Anti-dripping silane crosslinking high-performance flame-retardant aerial cable material and preparation method thereof

Abstract

The invention discloses an anti-dripping silane crosslinking high-performance flame-retardant aerial cable material and a preparation method thereof, and belongs to the field of cable materials. The invention discloses an anti-dripping silane crosslinking high-performance flame-retardant aerial cable material. The anti-dripping silane crosslinking high-performance flame-retardant aerial cable material is prepared from the following raw material components: a component A, a component B, a component C and a component D, the component A is prepared from the following raw material components: high-density polyethylene, linear low-density polyethylene, bimodal polyethylene, a silane coupling agent, a grafting initiator and an antioxidant; the component B is prepared from the following raw material components: linear low-density polyethylene, carbon black, a silane crosslinking catalyst and an antioxidant; the component C is prepared from the following raw material components: high-density polyethylene, a polyolefin elastomer and a flame retardant; the component D is prepared from the following raw material components: high-density polyethylene and an anti-dripping agent.

Description

Technical Field

[0001] The invention relates to the field of cable materials, in particular to an anti-dripping silane cross-linked high-performance flame-retardant overhead cable material and a preparation method thereof. Background Art

[0002] With the acceleration of urbanization, the improvement of industrialization level and the continuous improvement of national requirements for safety and environmental protection, flame-retardant cable materials have shown a steadily growing demand trend in the cable industry and are being used more and more widely in many fields.

[0003] The preparation of flame-retardant cable materials is mainly to improve the flame retardant properties of cables by adding flame retardants. In practical applications, commonly used flame retardants include organic flame retardants, inorganic flame retardants, halogen flame retardants (such as organic chlorides and organic bromides) and non-halogen flame retardants. Among them, organic flame retardants are represented by bromine, phosphorus-nitrogen, nitrogen, red phosphorus and their compounds; inorganic flame retardants mainly include antimony trioxide, magnesium hydroxide, aluminum hydroxide and silicon-based flame retardant systems. In particular, bromine-based flame retardants are widely used worldwide because of their high flame retardant effect, low usage and relatively low price, and they dominate the organic flame retardant market. The bromine / antimony flame retardant system has become one of the most widely used flame retardant systems due to its synergistic flame retardant effect.

[0004] In addition to flame retardants, flame retardant and anti-drip agents are usually added to enhance the fire resistance of cable materials. The mechanism of action of this type of additive is to form an adhesion layer on the surface of the material to prevent the heat and flame generated during combustion from spreading into the material, and to reduce the droplets generated during the combustion process, thereby reducing the risk of fire spreading.

[0005] However, the existing flame retardant and anti-dripping agents and the compatibility issues between the flame retardant and the substrate often affect the processing performance of the cable material. In order to solve this problem, the present invention prepares an anti-dripping silane cross-linked high-performance flame retardant overhead cable material. Summary of the invention

[0006] The purpose of the present invention is to provide an anti-dripping silane cross-linked high-performance flame-retardant overhead cable material and a preparation method thereof, so as to solve the technical problems mentioned in the above background technology.

[0007] The technical solution to achieve the purpose of the present invention is: the present invention provides an anti-dripping silane cross-linked high-performance flame-retardant overhead cable material, the raw material components of the anti-dripping silane cross-linked high-performance flame-retardant overhead cable material include a cable base material component A, a component B with an aging resistance function, a component C with a flame retardant function, and a component D with an anti-dripping function;

[0008] The raw material components of component A include, by weight: 50-70 parts of high-density polyethylene, 20-30 parts of linear low-density polyethylene, 5-10 parts of bimodal polyethylene, 1-3 parts of silane coupling agent, 0.1-1 parts of grafting initiator, and 0.1-1 parts of antioxidant;

[0009] The raw material components of component B include, by weight: 70-90 parts of linear low-density polyethylene, 10-30 parts of carbon black, 0.5-1.5 parts of silane cross-linking catalyst, and 2-5 parts of antioxidant;

[0010] The raw material components of component C include, by weight: 10-15 parts of high-density polyethylene, 10-15 parts of polyolefin elastomer, and 50-80 parts of flame retardant;

[0011] The raw material components of the D component include: 30-40 parts of high-density polyethylene and 60-70 parts of anti-dripping agent in terms of mass fraction.

[0012] The present invention adds component B with anti-aging function, component C with flame retardant function and component D with anti-dripping function to component A of cable base material, wherein bimodal polyethylene is added to component A of cable base material, so that the anti-dripping silane cross-linked high-performance flame retardant overhead cable material can have good anti-aging function, flame retardant function and anti-dripping function, and can improve the problem of poor compatibility between flame retardant, anti-dripping agent and cable base material, so that the surface of the anti-dripping silane cross-linked high-performance flame retardant overhead cable material is smooth and the processing performance is good; by adding antioxidant and high concentration of carbon black, the anti-dripping silane cross-linked high-performance flame retardant overhead cable material has good weather aging resistance.

[0013] Furthermore, the mass ratio of the component A, the component B, the component C and the component D is 45-50:3-5:43-48:2-4.

[0014] The mass ratio of component A, component B, component C and component D of the present invention is 45-50:3-5:43-48:2-4; under this ratio, the compatibility between the flame retardant, the anti-dripping agent and the cable base material is better, and while ensuring that the anti-dripping silane cross-linked high-performance flame-retardant overhead cable material can pass the V-1 flame retardant grade test and has no dripping within 60 seconds, it can also ensure that the anti-dripping silane cross-linked high-performance flame-retardant overhead cable material has a smooth surface and good processing performance.

[0015] Furthermore, the flame retardant is any one of bromine / antimony flame retardant and magnesium / aluminum flame retardant; the bromine / antimony flame retardant is a mixture of decabromodiphenylethane and antimony trioxide, and the magnesium / aluminum flame retardant is a mixture of magnesium hydroxide and aluminum hydroxide, and the mass ratio of decabromodiphenylethane and antimony trioxide or magnesium hydroxide and aluminum hydroxide is 2:1.

[0016] The flame retardant of the present invention adopts compound flame retardants such as bromine / antimony flame retardant or magnesium / aluminum flame retardant, and utilizes the synergistic effect between compound flame retardants to greatly improve the flame retardant effect.

[0017] Furthermore, the flame retardant is bromine / antimony flame retardant.

[0018] The flame retardant of the present invention adopts bromine / antimony flame retardant, which has better compatibility with the cable base material system than magnesium / aluminum flame retardant, and the obtained anti-dripping silane cross-linked high-performance flame retardant overhead cable material has good extrusion performance, mechanical properties and electrical properties.

[0019] Furthermore, the anti-dripping agent is one or more of a boron-containing compound, a fluorine-based polymer, and a phosphoric acid compound. The present invention forms an adhesion layer on the surface of the material by adding the anti-dripping agent to prevent the heat and flame generated during combustion from spreading to the inside. At the same time, the addition of the anti-dripping agent can reduce the droplets generated after combustion, thereby reducing the possibility of fire spreading.

[0020] Furthermore, the anti-dripping agent is a boron-containing compound.

[0021] The anti-drip agent of the present application uses a boron-containing compound as the anti-drip agent and has good compatibility with the cable base material system. When the mass ratio of component A, component B, component C, and component D is 45-50:3-5:43-48:2-4, the anti-drip effect is better than that of the anti-drip agent fluorine polymer.

[0022] Furthermore, the silane coupling agent is one or more of vinyl trimethoxy silane, vinyl triethoxy silane, and vinyl tri (2-methoxyethoxy) silane.

[0023] A silane coupling agent is added to the anti-dripping silane cross-linked high-performance flame-retardant overhead cable material of the present invention, and the silane coupling agent cross-links polyethylene to form a three-dimensional network cross-linked structure, so that the cable material has the advantages of high heat resistance, good aging resistance, excellent processing performance, simple equipment, low production cost, etc. The flame retardant and anti-dripping agent in the anti-dripping silane cross-linked high-performance flame-retardant overhead cable material can improve the flame retardant and anti-dripping properties of the silane coupling agent cross-linked polyethylene; and the three-dimensional network cross-linked structure formed by the silane coupling agent cross-linked polyethylene can improve the dispersibility of the flame retardant, which is beneficial to the carbonization effect when the silane cross-linked material burns, thereby improving the flame retardant performance.

[0024] Furthermore, the antioxidant is a composite mixture of tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentyl erythritol ester, tris(2,4-di-tert-butylphenyl)phosphite, and 1,2-bis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine.

[0025] Furthermore, the grafting initiator is dicumyl peroxide.

[0026] Furthermore, the silane cross-linking catalyst is any one or both of dibutyltin dilaurate and benzenesulfonic acid.

[0027] The present invention also provides a method for preparing an anti-dripping silane cross-linked high-performance flame-retardant overhead cable material, comprising the following steps:

[0028] (1) Weigh the raw materials of component A in proportion, mix them evenly, add them into a twin-screw extruder for extrusion and granulation, pull out the material strips, cool them in a water tank, cut them into pellets, dry them, and then package them to obtain component A;

[0029] (2) Weighing the raw materials of component B according to the proportion, mixing them evenly, adding them to a twin-screw extruder for extrusion and granulation, pulling out the material strips, cooling them in a water tank, cutting them into pellets, drying them, and packaging them to obtain component B;

[0030] (3) Weigh the raw materials of component C in proportion, mix them evenly, add them into an internal mixer for mixing and granulation, and obtain component C;

[0031] (4) Weigh the raw materials of component D according to the proportion, mix them evenly, add them into an internal mixer for mixing and granulation, and obtain component D;

[0032] (5) The components A, B, C and D are mixed according to a mass ratio, extruded and then cross-linked to obtain an anti-drip silane cross-linked high-performance flame-retardant overhead cable material.

[0033] Furthermore, the crosslinking in step (5) is carried out in water or steam at 90-100°C.

[0034] Furthermore, in step (5), the C component is subjected to a modification treatment before mixing, and the modification treatment method is as follows: at 70 to 90° C., free water and crystal water remaining in the C component are extracted by vacuum negative pressure, and then a coupling agent of 0.2% to 2% by mass of the C component is added to improve the surface properties and performance of the material; the coupling agent includes any one or more combinations of vinyltrimethoxysilane, vinyltriethoxysilane, and vinyltri(2-methoxyethoxy)silane.

[0035] By adopting the above technical solution, the present invention has the following beneficial effects:

[0036] (1) The present invention adds component B with anti-aging function, component C with flame retardant function, and component D with anti-dripping function to component A of the cable base material, wherein bimodal polyethylene is added to component A of the cable base material, so that the anti-dripping silane cross-linked high-performance flame retardant overhead cable material can have good anti-aging function, flame retardant function, and anti-dripping function, and can also improve the poor compatibility between the flame retardant, the anti-dripping agent and the cable base material, so that the surface of the anti-dripping silane cross-linked high-performance flame retardant overhead cable material is smooth and the processing performance is good; by adding antioxidants and high-concentration carbon black, the anti-dripping silane cross-linked high-performance flame retardant overhead cable material has better weather aging resistance.

[0037] (2) The mass ratio of component A, component B, component C and component D of the present invention is 45-50:3-5:43-48:2-4; under this ratio, the compatibility between the flame retardant, the anti-dripping agent and the cable base material is better, while ensuring that the anti-dripping silane cross-linked high-performance flame retardant overhead cable material can pass the V-1 flame retardant grade test and has no dripping within 60 seconds, it can also ensure that the anti-dripping silane cross-linked high-performance flame retardant overhead cable material has a smooth surface and good processing performance.

[0038] (3) The flame retardant of the present invention adopts a compound flame retardant such as bromine / antimony flame retardant or magnesium / aluminum flame retardant, and utilizes the synergistic effect between the compound flame retardants to greatly enhance its flame retardant effect.

[0039] (4) The flame retardant of the present invention adopts bromine / antimony flame retardant, which has better compatibility with the cable base material system than magnesium / aluminum flame retardant. The obtained anti-drip silane cross-linked high-performance flame retardant overhead cable material has better extrusion performance, mechanical properties and electrical properties.

[0040] (5) The present invention forms an adhesion layer on the surface of the material by adding an anti-drip agent to prevent the heat and flame generated during combustion from spreading to the inside. At the same time, the addition of the anti-drip agent can reduce the droplets generated after combustion, thereby reducing the possibility of fire spreading.

[0041] (6) The anti-drip agent of the present invention uses a boron-containing compound as an anti-drip agent and has good compatibility with the cable base material system. When the mass ratio of component A, component B, component C, and component D is 45-50:3-5:43-48:2-4, the anti-drip effect is better than that of the anti-drip agent fluorine polymer.

[0042] (7) Silane coupling agent is added to the anti-dripping silane cross-linked high-performance flame-retardant overhead cable material of the present invention, and the silane coupling agent cross-links polyethylene to form a three-dimensional network cross-linked structure, so that the cable material has the advantages of high heat resistance, good aging resistance, excellent processing performance, simple equipment, and low production cost; the flame retardant and anti-dripping agent in the anti-dripping silane cross-linked high-performance flame-retardant overhead cable material can improve the flame retardant and anti-dripping properties of the silane coupling agent cross-linked polyethylene; and the three-dimensional network cross-linked structure formed by the silane coupling agent cross-linked polyethylene can improve the dispersibility of the flame retardant, which is beneficial to the carbonization effect when the silane cross-linked material burns, thereby improving the flame retardant performance.

[0043] (8) Component C of the present invention is subjected to a modification treatment before being mixed with components A, B and D, thereby removing the residual free water and crystal water in component C, and improving the surface properties and performance of the material by adding a coupling agent. DETAILED DESCRIPTION

[0044] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with specific implementation methods. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the scope of protection of the present invention.

[0045] (Example)

[0046] An anti-dripping silane cross-linked high-performance flame-retardant overhead cable material comprises four components A, B, C and D, wherein the mass ratio of the four components A, B, C and D is 45-50:3-5:43-48:2-4. The raw material components of component A include, by mass, 50-70 parts of high-density polyethylene, 20-30 parts of linear low-density polyethylene, 5-10 parts of bimodal polyethylene, 1-3 parts of silane coupling agent, 0.1-1 part of grafting initiator, and 0.1-1 part of antioxidant; the raw material components of component B include, by mass, 70-90 parts of linear low-density polyethylene, 10-30 parts of carbon black, 0.5-1.5 parts of silane cross-linking catalyst, and 2-5 parts of antioxidant; the raw material components of component C include, by mass, 10-15 parts of high-density polyethylene, 10-15 parts of polyolefin elastomer, and 50-80 parts of flame retardant; the raw material components of component D include, by mass, 30-40 parts of high-density polyethylene and 60-70 parts of anti-drip agent.

[0047] The flame retardant is a bromine / antimony flame retardant, which is a mixture of decabromodiphenylethane and antimony trioxide, and the compounding mass ratio is 2:1.

[0048] The anti-dripping agent is a boron-containing compound; the preferred boron-containing compound in this embodiment is 203CV-D produced by Zhejiang Wanma Polymer Materials Group Co., Ltd.

[0049] The antioxidant is a compound mixture of tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentyl alcohol ester, tris(2,4-di-tert-butylphenyl)phosphite and 1,2-bis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine in a weight ratio of 1:1.5:1.5.

[0050] The silane coupling agent is vinyltrimethoxysilane.

[0051] The grafting initiator is dicumyl peroxide.

[0052] The silane cross-linking catalyst is dibutyltin dilaurate.

[0053] The method for preparing the anti-dripping silane cross-linked high-performance flame-retardant overhead cable material comprises the following steps:

[0054] (1) Weigh the raw materials of component A in proportion, mix them evenly, add them into a twin-screw extruder for extrusion and granulation, pull out the material strips, cool them in a water tank, cut them into pellets, dry them, and then package them to obtain component A;

[0055] (2) Weighing the raw materials of component B according to the proportion, mixing them evenly, adding them to a twin-screw extruder for extrusion and granulation, pulling out the material strips, cooling them in a water tank, cutting them into pellets, drying them, and packaging them to obtain component B;

[0056] (3) Weigh the raw materials of component C in proportion, mix them evenly, add them into an internal mixer for mixing and granulation, and obtain component C;

[0057] (4) Weigh the raw materials of component D according to the proportion, mix them evenly, add them into an internal mixer for mixing and granulation, and obtain component D;

[0058] (5) The components A, B, C and D are mixed according to a mass ratio, extruded and then cross-linked in water or steam at 90 to 100° C. to obtain an anti-drip silane cross-linked high-performance flame-retardant overhead cable material.

[0059] The temperature settings of each stage of the extrusion molding in step (5) are: 120-140° C. for the feeding section, 150-190° C. for the compression section, 205-225° C. for the plasticizing section, 170-180° C. for the flange, 170-180° C. for the machine neck, 210-230° C. for the machine head, and 230-240° C. for the eye mold.

[0060] In step (5), the C component is subjected to a modification treatment before mixing, and the modification treatment method is as follows: at 70 to 90° C., free water and crystal water remaining in the C component are extracted by vacuum negative pressure, and then a coupling agent of 0.2% to 2% by mass of the C component is added to improve the surface properties and performance of the material; the coupling agent includes any one or more combinations of vinyl trimethoxy silane, vinyl triethoxy silane, and vinyl tri (2-methoxyethoxy) silane.

[0061] (Example 1)

[0062] A high-performance flame-retardant anti-dripping silane cross-linked overhead cable material includes four components A, B, C, and D, and the mass ratio of the four components A, B, C, and D is 47.5:5:45:2.5. The raw material components of the A component include, by mass, 60 parts of high-density polyethylene, 28 parts of linear low-density polyethylene, 10 parts of bimodal polyethylene, 1.4 parts of silane coupling agent, 0.2 parts of grafting initiator, and 0.4 parts of antioxidant; the raw material components of the B component include, by mass, 76.5 parts of linear low-density polyethylene, 20 parts of carbon black, 1 part of silane cross-linking catalyst, and 2.5 parts of antioxidant; the raw material components of the C component include, by mass, 15 parts of high-density polyethylene, 10 parts of polyolefin elastomer, and 75 parts of flame retardant; the raw material components of the D component include, by mass, 40 parts of high-density polyethylene and 60 parts of anti-dripping agent.

[0063] The flame retardant is a mixture of decabromodiphenylethane and antimony trioxide in a weight ratio of 2:1;

[0064] The antioxidant is a compound mixture of tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentyl alcohol ester, tris(2,4-di-tert-butylphenyl)phosphite, and 1,2-bis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine in a weight ratio of 1:1.5:1.5;

[0065] The anti-dripping agent is a boron-containing compound;

[0066] The silane coupling agent is vinyl trimethoxy silane;

[0067] The grafting initiator is dicumyl peroxide;

[0068] The silane cross-linking catalyst is dibutyltin dilaurate.

[0069] The method for preparing the anti-dripping silane cross-linked high-performance flame-retardant overhead cable material comprises the following steps:

[0070] (1) Weigh the raw materials of component A in proportion, mix them evenly, add them into a twin-screw extruder for extrusion and granulation, pull out the material strips, cool them in a water tank, cut them into pellets, dry them, and then package them to obtain component A;

[0071] (2) Weighing the raw materials of component B according to the proportion, mixing them evenly, adding them to a twin-screw extruder for extrusion and granulation, pulling out the material strips, cooling them in a water tank, cutting them into pellets, drying them, and packaging them to obtain component B;

[0072] (3) Weigh the raw materials of component C in proportion, mix them evenly, add them into an internal mixer for mixing and granulation, and obtain component C;

[0073] (4) Weigh the raw materials of component D according to the proportion, mix them evenly, add them into an internal mixer for mixing and granulation, and obtain component D;

[0074] (5) The components A, B, C and D are mixed according to a mass ratio, extruded and then cross-linked in water or steam at 90 to 100° C. to obtain an anti-drip silane cross-linked high-performance flame-retardant overhead cable material.

[0075] The temperature settings of each stage of the extrusion molding in step (5) are: 120-140° C. for the feeding section, 150-190° C. for the compression section, 205-225° C. for the plasticizing section, 170-180° C. for the flange, 170-180° C. for the machine neck, 210-230° C. for the machine head, and 230-240° C. for the eye mold.

[0076] (Example 2)

[0077] The difference from Example 1 is that the mass ratio of the four components A, B, C, and D is 50:3:43:4.

[0078] (Example 3)

[0079] The difference from Example 1 is that the mass ratio of the four components A, B, C, and D is 45:5:48:2.

[0080] (Comparative Example 1)

[0081] The difference from Example 1 is that the raw material components of component A include, by mass, 28 parts of high-density polyethylene, 70 parts of linear low-density polyethylene, 1.4 parts of silane coupling agent, 0.2 parts of grafting initiator, and 0.4 parts of antioxidant.

[0082] (Comparative Example 2)

[0083] The difference from Example 1 is that the raw material components of the B component include, by mass, 92.5 parts of linear low-density polyethylene, 4 parts of carbon black, 1 part of silane cross-linking catalyst, and 2.5 parts of antioxidant.

[0084] (Comparative Example 3)

[0085] The difference from Example 1 is that the addition ratio of the C component is 30%, so the mass ratio of the four components A, B, C, and D is 62.5:5:30:2.5.

[0086] (Comparative Example 4)

[0087] The difference from Example 1 is that the raw material components of the C component include, by mass, 10 parts of high-density polyethylene, 10 parts of polyolefin elastomer, 5 parts of compatibilizer, and 75 parts of flame retardant. The flame retardant is a magnesium / aluminum flame retardant, which is a mixture of magnesium hydroxide and aluminum hydroxide, and the compounding mass ratio is 2:1. Therefore, the mass fraction of magnesium hydroxide is 50 parts, and the mass fraction of aluminum hydroxide is 25 parts.

[0088] (Comparative Example 5)

[0089] The difference from Comparative Example 3 is that the raw material components of the C component include: 10 parts of high-density polyethylene, 10 parts of polyolefin elastomer, 5 parts of compatibilizer, and 75 parts of flame retardant by mass. The flame retardant is a magnesium / aluminum flame retardant, which is a mixture of magnesium hydroxide and aluminum hydroxide, and the compounding mass ratio is 2:1. Therefore, the mass fraction of magnesium hydroxide is 50 parts, and the mass fraction of aluminum hydroxide is 25 parts. It is consistent with the C component and mass fraction used in Comparative Example 4.

[0090] (Comparative Example 6)

[0091] The difference from Example 1 is that the mass ratio of the four components A, B, C, and D is 45:5:45:5.

[0092] (Comparative Example 7)

[0093] The difference from Example 1 is that the mass ratio of the four components A, B, C, and D is 48.5:5:45:1.5.

[0094] (Comparative Example 8)

[0095] The difference from Example 1 is that the D component is a fluorine-based polymer; the fluorine-based polymer is 103F produced by Zhejiang Wanma Polymer Materials Group Co., Ltd.

[0096] (Comparative Example 9)

[0097] The difference from Comparative Example 8 is that the addition ratio of the D component is 5%, so the mass ratio of the four components A, B, C, and D is 45:5:45:5.

[0098] (Comparative Example 10)

[0099] The difference from Example 1 is that component C and component D are not added, so the mass ratio of components A and B is 95:5;

[0100] The raw material components of component A include, by mass, 28 parts of high-density polyethylene, 70 parts of linear low-density polyethylene, 1.4 parts of silane coupling agent, 0.2 parts of grafting initiator, and 0.4 parts of antioxidant; the raw material components of component B include, by mass, 92.5 parts of linear low-density polyethylene, 4 parts of carbon black, 1 part of silane cross-linking catalyst, and 2.5 parts of antioxidant.

[0101] (Effect Example)

[0102] The anti-dripping silane cross-linked high-performance flame-retardant overhead cable materials prepared in each embodiment and comparative example were tested for appearance, extrusion, mechanical properties, artificial weathering aging resistance, electrical properties, anti-dripping performance, and flame retardancy. The test methods and technical requirements are as follows:

[0103] Appearance: Anti-drip silane cross-linked high-performance flame-retardant overhead cable materials are required to be in the form of granules with uniform size and color, no larger than 3×4mm, and no obvious powdery matter between the particles.

[0104] Extrusion performance: Take the anti-drip silane cross-linked high-performance flame-retardant overhead cable material prepared in the examples and comparative examples, and extrude it continuously for 5 minutes in a single-screw extruder to observe whether the extruded surface is smooth and whether it can be elongated during extrusion to verify the material processing performance.

[0105] Mechanical properties: The anti-drip silane cross-linked high-performance flame-retardant overhead cable materials prepared in the examples and comparative examples were tested according to the GB / T 1040.3-2006 method, requiring a tensile strength of ≥13.5 MPa and an elongation at break of ≥350%.

[0106] Artificial weathering aging resistance: The anti-drip silane cross-linked high-performance flame-retardant overhead cable materials prepared in the embodiments and comparative examples were tested in accordance with Appendix C of GB / T 14049, with the requirements that ① the change rate of tensile strength and the change rate of elongation at break after 42 days of artificial weathering aging are ≤±30%; ② the change rate of tensile strength after 42 days compared with 21 days of artificial weathering aging, and the change rate of elongation at break after 42 days compared with 21 days are ≤±15%.

[0107] Electrical properties: The anti-drip silane cross-linked high-performance flame-retardant overhead cable materials prepared in the examples and comparative examples were tested according to GB / T 31838.2, requiring a volume resistivity (20°C) of ≥1.0×10^14Ω.m

[0108] Flame retardant properties: Take the anti-drip silane cross-linked high-performance flame retardant overhead cable materials prepared in the examples and comparative examples. ① Flame retardant grade is in accordance with the requirements of GB / T 2408 test V-1. After two 10s combustion tests on the samples, the flame is extinguished within 60s and no burning materials can fall.

[0109] Anti-dripping performance: Take the anti-dripping silane cross-linked high-performance flame-retardant overhead cable material prepared in the embodiment and the comparative example, and during the combustion process according to actual demand requirements, there is no dripping within 60 seconds after the fire supply is stopped.

[0110] The specific results are shown in the following table.

[0111]

[0112]

[0113]

[0114] Analyzing the above table, all properties of the anti-dripping silane cross-linked high-performance flame-retardant overhead cable materials prepared according to the method of the present invention in Examples 1-3 meet the requirements. Compared with Example 1, Comparative Example 1 does not add bimodal polyethylene and changes the proportion of raw materials of component A, resulting in an uneven surface of the material during continuous extrusion, affecting mass production. The anti-dripping silane cross-linked high-performance flame-retardant overhead cable material prepared in Example 1 has a smooth surface during continuous extrusion and good extrusion performance; Compared with Example 1, Comparative Example 2 reduces the carbon black content of component B, and the product's resistance to artificial weathering aging does not meet the standards, which is a necessary indicator for overhead cables. Therefore, sufficient carbon black must be added to meet the actual use requirements of the product. Under the amount of carbon black added in Example 1, the prepared The artificial weathering aging resistance of the anti-dripping silane cross-linked high-performance flame-retardant overhead cable material meets the standard; compared with Example 1, the proportion of the flame retardant component of the material is reduced in Comparative Example 3, resulting in the material failing to pass the V-1 test, indicating that the addition ratio of the flame retardant of the present invention has a great influence on the flame retardant performance; compared with Example 1, the magnesium / aluminum flame retardant system is selected in Comparative Examples 4-5, resulting in poor extrusion performance, mechanical properties, and electrical properties of the material, indicating that the compatibility of the magnesium / aluminum flame retardant with the substrate system is poor, and even if the proportion of the flame retardant component is reduced by 1 / 3, the material performance is still not much improved; compared with Example 1, the anti-dripping agent of Comparative Examples 6-7 The addition ratio is not within the preferred range. When the addition ratio is greater than the optimal ratio, small spots and bumps begin to appear on the surface after continuous extrusion for a period of time. When the addition ratio is less than the optimal ratio, the dripping time is less than 60s. Compared with Example 1, Comparative Examples 8-9 use fluorine-based polymers as anti-drip agents. During the extrusion process, the fluorine-based polymers are fiberized and extruded under the action of shear force, and can shrink when the material burns, thereby achieving an anti-drip effect. However, the compatibility of fluorine-based polymers with the substrate system is poor, and the anti-drip effect is also poor at the same addition ratio. Therefore, boron-containing compounds are selected as the anti-drip agent of the system. agent; compared with Example 1, Comparative Example 10 selects component A and component B with poor performance, and does not add components C and D; it can be seen that when there are no components C and D, the formula is continuously extruded without abnormalities. It can be seen from Comparative Example 1 that component A has poor compatibility with the filled components C and D; due to the low carbon black content of component B, it cannot pass the artificial weathering resistance test; at the same time, due to the lack of addition of components C and D, i.e., flame retardant and anti-dripping agent, the finished product cannot pass the flame retardant and anti-dripping tests. It can be seen that the raw materials and mass fractions of each component, the ratio and combination of each component have a significant impact on the finished product.

[0115] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An anti-drip silane cross-linked high-performance flame-retardant overhead cable material, characterized in that: The raw material components of the anti-dripping silane cross-linked high-performance flame-retardant overhead cable material include a cable base material component A, a component B with an aging resistance function, a component C with a flame-retardant function, and a component D with an anti-dripping function; The raw material components of component A include, by weight: 50-70 parts of high-density polyethylene, 20-30 parts of linear low-density polyethylene, 5-10 parts of bimodal polyethylene, 1-3 parts of silane coupling agent, 0.1-1 parts of grafting initiator, and 0.1-1 parts of antioxidant; The raw material components of component B include, by weight: 70-90 parts of linear low-density polyethylene, 10-30 parts of carbon black, 0.5-1.5 parts of silane cross-linking catalyst, and 2-5 parts of antioxidant; The raw material components of component C include, by weight: 10-15 parts of high-density polyethylene, 10-15 parts of polyolefin elastomer, and 50-80 parts of flame retardant; The raw material components of the D component include: 30-40 parts of high-density polyethylene and 60-70 parts of anti-dripping agent in terms of mass fraction.

2. The anti-drip silane cross-linked high-performance flame-retardant overhead cable material according to claim 1, characterized in that: The mass ratio of the component A, the component B, the component C and the component D is 45-50:3-5:43-48:2-4.

3. The anti-drip silane cross-linked high-performance flame-retardant overhead cable material according to claim 1, characterized in that: The flame retardant is any one of bromine / antimony flame retardant and magnesium / aluminum flame retardant; the bromine / antimony flame retardant is a mixture of decabromodiphenylethane and antimony trioxide, and the magnesium / aluminum flame retardant is a mixture of magnesium hydroxide and aluminum hydroxide. The mass ratio of decabromodiphenylethane and antimony trioxide or magnesium hydroxide and aluminum hydroxide is 2:

1.

4. The anti-drip silane cross-linked high-performance flame-retardant overhead cable material according to claim 1, characterized in that: The flame retardant is bromine / antimony flame retardant.

5. The anti-drip silane cross-linked high-performance flame-retardant overhead cable material according to claim 1, characterized in that: The anti-dripping agent is one or more of a boron-containing compound, a fluorine-based polymer, and a phosphoric acid compound.

6. The anti-drip silane cross-linked high-performance flame-retardant overhead cable material according to claim 1, characterized in that: The anti-dripping agent is a boron-containing compound.

7. The anti-drip silane cross-linked high-performance flame-retardant overhead cable material according to claim 1, characterized in that: The silane coupling agent is one or more of vinyl trimethoxy silane, vinyl triethoxy silane and vinyl tri (2-methoxyethoxy) silane.

8. The anti-drip silane cross-linked high-performance flame-retardant overhead cable material according to claim 1, characterized in that: The antioxidant is a composite mixture of tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentyl alcohol ester, tris(2,4-di-tert-butylphenyl)phosphite and 1,2-bis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hydrazine.

9. The method for preparing the anti-dripping silane cross-linked high-performance flame-retardant overhead cable material according to any one of claims 1 to 8, characterized in that: The following steps are involved: (1) Weigh the raw materials of component A in proportion, mix them evenly, add them into a twin-screw extruder for extrusion and granulation, pull out the material strips, cool them in a water tank, cut them into pellets, dry them, and then package them to obtain component A; (2) Weighing the raw materials of component B according to the proportion, mixing them evenly, adding them to a twin-screw extruder for extrusion and granulation, pulling out the material strips, cooling them in a water tank, cutting them into pellets, drying them, and packaging them to obtain component B; (3) Weigh the raw materials of component C in proportion, mix them evenly, add them into an internal mixer for mixing and granulation, and obtain component C; (4) Weigh the raw materials of component D according to the proportion, mix them evenly, add them into an internal mixer for mixing and granulation, and obtain component D; (5) The components A, B, C and D are mixed according to a mass ratio, extruded and then cross-linked to obtain an anti-drip silane cross-linked high-performance flame-retardant overhead cable material.

10. The method for preparing the anti-drip silane cross-linked high-performance flame-retardant overhead cable material according to claim 9, characterized in that: The crosslinking in step (5) is carried out in water or steam at 90-100°C.

Images