Waterproof flame-retardant cable material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of high polymer materials, and particularly relates to a water-resistant flame-retardant cable material as well as a preparation method and application thereof. The water-resistant flame-retardant cable material is prepared from the following components in parts by weight: 70 to 100 parts of polyolefin resin, 100 to 180 parts of a halogen-free flame retardant, 0.5 to 1.8 parts of a silane coupling agent, 0.05 to 0.2 part of dicumyl peroxide, 0.5 to 3 parts of a lubricating agent and 0.3 to 1 part of an antioxidant, the polyolefin resin is a blend of polyethylene, an ethylene-vinyl acetate copolymer, maleic anhydride grafted polyolefin and a polyolefin elastomer. The cable material prepared by the invention not only ensures excellent flame retardance and physical and mechanical properties, but also has excellent water resistance, and the change rate of strength elongation after soaking in water at 70 DEG C for 168 hours is not greater than + / -30%. Wherein the change rate of the tensile strength is as low as 15.67% and is basically not more than 20%; and the change rate of the elongation at break is basically not more than 18% and even can be as low as 10.56%.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and in particular relates to a water-resistant and flame-retardant cable material and a preparation method and application thereof. Background Art

[0002] Flame-retardant cables can prevent the spread of fire in the event of a fire, but their waterproof performance is equally important. In some special environments, such as at sea or in areas with high groundwater levels, cables need to have good waterproof performance to prevent water erosion and penetration, thereby ensuring stable operation of the cable and extending its service life.

[0003] However, the water resistance of flame-retardant cable materials is relatively poor, mainly due to their composition and structural characteristics. A large amount of flame retardants are added to flame-retardant cable materials during the production process. These flame retardants usually contain a large number of hydrophilic groups, which leads to a significant decrease in the performance of the cable materials after immersion in water. In order to ensure the flame retardant properties of the materials, a large amount of powder filling must be added to ensure the mixing process of the materials. Polar resins are also prone to hydrophilicity, resulting in a decrease in performance after immersion in water. A large amount of powder is mixed with resin, and the interface adhesion is poor. Water molecules enter the weak points of the interface, which will destroy the material structure and cause the material performance to deteriorate.

[0004] At present, the existing improvement technology mainly improves the water resistance of cable materials by reducing the content of hydrophilic groups and adding some lipophilic groups. However, the reduction of a large amount of powder and polar resin in the flame-retardant cable material will not guarantee the flame retardant properties of the material. Therefore, the existing technology cannot significantly improve the water resistance of high-filled and high-flame-retardant cable materials without destroying the flame retardant properties. If the amount of traditional inorganic flame retardants is reduced, the flame retardant properties of the material will not pass the test; if the amount of polar resin in the material is simply reduced, the mechanical and processing properties of the material will become very poor.

[0005] Therefore, it is necessary to develop a cable material with excellent water resistance and little effect on flame retardancy and mechanical properties. Summary of the invention

[0006] In order to solve the existing problems in current cable materials, the present invention provides a water-resistant and flame-retardant cable material and a preparation method thereof. The prepared cable material has excellent flame retardant and physical and mechanical properties and excellent water resistance, and can meet the BS7655-6.1 standard of 70°C for 168h, and the change rate of strength and elongation after immersion in water is not more than ±30%.

[0007] The first aspect of the present application is to provide a water-resistant flame-retardant cable material comprising the following components in parts by weight:

[0008] Polyolefin resin 70-100 parts,

[0009] 100 - 180 parts of halogen - free flame retardant,

[0010] 0.5 - 1.8 parts of silane coupling agent,

[0011] 0.05 - 0.2 parts of dicumyl peroxide,

[0012] 0.5 - 3 parts of lubricant,

[0013] 0.3 - 1 part of antioxidant;

[0014] The polyolefin resin is a blend of polyethylene, ethylene - vinyl acetate copolymer, maleic anhydride - grafted polyolefin, and polyolefin elastomer;

[0015] In some embodiments, the ratio of polyethylene, ethylene - vinyl acetate copolymer, and polyolefin elastomer in the polyolefin resin is 1:4:0.5 to 3:1:1.

[0016] In some embodiments, the polyolefin resin is a mixture of polyethylene and maleic anhydride - grafted polyolefin, and the ratio is 1:1 to 3:1.

[0017] Furthermore, the melt index of the polyethylene is 0.5 - 10 g / 10 min; preferably, it is one or a combination of low - density polyethylene, metallocene linear low - density polyethylene, and high - density polyethylene;

[0018] In some embodiments, the mass content of vinyl acetate in the ethylene - vinyl acetate copolymer is 9% - 70%;

[0019] In some embodiments, the maleic anhydride - grafted polyolefin is selected from one or a combination of maleic anhydride - grafted polyethylene, maleic anhydride - grafted ethylene - vinyl acetate copolymer, and maleic anhydride - grafted ethylene - octene copolymer;

[0020] In some embodiments, the polyolefin elastomer is selected from one or a combination of ethylene - octene copolymer elastomer, ethylene - propylene copolymer elastomer, and ethylene - butene copolymer elastomer.

[0021] Furthermore, the halogen - free flame retardant is selected from one or a combination of magnesium hydroxide and aluminum hydroxide; in some preferred embodiments, to ensure flame - retardant and processing properties, the particle size of the halogen - free flame retardant is preferably 0.5 - 3 μm.

[0022] Furthermore, the silane coupling agent is a silane coupling agent containing vinyl, long - chain fatty, and benzene ring functional groups.

[0023] In some embodiments of the present invention, the silane coupling agent is composed of vinyltrimethoxysilane, cetyltrimethoxysilane, and phenyltriethoxysilane.

[0024] In some embodiments of the present invention, in order to further improve the water resistance of the cable material and further reduce the penetration of water into the powder, it is preferred that the silane coupling agent adopts a vinyl mixed long-chain fatty and benzene ring structural unit. The vinyl acts as an active silane and participates in the reaction to increase the interfacial bonding. The long-chain fatty acid acts as a strong hydrophobic group to improve the water resistance of the powder, and the steric hindrance effect of the benzene ring structure can slow down the erosion of water on the material, thereby achieving the purpose of water resistance.

[0025] Further, the lubricant is selected from one or a combination of silicone masterbatch, ethylene bisstearamide, zinc stearate or polyethylene wax.

[0026] Further, the antioxidant is selected from one or a combination of hindered phenols, phosphites or hindered amine antioxidants. To ensure the thermal aging performance and service life of the flame-retardant cable material; the antioxidant is preferably a mixture of hindered phenol and phosphite, and the ratio is 1:2.

[0027] Further, the cable material prepared in this application has excellent water resistance. After immersion in water at 70 °C for 168 hours, the change rate of the tensile strength of the sample is ≤20.13%; the change rate of the elongation at break is ≤18.13%.

[0028] The second aspect of this application is to provide the application of the water-resistant flame-retardant cable material in wires or cables.

[0029] The third aspect of this application is to provide a preparation method of the water-resistant flame-retardant cable material, including the following steps:

[0030] S1. Perform silane modification on the halogen-free flame retardant: Add the halogen-free flame retardant and the silane coupling agent to a powder modifier to perform silane modification on the halogen-free flame retardant;

[0031] S2. Knead the silane-modified halogen-free flame retardant obtained in step S1 with other components in a kneader, and then extrude and pelletize to obtain the water-resistant flame-retardant cable material.

[0032] In some embodiments, in step S1, a powder modifier is used to perform silane modification on the halogen-free flame retardant at a temperature of 60-80 °C for 30 min; in some embodiments, the modification amount of the silane coupling agent is 0.5-1.5%.

[0033] In some embodiments, in step S2, the discharge temperature of the kneader is 160-170 °C, and the upper cover of the kneader is intermittently lifted during the kneading process to ensure uniform mixing of the materials. In one embodiment, the upper cover is lifted once every 3 minutes during the kneading process.

[0034] In some embodiments, a method for preparing a water-resistant and flame-retardant cable compound includes the following steps: First, a powder modifier is used to perform silane modification on the halogen-free flame retardant at a temperature of 70°C for 30 minutes, and the modification amount of the silane coupling agent is 1%. After modification, the powder is added to a kneader together with other components for kneading, and then extruded and granulated through a two-stage unit to obtain the flame-retardant cable compound. Among them, the discharging temperature of the kneader is 160-170°C, the kneading time is 20 minutes, and the upper cover of the kneader is lifted once every 3 minutes during the kneading process to ensure uniform mixing of the materials; the temperature settings of the twin-screw and single-screw in the two-stage unit are both 170°C.

[0035] The beneficial effects of the present invention are at least as follows:

[0036] The water-resistant and flame-retardant cable compound and its preparation method provided by the present invention, the prepared cable compound not only has excellent flame retardancy and physical and mechanical properties, but also has excellent water resistance, and can meet the requirements of BS7655-6.1 standard at 70°C for 168 hours, and the change rate of strength and elongation after immersion in water is not more than ±30%. Among them, the change rate of tensile strength is as low as 15.67%, and basically does not exceed 20%; the change rate of elongation at break basically does not exceed 18%, and can even be as low as 10.56%.

[0037] To achieve the above effects, the advantages of the present invention are:

[0038] (1) The present invention first pretreats the flame retardant containing a large amount of hydroxyl groups, which is easy to absorb water and cause performance degradation, and coats a layer of silane coupling agent on the surface of the flame retardant powder to prevent water from directly contacting the powder. At the same time, the silane coupling agent also has a bridging effect. The hydrophilic end directly acts with the flame retardant powder, and the lipophilic end is connected to the resin phase during blending, increasing the interfacial bonding force between the powder and the resin, improving the material performance, and at the same time, the enhanced interfacial bonding force also reduces the ability of water molecules to damage the material structure through the interface;

[0039] (2) The present invention adds a small amount of crosslinking agent dicumyl peroxide to the system. On the one hand, DCP promotes the micro-crosslinking of the resin. After micro-crosslinking, the resin forms a network to lock the inorganic powder, increasing the strength and improving the water resistance. On the other hand, DCP acts as a catalyst to promote the chemical reaction between vinyl silane coupling agent and resin and powder, enhancing the bridging effect, further improving the bonding force between phases, thereby improving the water resistance, flame retardancy and mechanical properties;

[0040] (3) The present invention preferably uses a vinyl mixed long-chain fatty acid and benzene ring structure unit as the silane coupling agent. As an active silane, it participates in the reaction to increase the interfacial bonding; the long-chain fatty acid is used as a strong hydrophobic group to improve the water resistance of the powder, and the steric hindrance effect of the benzene ring structure slows down the erosion of water on the material, thereby achieving the purpose of water resistance. Specific embodiments

[0041] In order to make the above objects, features and advantages of the present invention more obvious and understandable, the following specifically describes the specific implementation manners of the present invention in conjunction with the embodiments of the specification. Many specific details are set forth in the following description in order to fully understand the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0042] The present invention will be further described below in conjunction with embodiments; the raw material information used in the specific implementation manners is shown in Table 1.

[0043] Performance testing of the cable compounds prepared in each embodiment: The obtained pellets are pressed into sheets on a flat vulcanizing machine at 180°C for 15 minutes under a pressure of 15 Mpa. After cold pressing, the sheets or strips are cut, and the performance is tested after being placed at room temperature for 16 hours.

[0044] Table 1 Raw materials, manufacturers and their abbreviations used in the specific implementation manners

[0045]

[0046] Examples 1 - 6: The raw material ratios of each example are shown in Table 2.

[0047] The preparation method of the water - resistant flame - retardant cable compound of the present invention includes the following steps:

[0048] First, a powder modifier is used to perform silane modification on the halogen - free flame retardant at a temperature of 70°C for 30 minutes, and the modification amount of the silane coupling agent is 1%.

[0049] Then, the modified powder is added to a kneader together with other components for kneading, and then extruded and pelletized through a two - stage unit to obtain a flame - retardant cable compound. The discharge temperature of the kneader is 160 - 170°C, the kneading time is 20 minutes, the upper cover of the kneader is lifted once every 3 minutes during the kneading process, and the temperature setting ranges of the twin - screw and single - screw in the two - stage unit are both 170°C.

[0050] Example 7:

[0051] The raw material ratio is shown in Table 2. The preparation method of the water - resistant flame - retardant cable compound includes the following steps:

[0052] First, a powder modifier is used to perform silane modification on the halogen - free flame retardant at a temperature of 70°C for 30 minutes, and the modification amount of the silane coupling agent is 1.07%.

[0053] Then, the modified powder is added to a kneader together with other components for kneading, and then extruded and granulated through a two-stage unit to obtain a flame-retardant cable compound. The discharge temperature of the kneader is 160-170 °C, the kneading time is 20 min, the upper cover is lifted once every 3 min during the kneading process, and the temperature setting ranges of the twin-screw and single-screw in the two-stage unit are both 170 °C.

[0054] Table 2 The proportion of each component used in Examples 1-7

[0055] Component Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 3518 15 15 0 30 15 15 15 2220HEC 0 0 15 0 0 0 0 EVA 28-03 47 0 47 32 47 47 47 EVM 500 0 47 0 0 0 0 0 DF810 8 8 8 8 8 8 8 877 6 6 6 6 6 6 6 A171 0.5 0.5 0.5 0.5 0.5 0.5 0.3 9116 0.5 0.5 0.5 0.5 0.5 0.5 0.8 9265 0.4 0.4 0.4 0.4 0.4 0.4 0.4 MB50-002 3 3 3 3 3 3 3 EBS 1 1 1 1 1 1 1 Aitemag 35 70 70 70 70 140 0 70 701 70 70 70 70 0 140 70 1010 0.25 0.25 0.25 0.25 0.25 0.25 0.25 168 0.5 0.5 0.5 0.5 0.5 0.5 0.5 DCP 0.1 0.1 0.1 0.1 0.1 0.1 0.1

[0056] Comparative Example 1: The powder was not pretreated with a silane coupling agent.

[0057] The raw material ratios of each comparative example are shown in Table 3.

[0058] The preparation method of the cable compound includes the following steps:

[0059] All raw material components are added to a kneader for kneading, and then extruded and granulated through a two-stage unit to obtain a flame-retardant cable compound. The discharge temperature of the kneader is 160-170 °C, the kneading time is 20 min, the upper cover is lifted once every 3 min during the kneading process, and the temperature setting ranges of the twin-screw and single-screw in the two-stage unit are both 170 °C.

[0060] Comparative Example 2: No silane coupling agent with vinyl functional groups was added when treating the powder.

[0061] The raw material ratio is shown in Table 3. The preparation method of the cable compound includes the following steps:

[0062] First, a powder modifier is used to perform silane modification on the halogen-free flame retardant at a temperature of 70 °C for 30 min;

[0063] Then, the modified powder is added to a kneader together with other components for kneading, and then extruded and granulated through a two-stage unit to obtain a flame-retardant cable compound. The discharge temperature of the kneader is 160-170 °C, the kneading time is 20 min, the upper cover is lifted once every 3 min during the kneading process, and the temperature setting ranges of the twin-screw and single-screw in the two-stage unit are both 170 °C.

[0064] Comparative Example 3: No water-resistant long-chain fatty silane coupling agent was added when treating the powder.

[0065] The raw material ratio is shown in Table 3. The preparation method of the cable compound includes the following steps:

[0066] First, a powder modifier is used to perform silane modification on the halogen-free flame retardant at a temperature of 70 °C for 30 min;

[0067] Then, the modified powder is kneaded together with other components in a kneader, and then extruded and granulated through a two-stage unit to obtain a flame-retardant cable compound. The discharge temperature of the kneader is 160 - 170 °C, the kneading time is 20 min, the upper cover is lifted once every 3 min during the kneading process, and the temperature setting ranges of both the twin-screw and single-screw in the two-stage unit are 170 °C.

[0068] Comparative Example 4: The water-resistant benzene ring-based silane coupling agent was not added during the treatment of the powder.

[0069] The raw material ratios are shown in Table 3. The preparation method of the cable compound includes the following steps:

[0070] First, the halogen-free flame retardant is modified with silane using a powder modifier at a temperature of 70 °C for 30 min.

[0071] Then, the modified powder is kneaded together with other components in a kneader, and then extruded and granulated through a two-stage unit to obtain a flame-retardant cable compound. The discharge temperature of the kneader is 160 - 170 °C, the kneading time is 20 min, the upper cover is lifted once every 3 min during the kneading process, and the temperature setting ranges of both the twin-screw and single-screw in the two-stage unit are 170 °C.

[0072] Comparative Example 5: Crosslinking agent DCP was not added.

[0073] The raw material ratios are shown in Table 3. The preparation method of the cable compound includes the following steps:

[0074] First, the halogen-free flame retardant is modified with silane using a powder modifier at a temperature of 70 °C for 30 min.

[0075] Then, the modified powder is kneaded together with other components in a kneader, and then extruded and granulated through a two-stage unit to obtain a flame-retardant cable compound. The discharge temperature of the kneader is 160 - 170 °C, the kneading time is 20 min, the upper cover is lifted once every 3 min during the kneading process, and the temperature setting ranges of both the twin-screw and single-screw in the two-stage unit are 170 °C.

[0076] Table 3 Ratios of each component used in Comparative Examples 1 - 5

[0077] Component Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 3518 15 15 15 15 15 2220HEC 0 0 0 0 0 EVA 28-03 47 47 47 47 47 EVM 500 0 0 0 0 0 DF810 8 8 8 8 8 877 6 6 5 6 6 A171 0 0 0.5 0.5 0.5 9116 0 0.5 0 0.5 0.5 9265 0 0.4 0.4 0 0.4 MB50-002 3 3 3 3 3 EBS 1 1 1 1 1 Aitemag 35 70 70 70 70 70 701 70 70 70 70 70 1010 0.25 0.25 0.25 0.25 0.25 168 0.5 0.5 0.5 0.5 0.25 DCP 0.1 0.1 0.1 0.1 0

[0078] Table 4 Performance tests of the cable compounds prepared in Examples 1 - 7

[0079]

[0080] Table 5 Performance tests of the cable compounds prepared in Comparative Examples 1 - 5

[0081]

[0082] The water resistance and flame retardancy performance tests of the samples obtained from the cable compounds prepared in each example and comparative example are shown in Tables 4 and 5. According to the test results in Table 4, it can be seen that for the cable compounds provided in Examples 1-7, powder pretreatment is adopted, and a silane coupling agent compounding system with a preferred specific functional group structure is used, combined with the micro-crosslinking of the cable compound, which ensures excellent mechanical and flame retardancy performance of the material and solves the problem of unqualified hot water resistance strength and elongation change rate of the cable compound. After soaking in hot water at 70 °C for 168 hours, the change rate of tensile strength is as low as 15.67%, basically not exceeding 20%; the change rate of elongation at break basically does not exceed 18%, and can even be as low as 10.56%. And by limiting the contents of the base resin, elastomer, and flame retardant within a specific range, the performance of the cable compound is optimized.

[0083] The water resistance and flame retardancy performance tests of the samples obtained from the cable compounds prepared in each comparative example are shown in Table 5. After soaking in hot water at 70 °C for 168 hours, the change rate of tensile strength is basically 25% or more; the change rate of elongation at break is all above 25%. The water resistance performance is significantly inferior to that of Examples 1-7. Among them, the flame retardant powder in Comparative Example 1 was not pretreated with a silane coupling agent, and the prepared sample had poor mechanical and flame retardancy performance and very poor hot water resistance performance. This is because the binding force between the untreated powder and the resin is poor. Secondly, a large number of hydroxyl groups on the powder surface directly combine with water, resulting in poor hot water resistance performance.

[0084] Compared with Example 1, in Comparative Example 2, a silane coupling agent with vinyl functional groups was not added during the treatment of the powder. Since the vinyl-functional silane coupling agent will chemically react with the resin under the action of DCP to increase the binding force between the powder and the resin, the performance shows a slight decrease after it is not added. Compared with Example 1, in Comparative Example 3, a water-resistant long-chain fatty silane coupling agent was not added during the treatment of the powder, lacking protection against the intrusion of water molecules. The mechanical and flame retardancy performance basically remains, but the hot water resistance performance decreases. Compared with Example 1, in Comparative Example 4, a water-resistant benzene ring type silane coupling agent was not added during the treatment of the powder, lacking a spatial barrier effect against the intrusion of water molecules. The mechanical and flame retardancy performance basically remains, but the hot water resistance performance decreases. Compared with Example 1, in Comparative Example 5, the crosslinking agent DCP was not added. On the one hand, the material itself did not form a micro-crosslinked network and did not have a certain crosslinking density, so it was easy to be attacked by water molecules. On the other hand, the vinyl silane coupling agent lacked the catalysis of DCP and could not chemically graft with the resin, weakening the bridging effect of the silane coupling agent and resulting in a poor interfacial binding force, making it relatively easy to be attacked by water, showing a decrease in various performances.

[0085] In summary, the present invention provides a water-resistant and flame-retardant cable material and a preparation method thereof. The prepared cable material has excellent water resistance while ensuring excellent flame retardancy and physical and mechanical properties. After being immersed in water at 70°C for 168 hours, the change rate of strength and elongation is not more than ±30%. Among them, the change rate of tensile strength is as low as 15.67%, basically not exceeding 20%; the change rate of elongation at break basically does not exceed 18%, and can even be as low as 10.56%.

[0086] In the present invention, a silane coupling agent is coated on the surface of the flame retardant powder to prevent water from directly contacting the powder. At the same time, the silane coupling agent also has a bridging effect, increasing the interfacial bonding force between the powder and the resin. The enhanced interfacial bonding force also reduces the ability of water molecules to damage the material structure through the interface. In the present invention, dicumyl peroxide is added to the system. On the one hand, it promotes the micro-crosslinking of the resin to form a network to lock the inorganic powder, increasing the strength and improving the water resistance; on the other hand, as a catalyst, it promotes the chemical reaction between the vinyl silane coupling agent and the resin and the powder, enhancing the bridging effect. The present invention selects a vinyl mixed long-chain fatty and benzene ring structural unit as the active silane to participate in the reaction, increasing the interfacial bonding; the long-chain fatty acid is used as a strong hydrophobic group to improve the water resistance of the powder, and the steric hindrance effect of the benzene ring structure slows down the erosion of water on the material, thereby achieving the purpose of water resistance.

[0087] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the present invention.

Claims

1. A water-resistant and flame-retardant cable material, characterized in that: The composition comprises the following components in parts by weight: Polyolefin resin 70-100 parts, Halogen-free flame retardant 100-180 parts, Silane coupling agent 0.5-1.8 parts, Dicumyl peroxide 0.05-0.2 parts, Lubricant 0.5-3 parts, Antioxidant 0.3-1 part; The polyolefin resin is a blend of polyethylene, ethylene-vinyl acetate copolymer, maleic anhydride grafted polyolefin and polyolefin elastomer.

2. The water-resistant and flame-retardant cable material according to claim 1, characterized in that: The polyethylene is one or a combination of low-density polyethylene, metallocene linear low-density polyethylene and high-density polyethylene, and has a melt index of 0.5-10 g / 10 min; And / or, the mass content of vinyl acetate in the ethylene-vinyl acetate copolymer is 9%-70%; And / or, the maleic anhydride grafted polyolefin is selected from one or a combination of maleic anhydride grafted polyethylene, maleic anhydride grafted ethylene-vinyl acetate copolymer, and maleic anhydride grafted ethylene-octene copolymer; And / or, the polyolefin elastomer is selected from one or a combination of ethylene-octene copolymer elastomer, ethylene-propylene copolymer elastomer and ethylene-butene copolymer elastomer.

3. The water-resistant and flame-retardant cable material according to claim 1, characterized in that: The halogen-free flame retardant is selected from one or a combination of magnesium hydroxide and aluminum hydroxide; And / or, the particle size of the halogen-free flame retardant is 0.5-3 μm.

4. The water-resistant and flame-retardant cable material according to claim 1, characterized in that: The silane coupling agent is a silane coupling agent containing vinyl, long-chain fat and benzene ring functional groups.

5. The water-resistant and flame-retardant cable material according to claim 1, characterized in that: The lubricant is selected from one or a combination of silicone masterbatch, ethylene bis stearamide, zinc stearate or polyethylene wax; And / or, the antioxidant is selected from one or a combination of hindered phenol, phosphite or hindered amine antioxidants.

6. The water-resistant and flame-retardant cable material according to any one of claims 1 to 5, characterized in that: After the 70℃ / 168h immersion test, the change rate of tensile strength of the specimen is ≤20.13%; the change rate of elongation at break is ≤18.13%.

7. Use of the water-resistant and flame-retardant cable material according to any one of claims 1 to 6 in electric wires or cables.

8. The method for preparing the water-resistant and flame-retardant cable material according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Silane modification of the halogen-free flame retardant: adding the halogen-free flame retardant and the silane coupling agent into a powder modification machine to perform silane modification on the halogen-free flame retardant; S2. Add the silane-modified halogen-free flame retardant prepared in step S1 and other components into a kneading machine for kneading, and then extrude and granulate to obtain a water-resistant and flame-retardant cable material.

9. The method for preparing a water-resistant and flame-retardant cable material according to claim 8, characterized in that: In step S1, a powder modification machine is used to perform silane modification on the halogen-free flame retardant at a temperature of 60-80° C. and a modification amount of silane coupling agent of 0.5-1.5%.

10. The method for preparing a water-resistant and flame-retardant cable material according to claim 8, characterized in that: In step S2, the discharge temperature of the kneading machine is 160-170°C, and the upper cover is intermittently lifted during the kneading process to ensure that the materials are mixed evenly.

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