Bundled C-type flame-retardant thermoplastic halogen-free low-smoke polyolefin sheath material for power cable and preparation method of bunched C-type flame-retardant thermoplastic halogen-free low-smoke polyolefin sheath material

Abstract

The invention discloses a bundled C-type flame-retardant thermoplastic halogen-free low-smoke polyolefin sheath material for a power cable and a preparation method of the bundled C-type flame-retardant thermoplastic halogen-free low-smoke polyolefin sheath material, and the bundled C-type flame-retardant thermoplastic halogen-free low-smoke polyolefin sheath material comprises the following components in parts by weight: 60-100 parts of polyolefin resin; 2 to 30 parts of compatilizer; 100 to 150 parts of a flame retardant; 20 to 40 parts of a filling agent; 1-10 parts of a lubricant; 1-4 parts of an antioxidant; and 1-6 parts of a coupling agent. According to the invention, the filling agent is added into the sheath material, the proportion of the ethylene-vinyl acetate copolymer in the polyolefin resin component in the formula is increased, and the flame-retardant effect can be improved by utilizing the synergistic flame-retardant effect of the flame retardant and the filling agent and the ethylene-vinyl acetate copolymer as compared with other polyolefin resins.

Description

Technical Field

[0001] The invention belongs to the technical field of composite materials, and in particular relates to a bundled C-type flame-retardant thermoplastic halogen-free low-smoke polyolefin sheath material for power cables and a preparation method thereof. Background Art

[0002] Polyolefin polymer materials are mainly composed of carbon, hydrogen and oxygen elements. Most of them have an oxygen index below 21, which means they are combustible and flammable materials. In the combustion process, they have a large heat release rate, high calorific value, fast flame propagation speed, and are not easy to extinguish. They even produce a lot of thick smoke and toxic gases when burning. At the same time, polyolefin polymer materials are widely used in industrial production and people's daily lives. Once a fire occurs, it will cause great harm to the environment and pose a huge threat to people's lives and property safety. Therefore, when using them, they need to be treated with low-smoke and halogen-free flame retardant to make them flame-retardant, self-extinguishing, low-smoke, non-toxic and non-corrosive, creating favorable conditions for people to fight fires and escape.

[0003] Bundled Class C flame-retardant thermoplastic halogen-free low-smoke polyolefin sheath material for power cables is a flame-retardant polymer material that has good flame-retardant properties in the event of a fire and can be used in power cables in daily life and industrial production. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention improves the processing and flame retardant properties of the sheath material so that it is flame retardant, self-extinguishing, low-smoke, non-toxic and non-corrosive. To this end, the present invention provides a bundled Class C flame retardant thermoplastic halogen-free low-smoke polyolefin sheath material for power cable and a preparation method thereof.

[0005] The present invention adopts the following technical solution:

[0006] On the one hand, the present invention provides a bundled Class C flame-retardant thermoplastic halogen-free low-smoke polyolefin sheath material for power cable, comprising the following components in parts by weight:

[0007] Polyolefin resin: 60-100 parts;

[0008] Compatibilizer: 2-30 parts;

[0009] Flame retardant: 100-150 parts;

[0010] Filler: 20-40 parts;

[0011] Lubricant: 1-10 parts;

[0012] Antioxidant: 1-4 parts;

[0013] Coupling agent: 1 to 6 parts.

[0014] Preferably, the following components are further included in parts by weight:

[0015] Polyolefin resin: 90-95 parts;

[0016] Compatibilizer: 5-10 parts;

[0017] Flame retardant: 110-150 parts;

[0018] Filler: 20-30 parts;

[0019] Lubricant: 4-5 parts;

[0020] Antioxidant: 1-2 parts;

[0021] Coupling agent: 2 to 4 parts.

[0022] The polyolefin resin includes one or more of 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.

[0023] The compatibilizer includes one or more 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.

[0024] The flame retardant includes one or more of aluminum hydroxide, magnesium hydroxide, ammonium polyphosphate, triphenyl phosphate, melamine polyphosphate, organic aluminum hypophosphite, inorganic aluminum hypophosphite, red phosphorus, montmorillonite and sepiolite.

[0025] Wherein, the filler includes: one or more of talc, calcium carbonate and kaolin.

[0026] Wherein, the lubricant includes: one or more of zinc stearate, calcium stearate, magnesium stearate, polyethylene wax, ethylene bisstearamide, silicone oil, and silicone.

[0027] The antioxidant comprises one or more 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).

[0028] Wherein, the coupling agent includes: one or more of a silane coupling agent, a titanate coupling agent, an aluminate coupling agent, and stearic acid.

[0029] On the other hand, the present invention provides a method for preparing a bundled Class C flame-retardant thermoplastic halogen-free low-smoke polyolefin sheath material for power cable, comprising the following steps:

[0030] Establish a formula according to the above-mentioned sheath material components;

[0031] Pour the polyolefin resin into the internal mixer and start the internal mixer under normal pressure;

[0032] Pour the coupling agent into the internal mixer and mix it with the polyolefin resin for 10 to 15 seconds, then stop the internal mixer;

[0033] Pour the remaining components of the sheath material and start the internal mixer;

[0034] Lower the pressure hammer, and lift it up when the pressure is increased and the temperature reaches 100-105℃;

[0035] After the material in the mixer is turned over, lower the pressure hammer, and when the pressure is increased to 120-125℃, lift the pressure hammer again.

[0036] After the material in the mixer is turned over, lower the pressure hammer and discharge the material when the mixer reaches 135-145℃;

[0037] The mixture is melt-extruded and dispersed by a twin-screw extruder at an extrusion temperature of 90 to 150°C, and then granulated by a single-screw extruder at an extrusion temperature of 90 to 140°C;

[0038] After hot cutting, air cooling and screening, the bundled Class C flame-retardant thermoplastic halogen-free low-smoke polyolefin sheath material for power cable is obtained.

[0039] The technical solution of the present invention has the following advantages:

[0040] A. The present invention adds a filler to the sheath material and increases the proportion of ethylene-vinyl acetate copolymer in the polyolefin resin component of the formula, thereby improving the flame retardant effect by utilizing the synergistic flame retardancy of the flame retardant and the filler and the better crusting effect of ethylene-vinyl acetate copolymer compared to other polyolefin resins.

[0041] B. The sheath material and preparation method provided by the present invention meet the requirements of the standard GB / T32129 for thermoplastic halogen-free, low-smoke, flame-retardant polyolefin sheath material through tests and determinations, and the oxygen index is much higher than the standard, and the flame retardant performance is much higher than that of general halogen-free, low-smoke, flame-retardant polyolefin.

[0042] C. Some low-priced raw materials selected in the present invention, such as fillers, have high cost performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the specific embodiments of the present invention, the drawings required for use in the specific embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 The present invention provides a flow chart of the method for preparing the sheath material. DETAILED DESCRIPTION

[0045] The technical solution of the present invention is described clearly and completely below in conjunction with the accompanying drawings. 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.

[0046] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0047] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] like Figure 1 As shown, the present invention provides a bundled Class C flame-retardant thermoplastic halogen-free low-smoke polyolefin sheath material for power cables, which comprises the following components in parts by weight:

[0049] Polyolefin resin: 60-100 parts, preferably 90-95 parts;

[0050] Compatibilizer: 2-30 parts, preferably 5-10 parts;

[0051] Flame retardant: 100-150 parts, preferably 110-150 parts;

[0052] Filler: 20-40 parts, preferably 20-30 parts;

[0053] Lubricant: 1-10 parts, preferably 4-5 parts;

[0054] Antioxidant: 1-4 parts, preferably 1-2 parts;

[0055] Coupling agent: 1-6 parts, preferably 2-4 parts.

[0056] Among them, the polyolefin resin includes: one or more of 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.

[0057] The compatibilizer includes one or more 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.

[0058] The flame retardant includes: one or more of aluminum hydroxide, magnesium hydroxide, ammonium polyphosphate, triphenyl phosphate, melamine polyphosphate, organic aluminum hypophosphite, inorganic aluminum hypophosphite, red phosphorus, montmorillonite and sepiolite.

[0059] The fillers include: one or more of talc, calcium carbonate and kaolin.

[0060] The lubricant includes: one or more of zinc stearate, calcium stearate, magnesium stearate, polyethylene wax, ethylene bisstearamide, silicone oil, and silicone.

[0061] The antioxidants include: one or more 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).

[0062] The coupling agent includes: one or more of a silane coupling agent, a titanate coupling agent, an aluminate coupling agent, and stearic acid.

[0063] like Figure 1 As shown, the present invention also provides a method for preparing a bundled Class C flame-retardant thermoplastic halogen-free low-smoke polyolefin sheath material for power cables, comprising the following steps:

[0064]

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[0065]

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[0066]

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[0067]

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[0068]

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[0069]

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[0070]

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[0073] The above-mentioned internal mixer, single-screw and twin-screw extruder equipment etc. all adopt the existing technology.

[0074] Example 1

[0075] Metallocene polyethylene: 14 parts, ethylene-vinyl acetate copolymer: 65 parts, maleic anhydride grafted polyethylene: 21 parts, aluminum hydroxide: 110 parts, magnesium hydroxide: 20 parts, red phosphorus: 5 parts, talc: 20 parts, silane coupling agent: 2 parts, polyethylene wax: 1 part, silicone: 2 parts, 1010 (pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate): 0.5 parts, DLTP (dilauryl thiodipropionate): 0.5 parts.

[0076] According to the formula composition, the polyolefin resin is first poured into the internal mixer, and the internal mixer is started without pressurization. Two parts of coupling agent are poured into the internal mixer and mixed with the polyolefin resin for 12 seconds, then the internal mixer is stopped, and the remaining components are poured according to the formula composition, and the internal mixer is started. The pressure hammer is lowered and the internal mixer is pressurized and kneaded to 105°C, and the pressure hammer is lifted up. After the material in the internal mixer is turned over, the pressure hammer is lowered again, and the pressure hammer is lifted up again after the internal mixer is pressurized and kneaded to 125°C. After the material in the internal mixer is turned over, the pressure hammer is lowered. When the internal mixer is kneaded to 140°C, the material is discharged and sent to a conical feeder. After being melt-extruded and dispersed by a twin-screw extruder with an extrusion temperature of 90-150°C, it enters a single-screw extrusion granulation with an extrusion temperature of 90-140°C. After hot cutting, air cooling and screening, a bundled Class C flame-retardant thermoplastic halogen-free and low-smoke polyolefin sheath material for power cable can be obtained.

[0077] Example 2

[0078] Metallocene polyethylene: 14 parts, ethylene-vinyl acetate copolymer: 65 parts, maleic anhydride grafted polyethylene: 21 parts, aluminum hydroxide: 110 parts, magnesium hydroxide: 20 parts, red phosphorus: 5 parts, talc: 10 parts, kaolin: 10 parts, silane coupling agent: 2 parts, polyethylene wax: 1 part, silicone: 2 parts, 1010: 0.5 parts, DLTP: 0.5 parts.

[0079] The preparation method is the same as that of Example 1

[0080] Example 3

[0081] Metallocene polyethylene: 14 parts, ethylene-vinyl acetate copolymer: 65 parts, maleic anhydride grafted polyethylene: 21 parts, aluminum hydroxide: 100 parts, magnesium hydroxide: 20 parts, red phosphorus: 5 parts, talc: 10 parts, kaolin: 10 parts, calcium carbonate: 10 parts, silane coupling agent: 2 parts, polyethylene wax: 1 part, silicone: 2 parts, 1010: 0.5 parts, DLTP: 0.5 parts.

[0082] The performance test data of the bundled Class C flame-retardant thermoplastic halogen-free low-smoke polyolefin sheath material for power cables prepared in Examples 1 to 3 are shown in Table 1 below:

[0083] Table 1

[0084]

[0085] It can be seen from the data in Table 1 that the bundled Class C flame-retardant thermoplastic halogen-free low-smoke polyolefin sheath material for power cable of the present invention meets the requirements of standard GB / T32129 on thermoplastic halogen-free low-smoke flame-retardant polyolefin sheath materials, and the oxygen index is much higher than the standard, indicating that the flame retardancy is better than that of general halogen-free low-smoke flame-retardant polyolefins.

[0086] The bundled Class C flame retardant thermoplastic halogen-free low-smoke polyolefin sheath material for power cables is used on WDZ-YJY3*4 cables. The results of the bundled Class C flame retardant test are shown in Table 2 below in accordance with GB / T18380.35:

[0087] Table 2

[0088] sample Example 1 Example 2 Example 3 Carbonization distance (m) 1.5 1.3 1.6

[0089] It can be seen from the data in Table 2 that the bundled Class C flame-retardant thermoplastic halogen-free low-smoke polyolefin sheath material for power cable of the present invention has good flame-retardant effect, can meet the bundled Class C flame-retardant requirements specified in GB / T18380.35, and leave a large margin.

[0090] 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 bundled Class C flame-retardant thermoplastic halogen-free low-smoke polyolefin sheath material for power cable, characterized in that: In parts by weight, it includes the following components:

2. The bundled Class C flame-retardant thermoplastic halogen-free low-smoke polyolefin sheath material for power cable according to claim 1, characterized in that: In parts by weight, it includes the following components:

3. The bundled class C flame-retardant thermoplastic halogen-free low-smoke polyolefin sheath material for power cable according to claim 1, characterized in that: The polyolefin resin includes one or more of 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.

4. The bundled Class C flame-retardant thermoplastic halogen-free low-smoke polyolefin sheath material for power cable according to claim 1, characterized in that: The compatibilizer includes one or more 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.

5. The bundled class C flame-retardant thermoplastic halogen-free low-smoke polyolefin sheath material for power cable according to claim 1, characterized in that: The flame retardant includes: one or more of aluminum hydroxide, magnesium hydroxide, ammonium polyphosphate, triphenyl phosphate, melamine polyphosphate, organic aluminum hypophosphite, inorganic aluminum hypophosphite, red phosphorus, montmorillonite and sepiolite.

6. The bundled Class C flame-retardant thermoplastic halogen-free low-smoke polyolefin sheath material for power cable according to claim 1, characterized in that: The filler includes: one or more of talc, calcium carbonate and kaolin.

7. The bundled Class C flame-retardant thermoplastic halogen-free low-smoke polyolefin sheath material for power cable according to claim 1, characterized in that: The lubricant includes: one or more of zinc stearate, calcium stearate, magnesium stearate, polyethylene wax, ethylene bis stearamide, silicone oil, and silicone.

8. The bundled class C flame-retardant thermoplastic halogen-free low-smoke polyolefin sheath material for power cable according to claim 1, characterized in that: The antioxidant comprises one or more 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).

9. The bundled Class C flame-retardant thermoplastic halogen-free low-smoke polyolefin sheath material for power cable according to claim 1, characterized in that: The coupling agent includes: one or more of a silane coupling agent, a titanate coupling agent, an aluminate coupling agent, and stearic acid.

10. A method for preparing a bundled Class C flame-retardant thermoplastic halogen-free low-smoke polyolefin sheath material for power cables, characterized in that: The steps include: Establish a formula according to the sheath material components of claims 1-9; Pour the polyolefin resin into the internal mixer and start the internal mixer under normal pressure; Pour the coupling agent into the internal mixer and mix it with the polyolefin resin for 10 to 15 seconds, then stop the internal mixer; Pour the remaining components of the sheath material and start the internal mixer; Lower the pressure hammer, and lift it up when the pressure is increased and the temperature reaches 100-105℃; After the material in the mixer is turned over, lower the pressure hammer, and when the pressure is increased to 120-125℃, lift the pressure hammer again. After the material in the mixer is turned over, lower the pressure hammer and discharge the material when the mixer reaches 135-145℃; The mixture is melt-extruded and dispersed by a twin-screw extruder at an extrusion temperature of 90 to 150°C, and then granulated by a single-screw extruder at an extrusion temperature of 90 to 140°C; After hot cutting, air cooling and screening, the bundled Class C flame-retardant thermoplastic halogen-free low-smoke polyolefin sheath material for power cable is obtained.

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