Halogen-free flame-retardant cable material composition as well as preparation method and application thereof

Abstract

The invention relates to the technical field of cable materials, in particular to a halogen-free flame-retardant cable material composition as well as a preparation method and application of the halogen-free flame-retardant cable material composition. 3-18 parts of ethylene propylene diene monomer; 5-12 parts of zinc oxide; 3-6 parts of an anti-aging agent; 0.5 to 2 parts of a lubricant; 1-5 parts of an organic silicon flame retardant; 8-15 parts of environment-friendly carbon black; 140-180 parts of an active inorganic flame retardant; 5-15 parts of a processing aid; 1-5 parts of a silane coupling agent; 1 to 1.5 parts of an assistant cross-linking agent; 3-5 parts of a peroxide cross-linking agent; 2 to 5 parts of trihydroxy polyhedral oligomeric silsesquioxane; 3 to 8 parts of nano clay; and 0.5-2 parts of an anti-dripping agent. By adding all the components, balanced optimization of the flame retardant property, the mechanical property and the processability is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of cable materials, and in particular to a halogen-free flame-retardant cable material composition, a preparation method and an application thereof. Background Art

[0002] With increasing demands for environmental protection, the development of high-performance, environmentally friendly cable materials has become a research hotspot. Conventional halogen-containing flame-retardant cable materials produce large amounts of harmful gases, such as hydrogen chloride, when burned. These gases are not only harmful to human health but can also corrode equipment and buildings. Therefore, the development of halogen-free flame-retardant cable materials is of great significance.

[0003] With the development of the power industry and increasing fire safety requirements, the market demand for flame-retardant cable materials is growing. While traditional halogen-based flame-retardant cable materials offer good flame retardancy, they produce large amounts of toxic smoke and corrosive gases when burned, posing a serious threat to personnel safety and equipment integrity. Therefore, halogen-free flame-retardant cable materials have become an industry trend.

[0004] In recent years, many researchers have devoted themselves to developing low-smoke zero-halogen (LSZH) flame-retardant cable materials to meet higher safety and environmental standards. However, existing LSZH cable materials often have the following problems:

[0005] It is difficult to strike a balance between flame retardancy and mechanical properties: some formulations improve flame retardancy but sacrifice the mechanical strength and flexibility of the material.

[0006] Difficulty in processing: Some high-efficiency flame retardants tend to agglomerate during processing, affecting the uniformity and processability of the material.

[0007] The anti-aging performance is insufficient at high temperatures and performance degradation is likely to occur after long-term use.

[0008] The low cross-linking efficiency results in a low thermal deformation temperature of the material, which limits its application in high-temperature environments. Summary of the Invention

[0009] In response to the shortcomings of the existing technology, the present invention provides a halogen-free flame-retardant cable material composition, a preparation method and application thereof, which adopts a composite matrix of EMA and EPDM, a flame retardant system of aluminum hydroxide / magnesium hydroxide in a specific ratio, and introduces new components such as silicone flame retardant, POSS-OH and nanoclay, thereby achieving balanced optimization of flame retardancy, mechanical properties and processing performance.

[0010] According to a first aspect of the present invention, there is provided a halogen-free flame retardant cable material composition comprising the following components in parts by mass:

[0011] 80-100 parts of ethylene-methyl methacrylate copolymer (EMA), EMA as the main base material, provides good electrical insulation and processing properties;

[0012] 3 to 18 parts of ethylene propylene diene monomer (EPDM), EPDM enhances the flexibility and weather resistance of the material;

[0013] 5-12 parts of zinc oxide, as a filler and stabilizer, enhances the thermal stability and mechanical strength of the material;

[0014] 3 to 6 parts of antioxidant can effectively delay the aging process of the material and extend its service life;

[0015] 0.5-2 parts of lubricant to reduce friction during processing, improve extrusion efficiency and surface finish;

[0016] 1 to 5 parts of organic silicon flame retardant to enhance the flame retardant properties of the material and improve the processing fluidity of the material;

[0017] 8-15 parts of environmentally friendly carbon black to increase the material's conductivity and UV protection;

[0018] 140-180 parts of active inorganic flame retardant, forming a dense char layer to prevent flame propagation and significantly improve the flame retardant effect;

[0019] 5-15 parts of processing aids to improve the processing properties of the material and reduce adhesion and bubbles;

[0020] 1 to 5 parts of silane coupling agent to enhance the compatibility and interfacial bonding between components and improve overall performance;

[0021] 1 to 1.5 parts of auxiliary cross-linking agent, which promotes the cross-linking reaction and improves the heat resistance and mechanical properties of the material;

[0022] 3-5 parts of peroxide crosslinking agent to achieve high temperature delayed crosslinking and ensure the long-term stability of the material;

[0023] 2-5 parts of trihydroxy polyhedral oligomeric silsesquioxane (POSS-OH), whose unique three-dimensional structure significantly improves the flame retardancy and heat resistance of the material, and produces a synergistic effect with aluminum hydroxide and magnesium hydroxide;

[0024] 3-8 parts of nanoclay improves the mechanical strength and thermal stability of the material and enhances the flame retardant effect;

[0025] 0.5 to 2 parts of anti-dripping agent can prevent dripping during combustion and improve safety.

[0026] EMA provides good polar groups, which is conducive to combining with inorganic fillers; the introduction of EPDM improves the flexibility and low-temperature performance of the material, and the two work together to provide a balanced mechanical performance platform.

[0027] According to an embodiment of the present invention, the active inorganic flame retardant is a mixture of aluminum hydroxide and magnesium hydroxide, with a particle size D50 of 0.5 to 2 μm and an active ingredient content of ≥99%;

[0028] The mass ratio of the aluminum hydroxide to the magnesium hydroxide is 1:0.5 to 1:2.

[0029] This combination exhibits flame retardancy at different temperature levels. Aluminum hydroxide decomposes and absorbs heat at 200-300°C, while magnesium hydroxide decomposes and absorbs heat at 300-400°C, forming a protective barrier across a wide temperature range. Aluminum hydroxide and magnesium hydroxide decompose and absorb heat at different temperatures, forming a continuous protective barrier. The organosilicon flame retardant promotes charring. The POSS-OH cage structure decomposes at high temperatures to form a SiO2 network. The nanoclay forms a physical barrier, and these four elements work together to achieve highly effective flame retardancy.

[0030] According to an embodiment of the present invention, the antioxidant is a composite hindered phenol / phosphite antioxidant, comprising:

[0031] 1-2 parts of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (antioxidant 1010);

[0032] 1-1.5 parts of tris(2,4-di-tert-butylphenyl)phosphite (Antioxidant 168);

[0033] 0.5-1 part of 2-mercaptobenzimidazole zinc salt (anti-aging agent MBZ);

[0034] Antioxidants 1010 (free radical scavenger), 168 (peroxide decomposer) and MBZ (metal passivator) constitute a comprehensive protection system that effectively inhibits thermal oxidative aging of materials during use.

[0035] According to an embodiment of the present invention, the organic silicon flame retardant is polysiloxane or silicone resin, which can form a dense silicon-carbon layer when burned;

[0036] The silane coupling agent is vinyltrimethoxysilane (A-172), which can improve the interface bonding between the inorganic filler and the resin;

[0037] The nanoclay is modified montmorillonite, which can form a nanocomposite structure and has a particle size D50 of 1 to 10 μm;

[0038] The anti-dripping agent is polytetrafluoroethylene (PTFE) powder with a particle size of 1 to 10 μm.

[0039] According to an embodiment of the present invention, the peroxide crosslinking agent is a high-temperature delayed crosslinking system comprising:

[0040] 3-4 parts of 1,4-bis(tert-butylperoxyisopropyl)benzene (BIPB);

[0041] 0.5 to 1 part of dicumyl peroxide (DCP).

[0042] According to an embodiment of the present invention, the auxiliary cross-linking agent is a multifunctional acrylate auxiliary cross-linking agent, including:

[0043] 1-1.2 parts of trimethylolpropane trimethacrylate (TMPTMA);

[0044] 0.3 to 0.5 parts of vinyltrimethoxysilane (A-171)

[0045] The combined use of BIPB and DCP ensures a smooth crosslinking reaction; TMPTMA, as a multifunctional monomer, improves crosslinking efficiency; A-171 improves the interfacial crosslinking between the inorganic filler and the resin, jointly constructing a complete three-dimensional network structure. Silane coupling agent A-172 improves the interfacial bonding between the inorganic filler and the resin through chemical bonding; and the layered structure of the nanoclay, after organic treatment, improves its compatibility with the resin, jointly resolving the interfacial issues of highly filled systems.

[0046] According to an embodiment of the present invention, the lubricant is zinc stearate or polyethylene wax.

[0047] The processing aid is low molecular weight polyethylene or fatty acid amide.

[0048] According to a second aspect of the present invention, there is provided a method for preparing a halogen-free flame retardant cable material composition, comprising the following steps:

[0049] Preliminary mixing: put ethylene-methyl methacrylate copolymer (EMA) and ethylene propylene diene monomer (EPDM) into an internal mixer and perform preliminary mixing at 100-120°C for 3-5 minutes to ensure that the two are fully mixed;

[0050] Add basic additives: add zinc oxide, antioxidant, and lubricant in sequence, and continue mixing at the same temperature for 2 to 3 minutes;

[0051] Add flame retardant system: Then add silicone flame retardant, environmentally friendly carbon black, active inorganic flame retardant (a mixture of aluminum hydroxide and magnesium hydroxide), and nanoclay, maintain the temperature at 120-140°C, and mix for 3-5 minutes;

[0052] Introducing reinforcing and auxiliary components: Subsequently, the processing aid, silane coupling agent (A-172), and co-crosslinking agents (TMPTMA and A-171) were added, and the temperature was adjusted to 130-150°C and mixing was continued for 3-4 minutes. The silane coupling agent was added by spraying, and the mixing speed was 800-1200 rpm.

[0053] Final cross-linking treatment: finally, add peroxide cross-linking agent (BIPB and DCP), anti-dripping agent (PTFE micropowder) and trihydroxy polyhedral oligomeric silsesquioxane (POSS-OH), control the temperature at 130-140° C., mix for 2-3 minutes, and obtain the halogen-free flame retardant cable material composition.

[0054] According to an embodiment of the present invention, after the mixing is completed in the final cross-linking process, a post-processing stage is further included, and the post-processing stage includes:

[0055] Filtration: After mixing is completed, filter the rubber through a filter with at least three filter layers, and the mesh sizes are 40-60 mesh / 80-100 mesh / 40-60 mesh respectively. The operating temperature should be maintained between 100-130°C to remove impurities and undispersed particles.

[0056] Secondary mixing: put the filtered rubber into the internal mixer again to ensure that all ingredients are evenly distributed. At this time, the room temperature is controlled at 90-120℃ and the mixing time is 1-2 minutes.

[0057] Molding: After further processing through the open mill, the finished cable material is calendered and sheeted.

[0058] According to a third aspect of the present invention, there is provided a use of a halogen-free flame-retardant cable material composition in insulating materials such as cables and wires.

[0059] The halogen-free flame-retardant cable material composition provided by the present invention forms a highly effective flame-retardant system through the synergistic effect of active inorganic flame retardants (aluminum hydroxide and magnesium hydroxide) and POSS-OH. This significantly improves the flame retardancy of the material, achieving UL94 V-0 rating and a limiting oxygen index >35% at a relatively low addition level (140-180 parts). The cage-like structure of POSS-OH promotes char formation during combustion, forming a protective layer with high thermal stability.

[0060] The halogen-free flame-retardant cable material composition provided by the present invention has nanoclay and a cross-linking agent, which enhances the mechanical strength and heat resistance of the material, enabling it to maintain good physical properties under extreme conditions. The addition of nanoclay enables the material to form an intercalated structure, and the reasonable ratio of EMA and EPDM balances rigidity and toughness.

[0061] The halogen-free flame-retardant cable material composition provided by the present invention does not contain halogen, generates less smoke and toxic gas during combustion, and meets modern environmental protection requirements.

[0062] The halogen-free flame-retardant cable material composition provided by this invention overcomes the processing difficulties of highly filled systems through the rational use of silane coupling agents and processing aids. It is adaptable to conventional cable extrusion processes and reduces defects and substandard product rates. The use of antioxidants effectively slows the aging process of the material, extending the service life of the cable. The peroxide crosslinking system imparts a high degree of crosslinking, achieving a heat deformation temperature exceeding 120°C, making it suitable for use in high-temperature environments. The composite antioxidant system ensures stable performance over long-term use. DETAILED DESCRIPTION

[0063] The embodiments of the present application provide a halogen-free flame retardant cable material composition.

[0064] Example 1

[0065] Ethylene-methyl methacrylate copolymer (EMA): 90 parts

[0066] EPDM: 10 parts

[0067] Zinc oxide: 8 parts

[0068] Antioxidant (antioxidant 1010: 1.5 parts; antioxidant 168: 1.2 parts; antioxidant MBZ: 0.7 parts)

[0069] Lubricant (zinc stearate): 1 part

[0070] Silicone flame retardant: 3 parts

[0071] Environmentally friendly carbon black: 10 parts

[0072] Active inorganic flame retardant (aluminum hydroxide and magnesium hydroxide mixture, mass ratio 1:1): 160 parts

[0073] Processing aid (low molecular weight polyethylene): 10 parts

[0074] Silane coupling agent (A-172): 2 parts

[0075] Cross-linking aid (TMPTMA: 1.1 parts; A-171: 0.4 parts)

[0076] Peroxide crosslinking agent (BIPB: 3.5 parts; DCP: 0.8 parts)

[0077] Trihydroxy polyhedral oligomeric silsesquioxane (POSS-OH): 5 parts

[0078] Nanoclay: 5 parts

[0079] Anti-dripping agent (PTFE powder): 1 part

[0080] Preparation method: Mix, filter and shape according to the above method.

[0081] Example 2

[0082] Ethylene-methyl methacrylate copolymer (EMA): 85 parts

[0083] EPDM: 15 parts

[0084] Zinc oxide: 10 parts

[0085] Antioxidant (same as above): 3.5 parts

[0086] Lubricant (polyethylene wax): 1.5 parts

[0087] Silicone flame retardant: 4 parts

[0088] Environmentally friendly carbon black: 12 parts

[0089] Active inorganic flame retardant (a mixture of aluminum hydroxide and magnesium hydroxide, mass ratio 1:1.5): 150 parts Processing aid: 8 parts

[0090] Silane coupling agent: 3 parts

[0091] Cross-linking agent: 1.3 parts

[0092] Peroxide crosslinker: 4 parts

[0093] Trihydroxy polyhedral oligomeric silsesquioxane (POSS-OH): 4 parts

[0094] Nanoclay: 6 parts

[0095] Anti-drip agent: 1.5 parts

[0096] Preparation method: same as Example 1.

[0097] Example 3

[0098] Ethylene-methyl methacrylate copolymer (EMA): 95 parts

[0099] EPDM: 5 parts

[0100] Zinc oxide: 7 parts

[0101] Antioxidant: 4.5 parts

[0102] Lubricant: 1 part

[0103] Silicone flame retardant: 2 parts

[0104] Environmentally friendly carbon black: 10 parts

[0105] Active inorganic flame retardant (a mixture of aluminum hydroxide and magnesium hydroxide, mass ratio 1:0.5): 170 parts Processing aid: 12 parts

[0106] Silane coupling agent: 1.5 parts

[0107] Cross-linking agent: 1.2 parts

[0108] Peroxide crosslinking agent: 3.8 parts

[0109] Trihydroxy polyhedral oligomeric silsesquioxane (POSS-OH): 3 parts

[0110] Nanoclay: 4 parts

[0111] Anti-drip agent: 1 part

[0112] Preparation method: same as Example 1.

[0113] Example 4

[0114] Ethylene-methyl methacrylate copolymer (EMA): 88 parts

[0115] EPDM: 8 parts

[0116] Zinc oxide: 6 parts

[0117] Anti-aging agent: 4 parts

[0118] Lubricant: 0.8 parts

[0119] Silicone flame retardant: 2.5 parts

[0120] Environmentally friendly carbon black: 9 parts

[0121] Active inorganic flame retardant (aluminum hydroxide and magnesium hydroxide mixture, mass ratio 1:1.2): 165 parts Processing aid: 9 parts

[0122] Silane coupling agent: 2.5 parts

[0123] Cross-linking agent: 1.4 parts

[0124] Peroxide crosslinker: 3.7 parts

[0125] Trihydroxy polyhedral oligomeric silsesquioxane (POSS-OH): 4.5 parts

[0126] Nanoclay: 7 parts

[0127] Anti-drip agent: 1.2 parts

[0128] Preparation method: same as Example 1.

[0129] Example 5

[0130] Ethylene-methyl methacrylate copolymer (EMA): 92 parts

[0131] EPDM: 6 parts

[0132] Zinc oxide: 9 parts

[0133] Anti-aging agent: 5 parts

[0134] Lubricant: 1.2 parts

[0135] Silicone flame retardant: 3.5 parts

[0136] Environmentally friendly carbon black: 11 parts

[0137] Active inorganic flame retardant (a mixture of aluminum hydroxide and magnesium hydroxide, mass ratio 1:1.8): 145 parts Processing aid: 11 parts

[0138] Silane coupling agent: 2 parts

[0139] Cross-linking agent: 1.3 parts

[0140] Peroxide crosslinker: 4.2 parts

[0141] Trihydroxy polyhedral oligomeric silsesquioxane (POSS-OH): 3.5 parts

[0142] Nanoclay: 5 parts

[0143] Anti-drip agent: 1.3 parts

[0144] Preparation method: same as Example 1.

[0145] Example 6

[0146] Ethylene-methyl methacrylate copolymer (EMA): 87 parts

[0147] EPDM: 12 parts

[0148] Zinc oxide: 11 parts

[0149] Antioxidant: 4.8 parts

[0150] Lubricant: 1.4 parts

[0151] Silicone flame retardant: 3 parts

[0152] Environmentally friendly carbon black: 13 parts

[0153] Active inorganic flame retardant (a mixture of aluminum hydroxide and magnesium hydroxide, mass ratio 1:1.5): 155 parts

[0154] Processing aid: 13 parts

[0155] Silane coupling agent: 3 parts

[0156] Cross-linking agent: 1.4 parts

[0157] Peroxide crosslinking agent: 4.5 parts

[0158] Trihydroxy polyhedral oligomeric silsesquioxane (POSS-OH): 4 parts

[0159] Nanoclay: 6.5 parts

[0160] Anti-drip agent: 1.5 parts

[0161] Preparation method: same as Example 1.

[0162] Comparative Example 1

[0163] Except for removing the POSS-OH component, the remaining components were the same as those in Example 1.

[0164] Comparative Example 2

[0165] Except for the nanoclay component, the remaining components are the same as those in Example 1.

[0166] Comparative Example 3

[0167] The active inorganic flame retardant was replaced by pure aluminum hydroxide (160 parts), and the remaining ingredients were the same as in Example 1.

[0168] Comparative Example 4

[0169] The active inorganic flame retardant was replaced with pure magnesium hydroxide (160 parts), and the remaining ingredients were the same as in Example 1.

[0170] Experimental example:

[0171] In order to verify the effectiveness of the technical solution of the halogen-free flame-retardant cable material composition, performance tests were conducted on Examples 1-6 and Comparative Examples 1-4. The following are the detailed experimental methods and results.

[0172] 1. Tensile strength and elongation at break

[0173] Prepare the specimen according to the standard requirements, clamp the specimen on a universal material testing machine, stretch it at a constant speed until it breaks, and record the maximum load (for calculating tensile strength) and elongation at break (for calculating elongation at break).

[0174] 2. Volume resistivity

[0175] Steps: Use a high resistance meter to measure the volume resistivity of the sample at 20°C, ensuring that the ambient temperature is stable and the humidity is controlled within the standard range.

[0176] 3. Oxygen index

[0177] Fix the sample vertically in the burner, adjust the ratio of oxygen and nitrogen, and gradually increase the oxygen content until the sample can just maintain combustion. The oxygen concentration percentage at this time is recorded as the oxygen index.

[0178] 4. Single vertical burning test

[0179] Using a vertical combustion tester, the sample is suspended vertically above a flame source, the sample is ignited and its combustion behavior is observed, and parameters such as flame propagation time and self-extinguishing time are recorded.

[0180] 5. Smoke density transmittance

[0181] Steps: Place the sample in a closed combustion chamber, ignite the sample under specified conditions, and measure the light transmittance of the smoke generated during the combustion process using a photoelectric sensor. The results are shown in Table 1.

[0182] Table 1. Performance test results of Examples 1-6 and Comparative Examples 1-4

[0183]

[0184]

[0185] The tensile strength and elongation at break of Examples 1-6 are relatively high, indicating that these materials have good mechanical properties. The tensile strength and elongation at break of Comparative Examples 1-4 are reduced due to the lack of certain key components (such as POSS-OH or nanoclay).

[0186] The volume resistivity in the examples is generally high, indicating that the materials have excellent electrical insulation properties. In the comparative examples, after removing certain components, the volume resistivity is reduced, which affects the electrical insulation properties of the materials.

[0187] The oxygen index of the embodiment is higher, indicating that the material has better flame retardancy. The oxygen index of the comparative example is lower, indicating that the removal of certain components will affect the flame retardancy of the material.

[0188] The examples all achieved the V-0 grade, indicating that the materials have excellent flame retardancy. The comparative examples failed to achieve the V-0 grade, indicating that certain ingredients are crucial for improving flame retardancy.

[0189] The smoke density and light transmittance of the examples are higher, indicating that less smoke is generated when the materials burn. The smoke density and light transmittance of the comparative examples are lower, indicating that removing certain components will lead to more smoke generation.

[0190] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0191] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A halogen-free flame-retardant cable material composition, characterized in that: The following components are included in parts by mass: 80-100 parts of ethylene-methyl methacrylate copolymer; 3-18 parts of EPDM rubber; 5-12 parts of zinc oxide; 3-6 parts of antioxidant; 0.5-2 parts of lubricant; 1 to 5 parts of silicone flame retardant; 8-15 parts of environmentally friendly carbon black; 140-180 parts of active inorganic flame retardant; 5-15 parts of processing aid; 1 to 5 parts of silane coupling agent; 1 to 1.5 parts of a cross-linking agent; 3-5 parts peroxide crosslinking agent; 2-5 parts of trihydroxy polyhedral oligomeric silsesquioxane; 3-8 parts of nanoclay; 0.5 to 2 parts of anti-dripping agent.

2. The halogen-free flame-retardant cable material composition according to claim 1, characterized in that: The active inorganic flame retardant is a mixture of aluminum hydroxide and magnesium hydroxide, with a particle size D50 of 0.5 to 2 μm and an active ingredient content of ≥99%; The mass ratio of the aluminum hydroxide to the magnesium hydroxide is 1:0.5 to 1:

2.

3. The halogen-free flame-retardant cable material composition according to claim 1, characterized in that: The antioxidant is a composite hindered phenol / phosphite antioxidant, comprising: 1-2 parts of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate; 1-1.5 parts of tris(2,4-di-tert-butylphenyl)phosphite; 0.5-1 part of 2-mercaptobenzimidazole zinc salt.

4. The halogen-free flame-retardant cable material composition according to claim 1, characterized in that: The organosilicon flame retardant is polysiloxane or silicone resin; The silane coupling agent is vinyltrimethoxysilane; The nanoclay is modified montmorillonite with a particle size D50 of 1 to 10 μm; The anti-dripping agent is polytetrafluoroethylene powder with a particle size of 1 to 10 μm.

5. The halogen-free flame-retardant cable material composition according to claim 1, characterized in that: The peroxide crosslinking agent is a high-temperature delayed crosslinking system, comprising: 3-4 parts of 1,4-bis(tert-butylperoxyisopropyl)benzene; 0.5 to 1 part of dicumyl peroxide.

6. The halogen-free flame-retardant cable material composition according to claim 1, characterized in that: The auxiliary cross-linking agent is a multifunctional acrylate auxiliary cross-linking agent, including: 1-1.2 parts of trimethylolpropane trimethacrylate; 0.3-0.5 parts of vinyltrimethoxysilane.

7. The halogen-free flame-retardant cable material composition according to claim 1, characterized in that: The lubricant is zinc stearate or polyethylene wax. The processing aid is low molecular weight polyethylene or fatty acid amide.

8. A method for preparing the halogen-free flame-retardant cable material composition according to any one of claims 1 to 7, characterized in that: The following steps are involved: Preliminary mixing: put ethylene-methyl methacrylate copolymer and EPDM rubber into an internal mixer and perform preliminary mixing at 100-120°C for 3-5 minutes to ensure that the two are fully mixed; Add basic additives: add zinc oxide, antioxidant, and lubricant in sequence, and continue mixing at the same temperature for 2 to 3 minutes; Add flame retardant system: Then add silicone flame retardant, environmentally friendly carbon black, active inorganic flame retardant, and nanoclay, maintain the temperature at 120-140°C, and mix for 3-5 minutes; Introducing reinforcing and auxiliary components: Subsequently, processing aids, silane coupling agents, and co-crosslinking agents are added, and the temperature is adjusted to 130-150°C and mixing is continued for 3-4 minutes, wherein the silane coupling agent is added in a spray manner and the mixing speed is 800-1200 rpm; Final cross-linking treatment: adding a peroxide cross-linking agent, an anti-dripping agent and trihydroxy polyhedral oligomeric silsesquioxane, controlling the temperature at 130-140° C., and mixing for 2-3 minutes to obtain the halogen-free flame retardant cable material composition.

9. The preparation method according to claim 8, characterized in that: After the mixing is completed in the final cross-linking process, a post-processing stage is also included, and the post-processing stage includes: Filtration: After mixing, filter the rubber through a filter with at least three layers of filter screens, with mesh sizes of 40-60, 80-100, and 40-60 respectively. The operating temperature should be maintained between 100-130°C to remove impurities and undispersed particles. Secondary mixing: put the filtered rubber into the internal mixer again to ensure that all ingredients are evenly distributed. At this time, the room temperature is controlled at 90-120℃ and the mixing time is 1-2 minutes; Molding: After further processing through the open mill, the finished cable material is calendered and sheeted.

10. Use of the halogen-free flame-retardant cable material composition according to any one of claims 1 to 8 in insulating materials such as cables and wires.

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