High-temperature-resistant low-halogen cable material as well as preparation method and application thereof

Abstract

The invention provides a high-temperature-resistant low-halogen cable material and a preparation method and application thereof.The high-temperature-resistant low-halogen cable material is prepared from, by mass, 20-40 parts of ethylene-vinyl acetate copolymer, 40-60 parts of polyethylene, 5-20 parts of butadiene-based polymer, 5-20 parts of thermoplastic elastomer and 1-10 parts of compatilizer, the halogen-free flame retardant is prepared from the following components in parts by weight: 20-30 parts of vinyl-containing oligomeric silsesquioxane, 2-10 parts of alkenyl-containing oligomeric silsesquioxane, 0.1-4 parts of a cross-linking agent, 0.1-4 parts of an assistant cross-linking agent and 40-100 parts of a halogen According to the high-temperature-resistant low-halogen cable material disclosed by the invention, all the components are designed and compounded, so that the components cooperate with one another, and a specific three-dimensional cross-linked network structure is formed in the cable material, so that the high-temperature-resistant low-halogen cable material has excellent mechanical properties, high-temperature aging resistance and humidity and heat resistance, and also has excellent performance in the aspects of flame retardance, weather resistance and UV aging resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of cable materials, and in particular relates to a high-temperature resistant low-halogen cable material and a preparation method and application thereof. Background Art

[0002] With the advancement of science and technology and the rapid development of the economy, electricity has become an indispensable resource for social development and people's lives. The performance of cable materials has a direct impact on the stable operation of the power system. At present, most cable materials are made of polyvinyl chloride (PVC). PVC wires and cables have the characteristics of low price, light weight, sufficient raw materials, good mechanical properties and electrical insulation, but they are prone to fire accidents when the current is overloaded, and the large amount of smoke and toxic smoke (mainly hydrogen chloride) released during the combustion of PVC not only has a serious impact on personnel health, but also has corrosive effects on facilities. Therefore, it is very important to develop low-halogen or halogen-free environmentally friendly cable materials. In addition, with the continuous popularization of green energy, the application of high-temperature resistant cables in wind power generation, solar power generation and other fields has gradually increased. In the future development process, high-temperature resistant cables will become an indispensable part of the power system and contribute to the construction of an efficient, stable and reliable power system.

[0003] In recent years, polyethylene (PE) and ethylene-vinyl acetate copolymer (EVA) have been widely used in the preparation of cable materials, gradually replacing PVC and becoming typical products of low-halogen cable materials. However, materials such as polyethylene and EVA have obvious limitations in high temperature environments and usually require modification.

[0004] CN117659540A discloses a high temperature resistant flame retardant polyethylene cable material, the raw materials for preparation include: 67-85.5% high density polyethylene, 5-10% nano aluminum trihydrate oxide, 5-10% ammonium phosphate, 2-5% expanded graphite, 1-3% silane coupling agent, 1-3% antioxidant, 0.5-2% ultraviolet absorber. The cable material adds nano aluminum trihydrate oxide and ammonium phosphate as high efficiency flame retardants, uses expanded graphite as a carbon source, can effectively prevent the burning of materials under high temperature conditions, and improves the overall safety performance of the cable.

[0005] CN117316516A discloses a ceramic high temperature resistant cable, comprising a conductor, an insulating layer, a flame retardant layer and a protective layer, wherein the insulating layer comprises the following components: 60-70 parts of linear low density polyethylene, 30-40 parts of ethylene-vinyl acetate copolymer, 5-10 parts of filler, 1-5 parts of compatibilizer, and 1-3 parts of antioxidant; the flame retardant layer comprises the following components: 60-70 parts of ethylene-vinyl acetate copolymer and 1-5 parts of flame retardant; the protective layer comprises the following components: 60-70 parts of ultra-high molecular weight polyethylene, 30-40 parts of ethylene-vinyl acetate copolymer, 5-10 parts of filler, 1-5 parts of compatibilizer and 1-3 parts of antioxidant; through the design and coordination of the three-layer structure, the mechanical properties and high temperature resistance of the ceramic high temperature resistant cable are improved.

[0006] CN106832507A discloses a heat-resistant and heat-conductive polyethylene cable material, comprising the following components: 100-120 parts of polyethylene, 30-50 parts of silicone rubber, 100-140 parts of filler, 2-4 parts of epoxy soybean oil, 2-4 parts of tributyl citrate, 20-40 parts of nano magnesium hydroxide, 1-5 parts of zinc borate, 0.8-1.2 parts of dicumyl peroxide, 0.2-0.4 parts of zinc oxide, 0.3-0.5 parts of stearic acid, 2-4 parts of maleic anhydride grafted compatibilizer, 4-6 parts of Ca / Zn composite stabilizer, 0.1-0.4 parts of antioxidant BHT, and 2-4 parts of paraffin. The material has good performance in terms of heat resistance, thermal conductivity and mechanical properties.

[0007] Existing research on cable materials mainly focuses on flame retardancy and high temperature resistance related to flame retardancy, but lacks sufficient attention to the aging resistance of cable materials in harsh working environments such as high temperature and high humidity. Current cable materials cannot well meet the continuous and stable working requirements of high temperature resistant cables. Based on this, developing a low-halogen environmentally friendly cable material with excellent high temperature aging resistance and moisture and heat resistance is the research focus in this field. Summary of the invention

[0008] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a high-temperature resistant low-halogen cable material and a preparation method and application thereof. Through the design and compounding of each component, a dense and stable cross-linking system can be formed, so that the high-temperature resistant low-halogen cable material has excellent mechanical properties, high-temperature aging resistance, moisture and heat resistance and salt spray corrosion resistance, and at the same time has excellent flame retardancy, which can fully meet the continuous and stable working requirements of high-temperature resistant cables.

[0009] To achieve this object, the present invention adopts the following technical solutions:

[0010] In a first aspect, the present invention provides a high temperature resistant low halogen cable material, wherein the raw materials for preparing the high temperature resistant low halogen cable material include the following components in parts by mass:

[0011]

[0012] In the preparation raw materials of the present invention, the compound of ethylene-vinyl acetate copolymer (EVA) and polyethylene (PE) is used as the matrix material, and a butadiene-based polymer, a thermoplastic elastomer, a crosslinking agent and a crosslinking aid are matched, and a specific crosslinking network can be formed through a crosslinking reaction of a free radical mechanism, a high degree of crosslinking is obtained, and the mechanical properties, high temperature resistance and moisture and heat resistance of the cable material are synergistically improved. The alkenyl-containing oligomeric silsesquioxane contains a Si-O-Si skeleton structure, which has flame retardant and heat-insulating properties on the one hand, and can synergistically exert a flame retardant effect with a halogen-free flame retardant; on the other hand, it contains an alkenyl functional group, which can react chemically with an organic system (including a butadiene-based polymer, a crosslinking aid, polyethylene and EVA, etc.), and the Si-O-Si skeleton structure is embedded in the crosslinking network of the polymer, further improving the mechanical properties and high temperature stability of the cable material, while being able to block water vapor intrusion and improve the moisture resistance and moisture and heat resistance of the cable material. The present invention forms a specific three-dimensional cross-linked network structure in the cable material through the design and mutual compounding of components, so that the high temperature resistant low halogen cable material has excellent mechanical properties, high temperature aging resistance and moisture and heat resistance, and also has excellent performance in flame retardancy and weather resistance, and can fully meet the continuous and stable working requirements of high temperature resistant cables.

[0013] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. Through the following preferred technical solutions, the objectives and beneficial effects of the present invention can be better achieved and realized.

[0014] In the raw materials for preparing the high temperature resistant and low halogen cable material provided by the present invention, the mass parts of the ethylene-vinyl acetate copolymer are 20-40 parts, for example, it can be 22 parts, 25 parts, 28 parts, 30 parts, 32 parts, 35 parts or 38 parts, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the said range.

[0015] The mass proportion of the polyethylene is 40-60 parts, for example, it can be 42 parts, 45 parts, 48 ​​parts, 50 parts, 52 parts, 55 parts or 58 parts, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0016] The mass parts of the butadiene-based polymer are 5-20 parts, for example, 6 parts, 8 parts, 10 parts, 12 parts, 14 parts, 15 parts, 16 parts or 18 parts, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the said range.

[0017] The mass proportion of the thermoplastic elastomer is 5-20 parts, for example, 6 parts, 8 parts, 10 parts, 12 parts, 14 parts, 15 parts, 16 parts or 18 parts, as well as specific values ​​between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific points included in the range.

[0018] The mass fraction of the compatibilizer is 1-10 parts, for example, it can be 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts or 9 parts, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0019] The mass fraction of the alkenyl-containing oligomeric silsesquioxane is 2-10 parts, for example, it can be 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts or 9 parts, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the said range.

[0020] The mass fraction of the cross-linking agent is 0.1-4 parts, for example, it can be 0.2 parts, 0.5 parts, 0.8 parts, 1 parts, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts, 2.2 parts, 2.5 parts, 2.8 parts, 3 parts, 3.2 parts, 3.5 parts or 3.8 parts, as well as specific values ​​between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific points included in the range.

[0021] The weight percentage of the auxiliary cross-linking agent is 0.1-4 parts, for example, it can be 0.2 parts, 0.5 parts, 0.8 parts, 1 parts, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts, 2.2 parts, 2.5 parts, 2.8 parts, 3 parts, 3.2 parts, 3.5 parts or 3.8 parts, as well as specific values ​​between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific points included in the range.

[0022] The mass fraction of the halogen-free flame retardant is 40-100 parts, for example, it can be 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts, 80 parts, 85 parts, 90 parts or 95 parts, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0023] Preferably, the melt index of the ethylene-vinyl acetate copolymer at 190°C and 2.16kg is 1-50g / 10min, for example, 2g / 10min, 5g / 10min, 10g / 10min, 15g / 10min, 18g / 10min, 20g / 10min, 22g / 10min, 25g / 10min, 28g / 10min, 30g / 10min, 32g / 10min, 35g / 10min, 38g / 10min, 40g / 10min or 45g / 10min, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0024] Optionally, the mass percentage of structural units based on vinyl acetate in the ethylene-vinyl acetate copolymer is 5-50%, for example, it can be 8%, 10%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, 32%, 35%, 38%, 40%, 42%, 45% or 48%, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0025] Preferably, the polyethylene includes any one of linear low-density polyethylene, high-density polyethylene, and metallocene polyethylene, or a combination of at least two thereof, and high-density polyethylene (HDPE) is further preferred.

[0026] As a preferred technical solution of the present invention, the polyethylene adopts HDPE, which has high hardness, excellent tensile strength, toughness and creep properties, and high chemical stability. HDPE and EVA are compounded as the matrix material, so that the high temperature resistant low halogen cable material has excellent mechanical properties and processing properties.

[0027] Preferably, the butadiene-based polymer comprises polybutadiene and / or butadiene-styrene copolymer.

[0028] Preferably, the number average molecular weight of the butadiene-based polymer is 1000-10000, for example, it may be 2000, 3000, 4000, 5000, 6000, 7000, 8000 or 9000, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0029] Preferably, the butadiene-based polymer comprises a structural unit represented by formula I;

[0030]

[0031] Preferably, the molar percentage of the structural unit represented by formula I in the butadiene-based polymer is 25-90%, for example, it can be 25%, 30%, 35%, 40%, 45%, 50%, 52%, 55%, 60%, 65%, 70%, 75%, 80%, 85% or 88%, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and 35-90% is further preferred.

[0032] In the present invention, the butadiene-based polymer contains a 1,2-vinyl structural unit shown in Formula I, and the vinyl in the side chain has a high reactivity, and can undergo a free radical crosslinking reaction with a co-crosslinking agent, a thermoplastic elastomer, polyethylene, EVA, and an olefin-containing oligomeric silsesquioxane under the action of a crosslinking agent, forming a specific three-dimensional crosslinked network structure in the cable material, thereby giving the high-temperature resistant and low-halogen cable material excellent mechanical properties, high-temperature aging resistance, and wet heat resistance. If the 1,2-vinyl structural unit shown in Formula I is not contained or its content is too low, the crosslinking degree will be reduced, resulting in a decrease in the heat aging resistance and wet heat resistance of the cable material.

[0033] Preferably, the thermoplastic elastomer comprises ethylene-octene copolymer (POE).

[0034] Preferably, the melt index of the thermoplastic elastomer (preferably POE) at 190°C and 2.16kg is 1-20g / 10min, for example, it can be 2g / 10min, 3g / 10min, 4g / 10min, 5g / 10min, 6g / 10min, 7g / 10min, 8g / 10min, 9g / 10min, 10g / 10min, 12g / 10min, 14g / 10min, 15g / 10min, 16g / 10min or 18g / 10min, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and 1.2-8g / 10min is further preferred.

[0035] Preferably, the mass ratio of the thermoplastic elastomer to the butadiene-based polymer is 1:(1.2-3), for example, it can be 1:1.3, 1:1.5, 1:1.6, 1:1.8, 1:2, 1:2.2, 1:2.4, 1:2.5, 1:2.6, 1:2.8, etc.

[0036] In the present invention, the butadiene-based polymer can provide abundant chemical crosslinking sites, which is helpful to improve the aging resistance and corrosion resistance of the cable material; the thermoplastic elastomer (preferably POE) has excellent flexibility, viscoelasticity and processing performance. By controlling the mass ratio of the thermoplastic elastomer to the butadiene-based polymer to be 1: (1.2-3), the high temperature resistant low halogen cable material can achieve an excellent balance between processing performance, mechanical properties, high temperature aging resistance, moisture and heat resistance and weather resistance. If the mass ratio of the two exceeds the aforementioned range, it will affect the performance balance of the cable material. Too much butadiene-based polymer will affect the flexibility and processing performance of the cable material, and too much thermoplastic elastomer will reduce the high temperature resistance and moisture and heat resistance to a certain extent.

[0037] Preferably, the compatibilizer includes any one of maleic anhydride grafted polyethylene, maleic anhydride grafted polypropylene, and maleic anhydride grafted ethylene-vinyl acetate copolymer, or a combination of at least two thereof.

[0038] Preferably, the alkenyl-containing oligomeric silsesquioxane has a polyhedral structure, and is preferably an alkenyl-containing cage-shaped oligomeric silsesquioxane.

[0039] Preferably, the alkenyl-containing oligomeric silsesquioxane includes any one of octavinyl cage-type oligomeric silsesquioxane, octamethacrylate cage-type oligomeric silsesquioxane, octaacrylate cage-type oligomeric silsesquioxane, octaacryloxy cage-type oligomeric silsesquioxane, octamethacryloxy cage-type oligomeric silsesquioxane, and methacryloxypropyl cage-type polysilsesquioxane, or a combination of at least two thereof.

[0040] Preferably, the cross-linking agent comprises an organic peroxide, and further preferably any one or a combination of at least two of isopropylbenzene hydroperoxide, di-tert-butyl peroxide, diisopropylbenzene hydroperoxide, dibenzoyl peroxide, cyclohexanone peroxide, tert-butyl perbenzoate, tert-butyl peracetate, tert-amyl peroxy (2-ethylhexyl) carbonate, di (4-methylbenzoyl) peroxide, 2,5-dimethyl-2,5-di-tert-butyl peroxide ethane, and tert-butyl peroxy-3,5,5-trimethylhexanoate.

[0041] Preferably, the auxiliary cross-linking agent is a compound containing at least 2 (≥2, such as 2, 3, 4, 5, 6, etc.) unsaturated groups (such as alkenyl groups).

[0042] Preferably, the auxiliary cross-linking agent includes any one of pentaerythritol triacrylate, triallyl isocyanurate, trimethylolpropane trimethacrylate, trimethylolpropane trimethacrylate, ethoxylated trimethylolpropane triacrylate, tri(1,2-propylene glycol) diacrylate, tri(2-hydroxyethyl)isocyanuric acid triacrylate, propoxylated trimethylolpropane triacrylate, or a combination of at least two thereof;

[0043] Preferably, the halogen-free flame retardant includes any one of antimony trioxide, aluminum hydroxide, and magnesium hydroxide, or a combination of at least two of them.

[0044] Preferably, the preparation raw materials further include any one of a lubricant, a silane coupling agent, a stabilizer, an ultraviolet absorber, and an antioxidant, or a combination of at least two thereof.

[0045] Preferably, the preparation raw material also includes 0.1-5 parts of lubricant by mass, and the mass parts of the lubricant can be 0.2 parts, 0.5 parts, 0.8 parts, 1 parts, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts, 2.2 parts, 2.5 parts, 2.8 parts, 3 parts, 3.5 parts, 4 parts or 4.5 parts, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0046] Preferably, the lubricant includes any one of silicone masterbatch, silicone phenol, polyethylene wax, or a combination of at least two thereof.

[0047] Preferably, the preparation raw materials further include 0.1-5 parts of a silane coupling agent by mass, and the mass parts of the silane coupling agent can be 0.2 parts, 0.5 parts, 0.8 parts, 1 parts, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts, 2.2 parts, 2.5 parts, 2.8 parts, 3 parts, 3.5 parts, 4 parts or 4.5 parts, as well as specific points between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific points included in the range.

[0048] Preferably, the silane coupling agent includes any one of an alkenyl-containing silane coupling agent, an epoxy silane coupling agent, an amino silane coupling agent, and a mercapto silane coupling agent, or a combination of at least two thereof.

[0049] Preferably, the silane coupling agent includes any one of γ-(methacryloyloxy)propyltrimethoxysilane, vinyltriethoxysilane, vinyltrimethoxysilane, methacryloxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, and γ-aminoethylaminopropyltrimethoxysilane, or a combination of at least two thereof.

[0050] Preferably, the preparation raw materials also include 0.1-5 parts of stabilizer by mass, and the mass parts of the stabilizer can be 0.2 parts, 0.5 parts, 0.8 parts, 1 parts, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts, 2.2 parts, 2.5 parts, 2.8 parts, 3 parts, 3.5 parts, 4 parts or 4.5 parts, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0051] Preferably, the stabilizer includes any one of zinc stearate, calcium stearate, and pentaerythritol tetrakis(β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) or a combination of at least two thereof.

[0052] Preferably, the preparation raw materials further include 0.1-3 parts of ultraviolet absorbers by mass, and the mass parts of the ultraviolet absorbers can be 0.2 parts, 0.5 parts, 0.8 parts, 1 parts, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts, 2.2 parts, 2.5 parts or 2.8 parts, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0053] Preferably, the ultraviolet absorber includes any one of benzotriazole additives, salicylate additives, benzophenone additives, substituted acrylonitrile additives, triazine additives, and hindered amine additives, or a combination of at least two thereof.

[0054] Preferably, the preparation raw materials further include 0.1-3 parts of antioxidants by mass, and the mass parts of the antioxidants can be 0.2 parts, 0.5 parts, 0.8 parts, 1 parts, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts, 2.2 parts, 2.5 parts or 2.8 parts, as well as specific points between the above points. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific points included in the range.

[0055] Preferably, the antioxidant includes any one of a hindered amine antioxidant, a hindered phenol antioxidant, and a phosphite antioxidant, or a combination of at least two thereof.

[0056] In a second aspect, the present invention provides a method for preparing the high temperature resistant low halogen cable material as described in the first aspect, the preparation method comprising:

[0057] The prepared raw materials are mixed and extruded to obtain granules;

[0058] The particles are made into wires through a wire extruder, and the wires are irradiated and cross-linked through an electron accelerator to obtain the high temperature resistant and low halogen cable material.

[0059] The preparation method of the high temperature resistant low halogen cable material provided by the present invention includes two cross-linking processes. The first cross-linking is heat-induced cross-linking, which mainly occurs during the mixing process, so that the obtained particles contain a certain cross-linked grid structure; further, after the particles are processed into wires, they are irradiated and cross-linked by an electron accelerator to cause the organic system to undergo secondary cross-linking to obtain a specific multi-dimensional cross-linked network structure, thereby giving the high temperature resistant low halogen cable material excellent mechanical properties, high temperature aging resistance, moisture and heat resistance, weather resistance, etc.

[0060] Preferably, the mixing is carried out in an internal mixer.

[0061] Preferably, the mixing temperature is 160-175°C, for example, it can be 162°C, 165°C, 168°C, 170°C, 172°C or 174°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0062] Preferably, the mixing time is 5-30 min, for example, it can be 6 min, 8 min, 10 min, 12 min, 15 min, 18 min, 20 min, 22 min, 25 min or 28 min, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0063] Preferably, the extrusion granulation is carried out in a screw extruder, such as a single-screw extruder or a twin-screw extruder.

[0064] Preferably, the operating temperature of the screw extruder is 100-150°C, for example, it can be 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C or 145°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range, and 110-130°C is further preferred.

[0065] Preferably, the screw extruder comprises a first zone, a second zone, a third zone, a fourth zone, a fifth zone, a sixth zone and a seventh zone connected in sequence, and the temperature of each zone is independently 110-130°C, for example, it can be 112°C, 115°C, 118°C, 120°C, 122°C, 125°C or 128°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0066] Preferably, the temperature of the first zone in the screw extruder is 110-115°C (e.g., 110°C, 111°C, 112°C, 113°C, 114°C or 115°C, etc.), the temperature of the second zone is 115-120°C (e.g., 115°C, 116°C, 117°C, 118°C, 119°C or 120°C, etc.), the temperature of the third zone is 115-120°C (e.g., 115°C, 116°C, 117°C, 118°C, 119°C or 120°C, etc.), and the temperature of the fourth zone is 120-125°C (e.g., 1 The temperature of the fifth zone is 120-125°C (for example, 120°C, 121°C, 122°C, 123°C, 124°C or 125°C, etc.), the temperature of the sixth zone is 120-130°C (for example, 120°C, 122°C, 124°C, 126°C, 128°C or 130°C, etc.), and the temperature of the seventh zone is 125-130°C (for example, 125°C, 126°C, 127°C, 128°C, 129°C or 130°C, etc.).

[0067] Preferably, the operating temperature of the wire extruder is 120-190°C, for example, it can be 125, 130°C, 140°C, 150°C, 160°C, 170°C or 180°C, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0068] Preferably, the wire extruder comprises a zone A, a zone B, a zone C and a zone D connected in sequence, so that the pellets can pass through zone A, zone B, zone C and zone D in sequence, wherein the operating temperature of zone A is 150-160°C (e.g., 152°C, 154°C, 155°C, 158°C, 159°C, etc.), the operating temperature of zone B is 160-180°C (e.g., 162°C, 165°C, 168°C, 170°C, 172°C, 175°C, 178°C, etc.), the operating temperature of zone C is 160-180°C (e.g., 162°C, 165°C, 168°C, 170°C, 172°C, 175°C, 178°C, etc.), and the operating temperature of zone D is 160-180°C (e.g., 162°C, 165°C, 168°C, 170°C, 172°C, 175°C, 178°C, etc.).

[0069] Preferably, the dose of the radiation cross-linking is 2-12 Mrad, for example, it can be 3 Mrad, 4 Mrad, 4.5 Mrad, 5 Mrad, 5.5 Mrad, 6 Mrad, 6.5 Mrad, 7 Mrad, 7.5 Mrad, 8 Mrad, 8.5 Mrad, 9 Mrad, 9.5 Mrad, 10 Mrad or 11 Mrad, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0070] In a third aspect, the present invention provides an application of the high temperature resistant low halogen cable material as described in the first aspect in a wind power generation device, a solar power generation device, a building cable or an ultra-fine electronic wire.

[0071] Compared with the prior art, the present invention has the following beneficial effects:

[0072] (1) In the high temperature resistant low halogen cable material provided by the present invention, the components are designed and compounded to cooperate with each other to form a cross-linking system jointly constructed by EVA, polyethylene, butadiene-based polymer, thermoplastic elastomer, co-crosslinking agent and alkenyl-containing oligomeric silsesquioxane, forming a specific three-dimensional cross-linked network structure in the cable material, so that the high temperature resistant low halogen cable material has excellent mechanical properties, high temperature aging resistance and moisture and heat resistance, and also has excellent performance in flame retardancy, weather resistance and UV aging resistance.

[0073] (2) Through the design and further optimization of the components, the present invention makes the tensile strength of the high temperature resistant low halogen cable material ≥14.8MPa, the elongation at break ≥340%, the change rate of tensile strength and the change rate of elongation at break after aging at 180°C for 168h ≤±8%, the tensile strength retention rate after double 85 test for 168h ≥90%, and can pass single vertical combustion. It has excellent comprehensive performance in mechanical properties, high temperature aging resistance, moisture and heat resistance and flame retardancy, and fully meets the continuous and stable working requirements of high temperature resistant cables. DETAILED DESCRIPTION

[0074] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0075] As used herein, the terms "comprises," "including," "having," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0076] "Optionally", "optionally" or "either" means that the subsequently described matter or event can or cannot occur, and that the description includes cases where the event occurs and cases where it does not.

[0077] In the following specific implementation of the present invention, the specific information of the materials used is as follows:

[0078]

[0079] The high temperature resistant low halogen cable material and the preparation method thereof according to the present invention will be described in detail below by taking multiple embodiments as examples, but the high temperature resistant low halogen cable material and the preparation method thereof according to the present invention are not limited to these embodiments.

[0080] Example 1

[0081] A high temperature resistant low halogen cable material, the raw materials for its preparation include the following components by weight:

[0082]

[0083] The preparation method of the high temperature resistant low halogen cable material is as follows:

[0084] (1) adding each component into a mixer according to the formula amount, premixing for 2 minutes to obtain a mixture; adding the mixture into an internal mixer, mixing at 165° C. for 20 minutes, and extruding and granulating through a single screw extruder to obtain granules; the operating temperatures of zones 1 to 7 in the single screw extruder are 112° C., 115° C., 115° C., 120° C., 120° C., and 125° C., respectively.

[0085] (2) adding the particles obtained in step (1) into a wire extruder and extruding to obtain wires, wherein the operating temperatures of the AD zone in the wire extruder are 150° C., 160° C., 170° C., and 170° C., respectively; irradiating the wires with an electron accelerator for cross-linking, and the irradiation dose is 5 Mrad to obtain the high temperature resistant low halogen cable material.

[0086] The following performance tests are conducted on high temperature resistant low halogen cable materials:

[0087] (1) Tensile strength and elongation at break: tested according to the method in GB / T 2951.11-2008;

[0088] (2) Heat resistance: After the cable material to be tested is aged at 180°C for 168 hours, the tensile strength and elongation at break are tested and compared with the data measured in (1) to obtain the change rate; change rate = (test value after aging - original test value) / original test value; the smaller the absolute value of the change rate, the better the heat resistance.

[0089] (3) Moisture and heat resistance: The cable material to be tested is placed in a moisture and heat aging test chamber at 85°C and 85% humidity. After 168 hours, the tensile strength is tested and compared with the data measured in (1) to obtain the tensile strength retention rate; tensile strength retention rate = test value after aging / original test value. The higher the retention rate, the better the moisture and heat resistance.

[0090] (4) Single vertical burning: Tested according to the method in GB / T 18380-2008;

[0091] The test results are shown in Table 1.

[0092] Examples 2-8, Comparative Examples 1-5

[0093] A high temperature resistant low halogen cable material, which differs from Example 1 only in that the types and / or amounts of raw materials used in the preparation are different, as shown in Tables 1 and 2, wherein "--" represents that the component is not added; the preparation method of the high temperature resistant low halogen cable material is the same as that in Example 1; the performance of the high temperature resistant low halogen cable material is tested by the same method as in Example 1, and the test data are shown in Tables 1 and 2.

[0094] Table 1

[0095]

[0096]

[0097] Table 2

[0098]

[0099]

[0100] According to the performance test data in Table 1, the present invention designs and compounds each component in the raw material to make it undergo a cross-linking reaction, so as to form a specific three-dimensional cross-linked network in the cable material, so that the high temperature resistant and low halogen cable material has excellent mechanical properties, high temperature aging resistance, moisture and heat resistance, flame retardancy and weather resistance; wherein, the tensile strength of Examples 1-5 is 14.8-15.6MPa, the elongation at break is 342-377%, the tensile strength retention rate after double 85 test for 168h is ≥90.2%, the change rate of tensile strength and the change rate of elongation at break after aging at 180°C for 168h are ≤±8%, and it can pass single vertical combustion, and has made significant progress in heat aging stability and moisture and heat resistance.

[0101] Further, in combination with the effect data of Example 1 and Example 6-8, it can be seen that the present invention realizes the improvement of the cross-linked structure by designing the content of 1,2-vinyl structural units in the butadiene-based polymer, designing and optimizing the dosage of the butadiene-based polymer and the thermoplastic elastomer POE, and synergistically improving the mechanical properties, high temperature aging resistance and moisture and heat resistance of the cable material. The dosage ratio of the thermoplastic elastomer to the butadiene-based polymer in Example 6-7 exceeds the preferred 1: (1.2-3) of the present invention, resulting in varying degrees of decrease in the mechanical properties, high temperature aging resistance and moisture and heat resistance of the material. The 1,2-vinyl structural unit content of the butadiene-based polymer in Example 8 is low, and the cross-linking density is reduced, which affects the mechanical properties, high temperature aging resistance and moisture and heat resistance of the cable material.

[0102] The present invention forms a cross-linking system composed of EVA, polyethylene, butadiene-based polymer, thermoplastic elastomer, co-crosslinking agent and alkenyl-containing oligomeric silsesquioxane in the cable material by designing and compounding each component in the raw material. Based on the construction of a three-dimensional cross-linking network with a specific structure, the high temperature resistant and low halogen cable material achieves an excellent balance between processing performance, mechanical properties, high temperature aging resistance, moisture and heat resistance and weather resistance. Combining Table 1 and Table 2, it can be seen that Comparative Example 1 does not contain a butadiene-based polymer, and Comparative Example 2 contains hydrogenated SEBS. Since the system does not contain reactive side chain alkenyl groups, the cross-linking degree of the cable material is insufficient, resulting in a significant reduction in its tensile strength, elongation, high temperature aging resistance and moisture and heat resistance. Comparative Example 3 does not contain oligomeric silsesquioxane, which reduces the mechanical properties, high temperature stability and moisture and heat resistance of the material. The oligomeric silsesquioxane in Comparative Example 4 does not contain a double bond functional group, and is only blended in the cable material as a filler, which affects the mechanical properties, high temperature aging resistance and moisture and heat resistance of the material. Comparative Example 5 does not contain a crosslinking agent, and the components are difficult to undergo heat-induced crosslinking reactions during the mixing stage. The crosslinked structure obtained by relying solely on radiation crosslinking is not dense enough, resulting in significantly insufficient mechanical properties, high temperature aging resistance and moisture and heat resistance of the cable material.

[0103] The applicant declares that the present invention uses the above-mentioned embodiments to illustrate the high temperature resistant low halogen cable material and its preparation method and application, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A high temperature resistant low halogen cable material, characterized in that: The raw materials for preparing the high temperature resistant low halogen cable material include the following components by mass:

2. The high temperature resistant low halogen cable material according to claim 1, characterized in that: The ethylene-vinyl acetate copolymer has a melt index of 1-50 g / 10 min at 190° C. and 2.16 kg; Preferably, the polyethylene includes any one of linear low-density polyethylene, high-density polyethylene, and metallocene polyethylene, or a combination of at least two thereof, and high-density polyethylene is further preferred.

3. The high temperature resistant low halogen cable material according to claim 1 or 2, characterized in that: The butadiene-based polymer includes polybutadiene and / or butadiene-styrene copolymer; Preferably, the number average molecular weight of the butadiene-based polymer is 1000-10000; Preferably, the butadiene-based polymer comprises a structural unit represented by formula I, and the molar percentage of the structural unit represented by formula I in the butadiene-based polymer is 25-90%; 4. The high temperature resistant low halogen cable material according to any one of claims 1 to 3, characterized in that: The thermoplastic elastomer comprises ethylene-octene copolymer; Preferably, the thermoplastic elastomer has a melt index of 1-20 g / 10 min at 190° C. and 2.16 kg; Preferably, the mass ratio of the thermoplastic elastomer to the butadiene-based polymer is 1:(1.2-3); Preferably, the compatibilizer includes any one of maleic anhydride grafted polyethylene, maleic anhydride grafted polypropylene, and maleic anhydride grafted ethylene-vinyl acetate copolymer, or a combination of at least two thereof.

5. The high temperature resistant low halogen cable material according to any one of claims 1 to 4, characterized in that: The alkenyl-containing oligomeric silsesquioxane includes any one of octavinyl cage-type oligomeric silsesquioxane, octamethacrylate cage-type oligomeric silsesquioxane, octaacrylate cage-type oligomeric silsesquioxane, octaacryloxy cage-type oligomeric silsesquioxane, octamethacryloxy cage-type oligomeric silsesquioxane, and methacryloxypropyl cage-type polysilsesquioxane, or a combination of at least two thereof.

6. The high temperature resistant low halogen cable material according to any one of claims 1 to 5, characterized in that: The cross-linking agent includes an organic peroxide, preferably any one or a combination of at least two of cumene hydroperoxide, di-tert-butyl peroxide, diisopropylbenzene hydroperoxide, dibenzoyl peroxide, cyclohexanone peroxide, tert-butyl perbenzoate, tert-butyl peracetate, tert-amyl peroxy (2-ethylhexyl) carbonate, di (4-methylbenzoyl) peroxide, 2,5-dimethyl-2,5-di-tert-butyl peroxide ethane, and tert-butyl peroxy-3,5,5-trimethylhexanoate; Preferably, the auxiliary cross-linking agent includes any one of pentaerythritol triacrylate, triallyl isocyanurate, trimethylolpropane trimethacrylate, trimethylolpropane trimethacrylate, ethoxylated trimethylolpropane triacrylate, tri(1,2-propylene glycol) diacrylate, tri(2-hydroxyethyl)isocyanuric acid triacrylate, propoxylated trimethylolpropane triacrylate, or a combination of at least two thereof; Preferably, the halogen-free flame retardant includes any one of antimony trioxide, aluminum hydroxide, and magnesium hydroxide, or a combination of at least two of them.

7. The high temperature resistant low halogen cable material according to any one of claims 1 to 6, characterized in that: The preparation raw materials also include any one or a combination of at least two of lubricants, silane coupling agents, stabilizers, ultraviolet absorbers, and antioxidants; Preferably, the raw material for preparation further comprises 0.1-5 parts by mass of a lubricant; Preferably, the lubricant comprises any one of silicone masterbatch, silicone phenol, polyethylene wax, or a combination of at least two thereof; Preferably, the raw material for preparation further comprises 0.1-5 parts by mass of a silane coupling agent; Preferably, the silane coupling agent includes any one of an alkenyl-containing silane coupling agent, an epoxy silane coupling agent, an amino silane coupling agent, and a mercapto silane coupling agent, or a combination of at least two thereof; Preferably, the raw material for preparation further comprises 0.1-5 parts of a stabilizer by weight; Preferably, the stabilizer includes any one of zinc stearate, calcium stearate, and pentaerythritol tetrakis(β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate) or a combination of at least two thereof; Preferably, the raw material for preparation further comprises 0.1-3 parts by mass of ultraviolet absorber; Preferably, the raw material for preparation further comprises 0.1-3 parts of antioxidant by mass.

8. A method for preparing a high temperature resistant low halogen cable material according to any one of claims 1 to 7, characterized in that: The preparation method comprises: The prepared raw materials are mixed and extruded to obtain granules; The particles are made into wires through a wire extruder, and the wires are irradiated and cross-linked through an electron accelerator to obtain the high temperature resistant and low halogen cable material.

9. The preparation method according to claim 8, characterized in that: The mixing is carried out in an internal mixer; Preferably, the mixing temperature is 160-175°C and the mixing time is 5-30 minutes; Preferably, the extrusion granulation is carried out in a screw extruder; Preferably, the operating temperature of the screw extruder is 100-150°C; Preferably, the working temperature of the wire extruder is 120-190°C; Preferably, the radiation cross-linking dosage is 2-12 Mrad.

10. Use of the high temperature resistant low halogen cable material according to any one of claims 1 to 7 in a wind power generation device, a solar power generation device, a building cable or an ultra-fine electronic wire.

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