Marine power cable bunched A-type flame-retardant thermoplastic halogen-free low-smoke oil-resistant polyolefin sheath material and preparation method thereof

Abstract

The invention discloses a marine power cable bunched A-type flame-retardant thermoplastic halogen-free low-smoke oil-resistant polyolefin sheath material and a preparation method thereof. The sheath material is prepared from the following raw materials in parts by weight: 60-100 parts of polyolefin resin, 2-30 parts of a compatilizer, 100-150 parts of a flame retardant, 20-40 parts of a filler, 1-10 parts of a lubricant, 1-4 parts of an antioxidant and 1-6 parts of a coupling agent. By carefully selecting a raw material formula and optimizing a preparation process, balance and improvement of multiple properties such as flame retardance, oil resistance, low smoke and no halogen are successfully realized, especially by adding a specific type of filler, not only is the dispersity of the flame retardant improved, but also the flame-retardant effect and oil resistance of the material are further enhanced, and the flame-retardant performance and the oil resistance of the material are improved. And a powerful guarantee is provided for safe use of the marine power cable.

Description

Technical Field

[0001] The invention relates to the technical field of wire and cable materials, and in particular to a bundled class A flame-retardant thermoplastic halogen-free, low-smoke, oil-resistant polyolefin sheath material for shipboard power cables and a preparation method thereof. Background Art

[0002] Polyolefin polymer materials are widely used in the wire and cable industry, thanks to their good physical and chemical properties. However, polyolefin materials themselves are flammable and combustible, and they produce a lot of smoke and toxic gases during combustion, which greatly limits their scope of use, especially in ship environments with extremely high safety requirements. Therefore, the development of polyolefin sheath materials with flame retardant, low smoke, halogen-free, oil-resistant and other properties has become an urgent need in the industry.

[0003] At present, there are some flame-retardant polyolefin materials on the market, but they often have difficulty in achieving a balance between flame retardancy, oil resistance and environmental protection. For example, although some flame-retardant materials can effectively prevent the spread of flames, they still produce a large amount of toxic smoke when burning, causing harm to the human body and the environment; while some materials with good oil resistance may not meet the safety standards for marine cables in terms of flame retardancy.

[0004] In addition, existing flame-retardant polyolefin materials often require a large amount of flame retardants during the preparation process, which not only increases production costs, but may also have adverse effects on the mechanical properties and processing properties of the materials. At the same time, the dispersibility of flame retardants and other additives is also one of the key factors restricting the improvement of material performance. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention proposes a class A flame-retardant thermoplastic halogen-free, low-smoke, oil-resistant polyolefin sheath material for bundled marine power cables and a preparation method thereof. By carefully selecting the raw material formula and optimizing the preparation process, the present invention successfully achieves the balance and improvement of multiple properties such as flame retardancy, oil resistance, low smoke, and halogen-free. In particular, by adding a specific type of filler, not only the dispersibility of the flame retardant is improved, but also the flame retardant effect and oil resistance of the material are further enhanced, providing a strong guarantee for the safe use of marine power cables.

[0006] The present invention adopts the following technical solution:

[0007] A class A flame-retardant thermoplastic halogen-free, low-smoke, oil-resistant polyolefin sheath material for marine power cables is prepared from the following raw materials in parts by weight:

[0008]

[0009] Preferably, the polyolefin resin is one or a combination of linear low density polyethylene, ethylene vinyl acetate copolymer, ethylene ethyl acrylate copolymer, ethylene methyl acrylate copolymer, ethylene butyl acrylate copolymer, ethylene propylene rubber, ethylene butene copolymer, ethylene hexene copolymer and ethylene octene copolymer.

[0010] Preferably, the compatibilizer is one or a combination of maleic anhydride grafted polyethylene, maleic anhydride grafted ethylene vinyl acetate, maleic anhydride grafted ethylene octene copolymer, maleic anhydride grafted ethylene propylene rubber and ethylene acrylate maleic anhydride terpolymer.

[0011] Preferably, the flame retardant is a combination of three or more of aluminum hydroxide, magnesium hydroxide, ammonium polyphosphate, triphenyl phosphate, melamine polyphosphate, organic aluminum hypophosphite, inorganic aluminum hypophosphite, red phosphorus, montmorillonite, and sepiolite.

[0012] Preferably, the filler is one or a combination of talc, calcium carbonate and kaolin.

[0013] Preferably, the lubricant is one or a combination of zinc stearate, calcium stearate, magnesium stearate, polyethylene wax, ethylene bisstearamide, silicone oil, and silicone.

[0014] Preferably, the antioxidant is one or a combination of tetrakis[β(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol, tris[2.4-di-tert-butylphenyl]phosphite, distearyl thiodipropionate, dilauryl thiodipropionate, 4.4'-bis(α.α-dimethylbenzyl)diphenylamine, and 4,4'-thiobis(6-tert-butyl-3-methylphenol).

[0015] Preferably, the coupling agent is one or a combination of silane coupling agent, titanate coupling agent, aluminate coupling agent, and stearic acid.

[0016] A method for preparing a bundled class A flame-retardant thermoplastic halogen-free, low-smoke, oil-resistant polyolefin sheath material for marine power cables comprises the following steps:

[0017] S1. Weigh each component according to the specified mass ratio and set aside;

[0018] S2, pouring the polyolefin resin into the internal mixer, starting the internal mixer without pressurizing, pouring the coupling agent into the internal mixer and mixing with the polyolefin resin for 10 to 15 seconds, and stopping the internal mixer;

[0019] S3. Pour the remaining components according to the formula composition, start the internal mixer, lower the pressure hammer, pressurize and internally mix to 100-105℃, then lift the pressure hammer, lower the pressure hammer again after the material in the internal mixer is turned over, pressurize and internally mix to 120-125℃, then lift the pressure hammer again, lower the pressure hammer for the third time after the material in the internal mixer is turned over, and discharge the material when the internal mixer is mixed to 135-145℃ and send it to the conical feeder;

[0020] S4. The material in the conical feeder is dispersed by a twin-screw melt extruder at an extrusion temperature of 90-150°C, and then enters a single-screw extruder at an extrusion temperature of 90-140°C for granulation. After hot cutting, air cooling and screening, the marine power cable bundled Class A flame-retardant thermoplastic halogen-free, low-smoke and oil-resistant polyolefin sheath material can be obtained.

[0021] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0022] A. The present invention achieves efficient flame retardant effect through a carefully selected flame retardant combination, including inorganic flame retardants such as aluminum hydroxide and magnesium hydroxide, and organic flame retardants such as ammonium polyphosphate and triphenyl phosphate. These flame retardants can absorb heat and dilute oxygen and combustible gases during the combustion of the material, thereby effectively inhibiting the spread of flames. At the same time, the addition of fillers further improves the dispersibility of the flame retardant and enhances the flame retardant effect, so that the polyolefin sheath material of the present invention has excellent bundled Class A flame retardant properties.

[0023] B. The present invention significantly improves the oil resistance of the material by selecting a specific polyolefin resin as the base material and combining it with the reinforcing effect of the filler. The filler not only helps to improve the mechanical strength of the material, but also effectively blocks the penetration of oil into the material, thereby ensuring that the cable sheath maintains good oil resistance during long-term use.

[0024] C. The raw materials used in the present invention are halogen-free, produce low smoke during combustion, and are non-toxic and non-corrosive. This feature enables the polyolefin sheath material of the present invention to significantly reduce smoke emissions in fire accidents when used in closed environments such as ships, reduce hazards to personnel and equipment, and meet the requirements of current environmental protection regulations. DETAILED DESCRIPTION

[0025] The present invention can be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. Instead, these embodiments are provided so that the present disclosure will be thorough and complete and will fully convey the concept of the present invention to those skilled in the art. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present invention.

[0026] Embodiment 1:

[0027] A class A flame-retardant thermoplastic halogen-free, low-smoke, oil-resistant polyolefin sheath material for marine power cables, which is made of the following raw materials in proportion by weight:

[0028] Linear low density polyethylene 29 parts

[0029] 50 parts of ethylene-vinyl acetate copolymer

[0030] Maleic anhydride grafted polyethylene 21 parts

[0031] Aluminum hydroxide 110 parts

[0032] 20 parts of magnesium hydroxide

[0033]

[0034] The preparation method of the bundled class A flame-retardant thermoplastic halogen-free, low-smoke, oil-resistant polyolefin sheath material for marine power cables of this embodiment comprises the following steps:

[0035] S1. Weigh each component according to the specified mass ratio and set aside;

[0036] S2, pouring the polyolefin resin into an internal mixer, starting the internal mixer without applying pressure, pouring the coupling agent into the internal mixer and mixing with the polyolefin resin for 12 seconds, and stopping the internal mixer;

[0037] S3. Pour the remaining components according to the formula, start the internal mixer, lower the pressure hammer, lift the pressure hammer when the internal mixer reaches 105°C, lower the pressure hammer again after the material in the internal mixer turns over, lift the pressure hammer again when the internal mixer reaches 125°C, lower the pressure hammer for the third time after the material in the internal mixer turns over, discharge the material when the internal mixer reaches 140°C and feed it into a conical feeder;

[0038] S4. The material in the conical feeder is dispersed by a twin-screw melt extruder at an extrusion temperature of 90-150°C, and then enters a single-screw extruder at an extrusion temperature of 90-140°C for granulation. After hot cutting, air cooling and screening, the marine power cable bundled Class A flame-retardant thermoplastic halogen-free, low-smoke and oil-resistant polyolefin sheath material can be obtained.

[0039] Embodiment 2:

[0040] A class A flame-retardant thermoplastic halogen-free, low-smoke, oil-resistant polyolefin sheath material for marine power cables, which is made of the following raw materials in proportion by weight:

[0041]

[0042]

[0043] The preparation method of the bundled class A flame-retardant thermoplastic halogen-free, low-smoke, oil-resistant polyolefin sheath material for marine power cables of this embodiment comprises the following steps:

[0044] S1. Weigh each component according to the specified mass ratio and set aside;

[0045] S2, pouring the polyolefin resin into an internal mixer, starting the internal mixer without pressurizing, pouring the coupling agent into the internal mixer and mixing with the polyolefin resin for 10 seconds, and stopping the internal mixer;

[0046] S3. Pour the remaining components according to the formula, start the internal mixer, lower the pressure hammer, lift the pressure hammer when the internal mixer reaches 103°C, lower the pressure hammer again after the material in the internal mixer turns over, lift the pressure hammer again when the internal mixer reaches 120°C, lower the pressure hammer for the third time after the material in the internal mixer turns over, discharge the material when the internal mixer reaches 145°C and feed it into the conical feeder;

[0047] S4. The material in the conical feeder is dispersed by a twin-screw melt extruder at an extrusion temperature of 90-150°C, and then enters a single-screw extruder at an extrusion temperature of 90-140°C for granulation. After hot cutting, air cooling and screening, the marine power cable bundled Class A flame-retardant thermoplastic halogen-free, low-smoke and oil-resistant polyolefin sheath material can be obtained.

[0048] Embodiment 3:

[0049] A class A flame-retardant thermoplastic halogen-free, low-smoke, oil-resistant polyolefin sheath material for marine power cables, which is made of the following raw materials in proportion by weight:

[0050]

[0051] The preparation method of the bundled class A flame-retardant thermoplastic halogen-free, low-smoke, oil-resistant polyolefin sheath material for marine power cables of this embodiment comprises the following steps:

[0052] S1. Weigh each component according to the specified mass ratio and set aside;

[0053] S2, pouring the polyolefin resin into an internal mixer, starting the internal mixer without applying pressure, pouring the coupling agent into the internal mixer and mixing with the polyolefin resin for 15 seconds, and stopping the internal mixer;

[0054] S3. Pour the remaining components according to the formula composition, start the internal mixer, lower the pressure hammer, pressurize and internally mix until the temperature reaches 100°C, then lift the pressure hammer, lower the pressure hammer again after the material in the internal mixer is turned over, pressurize and internally mix until the temperature reaches 122°C, then lift the pressure hammer again, lower the pressure hammer for the third time after the material in the internal mixer is turned over, and discharge the material when the temperature reaches 135°C and feed it into a conical feeder;

[0055] S4. The material in the conical feeder is dispersed by a twin-screw melt extruder at an extrusion temperature of 90-150°C, and then enters a single-screw extruder at an extrusion temperature of 90-140°C for granulation. After hot cutting, air cooling and screening, the marine power cable bundled Class A flame-retardant thermoplastic halogen-free, low-smoke and oil-resistant polyolefin sheath material can be obtained.

[0056] The performance test of the bundled Class A flame-retardant thermoplastic halogen-free, low-smoke, oil-resistant polyolefin sheath material for marine power cables prepared in Examples 1 to 3 was performed, and the results are shown in Table 1:

[0057] Table 1 Performance test of the above polyolefin sheath materials

[0058]

[0059] It can be seen from the test results in the table that the class A flame retardant thermoplastic halogen-free, low-smoke, oil-resistant polyolefin sheath material for bundled marine power cables of the present invention meets the requirements of standard GB / T33596 on thermoplastic halogen-free, low-smoke, flame retardant polyolefin sheath materials, and the oxygen index is much higher than the standard value of 30, indicating that the flame retardancy is better than that of general halogen-free, low-smoke, flame retardant polyolefins.

[0060] The WDZ-YJY3*4 cable uses a class A flame retardant thermoplastic halogen-free, low-smoke, oil-resistant polyolefin sheath material for marine power cables. The results of the class A flame retardant test for bundled cables are shown in Table 2 in accordance with GB / T18380.33:

[0061] Table 2 Test results of class A flame retardant test for bundled

[0062] sample Example 1 Example 2 Example 3 Carbonization distance (m) 1.7 1.5 1.8

[0063] According to the test results in Table 2, it can be seen that the bundled Class A flame-retardant thermoplastic halogen-free, low-smoke, oil-resistant polyolefin sheath material for marine power cables of the present invention meets the requirement of the standard GB / T18380.33 bundled Class A flame-retardant test for a carbonization distance of less than 2.5 m, and leaves a large margin, indicating that the material has excellent flame retardant properties.

[0064] The present invention achieves a highly efficient flame retardant effect through a carefully selected flame retardant combination, including inorganic flame retardants such as aluminum hydroxide and magnesium hydroxide, and organic flame retardants such as ammonium polyphosphate and triphenyl phosphate. These flame retardants can absorb heat and dilute oxygen and combustible gases during the combustion of the material, thereby effectively inhibiting the spread of flames. At the same time, the addition of fillers further improves the dispersibility of the flame retardants and enhances the flame retardant effect, so that the polyolefin sheath material of the present invention has excellent bundled Class A flame retardant properties.

[0065] The present invention significantly improves the oil resistance of the material by selecting a specific polyolefin resin as the base material and combining the reinforcing effect of the filler. The filler not only helps to improve the mechanical strength of the material, but also effectively blocks the penetration of oil into the material, thereby ensuring that the cable sheath maintains good oil resistance during long-term use.

[0066] The raw materials used in the present invention are all halogen-free, produce low smoke during combustion, and are non-toxic and non-corrosive. This feature enables the polyolefin sheath material of the present invention to significantly reduce smoke emissions in fire accidents when used in closed environments such as ships, reduce harm to personnel and equipment, and comply with the requirements of current environmental protection regulations.

[0067] Anything not described in the present invention is applicable to the prior art.

[0068] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. However, the obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A class A flame-retardant thermoplastic halogen-free, low-smoke, oil-resistant polyolefin sheath material for marine power cables, characterized in that: It is prepared from the following raw materials in parts by weight:

2. The marine power cable bundled class A flame-retardant thermoplastic halogen-free, low-smoke, oil-resistant polyolefin sheath material according to claim 1, characterized in that: The polyolefin resin is one or a combination of linear low-density polyethylene, ethylene vinyl acetate copolymer, ethylene ethyl acrylate copolymer, ethylene methyl acrylate copolymer, ethylene butyl acrylate copolymer, ethylene propylene rubber, ethylene butene copolymer, ethylene hexene copolymer and ethylene octene copolymer.

3. The class A flame-retardant thermoplastic halogen-free, low-smoke, oil-resistant polyolefin sheath material for bundled marine power cables according to claim 1, characterized in that: The compatibilizer is one or a combination of maleic anhydride grafted polyethylene, maleic anhydride grafted ethylene vinyl acetate, maleic anhydride grafted ethylene octene copolymer, maleic anhydride grafted ethylene propylene rubber and ethylene acrylate maleic anhydride terpolymer.

4. The class A flame-retardant thermoplastic halogen-free, low-smoke, oil-resistant polyolefin sheath material for bundled marine power cables according to claim 1, characterized in that: The flame retardant is a combination of three or more of aluminum hydroxide, magnesium hydroxide, ammonium polyphosphate, triphenyl phosphate, melamine polyphosphate, organic aluminum hypophosphite, inorganic aluminum hypophosphite, red phosphorus, montmorillonite and sepiolite.

5. The class A flame-retardant thermoplastic halogen-free, low-smoke, oil-resistant polyolefin sheath material for bundled marine power cables according to claim 1, characterized in that: The filler is one or a combination of talc, calcium carbonate and kaolin.

6. The class A flame-retardant thermoplastic halogen-free, low-smoke, oil-resistant polyolefin sheath material for bundled marine power cables according to claim 1, characterized in that: The lubricant is one or a combination of zinc stearate, calcium stearate, magnesium stearate, polyethylene wax, ethylene bis stearamide, silicone oil and silicone.

7. The class A flame-retardant thermoplastic halogen-free, low-smoke, oil-resistant polyolefin sheath material for bundled marine power cables according to claim 1, characterized in that: The antioxidant is one of tetrakis[β(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester, tris[2,4-di-tert-butylphenyl]phosphite, distearyl thiodipropionate, dilauryl thiodipropionate, 4,4'-bis(α.α-dimethylbenzyl)diphenylamine, 4,4'-thiobis(6-tert-butyl-3-methylphenol), or a combination of several thereof.

8. The class A flame-retardant thermoplastic halogen-free, low-smoke, oil-resistant polyolefin sheath material for bundled marine power cables according to claim 1, characterized in that: The coupling agent is one or a combination of silane coupling agent, titanate coupling agent, aluminate coupling agent and stearic acid.

9. A method for preparing the bundled class A flame-retardant thermoplastic halogen-free, low-smoke, oil-resistant polyolefin sheath material for marine power cables according to any one of claims 1 to 8, characterized in that: The steps include: S1. Weigh each component according to the specified mass ratio and set aside; S2, pouring the polyolefin resin into the internal mixer, starting the internal mixer without pressurizing, pouring the coupling agent into the internal mixer and mixing with the polyolefin resin for 10 to 15 seconds, and stopping the internal mixer; S3. Pour the remaining components according to the formula composition, start the internal mixer, lower the pressure hammer, pressurize and internally mix to 100-105℃, then lift the pressure hammer, lower the pressure hammer again after the material in the internal mixer is turned over, pressurize and internally mix to 120-125℃, then lift the pressure hammer again, lower the pressure hammer for the third time after the material in the internal mixer is turned over, and discharge the material when the internal mixer is mixed to 135-145℃ and send it to the conical feeder; S4. The material in the conical feeder is dispersed by a twin-screw melt extruder at an extrusion temperature of 90-150°C, and then enters a single-screw extruder at an extrusion temperature of 90-140°C for granulation. After hot cutting, air cooling and screening, the marine power cable bundled Class A flame-retardant thermoplastic halogen-free, low-smoke and oil-resistant polyolefin sheath material can be obtained.

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