CN113736183B - A kind of anti-seismic low-smoke halogen-free flame retardant cable sheath material and its preparation method and application - Google Patents

Abstract

The invention provides an anti-shock, low-smoke, halogen-free and flame-retardant cable sheathing material and a preparation method and application thereof. In terms of mass percentage, the cable sheathing material includes 40-50% EPDM rubber, 1-5% EPDM Unsaturated acid, 5-10% polymer compatibilizer, 30-50% flame retardant, 1-2% vulcanizing agent, 0.5-1% vulcanization accelerator, 0.2-0.4% antioxidant, 5‑10% silica and 0.5‑0.8% antioxidant. The invention constructs a cable material with an ion-covalent double cross-linked network structure in the system through chemical cross-linking and ion coordination of metal cations and carboxyl, phosphate and other anionic groups in the inorganic flame retardant, wherein the covalent The valence cross-linked network ensures the stability of the material structure. The dissociation, bonding and dynamic exchange between anions and ions in the ionic cross-linked structure can consume the energy generated by vibration, and the material structure is stable under forced vibration conditions. , No cracking, good dimensional stability and so on.

Description

A kind of anti-seismic low-smoke halogen-free flame retardant cable sheath material and its preparation method and application

technical field

The invention belongs to the technical field of the field of polymer materials, and in particular relates to an anti-seismic low-smoke halogen-free flame retardant cable sheath material and a preparation method and application thereof.

Background technique

Cables for high-speed EMUs are the foundation and guarantee for the stable operation of high-speed trains. With the continuous increase in speed of high-speed railways, the requirements for the stability and safety of cables used in high-speed railways are also increasing. In order to ensure the continuous and stable power or signal transmission of the train cables during the high-speed operation of the locomotive, special performance requirements are put forward for the sheath materials of the cables. On the one hand, it needs to meet the basic performance requirements of halogen-free flame retardant, high strength, bending resistance, wear resistance, tear resistance, high dimensional stability, etc., on the other hand, it is also required that the cable sheath material be used under the vibration conditions of high-speed train operation. It can keep the structure and size stable and not crack, and provide guarantee for the stable structure of the cable and the stable operation of the high-speed train.

Regarding the research and development of the above-mentioned low-smoke halogen-free flame-retardant high-speed train cable sheathing materials for high-speed trains, some related invention patents have been disclosed so far, among which the patent number is CN 103214749 A, using modified sulfonated polyethylene, horse A thermoplastic polyurethane elastomer cable material is prepared by compounding lyric anhydride grafted polyolefin elastomer, thermoplastic polyurethane elastomer, flame retardant and other additives, which can meet the requirements of working at high temperature and has good flame retardant performance and mechanical properties.

However, the cable materials reported in these patents do not involve the design of the structural stability and anti-vibration performance of the cable sheath material during the forced vibration process of the cable.

SUMMARY OF THE INVENTION

In view of the above-mentioned defects of the prior art, the purpose of the present invention is to propose a shock-resistant low-smoke halogen-free flame retardant cable sheathing material and a preparation method thereof. Coordination, an ion-covalent double cross-linked network structure is constructed in the system, and the covalent cross-linked network ensures the stability of the material structure. The dynamic exchange characteristics between them can consume the energy generated by vibration, and have the characteristics of stable material structure, no cracking, and good dimensional stability under forced vibration conditions.

In order to achieve the above-mentioned purpose and other purposes, the present invention proposes a kind of anti-seismic low-smoke halogen-free flame retardant cable sheathing material, in terms of mass percentage, including:

Preferably, the third monomer of the EPDM rubber is ethylidene norbornene, and the mass percentage of the ethylidene norbornene is 0.5-9.0% of the EPDM rubber.

Preferably, the unsaturated acid includes one or more of acrylic acid and its derivatives, itaconic acid and its derivatives, unsaturated phosphoric acid and its derivatives.

Preferably, the polymer compatibilizer includes one or both of EPDM grafted glycidyl methacrylate compatibilizer and EPDM grafted maleic anhydride compatibilizer ; The graft ratio of the polymer compatibilizer is 1.0-3.5wt%.

Preferably, the flame retardant includes an inorganic flame retardant and a synergistic flame retardant; the inorganic flame retardant includes magnesium hydroxide and aluminum hydroxide; the synergistic flame retardant includes a metal borate; the The average particle size D50 of the flame retardant is 0.5-3 μm.

Preferably, the vulcanizing agent includes one or more of sulfur, sulfur-containing compounds, dicumyl peroxide, 2,5-dimethyl-2,5 bis(tert-butylperoxide)hexane.

Preferably, the vulcanization accelerator includes one or more of metal oxides, triallyl cyanurate, triallyl isocyanurate, and trimethylolpropane triacrylate.

Preferably, the antioxidant includes a main antioxidant and an auxiliary antioxidant, and the mass ratio of the main antioxidant and the auxiliary antioxidant is 1:1-2.

The present invention also provides a preparation method of the above-mentioned anti-seismic low-smoke halogen-free flame retardant cable sheath material, comprising the following steps:

Premix the flame retardant, antioxidant, white carbon black and anti-aging agent at a speed of 1000-2500 rpm for 2-4 minutes to obtain a primary mixed filler;

adding the unsaturated acid to the primary mixed filler, dispersing and mixing for 5-8 min at a rotational speed of 1500-2500 rpm, to obtain a modified mixed filler;

The modified mixed filler, EPDM rubber and polymer compatibilizer are mixed for 10 to 15 minutes, then a vulcanizing agent and a vulcanization accelerator are added, and the mixing is continued for 5 to 8 minutes, and the mixing temperature is 80 to 120 ° C to obtain a cable Sheath material.

In addition, the present invention also provides the application of the above-mentioned anti-seismic low-smoke halogen-free flame retardant cable sheath material in the preparation of high-speed train cable sheath.

As mentioned above, the anti-seismic low-smoke halogen-free flame retardant cable sheath material of the present invention has the following beneficial effects:

The cable sheath material of the invention introduces unsaturated acid, the double bond in the unsaturated acid and the polymer matrix produce chemical cross-linking effect, the anionic groups such as carboxyl group in the unsaturated acid and the metal cation of the inorganic flame retardant Ionic coordination is formed between them, thereby constructing an ion-covalent cross-linked network coexistence structure in the material, which improves the interfacial compatibility between the inorganic flame retardant hydroxide and the polymer matrix. On the one hand, the covalent cross-linked network ensures the stability of its structure; on the other hand, the dissociation and bonding between anions and cations in the ionic cross-linked structure and the dynamic exchange characteristics between ions can consume the energy generated by vibration, Therefore, the prepared cable sheath material is suitable for the vibration condition, and can be applied to prepare the cable sheath of the high-speed train, thereby providing a guarantee for the stable operation of the high-speed train. At the same time, the cable sheath material of the present invention has a tensile strength of 40±2MPa, a limiting oxygen index LOI% of more than 35, and oil resistance, aging resistance and environmental stress crack resistance.

Detailed ways

The embodiments of the present invention are described below through specific specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

When numerical ranges are given in the examples, it is to be understood that, unless otherwise indicated herein, both endpoints of each numerical range and any number between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in the present invention and those skilled in the art have mastered the prior art and the description of the present invention, and can also use the methods, equipment, and materials described in the embodiments of the present invention. Any methods, devices and materials similar or equivalent to those of the prior art can be used to implement the present invention.

Note that "%" and "part" shown in the description herein mean "% by mass" and "part by mass", respectively, unless otherwise specified.

The invention provides an anti-shock, low-smoke, halogen-free and flame-retardant cable sheathing material, which in terms of mass percentage, comprises 40-50% EPDM rubber, 1-5% unsaturated acid, 5-10% Polymer compatibilizer, 30-50% flame retardant, 1-2% vulcanizing agent, 0.5-1% vulcanization accelerator, 0.2-0.4% antioxidant, 5-10% silica and 0.5-0.8% antioxidant.

In a specific embodiment, ethylidene norbornene can be selected as the third monomer of the EPDM rubber, and the mass percentage of ethylidene norbornene is, for example, 0.5-9.0% of the 0.5%, 1.0%, 3.0%, 9.0%, etc. As the third monomer, ethylidene norbornene can not only improve the vulcanization speed of EPDM rubber, but also has the properties of ozone resistance, chemical resistance (solvent, acid, alkali, etc.), discharge resistance, water vapor resistance, etc. The applied cable jacket material can be used in more severe environments.

In a specific embodiment, the unsaturated acid may include, for example, one or more of acrylic acid and its derivatives, itaconic acid and its derivatives, unsaturated phosphoric acid and its derivatives, such as acrylic acid, such as Itaconic acid, for example, can be unsaturated phosphoric acid, for example, vinyl phosphoric acid.

In a specific embodiment, the flame retardant may include an inorganic flame retardant and a synergistic flame retardant; the inorganic flame retardant may include, for example, magnesium hydroxide and aluminum hydroxide; the synergistic flame retardant may include, for example, a metal Borate; the average particle size D50 of the flame retardant can be 0.5-3 μm, for example, 0.5 μm, 1.0 μm, 2.0 μm, and the like.

On the one hand, the double bond in the unsaturated acid can form a chemical cross-linking structure with the polymer matrix; Metal cations such as Mg ²⁺ and Al ³⁺ in inorganic flame retardants such as magnesium oxide and aluminum hydroxide form ionic coordination, thereby constructing an ion-covalent cross-linked network coexistence structure in the material.

In a specific embodiment, the macromolecular compatibilizer can include one of EPDM grafted glycidyl methacrylate compatibilizer and EPDM grafted maleic anhydride compatibilizer. or both. Specifically, for example, it can be ethylene propylene rubber grafted with maleic anhydride, and the maleic anhydride graft compatibilizer can make the material have high polarity and reactivity by introducing strong polar reactive groups, which can greatly improve the composite Compatibility of materials and dispersion of fillers, thereby improving the mechanical strength of composites. The graft ratio of the polymer compatibilizer can be 1.0-3.5wt%, for example, 1.0wt%, 1.5wt%, 2.0wt%, 3.0wt%, 3.5wt%. The melt index of the polymer compatibilizer can be 2.0-6.0g/10min (test condition, 190℃/2.16kg), such as 2.0g/10min, 4.0g/10min, 6.0g/10min; The density may be 0.80-1.10 g/cm ³ , for example 0.8 g/cm ³ , 0.9 g/cm ³ , 1.0 g/cm ³ , 1.1 g/cm ³ .

In a specific embodiment, the vulcanizing agent can be selected from one of sulfur, sulfur-containing compounds, dicumyl peroxide, 2,5-dimethyl-2,5 bis(tert-butyl peroxide) hexane or Various, for example, sulfur, for example, dicumyl peroxide, and another example is a mixture of dicumyl peroxide, 2,5-dimethyl-2,5 bis(tert-butylperoxide)hexane. The vulcanization accelerator can be selected from one or more of metal oxide, triallyl cyanurate, triallyl isocyanurate, trimethylolpropane triacrylate, such as tricyanuric acid triacrylate Allyl esters, such as triallyl isocyanurate, and also mixtures of metal oxides, triallyl cyanurate, triallyl isocyanurate.

In a specific embodiment, antioxidants may include primary antioxidants and secondary antioxidants, primary antioxidants such as tetrakis[beta-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid ] Pentaerythritol ester, auxiliary antioxidant such as tris(2,4-di-tert-butylphenyl)phosphite. Further, the mass ratio of the main antioxidant and the auxiliary antioxidant may be 1:1-2, specifically, 1:1, 1:2.

In a specific embodiment, the silica can be, for example, vapor-phase hydrophobic silica, and its average particle size D50 can be 0.9-2 μm, such as 0.9 μm, 1.1 μm, 1.5 μm, 2 μm, and the like. Fumed silica, commonly known as "nano silica", has high chemical purity, good dispersion performance, high temperature resistance and good electrical insulation. It is used in the cable sheathing material of the present invention and can well reinforce the mechanical properties of the material. , while improving the flame retardant and insulating properties of the material.

In a specific embodiment, the anti-aging agent is, for example, a hindered phenol type thermal-oxidative anti-aging agent, specifically, N,N'-bis-(3-(3,5-di-tert-butyl-4hydroxyphenyl) propionyl)hexamethylenediamine, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) or a mixture of both. More specifically, for example, N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine, 1,3,5-tris(4-tert-butyl) -3-Hydroxy-2,6-dimethylbenzyl) in a mass ratio of 1:1.

In addition, the present invention also provides the above-mentioned preparation method of the anti-seismic low-smoke halogen-free flame retardant cable sheath material, comprising the following steps:

S1 Premix flame retardant, antioxidant, white carbon black and antioxidant at a speed of 1000-2500rpm for 2-4min to obtain primary mixed filler;

S2 adding the unsaturated acid to the primary mixed filler, dispersing and mixing for 5-8 min at a rotational speed of 1500-2500 rpm, to obtain a modified mixed filler;

S3 mix the modified mixed filler, EPDM rubber and polymer compatibilizer for 10-15min, then add vulcanizing agent and vulcanization accelerator, and continue to mix for 5-8min, and the mixing temperature is 80-120 ℃ to obtain Anti-vibration low-smoke halogen-free flame retardant cable jacket material.

In a specific embodiment, in step S1, the premixing process is performed in a high-speed mixer. In step S2, the unsaturated acid is uniformly added dropwise to the primary mixed filler by dropwise addition. The kneading in step S3 is carried out in an internal mixer.

The present invention will be further described in detail below with reference to specific examples, but the protection scope of the present invention is not limited to these examples.

Each raw material used in the embodiment is introduced as follows:

The mass fraction of the third monomer ethylidene norbornene (ENB) in the EPDM rubber is 0.5wt%, and the Mooney viscosity [ML 1+4125℃] is 20;

Under the test conditions of 280°C/2.16kg, the EPDM grafted maleic anhydride melt index is 15-25g/10min, the Shore A hardness is 55-90, and the density is 0.80-1.10g/cm ³ ;

Among the flame retardants, the inorganic flame retardants are magnesium hydroxide and aluminum hydroxide, the synergistic flame retardant is zinc borate, and the average particle size D50 of the flame retardant is 0.5-3 μm.

The vulcanizing agent is dicumyl peroxide (DCP); the vulcanization accelerator triallyl isocyanurate (TAIC);

Among the antioxidants, the main antioxidant is tetrakis[beta-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] pentaerythritol ester, and the auxiliary antioxidant is tris(2,4-di-tert-butyl) (base phenyl) phosphite, mix according to mass ratio 1:1;

Silica is gas phase hydrophobic silica with a fineness of 5000 mesh and a specific surface area of 200m/g.

The antioxidant is N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine, 1,3,5-tris(4-tert-butyl-3- Hydroxy-2,6-dimethylbenzyl) is mixed according to the mass ratio of 1:1;

Example 1

(1) Weigh each raw material according to the gram weight of each component listed in Table 1, add flame retardant magnesium hydroxide, aluminum hydroxide, zinc borate, antioxidant tetrakis[β-(3,5-di-tert-butyl) yl-4-hydroxyphenyl) propionate] pentaerythritol ester, tris(2,4-di-tert-butylphenyl) phosphite, silica, antioxidant N,N'-bis-(3-(3, 5-Di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) into high-speed mixing In the machine, the premixed material was premixed at 2000 rpm for 3 min to obtain the primary mixed filler.

(2) 1 g of acrylic acid was evenly added dropwise to the primary mixed filler, and the mixing was continued for 5 min at a speed of 2000 rpm, so that the acrylic acid and the inorganic flame retardant had sufficient ionic coordination to obtain a modified mixed filler.

(3) Set the mixing temperature of the internal mixer to 100°C, place the modified mixed filler, EPDM rubber and polymer compatibilizer EPDM rubber grafted with maleic anhydride in the internal mixer, mix After kneading for 10-15min, add vulcanizing agent dicumyl peroxide (DCP) and vulcanizing accelerator triallyl isocyanurate (TAIC), and continue to knead for 5-8min to obtain cable sheath material.

In order to test the properties of the cable sheathing material, the prepared cable sheathing material was subjected to hot pressing vulcanization on a parallel plate vulcanizer, the hot pressing pressure was 10MPa, the temperature was 180°C, and the vulcanization time was 20min to obtain the test specimens.

Example 2

(1) Weigh each raw material according to the gram weight of each component listed in Table 1, add flame retardant magnesium hydroxide, aluminum hydroxide, zinc borate, antioxidant tetrakis[β-(3,5-di-tert-butyl) yl-4-hydroxyphenyl) propionate] pentaerythritol ester, tris(2,4-di-tert-butylphenyl) phosphite, silica, antioxidant N,N'-bis-(3-(3, 5-Di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) into high-speed mixing In the machine, the premixed material was premixed at 2000 rpm for 3 min to obtain the primary mixed filler.

(2) 3g of acrylic acid was evenly added dropwise to the primary mixed filler, and the mixing was continued for 5 minutes at a speed of 2000 rpm, so that the acrylic acid and the inorganic flame retardant had sufficient ionic coordination to obtain a modified mixed filler.

(3) Set the mixing temperature of the internal mixer to 100°C, place the modified mixed filler, EPDM rubber and polymer compatibilizer EPDM rubber grafted with maleic anhydride in the internal mixer, mix After kneading for 10-15min, add vulcanizing agent dicumyl peroxide (DCP) and vulcanizing accelerator triallyl isocyanurate (TAIC), and continue to knead for 5-8min to obtain cable sheath material.

In order to test the properties of the cable sheathing material, the prepared cable sheathing material was subjected to hot pressing vulcanization on a parallel plate vulcanizer, the hot pressing pressure was 10MPa, the temperature was 180°C, and the vulcanization time was 20min to obtain the test specimens.

Example 3

(1) Weigh each raw material according to the gram weight of each component listed in Table 1, add flame retardant magnesium hydroxide, aluminum hydroxide, zinc borate, antioxidant tetrakis[β-(3,5-di-tert-butyl) yl-4-hydroxyphenyl) propionate] pentaerythritol ester, tris(2,4-di-tert-butylphenyl) phosphite, silica, antioxidant N,N'-bis-(3-(3, 5-Di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) into high-speed mixing In the machine, the premixed material was premixed at 2000 rpm for 3 min to obtain the primary mixed filler.

(2) Add 1 g of vinyl phosphoric acid dropwise to the primary mixed filler evenly, and continue to mix for 5 minutes at a speed of 2000 rpm, so that the vinyl phosphoric acid and the inorganic flame retardant have sufficient ionic coordination to obtain a modified mixed filler.

(3) Set the mixing temperature of the internal mixer to 100°C, place the modified mixed filler, EPDM rubber and polymer compatibilizer EPDM rubber grafted with maleic anhydride in the internal mixer, mix After kneading for 10-15min, add vulcanizing agent dicumyl peroxide (DCP) and vulcanizing accelerator triallyl isocyanurate (TAIC), and continue to knead for 5-8min to obtain cable sheath material.

In order to test the properties of the cable sheathing material, the prepared cable sheathing material was subjected to hot pressing vulcanization on a parallel plate vulcanizer, the hot pressing pressure was 10MPa, the temperature was 180°C, and the vulcanization time was 20min to obtain the test specimens.

Example 4

(1) Weigh each raw material according to the gram weight of each component listed in Table 1, add flame retardant magnesium hydroxide, aluminum hydroxide, zinc borate, antioxidant tetrakis[β-(3,5-di-tert-butyl) yl-4-hydroxyphenyl) propionate] pentaerythritol ester, tris(2,4-di-tert-butylphenyl) phosphite, silica, antioxidant N,N'-bis-(3-(3, 5-Di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) into high-speed mixing In the machine, the premixed material was premixed at 2000 rpm for 3 min to obtain the primary mixed filler.

(2) 3g of vinyl phosphoric acid was evenly added dropwise to the primary mixed filler, and the mixing was continued for 5 minutes at a speed of 2000 rpm, so that the vinyl phosphoric acid and the inorganic flame retardant had sufficient ionic coordination to obtain a modified mixed filler.

(3) Set the mixing temperature of the internal mixer to 100°C, place the modified mixed filler, EPDM rubber and polymer compatibilizer EPDM rubber grafted with maleic anhydride in the internal mixer, mix After kneading for 10-15min, add vulcanizing agent dicumyl peroxide (DCP) and vulcanizing accelerator triallyl isocyanurate (TAIC), and continue to knead for 5-8min to obtain cable sheath material.

In order to test the properties of the cable sheathing material, the prepared cable sheathing material was subjected to hot pressing vulcanization on a parallel plate vulcanizer, the hot pressing pressure was 10MPa, the temperature was 180°C, and the vulcanization time was 20min to obtain the test specimens.

Comparative ratio

(1) Weigh each raw material according to the gram weight of each component listed in Table 1, add flame retardant magnesium hydroxide, aluminum hydroxide, zinc borate, antioxidant tetrakis[β-(3,5-di-tert-butyl) yl-4-hydroxyphenyl) propionate] pentaerythritol ester, tris(2,4-di-tert-butylphenyl) phosphite, silica, antioxidant N,N'-bis-(3-(3, 5-Di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine, 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) into high-speed mixing In the machine, the premixed material was premixed at 2000 rpm for 3 min to obtain the primary mixed filler.

(3) Set the mixing temperature of the internal mixer to 100°C, place the primary mixed filler, EPDM rubber and polymer compatibilizer EPDM rubber grafted with maleic anhydride in the internal mixer, and mix After 10-15 minutes, add the vulcanizing agent dicumyl peroxide (DCP) and the vulcanization accelerator triallyl isocyanurate (TAIC), and continue to mix for 5-8 minutes to obtain the cable sheath material.

In order to test the properties of the cable sheathing material, the prepared cable sheathing material was subjected to hot pressing vulcanization on a parallel plate vulcanizer, the hot pressing pressure was 10MPa, the temperature was 180°C, and the vulcanization time was 20min to obtain the test specimens.

Table 1 Composition of raw materials of Examples 1-4 and Comparative Examples (unit: grams)

Performance Testing

The main properties of the cable sheathing materials prepared in Examples 1-4 and Comparative Examples are shown in Table 1.

Table 1 Main properties of the cable sheathing materials of Examples 1-4 and Comparative Examples

Through the performance comparison between Examples 1-4 in Table 2 and the comparative example, it can be found that: the introduction of unsaturated acid into the material, through the ionic coordination of metal cations and anionic groups such as carboxyl and phosphate in the inorganic flame retardant, and chemical The covalent cross-linked structure formed by cross-linking can build a cable material with an ion-covalent double cross-linked network structure in the system, which significantly improves the compatibility between the flame retardant and the EPDM rubber, and improves the material The mechanical properties and oil resistance improve the flame retardant effect of the hydroxide flame retardant and enhance the halogen-free flame retardant performance of the cable sheath material. Since the inorganic mineral filler itself has the characteristics of high heat resistance, gas barrier, electrical insulation, etc., after the inorganic mineral filler is introduced into the material, the volume resistivity of the material is further improved, thereby improving the insulation performance. In addition, the dynamic exchange of cross-linking formed by the ionic cross-linking structure in the material dissipates the energy generated during forced vibration, which provides a basis and guarantee for the structural stability of the material and the dimensional stability of the sheath. The cable sheath made of the material has the characteristics of no cracking and good dimensional stability under the vibration condition of the high-speed train, which provides a guarantee for the stable operation of the high-speed train.

The above examples are intended to illustrate the disclosed embodiments of the present invention, and should not be construed as limiting the present invention. Furthermore, various modifications set forth herein and variations in the methods and compositions of the invention will be apparent to those skilled in the art without departing from the scope and spirit of the invention. Although the present invention has been described in detail in conjunction with various specific preferred embodiments of the present invention, it should be understood that the present invention should not be limited to these specific embodiments. Indeed, various modifications as described above which are obvious to those skilled in the art to obtain the invention are intended to be included within the scope of the present invention.

Claims (9)

1. an anti-shock low-smoke halogen-free flame retardant cable sheathing material, is characterized in that, in mass percentage, comprising: EPDM 40-50 % Unsaturated acid 1-5 % Polymer Compatibilizer 5-10 % Flame Retardant 30-50 % Vulcanizing agent 1-2 % Vulcanization accelerator 0.5-1 % Antioxidant 0.2-0.4 % Silica 5-10 % Anti-aging agent 0.5-0.8%; Wherein, the unsaturated acid includes one or more of unsaturated phosphoric acid and its derivatives; the flame retardant includes an inorganic flame retardant and a synergistic flame retardant; the inorganic flame retardant includes magnesium hydroxide and aluminum hydroxide; the synergistic flame retardant includes metal borates. 2. The anti-vibration low-smoke halogen-free flame retardant cable sheath material according to claim 1, wherein the third monomer of the EPDM rubber is ethylidene norbornene, and the ethylidene norbornene The mass percentage content of olefin is 0.5-9.0% of the EPDM rubber. 3. The anti-vibration low-smoke halogen-free flame retardant cable sheath material according to claim 1, wherein the polymer compatibilizer comprises EPDM grafted glycidyl methacrylate compatibilizer , one or both of EPDM grafted maleic anhydride compatibilizers; the graft ratio of the polymer compatibilizer is 1.0-3.5wt%. 4 . The anti-seismic low-smoke halogen-free flame retardant cable sheath material according to claim 1 , wherein the average particle size D50 of the flame retardant is 0.5-3 μm. 5 . 5. The anti-vibration low-smoke halogen-free flame retardant cable sheath material according to claim 1, wherein the vulcanizing agent comprises sulfur, sulfur-containing compounds, dicumyl peroxide, 2,5-dimethyl - One or more of 2,5 bis(tert-butylperoxide)hexane. 6. The anti-vibration low-smoke halogen-free flame retardant cable sheath material according to claim 1, wherein the vulcanization accelerator comprises metal oxide, triallyl cyanurate, triallyl isotri One or more of polycyanate and trimethylolpropane triacrylate. 7. The anti-vibration low-smoke halogen-free flame retardant cable sheath material according to claim 1, wherein the antioxidant comprises a main antioxidant and an auxiliary antioxidant, and the main antioxidant and the auxiliary antioxidant The mass ratio of the oxygen agent is 1:1~2. 8. the preparation method of the anti-seismic low-smoke halogen-free flame retardant cable sheath material according to claim 1, is characterized in that, comprises the steps: The flame retardant, antioxidant, silica and antioxidant are premixed at 1000-2500 rpm for 2-4 min to obtain the primary mixed filler; adding the unsaturated acid to the primary mixed filler, dispersing and mixing for 5-8 min at a rotational speed of 1500-2500 rpm, to obtain a modified mixed filler; Mix the modified mixed filler, EPDM rubber and polymer compatibilizer for 10~15 minutes, then add vulcanizing agent and vulcanization accelerator, and continue mixing for 5~8 minutes, and the mixing temperature is 80~120℃. Get the cable jacket material. 9. Application of the anti-seismic low-smoke halogen-free flame retardant cable sheath material according to any one of claims 1 to 7 in the preparation of high-speed train cable sheath.