Flame-retardant, age-resistant polyolefin cable material, method for its production and cable produced from the cable material

Abstract

The application discloses a kind of flame-retardant ageing-resistant polyolefin cable material, preparation method and the cable made by the cable material.The ingredients of the flame-retardant ageing-resistant polyolefin cable material include polyethylene 20-40 parts by weight, polyolefin elastomer 20-30 parts by weight, organic compatilizer 5-10 parts by weight, modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder 5-15 parts by weight and flame retardant 10-30 parts by weight.The flame-retardant ageing-resistant polyolefin cable material provided by the application has good mechanical properties and scratch resistance, and has high flame retardant performance, suitable for cable industry.

Description

Technical Field

[0001] This invention relates to the field of wires and cables, specifically to a flame-retardant and aging-resistant polyolefin cable material, its preparation method, and a cable made from the cable material. Background Technology

[0002] In the cable industry, cross-linked polyolefin (XLPE) materials are widely used due to their excellent electrical properties and good mechanical strength. Although XLPE plays a crucial role in cable applications, it still has some performance limitations. First, the flame retardancy of XLPE materials is insufficient to meet certain stringent safety standards. Second, the insufficient scratch resistance of XLPE materials can lead to sheath damage and shorten the cable's lifespan. Therefore, there is an urgent need for a cable with strong scratch resistance and high flame retardancy while maintaining its electrical performance. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the present invention proposes a flame-retardant and aging-resistant polyolefin cable material, a preparation method thereof, and a cable made from the cable material, aiming to solve the problems of insufficient scratch resistance and flame retardant performance of current cross-linked polyolefin cables.

[0004] To achieve the above objectives, the present invention proposes a flame-retardant and aging-resistant polyolefin cable material, wherein the ingredients of the flame-retardant and aging-resistant polyolefin cable material, by weight, include: 20-40 parts of polyethylene; 20-30 parts of polyolefin elastomer; 5-10 parts of organic compatibilizer; 5-15 parts of modified nano aluminum hydroxide / hexagonal boron nitride nanocomposite powder; and 10-30 parts of flame retardant.

[0005] Optionally, the modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder is in the form of 8-12 parts.

[0006] Optionally, the polyethylene comprises 15-30 parts of high-density polyethylene and 5-10 parts of linear low-density polyethylene.

[0007] Optionally, the polyolefin elastomer is at least one selected from ethylene-methyl acrylate copolymer, ethylene-butyl acrylate copolymer, ethylene-butene copolymer, and ethylene-octene copolymer.

[0008] Optionally, the organic compatibilizer is at least one of polyethylene grafted with maleic anhydride, polypropylene grafted with maleic anhydride, a copolymer of styrene and maleic anhydride, and polyolefin elastomer grafted with maleic anhydride.

[0009] Optionally, the flame retardant is a compound of organic and inorganic flame retardants, wherein the weight ratio of the organic flame retardant to the inorganic flame retardant is (0-10):(10-20).

[0010] Optionally, the flame-retardant and aging-resistant polyolefin cable material further includes a lubricant, wherein the lubricant is at least one of fatty acids, aliphatic amides, metal soaps, and fatty alcohols.

[0011] Optionally, the flame-retardant and aging-resistant polyolefin cable material further includes an antioxidant, wherein the antioxidant is at least one selected from bis(octadecyl)hydroxylamine, tris[2,4-di-tert-butylphenyl]phosphite, pentaerythritol tetra(3-lauryl thiopropionate), bis[3-[3-tert-butyl-4-hydroxy-5-tolyl]2,4,8,10-tetraoxazolo[5,5]undecane-3,9-diylbis(2-methylpropane-2,1-diyl) ester, 1,5,8,12-tetra[4,6-bis(N-1,2,2,6,6-pentamethyl-4-piperidinylamino)-1,3,5-triazin-2-yl]-1,5,8,12-tetraazadodecane and N-salicylamidophthalimide.

[0012] Optionally, the flame-retardant and aging-resistant polyolefin cable material further includes a crosslinking aid, which is at least one selected from the following: trimethylolpropane triacrylate, trimethylolpropane trimethacrylate diacrylate, ethylene glycol dimethacrylate, N,N-p-phenylbismaleimide, zinc diacrylate, and zinc dimethacrylate.

[0013] To achieve the above objectives, this invention also proposes a method for preparing flame-retardant and aging-resistant polyolefin cable material, comprising the following steps: preparing modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder: preparing modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder by solution method using hexagonal boron nitride, isopropanol, hydrated aluminum chloride, n-butanol, ammonia, and silane coupling agent; preparing flame-retardant and aging-resistant polyolefin cable material: pre-mixing polyethylene, polyolefin elastomer, organic compatibilizer, modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder, flame retardant, lubricant, antioxidant, and crosslinking aid evenly, and then performing internal mixing in an internal mixer to prepare a melt blend; granulating the melt blend using a twin-screw-single-screw hot-cutting air-cooled granulation unit, followed by secondary air cooling and vibrating sieving to finally obtain the flame-retardant and aging-resistant polyolefin cable material.

[0014] Optionally, the preparation method of the modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder includes the following steps: exfoliating hexagonal boron nitride to form hexagonal boron nitride nanosheets and hydroxylating them to obtain micro-nano hexagonal boron nitride powder; then growing nano-aluminum hydroxide on the surface of the micro-nano hexagonal boron nitride powder in situ to obtain nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder; then adding the nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder and a silane coupling agent into an ethanol solution, and drying after ultrasonic dispersion and vacuum filtration to obtain the modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder.

[0015] Optionally, the silane coupling agent is at least one selected from 3-aminopropyltriethoxysilane, γ-aminopropyltriethoxysilane, and γ-glycidoxypropyltrimethoxysilane.

[0016] To achieve the above objectives, the present invention also proposes a cable made from any of the aforementioned flame-retardant and aging-resistant polyolefin cable materials.

[0017] The beneficial effects of this invention are as follows: In this invention, polyethylene, polyolefin elastomer, organic compatibilizer and flame retardant are mixed together as the mixed elastomer component of flame-retardant and aging-resistant polyolefin cable material. By adding modified nano aluminum hydroxide / hexagonal boron nitride nanocomposite powder, not only can the scratch resistance of the matrix be improved, but also the deformation resistance of the sheath material can be enhanced. After adding modified nano aluminum hydroxide / hexagonal boron nitride nanocomposite powder, the flame-retardant effect of flame-retardant and aging-resistant polyolefin cable material can be improved to a certain extent, thereby realizing the composite modification of flame-retardant and aging-resistant polyolefin cable material, so as to obtain excellent aging resistance. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. It should be understood that the following embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0019] Unless otherwise specified, all technical and scientific terms used herein have their usual meaning within the field to which the subject matter is claimed.

[0020] In the cable industry, cross-linked polyolefin (XLPE) materials are widely used due to their excellent electrical properties and good mechanical strength. Although XLPE plays a crucial role in cable applications, it still has some performance limitations. First, the flame retardancy of XLPE materials is insufficient to meet certain stringent safety standards. Second, the insufficient scratch resistance of XLPE materials can lead to sheath damage and shorten the cable's lifespan. Therefore, there is an urgent need for a cable with strong scratch resistance and high flame retardancy while maintaining its electrical performance.

[0021] To address the aforementioned problems, this invention proposes a flame-retardant and aging-resistant polyolefin cable material. The ingredients of the flame-retardant and aging-resistant polyolefin cable material, by weight, include: 20-40 parts of polyethylene; 20-30 parts of polyolefin elastomer; 5-10 parts of organic compatibilizer; 5-15 parts of modified nano aluminum hydroxide / hexagonal boron nitride nanocomposite powder; and 10-30 parts of flame retardant.

[0022] In this invention, polyethylene, polyolefin elastomer, organic compatibilizer, and flame retardant are mixed together as the mixed elastomer component of flame-retardant and aging-resistant polyolefin cable material. By adding modified nano aluminum hydroxide / hexagonal boron nitride nanocomposite powder, not only can the scratch resistance of the matrix be improved, but the deformation resistance of the sheath material can also be enhanced. After adding modified nano aluminum hydroxide / hexagonal boron nitride nanocomposite powder, the flame-retardant effect of the flame-retardant and aging-resistant polyolefin cable material can be improved to a certain extent, thereby realizing the composite modification of the flame-retardant and aging-resistant polyolefin cable material, enabling it to obtain excellent aging resistance.

[0023] In some embodiments, the ingredients of the flame-retardant and aging-resistant polyolefin cable material, by weight, preferably include: 20-40 parts of polyethylene; 20-30 parts of polyolefin elastomer; 5-10 parts of organic compatibilizer; 5-15 parts of modified nano aluminum hydroxide / hexagonal boron nitride nanocomposite powder; and 10-30 parts of flame retardant.

[0024] Furthermore, 8-12 parts of modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder.

[0025] In some embodiments, the modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder is preferably 8 parts.

[0026] In some embodiments, the modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder is preferably 12 parts.

[0027] Furthermore, the polyethylene includes 15-30 parts of high-density polyethylene and 5-10 parts of linear low-density polyethylene.

[0028] In some embodiments, the melt flow rate of high-density polyethylene is 5-15 g / 10 min at 190°C / 2.16 kg under test conditions, and the melt flow rate of linear low-density polyethylene is 5-10 g / 10 min at 190°C / 2.16 kg under test conditions.

[0029] Furthermore, the polyolefin elastomer is at least one of ethylene-methyl acrylate copolymer, ethylene-butyl acrylate copolymer, ethylene-butene copolymer, or ethylene-octene copolymer.

[0030] In some embodiments, the polyolefin elastomer is preferably an ethylene-methyl acrylate copolymer.

[0031] In some embodiments, the polyolefin elastomer is preferably a mixture of ethylene-butene copolymer and ethylene-octene copolymer.

[0032] Furthermore, the organic compatibilizer is at least one of polyethylene grafted with maleic anhydride, polypropylene grafted with maleic anhydride, a copolymer of styrene and maleic anhydride, and polyolefin elastomer grafted with maleic anhydride.

[0033] Polyethylene grafted with maleic anhydride, polypropylene grafted with maleic anhydride, copolymers of styrene and maleic anhydride, or polyolefin elastomers grafted with maleic anhydride are used as organic compatibilizers to effectively reduce the size of the dispersed phase, maintain the phase structure, reduce the surface tension between polymers, improve the mechanical properties of the mixture, ensure the mechanical properties of flame-retardant and aging-resistant polyolefin cable materials, and reduce the interaction forces between components, thus ensuring the uniformity and stability of the mixture of polyethylene, polyolefin elastomers, and flame retardants.

[0034] In some embodiments, the organic compatibilizer is preferably polyethylene grafted with maleic anhydride.

[0035] Furthermore, the flame retardant is a compound of organic and inorganic flame retardants, with a weight ratio of (0-10):(10-20).

[0036] The flame retardant is a compound of organic and inorganic flame retardants. Compared with single-component flame retardants, this flame retardant utilizes the synergistic effect of multiple flame retardant elements to compensate for the shortcomings of a single flame retardant element, thereby better balancing the relationship between the amount of flame retardant, performance and cost, making it more environmentally friendly and safer.

[0037] In some embodiments, the organic flame retardant is at least one of phosphorus-based flame retardants and nitrogen-based flame retardants.

[0038] In some embodiments, the inorganic flame retardant is at least one of magnesium hydroxide and aluminum hydroxide.

[0039] In some embodiments, the flame retardant is a compound of organic and inorganic flame retardants, with a weight ratio of 5:20.

[0040] Furthermore, the flame-retardant and aging-resistant polyolefin cable material also includes a lubricant, which is at least one of fatty acids, aliphatic amides, metal soaps, and fatty alcohols.

[0041] In some embodiments, the lubricant is preferably 0.5 parts fatty acid lubricant.

[0042] Furthermore, the flame-retardant and aging-resistant polyolefin cable material also includes antioxidants, which are at least one of bis(octadecyl)hydroxylamine, tris[2,4-di-tert-butylphenyl]phosphite, pentaerythritol tetra(3-lauryl thiopropionate), bis[3-[3-tert-butyl-4-hydroxy-5-tolyl]2,4,8,10-tetraoxazolo[5,5]undecane-3,9-diylbis(2-methylpropane-2,1-diyl) ester, 1,5,8,12-tetra[4,6-bis(N-1,2,2,6,6-pentamethyl-4-piperidinylamino)-1,3,5-triazin-2-yl]-1,5,8,12-tetraazadodecane and N-salicylicamide phthalimide.

[0043] In some embodiments, the antioxidant is preferably 0.5 parts of bis(octadecyl)hydroxylamine.

[0044] Furthermore, the flame-retardant and aging-resistant polyolefin cable material also includes a crosslinking aid, which is at least one of trimethylolpropane triacrylate, trimethylolpropane trimethacrylate ethylene glycol diacrylate, ethylene glycol dimethacrylate, N,N-p-phenylbismaleimide, zinc diacrylate, and zinc dimethacrylate.

[0045] In some embodiments, the crosslinking aid is preferably 2 parts of trimethylolpropane triacrylate.

[0046] Lubricants improve flowability during processing, increase the impact strength of materials, reduce water absorption on cable surfaces, improve cable scratches and surface defects, and reduce heat release and smoke emission. All of these contribute to improving cable performance and safety. Adding antioxidants prevents thermal oxidative degradation of elastomers, while crosslinking aids significantly improve the material's heat resistance, aging resistance, electrical properties, and mechanical properties by promoting crosslinking between polyethylene molecular chains.

[0047] To address the above problems, this invention also proposes a method for preparing flame-retardant and aging-resistant polyolefin cable material, comprising the following steps:

[0048] S1: Preparation of modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder: Modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder was prepared by solution method using hexagonal boron nitride, isopropanol, hydrated aluminum chloride, n-butanol, ammonia and silane coupling agent.

[0049] In this scheme, the hexagonal boron nitride in the modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder is processed to obtain a micro-nano hexagonal boron nitride, which combines the characteristics of nanomaterials and micron fillers. First, the micron-sheet filler, due to the low coefficient of friction of hexagonal boron nitride itself, can improve the scratch resistance of the matrix. Second, the nanosheet structure facilitates the subsequent growth of nano-aluminum hydroxide. The nano-aluminum hydroxide generated in situ on the surface of the hexagonal boron nitride nanosheets has a large specific surface area, which reduces the water vapor partial pressure on the particle surface and can improve the flame retardant effect to a certain extent. In addition, due to the excellent thermal conductivity and thermal stability of hexagonal boron nitride, it can improve the heat resistance of nano-aluminum hydroxide. Therefore, the combination of the two has synergistic flame retardant and smoke suppression characteristics. When used in combination with flame retardants, the dosage can be reduced and excellent flame retardant effect can be achieved. Finally, the sheet-like structure of micro-nano hexagonal boron nitride can also change the pathway of oxygen, moisture and other substances into the resin matrix, thereby improving the aging resistance.

[0050] S2: Preparation of flame-retardant and aging-resistant polyolefin cable material: Polyethylene, polyolefin elastomer, organic compatibilizer, modified nano aluminum hydroxide / hexagonal boron nitride nanocomposite powder, flame retardant, lubricant, antioxidant and crosslinking aid are premixed evenly and then kneaded in an internal mixer to prepare a melt blend.

[0051] In some embodiments, mixing is performed in an internal mixer.

[0052] S3: The molten blend is extruded and granulated, then air-cooled and screened to finally obtain flame-retardant and aging-resistant polyolefin cable material.

[0053] In some embodiments, extrusion granulation is achieved using a twin-screw to single-screw hot-cut air-cooled granulation unit.

[0054] In some embodiments, the irradiated crosslinked polyolefin material is irradiated using an 18-Mrad electron beam.

[0055] Furthermore, the preparation method of modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder includes the following steps:

[0056] Hexagonal boron nitride was exfoliated to form hexagonal boron nitride nanosheets, which were then hydroxylated to obtain micro / nano hexagonal boron nitride powder. Nano-aluminum hydroxide was then grown in situ on the surface of the micro / nano hexagonal boron nitride powder to obtain nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder. Subsequently, the nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder and a silane coupling agent were added to an ethanol solution. After ultrasonic dispersion and vacuum filtration, the solution was dried to obtain modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder.

[0057] In some embodiments, hexagonal boron nitride is placed in an isopropanol solution, then ultrasonically dispersed at 500W for 24 hours, vacuum filtered, and dried in a vacuum oven at 80-100℃ for 6-8 hours to obtain micro-nano hexagonal boron nitride powder.

[0058] In some embodiments, hydrated aluminum chloride is dissolved in a n-butanol solution, and then hexagonal boron nitride nanosheet powder is added to the solution and stirred until homogeneous. Then, ammonia water is rapidly poured into the n-butanol solution of hydrated aluminum chloride under vigorous stirring and reacted for 1-2 hours. After the reaction is complete, vacuum filtration is performed, and the mixture is washed 5-8 times with deionized water until Cl is removed. - .

[0059] In some embodiments, nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder and silane coupling agent are added to an ethanol solution, ultrasonically dispersed at 40-80°C and 120W power for 4 hours, followed by vacuum filtration and drying in a vacuum oven at 70-90°C for 24-30 hours to finally obtain modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder.

[0060] Furthermore, the silane coupling agent is at least one selected from 3-aminopropyltriethoxysilane, γ-aminopropyltriethoxysilane, and γ-glycidoxypropyltrimethoxysilane.

[0061] In some embodiments, the silane coupling agent is preferably 3-aminopropyltriethoxysilane.

[0062] To address the aforementioned problems, the present invention also proposes a cable prepared by the above-mentioned method for preparing a flame-retardant and aging-resistant polyolefin cable material.

[0063] The following specific embodiments and data explain the content of the present invention.

[0064] Example 1:

[0065] Hexagonal boron nitride was exfoliated to form hexagonal boron nitride nanosheets, which were then hydroxylated. The hexagonal boron nitride was placed in an isopropanol solution and then ultrasonically dispersed at 500W for 24 hours. After vacuum filtration, it was dried in a vacuum oven at 80-100℃ for 6-8 hours to obtain micro / nano hexagonal boron nitride powder. Next, nano-aluminum hydroxide was grown in situ on the surface of the hexagonal boron nitride nanosheets. Hydrated aluminum chloride was dissolved in a n-butanol solution, and the hexagonal boron nitride nanosheet powder was added to the solution and stirred until homogeneous. Then, ammonia was rapidly poured into the n-butanol solution of hydrated aluminum chloride under vigorous stirring and reacted for 1-2 hours. After the reaction was complete, vacuum filtration was performed, and the nanosheets were washed 5-8 times with deionized water until Cl was removed. -Next, the nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder and silane coupling agent were added to an ethanol solution, and ultrasonically dispersed at 40-80℃ and 120W power for 4 hours. Then, the mixture was vacuum filtered and dried in a vacuum oven at 70-90℃ for 24-30 hours to obtain the modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder.

[0066] 20 parts of high-density polyethylene, 5 parts of linear low-density polyethylene, 20 parts of polyolefin elastomer, 6 parts of organic compatibilizer, 5 parts of modified nano aluminum hydroxide / hexagonal boron nitride nanocomposite powder, 20 parts of inorganic flame retardant, 1 part of lubricant, 1 part of antioxidant and 2 parts of crosslinking aid are mixed and then extruded and granulated to obtain granules.

[0067] Granular materials are irradiated with an 18Mrad electron beam to obtain flame-retardant and aging-resistant polyolefin cable material.

[0068] Example 2:

[0069] The preparation method is the same as in Example 1, except that:

[0070] 20 parts high-density polyethylene, 5 parts linear low-density polyethylene, 20 parts polyolefin elastomer, 6 parts organic compatibilizer, 8 parts modified nano aluminum hydroxide / hexagonal boron nitride nanocomposite powder, 20 parts inorganic flame retardant, 1 part lubricant, 1 part antioxidant and 2 parts crosslinking aid are mixed and then extruded to obtain granules.

[0071] Example 3:

[0072] The preparation method is the same as in Example 1, except that:

[0073] 20 parts of high-density polyethylene, 5 parts of linear low-density polyethylene, 20 parts of polyolefin elastomer, 6 parts of organic compatibilizer, 10 parts of modified nano aluminum hydroxide / hexagonal boron nitride nanocomposite powder, 20 parts of inorganic flame retardant, 1 part of lubricant, 1 part of antioxidant and 2 parts of crosslinking aid are mixed and then extruded and granulated to obtain granules.

[0074] Example 4:

[0075] The preparation method is the same as in Example 1, except that:

[0076] 20 parts of high-density polyethylene, 5 parts of linear low-density polyethylene, 20 parts of polyolefin elastomer, 6 parts of organic compatibilizer, 12 parts of modified nano aluminum hydroxide / hexagonal boron nitride nanocomposite powder, 20 parts of inorganic flame retardant, 1 part of lubricant, 1 part of antioxidant and 2 parts of crosslinking aid are mixed and then extruded and granulated to obtain granules.

[0077] Example 5:

[0078] The preparation method is the same as in Example 1, except that:

[0079] 20 parts of high-density polyethylene, 5 parts of linear low-density polyethylene, 20 parts of polyolefin elastomer, 6 parts of organic compatibilizer, 15 parts of modified nano aluminum hydroxide / hexagonal boron nitride nanocomposite powder, 20 parts of inorganic flame retardant, 1 part of lubricant, 1 part of antioxidant and 2 parts of crosslinking aid are mixed and then extruded and granulated to obtain granules.

[0080] Example 6:

[0081] The preparation method is the same as in Example 1, except that:

[0082] 30 parts high-density polyethylene, 5 parts linear low-density polyethylene, 20 parts polyolefin elastomer, 6 parts organic compatibilizer, 5 parts modified nano aluminum hydroxide / hexagonal boron nitride nanocomposite powder, 20 parts inorganic flame retardant, 1 part lubricant, 1 part antioxidant and 2 parts crosslinking aid are mixed and then extruded to obtain granules.

[0083] Example 7:

[0084] The preparation method is the same as in Example 1, except that:

[0085] 20 parts high-density polyethylene, 5 parts linear low-density polyethylene, 20 parts polyolefin elastomer, 6 parts organic compatibilizer, 5 parts modified nano aluminum hydroxide / hexagonal boron nitride nanocomposite powder, 15 parts inorganic flame retardant, 1 part lubricant, 1 part antioxidant and 2 parts crosslinking aid are mixed and then extruded to obtain granules.

[0086] Example 8:

[0087] The preparation method is the same as in Example 1, except that:

[0088] 20 parts high-density polyethylene, 5 parts linear low-density polyethylene, 20 parts polyolefin elastomer, 6 parts organic compatibilizer, 5 parts modified nano aluminum hydroxide / hexagonal boron nitride nanocomposite powder, 5 parts organic flame retardant, 20 parts inorganic flame retardant, 1 part lubricant, 1 part antioxidant and 2 parts crosslinking aid are mixed and then extruded to obtain granules.

[0089] Example 9:

[0090] The preparation method is the same as in Example 1, except that:

[0091] 20 parts high-density polyethylene, 5 parts linear low-density polyethylene, 20 parts polyolefin elastomer, 6 parts organic compatibilizer, 5 parts modified nano aluminum hydroxide / hexagonal boron nitride nanocomposite powder, 10 parts organic flame retardant, 10 parts inorganic flame retardant, 1 part lubricant, 1 part antioxidant and 2 parts crosslinking aid are mixed and then extruded and granulated to obtain granules.

[0092] Comparative Example 1:

[0093] 20 parts high-density polyethylene, 5 parts linear low-density polyethylene, 20 parts polyolefin elastomer, 6 parts organic compatibilizer, 20 parts inorganic flame retardant, 1 part lubricant, 1 part antioxidant and 2 parts crosslinking aid are mixed and then extruded and granulated to obtain granules.

[0094] Granular materials are irradiated with an 18Mrad electron beam to obtain flame-retardant and aging-resistant polyolefin cable material.

[0095] Comparative Example 2:

[0096] 20 parts of high-density polyethylene, 5 parts of linear low-density polyethylene, 20 parts of polyolefin elastomer, 6 parts of organic compatibilizer, 10 parts of organic flame retardant, 10 parts of inorganic flame retardant, 1 part of lubricant, 1 part of antioxidant and 2 parts of crosslinking aid are mixed and then extruded and granulated to obtain granules.

[0097] Granular materials are irradiated with an 18Mrad electron beam to obtain flame-retardant and aging-resistant polyolefin cable material.

[0098] Comparative Example 3:

[0099] 20 parts of high-density polyethylene, 5 parts of linear low-density polyethylene, 20 parts of polyolefin elastomer, 6 parts of organic compatibilizer, 5 parts of untreated hexagonal boron nitride, 20 parts of inorganic flame retardant, 1 part of lubricant, 1 part of antioxidant and 2 parts of crosslinking aid are mixed and then extruded and granulated to obtain granules.

[0100] Granular materials are irradiated with an 18Mrad electron beam to obtain flame-retardant and aging-resistant polyolefin cable material.

[0101] Comparative Example 4:

[0102] 20 parts high-density polyethylene, 5 parts linear low-density polyethylene, 20 parts polyolefin elastomer, 6 parts organic compatibilizer, 5 parts modified hexagonal boron nitride, 20 parts inorganic flame retardant, 1 part lubricant, 1 part antioxidant and 2 parts crosslinking aid are mixed and then extruded and granulated to obtain granules.

[0103] Granular materials are irradiated with an 18Mrad electron beam to obtain flame-retardant and aging-resistant polyolefin cable material.

[0104] Comparative Example 5:

[0105] The preparation method is the same as in Example 1, except that:

[0106] 20 parts of high-density polyethylene, 5 parts of linear low-density polyethylene, 20 parts of polyolefin elastomer, 6 parts of organic compatibilizer, 1 part of modified nano aluminum hydroxide / hexagonal boron nitride nanocomposite powder, 20 parts of inorganic flame retardant, 1 part of lubricant, 1 part of antioxidant and 2 parts of crosslinking aid are mixed and then extruded and granulated to obtain granules.

[0107] Granular materials are irradiated with an 18Mrad electron beam to obtain flame-retardant and aging-resistant polyolefin cable material.

[0108] Comparative Example 6:

[0109] The preparation method is the same as in Example 1, except that:

[0110] 20 parts of high-density polyethylene, 5 parts of linear low-density polyethylene, 20 parts of polyolefin elastomer, 6 parts of organic compatibilizer, 20 parts of modified nano aluminum hydroxide / hexagonal boron nitride nanocomposite powder, 20 parts of inorganic flame retardant, 1 part of lubricant, 1 part of antioxidant and 2 parts of crosslinking aid are mixed and then extruded and granulated to obtain granules.

[0111] Granular materials are irradiated with an 18Mrad electron beam to obtain flame-retardant and aging-resistant polyolefin cable material.

[0112] Table 1 summarizes the components and key preparation variables of Examples 1-9 and Comparative Examples 1-6.

[0113] Table 1. Components of Examples 1-9 and Comparative Examples 1-6 of the present invention

[0114]

[0115] According to relevant testing standards, the flame-retardant and aging-resistant polyolefin cable materials in Examples 1-9 and Comparative Examples 1-6 were tested for tensile strength, elongation at break, flame retardancy rating, and abrasion resistance. The test results are recorded in Table 2 below:

[0116] Table 2. Performance of Examples 1-9 and Comparative Examples 1-6 of the present invention

[0117]

[0118] As can be seen from the test results above, in Examples 1-5, the amount of modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder gradually increases within the range of 5-15 parts by weight of modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder in this invention. The amount of modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder added in Examples 1-5 is 5 parts, 8 parts, 10 parts, 12 parts, and 15 parts, respectively. Compared with Examples 1-5, the amount of modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder in Comparative Example 5 is 1 part, and the amount in Comparative Example 6 is 20 parts, both of which are not included in this invention. Within the range of 3-10 parts by weight of the modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder, the test results of Comparative Examples 1-5 and Comparative Examples 5-6 show that, within the range of 5-15 parts by weight of the modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder in this invention, the modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder can improve the flame retardant efficiency of organic flame retardants and reduce the amount of flame retardant used. Moreover, within this range, as the amount of modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder increases, the mechanical properties and flame retardancy of the prepared flame-retardant and aging-resistant polyolefin cable material also increase accordingly. The tensile strength of Example 1 is 1. The tensile strength of Comparative Example 3 was 7.6 MPa, the elongation at break was 482%, the tensile strength after aging was 90 MPa, the elongation at break was 92%, the flame retardancy rating was V-0, and the abrasion resistance was 382 cycles. Comparative Example 4 had 5 parts of modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder replaced with 5 parts of untreated hexagonal boron nitride microparticles. The tensile strength of Comparative Example 3 was 11.3 MPa, the elongation at break was 300%, the tensile strength after aging was 81 MPa, the elongation at break was 82%, the flame retardancy rating was V-1, and the abrasion resistance was 1 cycle. After 36 cycles, the tensile strength of Comparative Example 4 was 16.8 MPa, the elongation at break was 426%, the tensile strength after aging was 87 MPa, the elongation at break was 86%, the flame retardancy rating was V-1, and the number of abrasion cycles was 353. The experimental data shows that, compared to Example 1 which added modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder, Examples 3-4 had poorer tensile strength, elongation at break, retention rate after aging, flame retardancy rating, and number of abrasion cycles. Therefore, adding modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder to crosslinked polyolefin materials can improve flame retardancy, abrasion resistance, and aging resistance.When modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder is used in combination with other flame retardants, it can improve the efficiency of the flame retardants, reduce the amount of flame retardants used, and achieve excellent flame retardant effect. Furthermore, the sheet-like structure of the modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder can also change the pathway of oxygen, moisture, etc. into the resin matrix, thereby improving aging resistance. Therefore, the cross-linked polyolefin material proposed in this invention has the characteristics of low smoke and halogen-free flame retardancy, as well as excellent scratch resistance and aging resistance, and is suitable for the manufacture of various automotive cables.

[0119] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the patent protection scope of the present invention.

Claims

1. A flame-retardant and aging-resistant polyolefin cable material, characterized in that, The flame-retardant and aging-resistant polyolefin cable material comprises, by weight, the following: 20-40 parts of polyethylene; 20-30 parts of polyolefin elastomer; 5-10 parts organic compatibilizer; 5-15 parts of modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder; 10-30 parts flame retardant; The process involves exfoliating hexagonal boron nitride to form hexagonal boron nitride nanosheets and then hydroxylating them: the hexagonal boron nitride is placed in an isopropanol solution, then ultrasonically dispersed at 500W for 24 hours, vacuum filtered, and dried in a vacuum oven at 80-100℃ for 6-8 hours to obtain micro / nano hexagonal boron nitride powder; next, nano-aluminum hydroxide is grown in situ on the surface of the hexagonal boron nitride nanosheets: hydrated aluminum chloride is dissolved in a n-butanol solution, and the hexagonal boron nitride nanosheet powder is placed in the solution and stirred evenly. Then, ammonia water is rapidly poured into the n-butanol solution of hydrated aluminum chloride under vigorous stirring and reacted for 1-2 hours; after the reaction is completed, vacuum filtration is performed, and the mixture is washed 5-8 times with deionized water until Cl is removed. - Next, the nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder and silane coupling agent were added to the ethanol solution, and ultrasonically dispersed at 40-80℃ with a power of 120W for 4 hours. Then, the mixture was vacuum filtered and dried in a vacuum oven at 70-90℃ for 24-30 hours to obtain the modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder.

2. The flame-retardant and aging-resistant polyolefin cable material as described in claim 1, characterized in that, The modified nano-aluminum hydroxide / hexagonal boron nitride nanocomposite powder is present in quantities of 8-12 parts.

3. The flame-retardant and aging-resistant polyolefin cable material as described in claim 1, characterized in that, The polyethylene comprises 15-30 parts of high-density polyethylene and 5-10 parts of linear low-density polyethylene.

4. The flame-retardant and aging-resistant polyolefin cable material as described in claim 1, characterized in that, The polyolefin elastomer is at least one of ethylene-methyl acrylate copolymer, ethylene-butyl acrylate copolymer, ethylene-butene copolymer, and ethylene-octene copolymer.

5. The flame-retardant and aging-resistant polyolefin cable material as described in claim 1, characterized in that, The organic compatibilizer is at least one of polyethylene grafted with maleic anhydride, polypropylene grafted with maleic anhydride, copolymer of styrene and maleic anhydride, and polyolefin elastomer grafted with maleic anhydride.

6. The flame-retardant and aging-resistant polyolefin cable material as described in claim 1, characterized in that, The flame retardant is a compound of organic and inorganic flame retardants.

7. The flame-retardant and aging-resistant polyolefin cable material as described in claim 1, characterized in that, The flame-retardant and aging-resistant polyolefin cable material also includes a lubricant, which is at least one of fatty acids, aliphatic amides, metal soaps, and fatty alcohols.

8. The flame-retardant and aging-resistant polyolefin cable material as described in claim 1, characterized in that, The flame-retardant and aging-resistant polyolefin cable material further includes an antioxidant, which is at least one selected from the following: bis(octadecyl)hydroxylamine, tris[2,4-di-tert-butylphenyl]phosphite, pentaerythritol tetra(3-lauryl thiopropionate), bis[3-[3-tert-butyl-4-hydroxy-5-tolyl]2,4,8,10-tetraoxaspiro[5,5]undecane-3,9-diylbis(2-methylpropane-2,1-diyl) ester, 1,5,8,12-tetra[4,6-bis(N-1,2,2,6,6-pentamethyl-4-piperidinylamino)-1,3,5-triazin-2-yl]-1,5,8,12-tetraazadodecane and N-salicylicamide phthalimide.

9. The flame-retardant and aging-resistant polyolefin cable material as described in claim 1, characterized in that, The flame-retardant and aging-resistant polyolefin cable material also includes a crosslinking aid, which is at least one of trimethylolpropane triacrylate, trimethylolpropane trimethacrylate diacrylate, ethylene glycol dimethacrylate, N,N-p-phenylbismaleimide, zinc diacrylate, and zinc dimethacrylate.

10. The method for preparing a flame-retardant and aging-resistant polyolefin cable material as described in claim 1, characterized in that, Includes the following steps: Preparation of flame-retardant and aging-resistant polyolefin cable material: Polyethylene, polyolefin elastomer, organic compatibilizer, modified nano aluminum hydroxide / hexagonal boron nitride nanocomposite powder, flame retardant, lubricant, antioxidant and crosslinking aid are premixed evenly and then kneaded in an internal mixer to prepare a melt blend; the melt blend is granulated in a twin-screw-single-screw hot-cutting air-cooled granulation unit, followed by secondary air cooling and vibrating screening to finally obtain the flame-retardant and aging-resistant polyolefin cable material.

11. The method for preparing the flame-retardant and aging-resistant polyolefin cable material as described in claim 10, characterized in that, The silane coupling agent is at least one of 3-aminopropyltriethoxysilane, γ-aminopropyltriethoxysilane, and γ-glycidoxypropyltrimethoxysilane.

12. A cable, characterized in that, The cable is made from the cable material of claim 1.

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