A high-strength high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material and a preparation method thereof

Abstract

The application belongs to the field of composite materials, and particularly relates to a high-strength and high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material and a preparation method thereof. The high-strength and high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material provided by the application comprises the following components in parts by weight: ethylene-vinyl acetate copolymer 30-40 parts, polyolefin elastomer 10-40 parts, metallocene polyethylene 30-40 parts, aramid fiber 0.1-5 parts, linear low-density polyethylene 10-40 parts, maleic anhydride grafting compatibilizer 5-15 parts, halogen-free flame retardant 120-150 parts, antioxidant 0.5-1.5 parts, coupling agent 1-2 parts, and lubricant 1-3 parts. The cable sheath material provided by the application has good strength, flexibility and flame retardancy, and has a good application prospect in the field of new energy vehicles.

Description

Technical Field

[0001] This invention belongs to the field of composite materials, and particularly relates to a high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material and its preparation method. Background Technology

[0002] As the core carrier of information transmission and energy delivery, the safety and reliability of cables directly affect the stable operation of industrial production, infrastructure, communication networks, and people's livelihoods. Cable sheaths, as an important component of cable systems, undertake key functions such as mechanical protection, environmental isolation, electrical insulation, and identification. With the increasing demands of modern industry for cable systems operating under complex conditions, the performance indicators and application scenario adaptability of cable sheath materials have become one of the core factors affecting the overall reliability of the system.

[0003] Different application areas have placed varying, even contradictory, performance requirements on cable sheath materials, and this demand has become the core driving force for material innovation. Taking the new energy vehicle sector as an example, the complex wiring environment inside vehicles requires protective sheath materials to possess characteristics such as high strength, high flexibility, and high flame retardancy. How to improve the overall performance of cable sheath materials in the new energy vehicle sector has become a research hotspot in this field. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material and its preparation method. The cable sheath material provided by this invention has good strength, flexibility and flame retardancy, and has good application prospects in the field of new energy vehicles.

[0005] This invention provides a high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material, comprising the following components by weight:

[0006] 30-40 parts of ethylene-vinyl acetate copolymer;

[0007] 10-40 parts of polyolefin elastomer;

[0008] 30-40 parts of metallocene polyethylene;

[0009] Aramid fiber 0.1~5 parts;

[0010] 10-40 parts of linear low-density polyethylene;

[0011] 5-15 parts of maleic anhydride graft compatibilizer;

[0012] 120-150 parts of halogen-free flame retardant;

[0013] Antioxidant 0.5~1.5 parts;

[0014] 1-2 parts of coupling agent;

[0015] 1-3 parts lubricant.

[0016] Preferably, the content of repeating units corresponding to vinyl acetate in the ethylene-vinyl acetate copolymer is 18~26wt%.

[0017] Preferably, the polyolefin elastomer is an ethylene-butene random copolymer polyolefin elastomer and / or an ethylene-octene random copolymer polyolefin elastomer; the melt index of the polyolefin elastomer measured at 190°C and 2.16 kg load is 0.5~15 g / 10 min; the melting temperature of the polyolefin elastomer is 40~65°C; the weight-average molecular weight of the polyolefin elastomer is 120,000~300,000 g / mol; and the molecular weight distribution index of the polyolefin elastomer is 2~2.4.

[0018] Preferably, the metallocene polyethylene has a melt flow index of 1~5 g / 10 min measured at 190°C and a load of 2.16 kg; and the density of the metallocene polyethylene is 0.9~0.92 g / cm³. 3 .

[0019] Preferably, the aramid fiber is a para-aramid chopped fiber; the fiber length of the aramid fiber is 3~8mm; and the fiber diameter of the aramid fiber is 10~15μm.

[0020] Preferably, the linear low-density polyethylene has a melt index of 3-4 g / 10 min measured at 190°C and a load of 2.16 kg; and the density of the linear low-density polyethylene is 0.9-0.93 g / cm³. 3 .

[0021] Preferably, the maleic anhydride graft compatibilizer is a polymer grafted with maleic anhydride groups, wherein the main chain structure of the polymer is one or more of ethylene-vinyl acetate copolymer, linear low-density polyethylene, and polyolefin elastomer; and the maleic anhydride grafting rate of the maleic anhydride graft compatibilizer is 0.8~1.1wt%.

[0022] Preferably, the halogen-free flame retardant comprises aluminum hydroxide and magnesium hydroxide; the mass ratio of aluminum hydroxide to magnesium hydroxide is (5~7):1.

[0023] Preferably, the antioxidant is a hindered phenolic antioxidant and / or an aromatic amine antioxidant;

[0024] And / or, the coupling agent is one or more of the following: silane coupling agent KH550, silane coupling agent KH570, silane coupling agent ZQ-172, and titanate coupling agent 131;

[0025] And / or, the lubricant is one or more of paraffin wax, silicone wax, and polyethylene wax.

[0026] This invention provides a method for preparing the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material described in the above technical solution, comprising the following steps:

[0027] Ethylene-vinyl acetate copolymer, polyolefin elastomer, metallocene polyethylene, aramid fiber, linear low-density polyethylene, maleic anhydride graft compatibilizer, halogen-free flame retardant, antioxidant, coupling agent and lubricant are compounded to obtain high-strength and high-toughness polyolefin elastomer halogen-free flame retardant cable sheath material.

[0028] Compared with the prior art, the present invention provides a high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material and its preparation method. By weight, the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material provided by the present invention comprises the following components: 30-40 parts of ethylene-vinyl acetate copolymer, 10-40 parts of polyolefin elastomer, 30-40 parts of metallocene polyethylene, 0.1-5 parts of aramid fiber, 10-40 parts of linear low-density polyethylene, 5-15 parts of maleic anhydride graft compatibilizer, 120-150 parts of halogen-free flame retardant, 0.5-1.5 parts of antioxidant, 1-2 parts of coupling agent, and 1-3 parts of lubricant. This invention leverages the combined performance advantages of ethylene-vinyl acetate copolymer, polyolefin elastomer, metallocene polyethylene, and linear low-density polyethylene matrix materials, along with the synergistic effects of aramid fiber, maleic anhydride graft compatibilizer, halogen-free flame retardant, antioxidant, coupling agent, and lubricant, to improve the tensile strength and flexibility of cable sheathing materials, while simultaneously enhancing their flame retardant properties. The cable sheathing material provided by this invention possesses excellent strength, flexibility, and flame retardancy, showing promising application prospects in the new energy vehicle field. Detailed Implementation

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] This invention provides a high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material, comprising the following components by weight:

[0031] 30-40 parts of ethylene-vinyl acetate copolymer;

[0032] 10-40 parts of polyolefin elastomer;

[0033] 30-40 parts of metallocene polyethylene;

[0034] Aramid fiber 0.1~5 parts;

[0035] 10-40 parts of linear low-density polyethylene;

[0036] 5-15 parts of maleic anhydride graft compatibilizer;

[0037] 120-150 parts of halogen-free flame retardant;

[0038] Antioxidant 0.5~1.5 parts;

[0039] 1-2 parts of coupling agent;

[0040] 1-3 parts lubricant.

[0041] In the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material provided by the present invention, the content of the repeating unit corresponding to vinyl acetate in the ethylene-vinyl acetate copolymer is preferably 18~26wt%, specifically 18wt%, 19wt%, 20wt%, 21wt%, 22wt%, 23wt%, 24wt%, 25wt%, or 26wt%; the ethylene-vinyl acetate copolymer can specifically be Formosa Plastics 7470K.

[0042] In the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material provided by the present invention, the content of the ethylene-vinyl acetate copolymer can be 30 parts by weight, 31 parts by weight, 32 parts by weight, 33 parts by weight, 34 parts by weight, 35 parts by weight, 36 parts by weight, 37 parts by weight, 38 parts by weight, 39 parts by weight, or 40 parts by weight.

[0043] In the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material provided by this invention, the polyolefin elastomer (POE) is preferably an ethylene-butene random copolymer polyolefin elastomer and / or an ethylene-octene random copolymer polyolefin elastomer; the melt index of the polyolefin elastomer measured at 190°C and a load of 2.16 kg is preferably 0.5~15 g / 10 min, specifically 0.5 g / 10 min, 1 g / 10 min, 1.2 g / 10 min, 2 g / 10 min, 3 g / 10 min, 4 g / 10 min, 5 g / 10 min, 6 g / 10 min, 7 g / 10 min, 8 g / 10 min, 9 g / 10 min, 10 g / 10 min, 11 g / 10 min, 12 g / 10 min, 13 g / 10 min, 13.8 g / 10 min, etc. The melting temperature of the polyolefin elastomer is preferably 40~65℃, specifically 40℃, 45℃, 50℃, 55℃, 60℃ or 65℃; the weight-average molecular weight (Mw) of the polyolefin elastomer is preferably 120000~300000g / mol, specifically 120000g / mol, 150000g / mol, 170000g / mol, 200000g / mol, 230000g / mol, 250000g / mol, 270000g / mol or 300000g / mol; the molecular weight distribution index of the polyolefin elastomer is preferably 2~2.4, specifically 2, 2.05, 2.1, 2.15, 2.2, 2.25, 2.3, 2.35 or 2.4.

[0044] In the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material provided by the present invention, the content of the polyolefin elastomer can be 10 parts by weight, 12 parts by weight, 15 parts by weight, 17 parts by weight, 20 parts by weight, 23 parts by weight, 25 parts by weight, 27 parts by weight, 30 parts by weight, 32 parts by weight, 35 parts by weight, 37 parts by weight, or 40 parts by weight.

[0045] In the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material provided by this invention, the polyolefin elastomer is introduced into the material. Due to its excellent organic-inorganic interface effect, it can fully encapsulate the inorganic filler and suppress stress concentration points. At the same time, as a tough matrix, the polyolefin elastomer can withstand greater plastic deformation, thereby synergistically enhancing the toughness of the composite material and breaking through the bottleneck of mechanical property degradation caused by high-filler flame-retardant systems. This is directly manifested as an increase in elongation at break.

[0046] In the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material provided by this invention, the melt index of the polyolefin elastomer has a crucial impact on the mechanical properties of the material. As the melt index of the polyolefin elastomer increases, the tensile strength and elongation at break of the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material show a trend of first increasing and then decreasing. When the melt index of the polyolefin elastomer is below the preferred range, the increased molecular chain size of the polyolefin elastomer leads to poor processing performance, uneven dispersion, and consequently, reduced performance. Conversely, when the melt index of the polyolefin elastomer is above the preferred range, the excessively short molecular chain of the polyolefin elastomer results in a significant decrease in the mechanical properties of the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material.

[0047] In the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material provided by this invention, the melt index of the metallocene polyethylene, measured under conditions of 190°C and 2.16 kg load, is preferably 1~5 g / 10 min, specifically 1 g / 10 min, 1.5 g / 10 min, 2 g / 10 min, 2.5 g / 10 min, 3 g / 10 min, 3.5 g / 10 min, 4 g / 10 min, 4.5 g / 10 min, or 5 g / 10 min; the density of the metallocene polyethylene is preferably 0.9~0.92 g / cm³. 3 Specifically, it can be 0.9 g / cm³. 3 0.902 g / cm 3 0.905g / cm 3 0.907 g / cm 3 0.91g / cm 3 0.912 g / cm 3 0.915g / cm 3 0.917 g / cm 3 Or 0.92g / cm 3 .

[0048] In the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material provided by the present invention, the content of metallocene polyethylene can be 30 parts by weight, 31 parts by weight, 32 parts by weight, 33 parts by weight, 34 parts by weight, 35 parts by weight, 36 parts by weight, 37 parts by weight, 38 parts by weight, 39 parts by weight, or 40 parts by weight.

[0049] In the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material provided by the present invention, the aramid fiber is preferably para-aramid chopped fiber; the fiber length of the aramid fiber is preferably 3-8 mm, specifically 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm or 8 mm; the fiber diameter of the aramid fiber is preferably 10-15 μm, specifically 10 μm, 10.5 μm, 11 μm, 11.5 μm, 12 μm, 12.5 μm, 13 μm, 13.5 μm, 14 μm, 14.5 μm or 15 μm.

[0050] In the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material provided by the present invention, the content of aramid fiber can be specifically 0.1 parts by weight, 0.5 parts by weight, 1 part by weight, 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight, 3 parts by weight, 3.5 parts by weight, 4 parts by weight, 4.5 parts by weight, or 5 parts by weight.

[0051] In the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material provided by this invention, the aramid fiber is introduced into the material. Its high strength, high modulus, and high flame-retardant properties enable it to bear most of the applied load, thereby improving the tensile strength of the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material. At the same time, its excellent thermal stability and char-forming properties further enhance the flame-retardant performance of the system. Combined with the toughness provided by POE, an optimized balance of strength, toughness, and flame retardancy is achieved, which can meet the stringent requirements of the new energy vehicle field for the mechanical strength and toughness of high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material.

[0052] In the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material provided by this invention, the melt index of the linear low-density polyethylene measured at 190°C and a load of 2.16 kg is preferably 3~4 g / 10 min, specifically 3 g / 10 min, 3.5 g / 10 min, 3.8 g / 10 min, or 4 g / 10 min; the density of the linear low-density polyethylene is preferably 0.9~0.93 g / cm³. 3 Specifically, it can be 0.9 g / cm³. 3 0.905g / cm 3 0.91g / cm 3 0.912 g / cm 3 0.917 g / cm 3 0.92g / cm 3 0.925g / cm 3 Or 0.93g / cm 3 .

[0053] In the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material provided by the present invention, the content of linear low-density polyethylene can be specifically 10 parts by weight, 12 parts by weight, 15 parts by weight, 17 parts by weight, 20 parts by weight, 23 parts by weight, 25 parts by weight, 27 parts by weight, 30 parts by weight, 32 parts by weight, 35 parts by weight, 37 parts by weight, or 40 parts by weight.

[0054] In the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material provided by the present invention, the maleic anhydride graft compatibilizer is a polymer grafted with maleic anhydride groups. The main chain structure of the polymer is preferably one or more of ethylene-vinyl acetate copolymer, linear low-density polyethylene, and polyolefin elastomer. The grafting rate of the maleic anhydride groups in the maleic anhydride graft compatibilizer is preferably 0.8~1.1wt%, specifically 0.8wt%, 0.85wt%, 0.9wt%, 0.95wt%, 1wt%, 1.05wt%, or 1.1wt%.

[0055] In the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material provided by the present invention, the content of the maleic anhydride graft compatibilizer can specifically be 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight, 10 parts by weight, 11 parts by weight, 12 parts by weight, 13 parts by weight, 14 parts by weight, or 15 parts by weight.

[0056] In the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material provided by the present invention, the halogen-free flame retardant preferably comprises aluminum hydroxide and magnesium hydroxide; the mass ratio of aluminum hydroxide to magnesium hydroxide is preferably (5~7):1, specifically 5:1, 5.5:1, 6:1, 6.5:1, or 7:1. In the present invention, aluminum hydroxide and magnesium hydroxide can synergistically improve the flame-retardant performance, and the combination of the two has excellent flame-retardant properties.

[0057] In the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material provided by the present invention, the content of the halogen-free flame retardant can specifically be 120 parts by weight, 123 parts by weight, 125 parts by weight, 127 parts by weight, 130 parts by weight, 132 parts by weight, 135 parts by weight, 136 parts by weight, 137 parts by weight, 140 parts by weight, 142 parts by weight, 145 parts by weight, 147 parts by weight, or 150 parts by weight.

[0058] In the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material provided by the present invention, the antioxidant is preferably a hindered phenolic antioxidant and / or an aromatic amine antioxidant, more preferably one or more of antioxidant 1024 (N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine), antioxidant 1010 (tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester), and antioxidant 168 (tris[2,4-di-tert-butylphenyl]phosphite).

[0059] In the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material provided by the present invention, the content of the antioxidant can specifically be 0.5 parts by weight, 0.6 parts by weight, 0.7 parts by weight, 0.8 parts by weight, 0.9 parts by weight, 1 part by weight, 1.1 parts by weight, 1.2 parts by weight, 1.3 parts by weight, 1.4 parts by weight, or 1.5 parts by weight.

[0060] In the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material provided by the present invention, the coupling agent is preferably one or more of the following: silane coupling agent KH550 (γ-aminopropyltriethoxysilane), silane coupling agent KH570 (γ-(methacryloyloxy)propyltrimethoxysilane), silane coupling agent ZQ-172 (vinyltris(2-methoxyethoxy)silane), and titanate coupling agent 131 (isopropyl tristearate titanate).

[0061] In the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material provided by the present invention, the content of the coupling agent can specifically be 1 part by weight, 1.1 parts by weight, 1.2 parts by weight, 1.3 parts by weight, 1.4 parts by weight, 1.5 parts by weight, 1.6 parts by weight, 1.7 parts by weight, 1.8 parts by weight, 1.9 parts by weight, or 2 parts by weight.

[0062] In the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material provided by the present invention, the lubricant is preferably one or more of paraffin wax, silicone, and polyethylene wax.

[0063] In the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material provided by the present invention, the content of the lubricant can specifically be 1 part by weight, 1.2 parts by weight, 1.5 parts by weight, 1.7 parts by weight, 2 parts by weight, 2.3 parts by weight, 2.5 parts by weight, 2.7 parts by weight, or 3 parts by weight.

[0064] This invention also provides a method for preparing the high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material described in the above technical solution, characterized by comprising the following steps:

[0065] Ethylene-vinyl acetate copolymer, polyolefin elastomer, metallocene polyethylene, aramid fiber, linear low-density polyethylene, maleic anhydride graft compatibilizer, halogen-free flame retardant, antioxidant, coupling agent and lubricant are compounded to obtain high-strength and high-toughness polyolefin elastomer halogen-free flame retardant cable sheath material.

[0066] In the preparation method provided by the present invention, the ethylene-vinyl acetate copolymer, polyolefin elastomer, metallocene polyethylene, aramid fiber, linear low-density polyethylene, maleic anhydride graft compatibilizer, halogen-free flame retardant, antioxidant, coupling agent and lubricant are preferably premixed before being compounded.

[0067] In the preparation method provided by the present invention, the mixing is preferably carried out in an internal mixer; the mixing speed is preferably 20~60 r / min, specifically 20 r / min, 25 r / min, 30 r / min, 35 r / min, 40 r / min, 45 r / min, 50 r / min, 55 r / min or 60 r / min; the mixing temperature is preferably 120~145℃, specifically 120℃, 125℃, 130℃, 135℃, 140℃ or 145℃; the mixing time is preferably 5~30 min, specifically 5 min, 10 min, 15 min, 20 min, 25 min or 30 min.

[0068] The technical solution provided by this invention utilizes the comprehensive performance advantages of ethylene-vinyl acetate copolymer, polyolefin elastomer, metallocene polyethylene, and linear low-density polyethylene matrix materials, as well as the synergistic effect of aramid fiber, maleic anhydride graft compatibilizer, halogen-free flame retardant, antioxidant, coupling agent, and lubricant, to improve the tensile strength and flexibility of cable sheath materials, while also enhancing the flame retardant properties of the materials. More specifically, the technical method of this invention has at least the following advantages:

[0069] (1) The present invention improves the heat resistance and flame retardant stability of the material by entanglement of polyolefin elastomer and aramid fiber. By adjusting the proportion of polyolefin elastomer and aramid fiber in the material system, the aramid fiber constructs a three-dimensional network skeleton in the cable sheath material. This structure can not only effectively block the oxygen diffusion path, but also the rigid benzene ring structure of aramid can absorb the heat energy of combustion and inhibit the breakage of polyolefin elastomer molecular chains, so that the material remains stable under long-term working conditions.

[0070] (2) Polyolefin elastomer and aramid fiber construct a rigid fiber-flexible polymer network structure: Aramid fiber forms a stress transmission network and serves as a stress transmission skeleton, imparting its ultra-high tensile modulus to the cable sheath material, thereby significantly improving the tensile strength of the material; At the same time, polyolefin elastomer serves as an energy dissipation unit, absorbing energy through chain segment slippage under external force, thereby improving the elongation at break of the material.

[0071] (3) The high-strength and high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material provided by the present invention has good strength, flexibility and flame retardancy, and low density, which solves the contradiction between lightweight and reliability of cable sheath material.

[0072] For clarity, the following examples and comparative models will be used to provide a detailed description.

[0073] In the following embodiments and comparative examples of the present invention, the ethylene-vinyl acetate copolymer EVA used was Formosa Plastics 7470K, with the following key parameters: vinyl acetate content of 26wt%, melt index of 5.5g / 10min (190℃ / 2.16kg), and density of 0.948g / cm³. 3 ;

[0074] In the following embodiments and comparative examples of the present invention, the polyolefin elastomers (POEs) used include G6012, G6045, and PV7200; wherein, G6012 is an ethylene-butene copolymer with a melt index of 1.2 g / 10 min (190 °C / 2.16 kg), a melting temperature of 40-50 °C, a weight-average molecular weight of 220,000-230,000 g / mol, and a molecular weight distribution index of 2-2.4; G6045 is an ethylene-butene copolymer with a melt index of... The melt index is 5 g / 10 min (190℃ / 2.16 kg), the melting temperature is 45~54℃, the weight-average molecular weight is 160000~180000 g / mol, and the molecular weight distribution index is 2~2.4; PV7200 is an ethylene-butene copolymer with a melt index of 13.8 g / 10 min (190℃ / 2.16 kg), a melting temperature of 58~63℃, a weight-average molecular weight of 130000~150000 g / mol, and a molecular weight distribution index of 2~2.4.

[0075] In the following embodiments and comparative examples of the present invention, the metallocene polyethylene used is grade 3518CB, with a melt flow index of 3.5 g / 10 min (190 °C / 2.16 kg) and a density of 0.918 g / cm³. 3 ;

[0076] In the following embodiments and comparative examples of the present invention, the maleic anhydride-grafted polyethylene used is grade MC226, whose main chain structure is linear low-density polyethylene, the maleic anhydride group grafting rate is 0.8%, and the density is 0.918 g / cm³. 3 ;

[0077] In the following embodiments and comparative examples of the present invention, the linear low-density polyethylene used has a melt index of 2~2.5 g / 10 min (190℃ / 2.16 kg) and a density of 0.920 g / cm³. 3 ;

[0078] In the following embodiments and comparative examples of the present invention, the aramid fibers used are from Shandong Jufang New Materials Co., Ltd., and are para-aramid short-cut fibers with a fiber length of 3 mm and a fiber diameter of 13-15 μm.

[0079] In the following embodiments and comparative examples of the present invention, the silane coupling agent used is ZQ-172, the composition of which is vinyltris(2-methoxyethoxy)silane;

[0080] In the following embodiments and comparative examples of the present invention, the lubricant used is silicone GM5007.

[0081] Example 1

[0082] A high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material, by weight, comprises the following raw materials: 30 parts ethylene-vinyl acetate copolymer (EVA), 20 parts polyolefin elastomer (POE) (G6012), 30 parts metallocene polyethylene, 14 parts maleic anhydride grafted polyethylene, 10 parts linear low-density polyethylene, 0.5 parts aramid fiber, 120 parts aluminum hydroxide, 20 parts magnesium hydroxide, 1 part antioxidant 1024, 1.5 parts silane coupling agent, and 1 part lubricant.

[0083] The above materials are mixed evenly to obtain a homogeneous mixture; the Hack mixer is preheated to 130°C and the rotor speed is set to 40 r / min; the mixture is added to the Hack mixer and mixed for 15 min before being removed to obtain a high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material.

[0084] To test the performance of the prepared cable sheath material, the prepared cable sheath material was rolled at 120℃ using an open mill to prepare 1.3~1.5mm thin sheets; then, a flat vulcanizing machine was used to set the hot pressing temperature to 170℃ and the hot pressing pressure to 10MPa, and the 1.3~1.5mm thin sheets were preheated for 3~5 minutes before being prepared as test samples through the hot pressing process.

[0085] Example 2

[0086] A high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material, by weight, has the following raw material composition: 30 parts ethylene-vinyl acetate copolymer (EVA), 20 parts polyolefin elastomer (POE) (G6012), 30 parts metallocene polyethylene, 14 parts maleic anhydride grafted polyethylene, 10 parts linear low-density polyethylene, 2 parts aramid fiber, 118 parts aluminum hydroxide, 18 parts magnesium hydroxide, 1 part antioxidant 1024, 1.5 parts silane coupling agent, and 1 part lubricant.

[0087] The above materials are mixed evenly to obtain a homogeneous mixture; the Hack mixer is preheated to 130°C and the rotor speed is set to 40 r / min; the mixture is added to the Hack mixer and mixed for 15 min before being removed to obtain a high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material.

[0088] To test the performance of the prepared cable sheath material, the prepared cable sheath material was rolled at 120℃ using an open mill to prepare 1.3~1.5mm thin sheets; then, a flat vulcanizing machine was used to set the hot pressing temperature to 170℃ and the hot pressing pressure to 10MPa, and the 1.3~1.5mm thin sheets were preheated for 3~5 minutes before being prepared as test samples through the hot pressing process.

[0089] Example 3

[0090] A high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material, by weight, comprises the following raw materials: 30 parts ethylene-vinyl acetate copolymer (EVA), 40 parts polyolefin elastomer (POE) (G6012), 30 parts metallocene polyethylene, 14 parts maleic anhydride grafted polyethylene, 10 parts linear low-density polyethylene, 0.5 parts aramid fiber, 120 parts aluminum hydroxide, 20 parts magnesium hydroxide, 1 part antioxidant 1024, 1.5 parts silane coupling agent, and 1 part lubricant.

[0091] The above materials are mixed evenly to obtain a homogeneous mixture; the Hack mixer is preheated to 130°C and the rotor speed is set to 40 r / min; the mixture is added to the Hack mixer and mixed for 15 min before being removed to obtain a high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material.

[0092] To test the performance of the prepared cable sheath material, the prepared cable sheath material was rolled at 120℃ using an open mill to prepare 1.3~1.5mm thin sheets; then, a flat vulcanizing machine was used to set the hot pressing temperature to 170℃ and the hot pressing pressure to 10MPa, and the 1.3~1.5mm thin sheets were preheated for 3~5 minutes before being prepared as test samples through the hot pressing process.

[0093] Example 4

[0094] A high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material, by weight, has the following raw material composition: 30 parts ethylene-vinyl acetate copolymer (EVA), 40 parts polyolefin elastomer (POE) (G6012), 30 parts metallocene polyethylene, 14 parts maleic anhydride grafted polyethylene, 10 parts linear low-density polyethylene, 2 parts aramid fiber, 120 parts aluminum hydroxide, 20 parts magnesium hydroxide, 1 part antioxidant 1024, 1.5 parts silane coupling agent, and 1 part lubricant.

[0095] The above materials are mixed evenly to obtain a homogeneous mixture; the Hack mixer is preheated to 130°C and the rotor speed is set to 40 r / min; the mixture is added to the Hack mixer and mixed for 15 min before being removed to obtain a high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material.

[0096] To test the performance of the prepared cable sheath material, the prepared cable sheath material was rolled at 120℃ using an open mill to prepare 1.3~1.5mm thin sheets; then, a flat vulcanizing machine was used to set the hot pressing temperature to 170℃ and the hot pressing pressure to 10MPa, and the 1.3~1.5mm thin sheets were preheated for 3~5 minutes before being prepared as test samples through the hot pressing process.

[0097] Example 5

[0098] A high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material, by weight, has the following raw material composition: 30 parts ethylene-vinyl acetate copolymer (EVA), 40 parts polyolefin elastomer (POE) (G6012), 30 parts metallocene polyethylene, 14 parts maleic anhydride grafted polyethylene, 10 parts linear low-density polyethylene, 5 parts aramid fiber, 120 parts aluminum hydroxide, 20 parts magnesium hydroxide, 1 part antioxidant 1024, 1.5 parts silane coupling agent, and 1 part lubricant.

[0099] The above materials are mixed evenly to obtain a homogeneous mixture; the Hack mixer is preheated to 130°C and the rotor speed is set to 40 r / min; the mixture is added to the Hack mixer and mixed for 15 min before being removed to obtain a high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material.

[0100] To test the performance of the prepared cable sheath material, the prepared cable sheath material was rolled at 120℃ using an open mill to prepare 1.3~1.5mm thin sheets; then, a flat vulcanizing machine was used to set the hot pressing temperature to 170℃ and the hot pressing pressure to 10MPa, and the 1.3~1.5mm thin sheets were preheated for 3~5 minutes before being prepared as test samples through the hot pressing process.

[0101] Comparative Example 1

[0102] A cable sheath material, by weight, comprises the following raw materials: 30 parts ethylene-vinyl acetate copolymer (EVA), 14 parts maleic anhydride grafted polyethylene, 10 parts linear low-density polyethylene, 30 parts metallocene polyethylene, 0.5 parts aramid fiber, 120 parts aluminum hydroxide, 20 parts magnesium hydroxide, 1 part antioxidant 1024, 1.5 parts silane coupling agent, and 1 part lubricant.

[0103] The above materials are mixed evenly to obtain a homogeneous mixture; the Hack mixer is preheated to 130°C and the rotor speed is set to 40 r / min; the mixture is added to the Hack mixer and mixed for 15 min before being removed to obtain the cable sheath material.

[0104] To test the performance of the prepared cable sheath material, the prepared cable sheath material was rolled at 120℃ using an open mill to prepare 1.3~1.5mm thin sheets; then, a flat vulcanizing machine was used to set the hot pressing temperature to 170℃ and the hot pressing pressure to 10MPa, and the 1.3~1.5mm thin sheets were preheated for 3~5 minutes before being prepared as test samples through the hot pressing process.

[0105] Comparative Example 2

[0106] A cable sheath material, by weight, comprises the following raw materials: 30 parts ethylene-vinyl acetate copolymer (EVA), 14 parts maleic anhydride grafted polyethylene, 10 parts linear low-density polyethylene, 30 parts metallocene polyethylene, 2 parts aramid fiber, 120 parts aluminum hydroxide, 20 parts magnesium hydroxide, 1 part antioxidant 1024, 1.5 parts silane coupling agent, and 1 part lubricant.

[0107] The above materials are mixed evenly to obtain a homogeneous mixture; the Hack mixer is preheated to 130°C and the rotor speed is set to 40 r / min; the mixture is added to the Hack mixer and mixed for 15 min before being removed to obtain the cable sheath material.

[0108] To test the performance of the prepared cable sheath material, the prepared cable sheath material was rolled at 120℃ using an open mill to prepare 1.3~1.5mm thin sheets; then, a flat vulcanizing machine was used to set the hot pressing temperature to 170℃ and the hot pressing pressure to 10MPa, and the 1.3~1.5mm thin sheets were preheated for 3~5 minutes before being prepared as test samples through the hot pressing process.

[0109] Comparative Example 3

[0110] A cable sheath material, by weight, comprises the following raw materials: 30 parts ethylene-vinyl acetate copolymer (EVA), 30 parts metallocene polyethylene, 14 parts maleic anhydride grafted polyethylene, 10 parts linear low-density polyethylene, 5 parts aramid fiber, 120 parts aluminum hydroxide, 20 parts magnesium hydroxide, 1 part antioxidant 1024, 1.5 parts silane coupling agent, and 1 part lubricant.

[0111] The above materials are mixed evenly to obtain a homogeneous mixture; the Hack mixer is preheated to 130°C and the rotor speed is set to 40 r / min; the mixture is added to the Hack mixer and mixed for 15 min before being removed to obtain the cable sheath material.

[0112] To test the performance of the prepared cable sheath material, the prepared cable sheath material was rolled at 120℃ using an open mill to prepare 1.3~1.5mm thin sheets; then, a flat vulcanizing machine was used to set the hot pressing temperature to 170℃ and the hot pressing pressure to 10MPa, and the 1.3~1.5mm thin sheets were preheated for 3~5 minutes before being prepared as test samples through the hot pressing process.

[0113] Comparative Example 4

[0114] A cable sheath material, by weight, has the following raw material composition: 30 parts ethylene-vinyl acetate copolymer (EVA), 30 parts metallocene polyethylene, 14 parts maleic anhydride grafted polyethylene, 10 parts linear low-density polyethylene, 120 parts aluminum hydroxide, 20 parts magnesium hydroxide, 1 part antioxidant 1024, 1.5 parts silane coupling agent, and 1 part lubricant.

[0115] The above materials are mixed evenly to obtain a homogeneous mixture; the Hack mixer is preheated to 130°C and the rotor speed is set to 40 r / min; the mixture is added to the Hack mixer and mixed for 15 min before being removed to obtain the cable sheath material.

[0116] To test the performance of the prepared cable sheath material, the prepared cable sheath material was rolled at 120℃ using an open mill to prepare 1.3~1.5mm thin sheets; then, a flat vulcanizing machine was used to set the hot pressing temperature to 170℃ and the hot pressing pressure to 10MPa, and the 1.3~1.5mm thin sheets were preheated for 3~5 minutes before being prepared as test samples through the hot pressing process.

[0117] Comparative Example 5

[0118] A cable sheath material, by weight, comprises the following raw materials: 30 parts ethylene-vinyl acetate copolymer (EVA), 20 parts polyolefin elastomer (POE) (G6012), 30 parts metallocene polyethylene, 14 parts maleic anhydride grafted polyethylene, 10 parts linear low-density polyethylene, 120 parts aluminum hydroxide, 20 parts magnesium hydroxide, 1 part antioxidant 1024, 1.5 parts silane coupling agent, and 1 part lubricant.

[0119] The above materials are mixed evenly to obtain a homogeneous mixture; the Hack mixer is preheated to 130°C and the rotor speed is set to 40 r / min; the mixture is added to the Hack mixer and mixed for 15 min before being removed to obtain the cable sheath material.

[0120] To test the performance of the prepared cable sheath material, the prepared cable sheath material was rolled at 120℃ using an open mill to prepare 1.3~1.5mm thin sheets; then, a flat vulcanizing machine was used to set the hot pressing temperature to 170℃ and the hot pressing pressure to 10MPa, and the 1.3~1.5mm thin sheets were preheated for 3~5 minutes before being prepared as test samples through the hot pressing process.

[0121] Comparative Example 6

[0122] A cable sheath material, by weight, comprises the following raw materials: 30 parts ethylene-vinyl acetate copolymer (EVA), 20 parts polyolefin elastomer (POE) (G6045), 30 parts metallocene polyethylene, 14 parts maleic anhydride grafted polyethylene, 10 parts linear low-density polyethylene, 120 parts aluminum hydroxide, 20 parts magnesium hydroxide, 1 part antioxidant 1024, 1.5 parts silane coupling agent, and 1 part lubricant.

[0123] The above materials are mixed evenly to obtain a homogeneous mixture; the Hack mixer is preheated to 130°C and the rotor speed is set to 40 r / min; the mixture is added to the Hack mixer and mixed for 15 min before being removed to obtain the cable sheath material.

[0124] To test the performance of the prepared cable sheath material, the prepared cable sheath material was rolled at 120℃ using an open mill to prepare 1.3~1.5mm thin sheets; then, a flat vulcanizing machine was used to set the hot pressing temperature to 170℃ and the hot pressing pressure to 10MPa, and the 1.3~1.5mm thin sheets were preheated for 3~5 minutes before being prepared as test samples through the hot pressing process.

[0125] Comparative Example 7

[0126] A cable sheath material, by weight, comprises the following raw materials: 30 parts ethylene-vinyl acetate copolymer (EVA), 20 parts polyolefin elastomer (POE) (PV7200), 30 parts metallocene polyethylene, 14 parts maleic anhydride grafted polyethylene, 10 parts linear low-density polyethylene, 120 parts aluminum hydroxide, 20 parts magnesium hydroxide, 1 part antioxidant 1024, 1.5 parts silane coupling agent, and 1 part lubricant.

[0127] The above materials are mixed evenly to obtain a homogeneous mixture; the Hack mixer is preheated to 130°C and the rotor speed is set to 40 r / min; the mixture is added to the Hack mixer and mixed for 15 min before being removed to obtain the cable sheath material.

[0128] To test the performance of the prepared cable sheath material, the prepared cable sheath material was rolled at 120℃ using an open mill to prepare 1.3~1.5mm thin sheets; then, a flat vulcanizing machine was used to set the hot pressing temperature to 170℃ and the hot pressing pressure to 10MPa, and the 1.3~1.5mm thin sheets were preheated for 3~5 minutes before being prepared as test samples through the hot pressing process.

[0129] Performance Evaluation

[0130] The cable sheath material test samples prepared in the above examples and comparative examples were placed in a laboratory environment at 23℃ and 45-55% relative humidity for one day to allow the samples to adjust to the environmental conditions. Following the standards of "GB / T 2406.2-2009 Determination of Combustion Behavior by Oxygen Index Method for Plastics" and "GB / T1040.3-2006 Determination of Tensile Properties of Plastics", corresponding samples were cut according to the standards, and the tensile strength, elongation at break, limiting oxygen index, and density of the materials were tested. The test results are shown below:

[0131] Table 1. Comparison of performance test results for Comparative Examples 5, 6, and 7

[0132]

[0133] The test results of Comparative Examples 5, 6, and 7 show that when the POE melt index is 1.2 g / 10 min (190℃ / 2.16 kg), the tensile strength and elongation at break of the cable sheath material reach relatively high levels. Performance decreases when the melt index is too low or too high. Therefore, selecting a polyolefin elastomer with a suitable melt index range, such as G6012, significantly improves the performance of the cable sheath material.

[0134] Table 1. Comparison of performance test results of Examples 1-5 and Comparative Examples 1-4

[0135]

[0136] As can be seen from Table 2, the cable sheath material provided in the examples has good strength, flexibility and flame retardancy, and low density; compared with the cable sheath material of Comparative Example 4, Example 1 has an 8.5% increase in tensile strength, a 75% increase in elongation, and a 3.7% decrease in density.

[0137] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material, characterized in that, By weight, it comprises the following components: 30-40 parts of ethylene-vinyl acetate copolymer; 10-40 parts of polyolefin elastomer; 30-40 parts of metallocene polyethylene; Aramid fiber 0.1~5 parts; 10-40 parts of linear low-density polyethylene; 5-15 parts of maleic anhydride graft compatibilizer; 120-150 parts of halogen-free flame retardant; Antioxidant 0.5~1.5 parts; 1-2 parts of coupling agent; 1-3 parts lubricant.

2. The high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material according to claim 1, characterized in that, The content of repeating units corresponding to vinyl acetate in the ethylene-vinyl acetate copolymer is 18~26wt%.

3. The high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material according to claim 1, characterized in that, The polyolefin elastomer is an ethylene-butene random copolymer polyolefin elastomer and / or an ethylene-octene random copolymer polyolefin elastomer; the melt index of the polyolefin elastomer measured at 190℃ and 2.16kg load is 0.5~15g / 10min; the melting temperature of the polyolefin elastomer is 40~65℃; the weight-average molecular weight of the polyolefin elastomer is 120000~300000g / mol; and the molecular weight distribution index of the polyolefin elastomer is 2~2.

4.

4. The high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material according to claim 1, characterized in that, The metallocene polyethylene, measured at 190°C and a load of 2.16 kg, has a melt index of 1–5 g / 10 min; the density of the metallocene polyethylene is 0.9–0.92 g / cm³. 3 .

5. The high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material according to claim 1, characterized in that, The aramid fiber is a para-aramid short-cut fiber; the fiber length of the aramid fiber is 3~8mm; the fiber diameter of the aramid fiber is 10~15μm.

6. The high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material according to claim 1, characterized in that, The linear low-density polyethylene (LLDPE) measured at 190°C and a load of 2.16 kg had a melt index of 3-4 g / 10 min; the density of the LLDPE was 0.9-0.93 g / cm³. 3 .

7. The high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material according to claim 1, characterized in that, The maleic anhydride graft compatibilizer is a polymer grafted with maleic anhydride groups. The main chain structure of the polymer is one or more of ethylene-vinyl acetate copolymer, linear low-density polyethylene, and polyolefin elastomer. The maleic anhydride grafting rate of the maleic anhydride graft compatibilizer is 0.8~1.1wt%.

8. The high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material according to claim 1, characterized in that, The halogen-free flame retardant comprises aluminum hydroxide and magnesium hydroxide; the mass ratio of aluminum hydroxide to magnesium hydroxide is (5~7):

1.

9. The high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material according to claim 1, characterized in that, The antioxidant is a hindered phenolic antioxidant and / or an aromatic amine antioxidant; And / or, the coupling agent is one or more of the following: silane coupling agent KH550, silane coupling agent KH570, silane coupling agent ZQ-172, and titanate coupling agent 131; And / or, the lubricant is one or more of paraffin wax, silicone wax, and polyethylene wax.

10. A method for preparing a high-strength, high-toughness polyolefin elastomer halogen-free flame-retardant cable sheath material according to any one of claims 1 to 9, characterized in that, Includes the following steps: Ethylene-vinyl acetate copolymer, polyolefin elastomer, metallocene polyethylene, aramid fiber, linear low-density polyethylene, maleic anhydride graft compatibilizer, halogen-free flame retardant, antioxidant, coupling agent and lubricant are compounded to obtain high-strength and high-toughness polyolefin elastomer halogen-free flame retardant cable sheath material.

Images