weight ratio in Table 1 or Table 2 to obtain a mixture; the obtained mixture is added into a double-screw extruder for extrusion granulation, the temperature of the double-screw extruder is 180-210°C, the drying temperature is 80°C, and the drying time is 2h to obtain the flame-retardant insulating cable material.

[0068] Table 1: The mass parts (g) of each component in Examples 1-5 are as follows.

[0069]

[0070] Table 2: The mass parts (g) of each component in Comparative Examples 1-9 are as follows.

[0071]

[0072]

[0073] 3. Performance evaluation:

[0074] The flame-retardant insulating cable material prepared in the examples and comparative examples is subjected to relevant performance tests, and the specific test methods are as follows:

[0075] (1) Dielectric loss factor

[0076] The dielectric loss factor of the material at 1-10 6 Hz is measured by using a broadband dielectric spectrometer (Concept80 type, Germany Novo-Control Company). The thickness of the circular thin sheet sample is 3mm, and the diameter is 60mm. Each type of sample is tested for 5 times, and the average value is taken.

[0077] (2) Test of breakdown strength

[0078] The DC breakdown strength of the prepared sample is tested by adopting the ball plate electrode according to the national standard GB / T 1408-2016 Insulating materials - Determination of electrical strength.

[0079] (3) Volume resistance

[0080] The volume resistance test is carried out according to GB / T 1410-2016.

[0081] (4) Aging resistance

[0082] The samples in the examples and comparative examples are heat aged at 150℃ / 300h, and the performance test is carried out to calculate the retention rate of tensile strength and elongation at break.

[0083] Tensile strength test: The tensile strength is tested according to ISO 527-2012 Plastics - Determination of tensile properties. Tensile strength retention rate = (tensile strength before aging - tensile strength after aging) / tensile strength before aging * 100%.

[0084] Elongation at break: tested according to ISO 527-1-2019: Test conditions: 23℃. Elongation at break retention rate = (elongation at break before aging - elongation at break after aging) / elongation at break before aging * 100%.

[0085] Table 3: Performance test of insulating cable material in examples and comparative examples

[0086]

[0087]

[0088] According to the test results in Table 3, the volume resistance of the flame-retardant insulating cable insulating material prepared in the application is 10 15 Ω·m or more, the tangent value of dielectric loss (tan δ) is less than 1.8*10 -4 , and the breakdown strength is greater than 84.9kV / mm; it has low dielectric loss, high breakdown field strength and insulating resistance; at the same time, the retention rate of tensile strength and elongation at break under heat aging at 150℃ / 300h is more than 88%, and it has excellent mechanical properties, and is suitable for the field of high insulation and low dielectric loss cable.

[0089] It can be seen from the comparison of Comparative Examples 1-4 and Example 1 that, in Example 1, the PMV resin modified barium titanate is prepared by reacting barium titanate with PMV resin, which is beneficial to promote the dispersion of barium titanate in the sea-island structure of the styrene elastomer, and the acetic acid ethylene in the PMV resin can also intertwine with the polypropylene molecular chain, prevent the mutual contact between barium titanate particles, improve the bonding force between barium titanate and polypropylene, further inhibit the injection of space charge, so that the material has higher breakdown strength and lower dielectric loss; and the dispersion of barium titanate in the material is more uniform, which is also beneficial to improve the heat resistance and mechanical properties of the polypropylene material, and the elongation at break and tensile strength retention of the material after aging are higher. Comparative Example 1 does not add dielectric particles, Comparative Example 2 only uses a coupling agent to modify barium titanate, Comparative Example 3 uses PMV resin to directly stir and mix with barium titanate, and the dispersion of the modified barium titanate in Comparative Examples 2-3 in the polypropylene material is poor, and Comparative Example 4 uses SMA resin to modify barium titanate, the compatibility of the styrene segment with PP is poor, and the phase separation interface is easy to form, which causes the distortion of the electric field at the interface, resulting in that the dielectric loss, breakdown field strength and aging resistance of Comparative Examples 1-4 are significantly lower than those of Example 1.

[0090] It can be seen from the comparison of Comparative Examples 5-8 and Example 1 that, when the mass ratio of SEBS elastomer and SBS elastomer in the styrene elastomer is (1.0-1.5):1, the overall polarity of the material is more uniform, the electric field distortion and charge accumulation caused by too large polarity difference are reduced, and thus the dielectric loss is reduced, the breakdown field strength and insulation resistance are improved. The combination of SEBS and SBS can also improve the mechanical properties and aging resistance, which can ensure that the material is not easy to deform and damage during use, so as to ensure the stable performance of the material. In Comparative Examples 5-6, only SEBS or SBS is used to modify polypropylene, and in Comparative Examples 7-8, the mass ratio of SEBS elastomer and SBS elastomer is not within the range of (1.0-1.5):1, which results in that the dielectric loss, breakdown field strength and insulation resistance, and aging resistance of Comparative Examples 5-8 are also significantly reduced.

[0091] It can be seen from the comparison of Comparative Example 9 and Example 1 that, the addition of fluororesin is beneficial to improve the breakdown field strength, insulation resistance, dielectric loss and aging resistance of the insulation cable material, which may be due to the strong polarity barrier formed by the fluororesin, reducing the accumulation of space charge and avoiding local electric field distortion; at the same time, the strong polarity of the fluororesin has a traction effect on the styrene elastomer particles, which increases the uniformity of the product composite resin.

[0092] The above examples are only provided to illustrate the present application, and are not intended to limit the possible embodiments of the present application. Based on the disclosure of the present application, those skilled in the art can make various modifications and adjustments. It is not necessary or possible to list all possible embodiments. Any modification, equivalent replacement or improvement made within the basic principles and scope of the present application should be considered as falling within the protection scope of the present application.

Claims

1. A flame retardant insulating cable material, characterized in that: The invention comprises the following raw materials in parts by weight: 100 parts of polypropylene, 30-50 parts of styrene elastomer, 5-10 parts of fluororesin, 10-30 parts of PMV resin-modified barium titanate, 30-50 parts of filler oil, 5-15 parts of compatibilizer, 10-20 parts of flame retardant, 2-5 parts of antioxidant, and 1-5 parts of lubricant; The styrene elastomer includes SEBS elastomer and SBS elastomer, and the mass ratio of the SEBS elastomer to the SBS elastomer is (1.0-1.5):1; The PMV resin modified barium titanate comprises the following steps: reacting aminoated barium titanate with PMV resin in a mass ratio of 1:0.9-2 to obtain the barium titanate.

2. The flame-retardant insulating cable material according to claim 1, characterized in that: The average particle size of the barium titanate is 10nm-300nm.

3. The flame-retardant insulating cable material according to claim 1, characterized in that: The mass content of maleic anhydride in the PMV resin is 30-50%; the mass fraction of styrene in the SEBS resin is 30-50%; and the mass fraction of styrene in the SBS resin is 25-45%.

4. The flame-retardant insulating cable material according to claim 1, characterized in that: The polypropylene is homopolymerized polypropylene or propylene-ethylene copolymer, and the melt index of the polypropylene resin under the test conditions of 230° C. and 2.16 kg is 10-100 g / 10 min.

5. The flame-retardant insulating cable material according to claim 1, characterized in that: The fluororesin is at least one selected from polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymer, ethylene-chlorotrifluoroethylene copolymer, and polyvinyl fluoride.

6. The flame retardant insulating cable material according to claim 1, characterized in that: The filler oil is at least one of industrial grade white mineral oil, silicone oil, and naphthenic oil; The compatibilizer is at least one of maleic anhydride grafted polypropylene, maleic anhydride grafted polyethylene, and maleic anhydride grafted styrene-butadiene-styrene block copolymer; The flame retardant includes at least one of piperazine pyrophosphate, melamine polyphosphate, and ammonium polyphosphate.

7. The flame retardant insulating cable material according to claim 1, characterized in that: The antioxidant includes at least one of hindered phenol antioxidants and phosphite antioxidants; the lubricant includes one or more of erucamide, oleamide, EBS amides, PE wax, and stearate.

8. A method for preparing a flame-retardant insulating cable material according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: uniformly mixing the components in proportion, melting and extruding in a twin-screw extruder, granulating, and drying to obtain an insulating material; The extrusion temperature of the twin-screw extruder is 180-210° C., the drying temperature is 80-100° C., and the drying time is 2-3 hours.

9. A method for preparing a flame-retardant insulated cable, characterized in that: The following steps are involved: (1) Preparation of conductor core layer: The conductor material is drawn to obtain a wire to prepare the conductor core layer; (2) preparing an insulating layer: using an extrusion die to coat the insulating layer on the surface of the conductor core in step (1) to obtain an insulating layer; the insulating layer is prepared using the flame-retardant insulating cable material according to any one of claims 1 to 7; (3) preparing a shielding layer: coating the surface of the insulating layer in step (2) with a shielding layer to obtain a shielding layer; (4) Preparing an outer sheath layer: Extruding an outer sheath layer on the surface of the shielding layer in step (3) to obtain a flame-retardant insulated cable.

10. Use of the flame-retardant insulated cable prepared by the method according to claim 9 in robots, rail transportation, and high-rise buildings.

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