A flame-retardant TPE cable material and its preparation method

Abstract

This invention provides a flame-retardant TPE cable material and its preparation method. Raw materials including hydrogenated styrene-butadiene block copolymer, polyphenylene ether, polystyrene, ethylene-α-octene copolymer thermoplastic elastomer, maleic anhydride-modified hydrogenated styrene-butadiene block copolymer, flame retardant, peroxide, and antioxidant are mixed evenly, then compounded using a twin-screw extruder, water-cooled, and pelletized to obtain the flame-retardant TPE cable material. This invention is a halogen-free and phosphorus-free flame-retardant system, environmentally friendly, and achieves a temperature resistance rating of 125℃ without the use of radiation crosslinking, simplifying the production process. The resulting flame-retardant TPE cable material exhibits excellent flame-retardant properties.

Description

Technical Field

[0001] This invention relates to the field of functional polymer materials, and more specifically, to a flame-retardant TPE cable material and its preparation method. The resulting flame-retardant TPE cable material can achieve a temperature resistance rating of 125°C without irradiation. Background Technology

[0002] Polyphenylene oxide (PPO) and hydrogenated styrene-butadiene block copolymer (SEBS) are widely used in the preparation of thermoplastic elastomer (TPE) cable materials due to their excellent properties. TPE cable materials are mainly used in UL electrical and electronic wires, headphone cables, and new energy charging pile sheaths, among other fields.

[0003] Currently, phosphorus-nitrogen intumescent flame retardant systems are commonly used for TPE flame retardancy. Intumescent flame retardancy involves three sources: acid source, char source, and gas source. Phosphorus-based flame retardants can act as an acid source to promote the dehydration and char formation of the polymer matrix during combustion, and can also form a liquid film on the surface of the condensed phase, providing heat insulation and oxygen barrier functions, thus achieving a flame-retardant effect. However, organophosphorus flame retardants can enter the environment during production and use, accumulating in water, soil, and air, and long-term accumulation can pose potential hazards to organisms.

[0004] Currently, international environmental regulations only prohibit or restrict the use of certain phosphorus-containing compounds, without restricting all phosphorus-containing compounds. It is foreseeable that as environmental regulations become increasingly stringent, the use of phosphorus-containing flame retardants will be gradually restricted. Therefore, the development of halogen-free and phosphorus-free flame retardant systems is of significant research importance for the preparation of green, highly flame-retardant products. Existing TPE products also use magnesium-based flame retardants, but these suffer from poor dispersion issues that need to be addressed.

[0005] In addition, although TPE materials used in wires and cables can achieve a temperature resistance rating of 105℃ without cross-linking, TPE wire products with a temperature resistance rating of 125℃ still need to undergo chemical irradiation cross-linking, which is a complicated process.

[0006] Therefore, it is necessary to study a halogen-free and phosphorus-free flame-retardant TPE material. On the one hand, a suitable halogen-free and phosphorus-free flame retardant should be selected, and the problem of flame retardant dispersion should be solved through chemical methods to achieve a better flame-retardant effect. On the other hand, by optimizing the types and ratios of polymers and additives, the 125℃ temperature resistance rating can be achieved without irradiation. Summary of the Invention

[0007] In order to solve the technical problems existing in the prior art, the present invention provides a flame-retardant TPE cable material and its preparation method.

[0008] This invention uses polyphenylene oxide (PPO) and hydrogenated styrene-butadiene block copolymer (SEBS) as the matrix, magnesium-based and silicon-based flame retardants as the halogen-free and phosphorus-free flame retardant system, and polystyrene, silane coupling agent and maleic anhydride graft material as phase interface modifiers. It also selects an aging antioxidant system and introduces dynamic crosslinking to obtain a halogen-free and phosphorus-free flame retardant TPE product with a temperature resistance rating of 125℃ without radiation.

[0009] This invention introduces a halogen-free and phosphorus-free flame retardant system, replacing the phosphorus-containing flame retardant system commonly used in existing technologies, achieving excellent flame retardant effects; it achieves a temperature resistance rating of 125°C without using irradiation crosslinking process, simplifying the process and overcoming the problems of existing technologies that require irradiation crosslinking to achieve a temperature resistance rating of 125°C and have cumbersome processes.

[0010] This invention solves the problem of flame retardant dispersion by introducing maleic anhydride-modified hydrogenated styrene-butadiene block copolymer and silane-modified chemically produced magnesium. By optimizing the types and ratios of polymers and antioxidants, polystyrene (PS) is introduced as a phase compatibilizer in the composite material, improving the dispersion of the hydrogenated styrene-butadiene block copolymer (SEBS) and polyphenylene ether (PPO). This achieves dynamic crosslinking through extrusion, meeting the requirement of a radiation-free 125°C temperature resistance rating.

[0011] One of the objectives of this invention is to provide a flame-retardant TPE cable material.

[0012] The flame-retardant TPE cable material is prepared from raw materials including hydrogenated styrene-butadiene block copolymer (SEBS), polyphenylene ether (PPO), polystyrene (PS), ethylene-α-octene copolymer thermoplastic elastomer (POE), maleic anhydride modified hydrogenated styrene-butadiene block copolymer (MA-SEBS), flame retardant, peroxide, and antioxidant.

[0013]

[0014]

[0015] In a preferred embodiment of the present invention,

[0016] The raw materials for the flame-retardant TPE cable material also include lubricants;

[0017] Based on 100 parts by weight of hydrogenated styrene-butadiene block copolymer,

[0018] The amount of lubricant used is 1 to 6 parts by weight; preferably 1.5 to 5 parts by weight.

[0019] The lubricant is at least one of stearic acid, zinc stearate, polyethylene wax, and erucamide.

[0020] In a preferred embodiment of the present invention,

[0021] The hydrogenated styrene-butadiene block copolymer is a hydrogenated polystyrene-polybutadiene-polystyrene block copolymer; preferably, it is a hydrogenated polystyrene-polybutadiene-polystyrene block copolymer with a styrene content of 30% to 55%; SEBS has excellent mechanical properties and processing properties, and the hard segment phase structure of polystyrene is similar to that of polyphenylene ether. The higher the content of the hard segment phase, the better the compatibility between SEBS and PPO.

[0022] The polyphenylene ether is poly2,6-dimethyl-1,4-phenylene ether; preferably, the intrinsic viscosity of the polyphenylene ether is 0.35-0.5 dl / g; polyphenylene ether resin is an engineering plastic, and poly2,6-dimethyl-1,4-phenylene ether has a glass transition temperature of 213℃ and excellent mechanical properties, heat resistance, flame retardancy and creep bending resistance.

[0023] The polystyrene is PS resin with a melt index of 1-10 g / 10 min (200℃, 5 kg). The main chain structure of polystyrene is similar to that of polyphenylene ether and consistent with the hard segment structure of SEBS. Therefore, the introduction of polystyrene can act as a compatibilizer between SEBS and PPO, significantly improving the dispersion of polyphenylene ether in SEBS. At the same time, PS has excellent processing characteristics (glass transition temperature Tg of 104℃), which can greatly reduce the overall processing temperature of TPE composite materials.

[0024] The ethylene-α-octene copolymer thermoplastic elastomer is POE resin, preferably POE resin with a melt index of 1-5 g / 10 min (190℃, 2.16Kg). The main chain of POE resin is saturated, with excellent resistance to environmental aging and ultraviolet radiation. At the same time, the POE molecular chain has partial crystallization, which gives it high flexibility. Introducing POE into the composite material system can improve processing and toughen it.

[0025] The maleic anhydride-modified hydrogenated styrene-butadiene block copolymer (MA-SEBS) is made by introducing maleic anhydride functional groups into the side chains of SEBS, with a grafting rate of 0.6% to 2% (mass grafting rate). Maleic anhydride has strong polarity and can react with functional groups such as hydroxyl groups on the surface of the filler, which can improve the dispersion of flame retardant fillers in the composite material system.

[0026] The peroxide is at least one of dicumyl peroxide (DCP), benzoyl peroxide (BPO), and 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane (bis-dipentane); a small amount of peroxide can enable dynamic cross-linking of the system during extrusion, and a small amount of chemical cross-linking can further improve the heat resistance of the material.

[0027] In a preferred embodiment of the present invention,

[0028] The flame retardant is a mixture of magnesium-based flame retardant and silicon-based flame retardant; the mass ratio of magnesium-based flame retardant to silicon-based flame retardant is (2-30):1; preferably (4-20):1.

[0029] In a preferred embodiment of the present invention,

[0030] The magnesium-based flame retardant is aminosilane-modified chemically produced magnesium hydroxide; preferably, the D50 particle size is 500 nm to 2 μm. During combustion, aminosilane-modified chemically produced magnesium hydroxide decomposes to produce water and magnesium oxide, resulting in both gas-phase and condensed-phase flame retardant effects. Furthermore, the generated magnesium oxide can undergo a ceramicization reaction with the silicon-based flame retardant at high temperatures, promoting the formation of a char layer in the composite material during combustion. The dense char layer structure provides good heat insulation and oxygen barrier effects, playing a synergistic flame retardant role and greatly improving the flame retardant performance of the composite material. Simultaneously, the amino functional groups can chemically react with maleic anhydride functional groups, improving the compatibility and bonding strength of the filler in the matrix resin, playing a synergistic reinforcing role.

[0031] The silicon-based flame retardant is at least one of silicon dioxide, wollastonite, silica powder, montmorillonite, and sepiolite. During combustion, the silicon-based flame retardant can undergo a synergistic reaction with the magnesium-based flame retardant to promote the formation of the char layer, increase the thickness and integrity of the char layer, and improve the flame retardant performance.

[0032] In a preferred embodiment of the present invention,

[0033] The antioxidant includes a primary antioxidant and a secondary antioxidant; the mass ratio of the primary antioxidant to the secondary antioxidant is (0.8-8):1; preferably (1.5-3):1.

[0034] In a preferred embodiment of the present invention,

[0035] The primary antioxidant is a hindered phenolic antioxidant; preferably antioxidant 1010; and / or...

[0036] The auxiliary antioxidant is at least one of thioester antioxidants and amine antioxidants;

[0037] The thioester antioxidant is dilaurate thiodipropionate (DLTP) or dioctadecyl thiodipropionate (DSTP).

[0038] The aging resistance of composite materials can be improved by using primary and secondary antioxidants in combination.

[0039] A second objective of this invention is to provide a method for preparing flame-retardant TPE cable material, comprising:

[0040] The raw materials, including polyphenylene ether, hydrogenated styrene-butadiene block copolymer, polystyrene, ethylene-α-octene copolymer thermoplastic elastomer, maleic anhydride modified hydrogenated styrene-butadiene block copolymer, flame retardant, peroxide, and antioxidant, are mixed evenly, and then compounded, water-cooled, and pelletized by a twin-screw extruder to obtain the flame-retardant TPE cable material.

[0041] In a preferred embodiment of the present invention,

[0042] The mixing temperature is 50℃~60℃; and / or,

[0043] The mixing temperature of the twin-screw extruder is 180℃~230℃, and the screw speed is 150r / min~300r / min.

[0044] The present invention can specifically adopt the following technical solutions:

[0045] A method for preparing a radiation-free, halogen-free, phosphorus-free flame-retardant TPE cable material with a temperature resistance rating of 125℃ includes the following steps:

[0046] Polyphenylene oxide (PPO), hydrogenated styrene-butadiene block copolymer (SEBS), polystyrene (PS), ethylene-α-octene copolymer thermoplastic elastomer (POE), maleic anhydride modified hydrogenated styrene-butadiene block copolymer (MA-SEBS), magnesium-based flame retardant, silicone-based flame retardant, lubricant, peroxide, primary antioxidant, and secondary antioxidant are mixed in a high-speed mixer for 5-10 minutes at a temperature of 50-60°C to obtain a uniformly dispersed mixture.

[0047] The mixed powder is mixed and kneaded in a twin-screw extruder. The temperature range of the heating section of the twin screw is 180-230℃, and the screw speed is 150-300 r / min. After being sheared and kneaded by the twin screw, it is water-cooled and pelletized to obtain the required TPE cable material.

[0048] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0049] (1) This invention introduces a halogen-free and phosphorus-free flame retardant system, replacing the phosphorus-containing flame retardant system commonly used in the prior art with magnesium-based and silicon-based flame retardant systems. It has a good flame retardant effect while being green and environmentally friendly.

[0050] (2) This invention does not use irradiation crosslinking process, and can achieve a temperature resistance level of 125°C. It simplifies the process and overcomes the problem that the existing technology must carry out irradiation crosslinking to achieve a temperature resistance level of 125°C and the process is complicated. The flame-retardant TPE cable material obtained retains more than 80% after aging at 158°C for 7 days.

[0051] (3) By introducing polystyrene as a compatibilizer, the dispersion of polyphenylene ether and SEBS is improved; by introducing maleic anhydride graft material and silane-modified chemical magnesium hydroxide, the dispersion of flame retardant in the system is improved; by using the main antioxidant and auxiliary antioxidant in combination, the aging resistance of the composite material can be improved; by the chemical crosslinking generated by a small amount of peroxide, the system can achieve dynamic crosslinking during the extrusion process; thus, the obtained flame-retardant TPE cable material has a very good flame-retardant effect. Detailed Implementation

[0052] The present invention will now be described in detail with reference to specific embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0053] The raw materials used in the examples and comparative examples were all commercially available.

[0054] The amounts of each raw material used in the examples and comparative examples are by weight.

[0055] Performance testing reference standards:

[0056] Mechanical properties and aging performance testing: UL758 Appliance Wiring Materials;

[0057] Limiting oxygen index standard: GB / T2406.2-2009;

[0058] UL94 flammability standard: ANSI / UL-94-1985;

[0059] Vertical burning test standard for electrical wires: UL1581 Reference Standard for Electrical Wires, Cables, and Flexible Cords.

[0060] Example 1

[0061] The formula is shown in Table 1.

[0062] The intrinsic viscosity of the poly(2,6-dimethyl-1,4-phenylene ether) (PPO) used was 0.4 dl / g, the styrene content of SEBS was 30%, the melt index of PS was 3 g / 10 min, the melt index of POE resin was 3 g / 10 min, the maleic anhydride grafting rate of MA-SEBS was 0.8%, the D50 particle size of the aminosilane-modified chemically processed magnesium hydroxide was 2 μm, the silicon-based flame retardant was silica, the lubricant was stearic acid, the peroxide was dicumyl peroxide, the main antioxidant was hindered phenolic antioxidant 1010, and the auxiliary antioxidant was thioester antioxidant DLTP. The preparation process conditions were as follows: The components were accurately weighed according to the mass ratio of each component in Example 1 in Table 1, mixed in a high-speed mixer for 5 min at a temperature of 50°C, and a uniformly dispersed mixture was obtained. The mixed powder is mixed and kneaded in a twin-screw extruder with a length-to-diameter ratio of 48:1. The temperatures of each heating zone are 190℃, 200℃, 205℃, 210℃, 210℃, 215℃, 215℃, 220℃, 220℃, 225℃, and 210℃, and the screw speed is 200 r / min. After being sheared and kneaded by the twin screw extruder, the mixture is water-cooled and pelletized to obtain TPE cable material.

[0063] Example 2

[0064] The formula is shown in Table 1.

[0065] The intrinsic viscosity of the poly(2,6-dimethyl-1,4-phenylene ether) (PPO) used was 0.45 dl / g, the styrene content of SEBS was 33%, the melt index of PS was 5 g / 10 min, the melt index of POE resin was 3 g / 10 min, the maleic anhydride grafting rate of MA-SEBS was 1%, the D50 particle size of the aminosilane-modified chemically processed magnesium hydroxide was 2 μm, the silicon-based flame retardant was silica powder, the lubricant was erucamide, the peroxide was 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, the main antioxidant was hindered phenolic antioxidant 1010, and the auxiliary antioxidant was thioester antioxidant DSTP. The preparation process conditions were as follows: The components were accurately weighed according to the mass ratio of each component in Example 2 in Table 1, and mixed in a high-speed mixer for 8 min at a temperature of 50°C to obtain a uniformly dispersed mixture. The mixed powder is compounded and kneaded in a twin-screw extruder with a length-to-diameter ratio of 48:1. The temperatures of each heating zone are 190℃, 200℃, 205℃, 210℃, 210℃, 215℃, 215℃, 220℃, 220℃, 225℃, and 210℃, and the screw speed is 250 r / min. After being sheared and kneaded by the twin screw extruder, the mixture is water-cooled and pelletized to obtain TPE cable material.

[0066] Example 3

[0067] The formula is shown in Table 1.

[0068] The intrinsic viscosity of the poly(2,6-dimethyl-1,4-phenylene ether) (PPO) used was 0.4 dl / g, the styrene content of SEBS was 50%, the melt index of PS was 1 g / 10 min, the melt index of POE resin was 1 g / 10 min, the maleic anhydride grafting rate of MA-SEBS was 1.2%, the D50 particle size of aminosilane-modified chemically processed magnesium hydroxide was 1 μm, the silicon-based flame retardant was silica powder, the lubricant was polyethylene wax, the peroxide was dicumyl peroxide (DCP), the main antioxidant was hindered phenolic antioxidant 1010, and the auxiliary antioxidant was thioester antioxidant DSTP. The preparation process conditions were as follows: The components were accurately weighed according to the mass ratio of each component in Example 3 in Table 1, mixed in a high-speed mixer for 10 min at a temperature of 60°C, and a uniformly dispersed mixture was obtained. The mixed powder is compounded and kneaded in a twin-screw extruder with a length-to-diameter ratio of 48:1. The temperatures of each heating zone are 190℃, 200℃, 205℃, 210℃, 210℃, 215℃, 215℃, 220℃, 220℃, 225℃, and 210℃, and the screw speed is 280 r / min. After being sheared and kneaded by the twin screw extruder, the mixture is water-cooled and pelletized to obtain TPE cable material.

[0069] Example 4

[0070] The formula is shown in Table 1.

[0071] The intrinsic viscosity of the poly(2,6-dimethyl-1,4-phenylene ether) (PPO) used was 0.4 dl / g, the styrene content of SEBS was 50%, the melt index of PS was 8 g / 10 min, the melt index of POE resin was 5 g / 10 min, the maleic anhydride grafting rate of MA-SEBS was 1.5%, the D50 particle size of the aminosilane-modified chemically processed magnesium hydroxide was 1 μm, the silicon-based flame retardant was sepiolite, the lubricant was zinc stearate, the peroxide was dicumyl peroxide (DCP), the main antioxidant was hindered phenolic antioxidant 1010, and the auxiliary antioxidant was an amine antioxidant, N-isopropyl-N'-phenyl-p-phenylenediamine. The preparation process conditions were as follows: The components were accurately weighed according to the mass ratio of each component in Example 4 in Table 1, mixed in a high-speed mixer for 10 min at a temperature of 60°C, and a uniformly dispersed mixture was obtained. The mixed powder is compounded and kneaded in a twin-screw extruder with a length-to-diameter ratio of 48:1. The temperatures of each heating zone are 190℃, 200℃, 205℃, 210℃, 210℃, 215℃, 215℃, 220℃, 220℃, 225℃, and 210℃, and the screw speed is 300 r / min. After being sheared and kneaded by the twin screw extruder, the mixture is water-cooled and pelletized to obtain TPE cable material.

[0072] Example 5

[0073] The formula is shown in Table 1.

[0074] The intrinsic viscosity of the poly(2,6-dimethyl-1,4-phenylene ether) (PPO) used was 0.35 dl / g, the styrene content of SEBS was 33%, the melt index of PS was 10 g / 10 min, the melt index of POE resin was 3 g / 10 min, the maleic anhydride grafting rate of MA-SEBS was 2%, the D50 particle size of the aminosilane-modified chemically processed magnesium hydroxide was 800 nm, the silicon-based flame retardant was wollastonite, the lubricant was erucamide, the peroxide was benzoyl peroxide (BPO), the main antioxidant was hindered phenolic antioxidant 1010, and the auxiliary antioxidant was thioester antioxidant DLTP. The preparation process conditions were as follows: The components were accurately weighed according to the mass ratio of each component in Example 5 in Table 1, mixed in a high-speed mixer for 8 min at a temperature of 50°C, and a uniformly dispersed mixture was obtained. The mixed powder is compounded and kneaded in a twin-screw extruder with a length-to-diameter ratio of 48:1. The temperatures of each heating zone are 190℃, 200℃, 205℃, 210℃, 210℃, 215℃, 215℃, 220℃, 220℃, 225℃, and 210℃, and the screw speed is 250 r / min. After being sheared and kneaded by the twin screw extruder, the mixture is water-cooled and pelletized to obtain TPE cable material.

[0075] Comparative Example

[0076] The formula is shown in Table 1.

[0077] Compared with Example 2, the comparative example did not contain polystyrene resin or silicone flame retardant;

[0078] The intrinsic viscosity of the poly(2,6-dimethyl-1,4-phenylene ether) (PPO) used was 0.45 dl / g, the styrene content of SEBS was 33%, the melt index of POE resin was 3 g / 10 min, the maleic anhydride grafting rate of MA-SEBS was 1%, the D50 particle size of the aminosilane-modified chemically processed magnesium hydroxide was 2 μm, the lubricant was erucamide, the peroxide was 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, the main antioxidant was hindered phenolic antioxidant 1010, and the auxiliary antioxidant was thioester antioxidant DSTP. The preparation process conditions were as follows: The components were accurately weighed according to the mass ratios in the comparative examples in Table 1, mixed in a high-speed mixer for 8 min at a temperature of 50℃, and a uniformly dispersed mixture was obtained. The mixed powder is compounded and kneaded in a twin-screw extruder with a length-to-diameter ratio of 48:1. The temperatures of each heating zone are 190℃, 200℃, 205℃, 210℃, 210℃, 215℃, 215℃, 220℃, 220℃, 225℃, and 210℃, and the screw speed is 280 r / min. After being sheared and kneaded by the twin screw extruder, the mixture is water-cooled and pelletized to obtain TPE cable material.

[0079] Table 1. Formulations of Examples 1-5 and Comparative Examples (by weight parts)

[0080] Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example SEBS 100 100 100 100 100 100 PPO 30 50 50 90 120 50 PS 30 25 40 30 30 0 POE 20 25 25 15 30 25 MA-SEBS 20 50 50 80 80 50 Magnesium-based flame retardants 250 375 400 565 375 400 Silicon-based flame retardants 50 25 20 35 25 0 lubricant 1.5 2.5 2.5 5 4 2.5 peroxide 0.1 0.15 0.2 0.25 0.3 0.15 main antioxidant 1.4 1.5 1.8 3.5 4.5 1.5 Co-antioxidants 0.6 1 1 1.5 1.5 1

[0081] The sheet preparation process of Examples 1-5 and the comparative examples is as follows: TPE cable material is thinned, packaged, plasticized and sheeted on an open mill (open mill roller temperature 160℃), and then hot-pressed (190℃, 10MPa, 10min) through a flat vulcanizing machine, followed by cold pressing (40℃, 5min) to obtain TPE cable material sheets of 100mm*100mm*1mm.

[0082] The wire preparation processes of Examples 1-5 and the comparative examples are as follows: TPE cable material is taken and extruded into wire using a single screw (45 machine) extruder. The extrusion temperatures are 180℃, 200℃, 215℃, 215℃, and 220℃ to obtain TPE cable material wire.

[0083] The mechanical properties, flame retardant properties, and aging resistance of the TPE cable sheets and wires prepared in Examples 1-5 and the comparative examples were tested, and the test results are listed in Table 2.

[0084] Table 2. Performance test results of sheets and wires from Examples 1-5 and the comparative examples.

[0085]

[0086] The key performance indicators of TPE materials according to the UL electronic wire standard are as follows: wire tensile strength > 10.3 MPa, wire elongation > 150%, wire flame retardancy rating reaching VW-1, and after aging at 158℃ for 7 days, the strength and elongation retention rate ≥ 80%. As can be seen from Table 2, the wire tensile strength of Examples 1–5 is all greater than 15 MPa, and after aging at 158℃ for 7 days, the strength retention rate is above 95%, indicating good mechanical properties.

[0087] Compared to Example 2, the comparative example, which did not contain any silicone-based flame retardant, showed no flame retardant rating in UL94 testing and had an oxygen index of 28. Example 2, however, achieved a V-0 rating in all UL94 tests, with an oxygen index increased to 33. Furthermore, with the addition of silicone-based flame retardant, the flame retardant rating of the wire improved from horizontal burning (FT-2) to vertical burning (VW-1). The addition of silicone-based flame retardant significantly increased the thickness of the char layer, forming a porous char layer structure. This porous char layer effectively isolates oxygen and heat during combustion, thus achieving a flame-retardant effect.

[0088] Compared with Example 2, the comparative example did not add polystyrene resin. The mechanical properties of the comparative example sheets and wires were worse than those of Example 2, and the appearance of the comparative example wires was rougher. This is because polyphenylene ether and SEBS are difficult to process. Without compatibilizer, polyphenylene ether and SEBS are difficult to disperse well. After adding polystyrene, the dispersion of polyphenylene ether and SEBS is better, which is reflected in the improved mechanical properties of the sheets and wires and the smooth appearance of the wires.

[0089] The flame-retardant TPE cable materials prepared in Examples 1-5 all exhibited an elongation retention rate greater than 80% after aging at 158°C for 7 days, demonstrating that the present invention achieves a temperature resistance rating of 125°C without using an irradiation crosslinking process. The aging resistance of the wire is affected by various factors, such as the type and amount of polymer in the system, the type and amount of antioxidant, and the degree of chemical crosslinking. Compared to Example 2, the comparative example wire showed an elongation retention rate of 75% after aging, proving that polystyrene, as a compatibilizer, improved the dispersion of polyphenylene ether and SEBS, thereby enhancing the aging resistance of the flame-retardant TPE cable material.

Claims

1. A flame-retardant TPE cable material, characterized in that: The flame-retardant TPE cable material is prepared from raw materials including hydrogenated styrene-butadiene block copolymer, polyphenylene ether, polystyrene, ethylene-α-octene copolymer thermoplastic elastomer, maleic anhydride modified hydrogenated styrene-butadiene block copolymer, flame retardant, peroxide, and antioxidant. Based on 100 parts by weight of hydrogenated styrene-butadiene block copolymer, 100 parts by weight of hydrogenated styrene-butadiene block copolymer; 20-120 parts by weight of polyphenylene ether; 10-50 parts by weight of polystyrene; 10-40 parts by weight of ethylene-α-octene copolymer thermoplastic elastomer; 10-100 parts by weight of maleic anhydride-modified hydrogenated styrene-butadiene block copolymer; Flame retardant 300-700 parts by weight; Peroxide 0.1~0.5 parts by weight; Antioxidant 1.5~7 parts by weight; The hydrogenated styrene-butadiene block copolymer is a hydrogenated polystyrene-polybutadiene-polystyrene block copolymer; The flame retardant is a mixture of magnesium-based flame retardant and silicon-based flame retardant; the magnesium-based flame retardant is aminosilane-modified chemically processed magnesium hydroxide; the silicon-based flame retardant is at least one of silicon dioxide, wollastonite, silica fume, montmorillonite, and sepiolite; the mass ratio of magnesium-based flame retardant to silicon-based flame retardant is (2~30):

1.

2. The flame-retardant TPE cable material as described in claim 1, characterized in that: 100 parts by weight of hydrogenated styrene-butadiene block copolymer; 30-100 parts by weight of polyphenylene ether; 25-40 parts by weight of polystyrene; 15-30 parts by weight of ethylene-α-octene copolymer thermoplastic elastomer; 20-80 parts by weight of maleic anhydride-modified hydrogenated styrene-butadiene block copolymer; Flame retardant 400-600 parts by weight; Peroxide 0.1~0.3 parts by weight; Antioxidant 2-5 parts by weight.

3. The flame-retardant TPE cable material as described in claim 1, characterized in that: The raw materials for the flame-retardant TPE cable material also include lubricants; Based on 100 parts by weight of hydrogenated styrene-butadiene block copolymer, The amount of lubricant used is 1 to 6 parts by weight; The lubricant is at least one of stearic acid, zinc stearate, polyethylene wax, and erucamide.

4. The flame-retardant TPE cable material as described in claim 3, characterized in that: Based on 100 parts by weight of hydrogenated styrene-butadiene block copolymer, The amount of lubricant used is 1.5 to 5 parts by weight.

5. The flame-retardant TPE cable material as described in claim 1, characterized in that: The hydrogenated styrene-butadiene block copolymer is a hydrogenated polystyrene-polybutadiene-polystyrene block copolymer with a styrene content of 30%~55%; and / or, The polyphenylene ether is poly2,6-dimethyl-1,4-phenylene ether; and / or... The polystyrene has a melt index of 1~10 g / 10 min; and / or, The melt index of the ethylene-α-octene copolymer thermoplastic elastomer is 1~5 g / 10min; and / or, The maleic anhydride-modified hydrogenated styrene-butadiene block copolymer has a maleic anhydride grafting rate of 0.6% to 2%; and / or, The peroxide is at least one of dicumyl peroxide, benzoyl peroxide, and 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane.

6. The flame-retardant TPE cable material as described in claim 5, characterized in that: The intrinsic viscosity of the poly(2,6-dimethyl-1,4-phenyl ether) is 0.35-0.5 dl / g.

7. The flame-retardant TPE cable material as described in claim 1, characterized in that: The mass ratio of magnesium-based flame retardant to silicon-based flame retardant is (4~20):

1.

8. The flame-retardant TPE cable material as described in claim 1, characterized in that: The D50 particle size of the magnesium-based flame retardant is 500 nm to 2 μm.

9. The flame-retardant TPE cable material as described in claim 1, characterized in that: The antioxidants include primary antioxidants and secondary antioxidants; the mass ratio of primary antioxidants to secondary antioxidants is (0.8~8):

1.

10. The flame-retardant TPE cable material as described in claim 9, characterized in that: The mass ratio of the primary antioxidant to the secondary antioxidant is (1.5~3):

1.

11. The flame-retardant TPE cable material as described in claim 9, characterized in that: The primary antioxidant is a hindered phenolic antioxidant; and / or... The auxiliary antioxidant is at least one of thioester antioxidants and amine antioxidants; The thioester antioxidant is dilaurate thiodipropionate or dioctadecyl thiodipropionate.

12. The method for preparing flame-retardant TPE cable material as described in any one of claims 1 to 11, characterized in that... The method includes: The raw materials, including polyphenylene ether, hydrogenated styrene-butadiene block copolymer, polystyrene, ethylene-α-octene copolymer thermoplastic elastomer, maleic anhydride modified hydrogenated styrene-butadiene block copolymer, flame retardant, peroxide, and antioxidant, are mixed evenly, and then compounded, water-cooled, and pelletized by a twin-screw extruder to obtain the flame-retardant TPE cable material.

13. The method for preparing flame-retardant TPE cable material as described in claim 12, characterized in that: The mixing temperature is 50℃~60℃; and / or, The mixing temperature of the twin-screw extruder is 180℃~230℃, and the screw speed is 150r / min~300r / min.

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