Low-smoke halogen-free flame-retardant cable material for locomotive cable and preparation method of low-smoke halogen-free flame-retardant cable material

Abstract

The invention relates to the technical field of cables, and provides a low-smoke halogen-free flame-retardant cable material for locomotive cables and a preparation method thereof.The cable material is prepared from, by weight, 50-70 parts of polyethylene, 30-50 parts of polyethylene glycol terephthalate, 30-40 parts of filler, 0.5-1.5 parts of antioxidant, 1-2 parts of lubricant, 2-4 parts of compatilizer and 20-30 parts of modified flame retardant; the modified flame retardant is obtained by modifying calcium borate with an amino compound. According to the technical scheme, the problems of poor flame retardance and mechanical property of the cable in the prior art are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of cables, and in particular to a low-smoke halogen-free flame-retardant cable material for locomotive cables and a preparation method thereof. Background Art

[0002] Locomotive cables refer to special cables used inside locomotive vehicles (such as trains, subways, light rails, etc.) and connecting various components. They are mainly used for power transmission, signal control, and other electrical devices with flame retardant requirements. These cables need to meet strict performance requirements because they not only have to work in complex electrical environments, but also have to withstand mechanical stress, temperature changes, and fire. In order to improve the flame retardancy of cables, halides are generally added to the cable sheath as flame retardants. However, when a fire occurs, the burning of the cable will release toxic gases and a large amount of smoke, which will not only harm the environment, but also the fine particles and toxic substances in the smoke will harm the human respiratory system, increasing the risk of escape. Therefore, in order to ensure the safety of equipment and personnel inside the locomotive, it is of great significance to prepare a low-smoke, halogen-free, and highly flame-retardant cable for use on locomotives. Summary of the invention

[0003] The invention provides a low-smoke halogen-free flame-retardant cable material for locomotive cables and a preparation method thereof, which solves the problem of poor flame retardancy and mechanical properties of cables in the related art.

[0004] The technical solution of the present invention is as follows: The present invention provides a low-smoke halogen-free flame-retardant cable material for locomotive cables, comprising the following raw materials in parts by weight: 50-70 parts of polyethylene, 30-50 parts of polyethylene terephthalate, 30-40 parts of filler, 0.5-1.5 parts of antioxidant, 1-2 parts of lubricant, 2-4 parts of compatibilizer, and 20-30 parts of modified flame retardant; The modified flame retardant is obtained by modifying calcium borate with an amino compound.

[0005] As a further technical solution, the amino compound includes one or two of vinylguanamine and polyhexamethylene sebacamide.

[0006] As a further technical solution, the amino compound consists of vinylguanamine and polyhexamethylenesebacate.

[0007] In the present invention, the flame retardancy and mechanical properties of the cable material are improved by limiting the amino compound to consist of vinylguanamine and polyhexamethylene sebacamide.

[0008] As a further technical solution, the mass ratio of the vinylguanamine to the polyhexamethylene sebacamide is 1:1.

[0009] As a further technical solution, the amount of the amino compound added is 1% to 5% of the mass of calcium borate.

[0010] As a further technical solution, the preparation method of the modified flame retardant comprises the following steps: adding calcium borate into water, adding a modifier for modification, filtering and drying to obtain the modified flame retardant.

[0011] As a further technical solution, the modification temperature is 50-60°C and the modification time is 4-6h.

[0012] As a further technical solution, the preparation method of the modified flame retardant includes the following steps: adding calcium borate to water, adding a first modifier for a first modification, adding a second modifier for a second modification, filtering, and drying to obtain the modified flame retardant.

[0013] As a further technical solution, the first modifier is polyhexamethylene sebacamide, and the second modifier is vinylguanamine.

[0014] In the present invention, by limiting the first modifier to polyhexamethylene sebacamide and the second modifier to vinylguanamine, the flame retardancy and mechanical properties of the cable material are further improved.

[0015] As a further technical solution, the polyethylene terephthalate is composed of a first polyethylene terephthalate and a second polyethylene terephthalate, and the first polyethylene terephthalate and the second polyethylene terephthalate have different terminal carboxyl group contents.

[0016] In the present invention, by limiting the terminal carboxyl content of the first polyethylene terephthalate and the second polyethylene terephthalate to be different, the flame retardancy and mechanical properties of the cable material are further improved.

[0017] As a further technical solution, the terminal carboxyl content of the first polyethylene terephthalate is 17 mmol / kg, and the terminal carboxyl content of the second polyethylene terephthalate is 33 mmol / kg.

[0018] As a further technical solution, the mass ratio of the first polyethylene terephthalate to the second polyethylene terephthalate is 2-5:1.

[0019] In the present invention, by limiting the mass ratio of the first polyethylene terephthalate to the second polyethylene terephthalate to 2-5:1, the flame retardancy and mechanical properties of the cable material are further improved.

[0020] As a further technical solution, the mass ratio of the first polyethylene terephthalate to the second polyethylene terephthalate is 4:1.

[0021] As a further technical solution, the polyethylene consists of high-density polyethylene and low-density polyethylene.

[0022] In the present invention, the mechanical properties of the cable material are improved by limiting the polyethylene to consist of high-density polyethylene and low-density polyethylene.

[0023] As a further technical solution, the mass ratio of the high-density polyethylene to the low-density polyethylene is 4:1.

[0024] As a further technical solution, the antioxidant includes one or more of antioxidant 1010 , antioxidant 1024 , and antioxidant 1098 .

[0025] As a further technical solution, the filler includes one or more of talc, white carbon black, and dolomite.

[0026] As a further technical solution, the lubricant includes one or more of oleamide, polyethylene wax, and calcium stearate.

[0027] As a further technical solution, the compatibilizer includes one or two of maleic anhydride grafted polyethylene and ethylene octene copolymer.

[0028] The present invention also provides a method for preparing a low-smoke halogen-free flame-retardant cable material for locomotive cables, comprising the following steps: The raw material components are mixed in proportion by weight and then extruded to obtain a low-smoke halogen-free flame-retardant cable material for locomotive cables.

[0029] The working principle and beneficial effects of the present invention are: In the present invention, polyethylene is used as the base material. Since it does not contain halogen, no toxic smoke and gas will be generated during combustion, thereby reducing potential harm to personnel and the environment. By adding polyethylene terephthalate to compound with polyethylene, the flame retardancy and tensile strength of the cable material are improved. Calcium borate modified by amino compounds is added as a flame retardant to further improve the flame retardancy and mechanical properties of the cable material, thereby solving the problem of poor flame retardancy and mechanical properties of the cable material. DETAILED DESCRIPTION

[0030] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] In the following embodiments and comparative examples: High-density polyethylene, brand: DGDX-6095H, low-density polyethylene, brand: 2426H, purchased from Maoming Yexiang Plastic Co., Ltd.; Polyethylene terephthalate, model: CR-7701, terminal carboxyl content: 33 mmol / kg, model: CR-8839, terminal carboxyl content: 17 mmol / kg, purchased from China Resources Chemical Materials Technology Co., Ltd.; Poly(hexamethylene sebacate), brand: xm-001, purchased from Dongguan Xinmiao New Materials Co., Ltd.; Calcium borate, particle size 1250 mesh, purchased from Hubei Xinghengye Technology Co., Ltd.; Polyethylene wax, model MR-162, purchased from Dongguan Dingxin Plastic Raw Materials Co., Ltd.; Maleic anhydride grafted polyethylene, model: SH-12L; ethylene octene copolymer, brand: C1085, were purchased from Dongguan Shenghao Plastic Raw Materials Co., Ltd.

[0032] Example 1 A method for preparing a low-smoke halogen-free flame-retardant cable material for locomotive cables comprises the following steps: 40 parts of high-density polyethylene, 10 parts of low-density polyethylene, 30 parts of CR-7701 polyethylene terephthalate (terminal carboxyl content: 33 mmol / kg), 30 parts of talc, 0.5 parts of antioxidant 1010, 1 part of oleamide, 2 parts of maleic anhydride grafted polyethylene, and 20 parts of modified flame retardant are mixed, and after melt extrusion, a low-smoke halogen-free flame retardant cable material for locomotive cables is obtained.

[0033] The preparation method of the modified flame retardant comprises the following steps: 50 g of calcium borate (1250 mesh) and 0.5 g of vinylguanamine were added to 400 mL of water, heated to 50° C., stirred for 6 h, filtered and dried to obtain a modified flame retardant.

[0034] Example 2 48 parts of high-density polyethylene, 12 parts of low-density polyethylene, 40 parts of CR-7701 polyethylene terephthalate (terminal carboxyl content: 33 mmol / kg), 35 parts of white carbon black, 1 part of antioxidant 1024, 1.5 parts of polyethylene wax, 3 parts of maleic anhydride grafted polyethylene, and 25 parts of modified flame retardant are mixed, and after melt extrusion, a low-smoke halogen-free flame retardant cable material for locomotive cables is obtained.

[0035] The preparation method of the modified flame retardant comprises the following steps: 50 g of calcium borate (1250 mesh) and 1.5 g of vinylguanamine were added into water, heated to 55° C., stirred for 5 h, filtered and dried to obtain a modified flame retardant.

[0036] Example 3 56 parts of high-density polyethylene, 14 parts of low-density polyethylene, 50 parts of CR-7701 polyethylene terephthalate (terminal carboxyl content: 33 mmol / kg), 40 parts of dolomite, 1.5 parts of antioxidant 1098, 2 parts of calcium stearate, 4 parts of ethylene octene copolymer, and 30 parts of modified flame retardant are mixed, and after melt extrusion, a low-smoke halogen-free flame retardant cable material for locomotive cables is obtained.

[0037] The preparation method of the modified flame retardant comprises the following steps: 50 g of calcium borate (1250 mesh) and 2.5 g of vinylguanamine were added into water, heated to 60° C., stirred for 4 h, filtered and dried to obtain a modified flame retardant.

[0038] Example 4 The difference between this embodiment and embodiment 1 is that vinylguanamine is replaced by an equal amount of polyhexamethylene sebacamide.

[0039] Example 5 The present embodiment is different from the embodiment 1 only in that the preparation method of the modified flame retardant comprises the following steps: adding 50 g of calcium borate (1250 mesh) to 400 mL of water, adding 0.25 g of polyhexamethylene sebacamide, stirring at 50° C. for 3 h for the first modification, then adding 0.25 g of vinylguanamine, continuing to stir at 50° C. for 3 h for the second modification, filtering and drying to obtain the modified flame retardant.

[0040] Example 6 The difference between this embodiment and embodiment 5 is that the first modifier is vinylguanamine and the second modifier is polyhexamethylene sebacamide.

[0041] Example 7 The only difference between this embodiment and embodiment 5 is that CR-7701 polyethylene terephthalate (terminal carboxyl content: 33 mmol / kg) is replaced by an equal amount of CR-8839 polyethylene terephthalate (terminal carboxyl content: 17 mmol / kg).

[0042] Example 8 The only difference between this embodiment and embodiment 7 is that CR-7701 polyethylene terephthalate (terminal carboxyl content: 33 mmol / kg) is replaced by equal amounts of CR-8839 polyethylene terephthalate (terminal carboxyl content: 17 mmol / kg) and CR-7701 polyethylene terephthalate (terminal carboxyl content: 33 mmol / kg) in a mass ratio of 1:1.

[0043] Example 9 The only difference between this embodiment and embodiment 7 is that the mass ratio of CR-8839 polyethylene terephthalate (terminal carboxyl content: 17 mmol / kg) to CR-7701 polyethylene terephthalate (terminal carboxyl content: 33 mmol / kg) is 7:1.

[0044] Example 10 The only difference between this embodiment and embodiment 7 is that the mass ratio of CR-8839 polyethylene terephthalate (terminal carboxyl content: 17 mmol / kg) to CR-7701 polyethylene terephthalate (terminal carboxyl content: 33 mmol / kg) is 2:1.

[0045] Embodiment 11 The only difference between this embodiment and embodiment 7 is that the mass ratio of CR-8839 polyethylene terephthalate (terminal carboxyl content: 17 mmol / kg) to CR-7701 polyethylene terephthalate (terminal carboxyl content: 33 mmol / kg) is 4:1.

[0046] Example 12 The only difference between this embodiment and embodiment 7 is that the mass ratio of CR-8839 polyethylene terephthalate (terminal carboxyl content: 17 mmol / kg) to CR-7701 polyethylene terephthalate (terminal carboxyl content: 33 mmol / kg) is 5:1.

[0047] Comparative Example 1 The only difference between this comparative example and Example 1 is that the calcium borate is not modified.

[0048] Comparative Example 2 The only difference between this comparative example and Example 1 is that vinylguanamine is replaced by an equal amount of γ-mercaptopropyltriethoxysilane.

[0049] The flame retardancy and mechanical properties of the cable materials prepared in Examples 1 to 12 and Comparative Examples 1 to 2 were tested respectively, and the specific testing methods are as follows: Flame retardancy: The oxygen index is measured according to the test method in GB / T 2406.2-2009 "Determination of combustion behavior of plastics by oxygen index method Part 2: Room temperature test"; Mechanical properties: The tensile strength is measured according to the test method in GB / T 1040.3-2006 "Determination of tensile properties of plastics Part 3: Test conditions for films and sheets"; The test results are shown in Table 1.

[0050] Table 1 Cable material performance test results

[0051] Compared with Example 1, Comparative Example 1 did not modify calcium borate, and Comparative Example 2 used γ-mercaptopropyltriethoxysilane to modify calcium borate. As a result, the oxygen index and tensile strength of the cable materials prepared in Comparative Examples 1~2 were lower than those in Example 1, indicating that the use of amino compounds to modify calcium borate can improve the oxygen index and tensile strength of the cable material.

[0052] Compared with Example 1, Examples 4 to 6 adjusted the modification order of the modifiers. As a result, the oxygen index and tensile strength of the cable material prepared in Example 5 were higher than those in Examples 1, 4, and 6, indicating that the oxygen index and tensile strength of the cable material can be further improved by using polyhexamethylene sebacate for the first modification and vinylguanamine for the second modification.

[0053] Compared with Example 5, Examples 7-8 changed the composition of polyethylene terephthalate. As a result, the oxygen index and tensile strength of the cable material prepared in Example 8 were higher than those in Examples 5 and 7, indicating that when polyethylene terephthalate is composed of polyethylene terephthalate with a terminal carboxyl content of 17 mmol / kg and polyethylene terephthalate with a terminal carboxyl content of 33 mmol / kg, the oxygen index and tensile strength of the cable material can be further improved.

[0054] Compared with Example 8, Examples 9 to 12 change the mass ratio of polyethylene terephthalate with a terminal carboxyl content of 17 mmol / kg to polyethylene terephthalate with a terminal carboxyl content of 33 mmol / kg. As a result, the oxygen index and tensile strength of the cable materials obtained in Examples 10 to 12 are higher than those in Examples 8 and 9, indicating that when the mass ratio of polyethylene terephthalate with a terminal carboxyl content of 17 mmol / kg to polyethylene terephthalate with a terminal carboxyl content of 33 mmol / kg is 2 to 5:1, the oxygen index and tensile strength of the cable material can be further improved; by comparing Examples 10 to 12, it is found that the oxygen index and tensile strength of the cable material obtained in Example 11 are higher than those in Examples 10 and 12, indicating that when the mass ratio of polyethylene terephthalate with a terminal carboxyl content of 17 mmol / kg to polyethylene terephthalate with a terminal carboxyl content of 33 mmol / kg is 4:1, the oxygen index and tensile strength of the obtained cable material are the highest.

[0055] The above are only preferred embodiments of the present invention and are 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. A low-smoke halogen-free flame-retardant cable material for locomotive cables, characterized in that: The raw materials include the following components in parts by weight: 50-70 parts of polyethylene, 30-50 parts of polyethylene terephthalate, 30-40 parts of filler, 0.5-1.5 parts of antioxidant, 1-2 parts of lubricant, 2-4 parts of compatibilizer, and 20-30 parts of modified flame retardant; The modified flame retardant is obtained by modifying calcium borate with an amino compound.

2. The low-smoke halogen-free flame-retardant cable material for locomotive cables according to claim 1, characterized in that: The amino compound includes one or both of vinylguanamine and polyhexamethylene sebacamide.

3. The low-smoke halogen-free flame-retardant cable material for locomotive cables according to claim 2, characterized in that: The amino compound consists of vinylguanamine and polyhexamethylene sebacate.

4. The low-smoke halogen-free flame-retardant cable material for locomotive cables according to claim 1, characterized in that: The amount of the amino compound added is 1% to 5% of the mass of calcium borate.

5. The low-smoke halogen-free flame-retardant cable material for locomotive cables according to claim 1, characterized in that: The polyethylene terephthalate consists of a first polyethylene terephthalate and a second polyethylene terephthalate, and the first polyethylene terephthalate and the second polyethylene terephthalate have different terminal carboxyl group contents.

6. The low-smoke halogen-free flame-retardant cable material for locomotive cables according to claim 5, characterized in that: The terminal carboxyl content of the first polyethylene terephthalate is 17 mmol / kg, and the terminal carboxyl content of the second polyethylene terephthalate is 33 mmol / kg.

7. The low-smoke halogen-free flame-retardant cable material for locomotive cables according to claim 1, characterized in that: The antioxidant includes one or more of antioxidant 1010 , antioxidant 1024 , and antioxidant 1098 .

8. The low-smoke halogen-free flame-retardant cable material for locomotive cables according to claim 1, characterized in that: The lubricant includes one or more of oleamide, polyethylene wax, and calcium stearate.

9. The low-smoke halogen-free flame-retardant cable material for locomotive cables according to claim 1, characterized in that: The compatibilizer includes one or two of maleic anhydride grafted polyethylene and ethylene octene copolymer.

10. The method for preparing a low-smoke halogen-free flame-retardant cable material for locomotive cables according to any one of claims 1 to 9, characterized in that: The following steps are involved: The raw material components are mixed in proportion by weight, and after extrusion, a low-smoke halogen-free flame-retardant cable material for locomotive cables is obtained.

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