Flame-retardant power cable for wind power generation and preparation method thereof

Abstract

The present invention discloses a flame-retardant power cable for wind power generation and a preparation method thereof, belonging to the technical field of power cables. It is composed of a conductor, an insulating layer and a protective sheath which are arranged in sequence from the inside to the outside. The insulating layer material is a mica tape, which can enhance the flame retardant performance of the cable to a certain extent; the protective sheath material is based on polypropylene, which gives the cable excellent mechanical properties and electrical insulation properties; the protective sheath material also contains nitrile rubber and a multi-effect flame retardant, wherein the nitrile rubber can enhance the low temperature resistance of the cable; wherein the various groups in the multi-effect flame retardant molecules can play a synergistic role, significantly enhancing the flame retardant, smoke suppression and UV resistance of the cable, and the performance is stable and not easy to fall off; therefore, the cable prepared by the present invention has excellent low temperature resistance and mechanical properties, and also has stable and efficient flame retardant, smoke suppression and UV resistance, and is halogen-free and environmentally friendly, and has important application value in the technical field of power cables.

Description

Technical Field

[0001] The present invention belongs to the technical field of power cables, and in particular, relates to a flame-retardant power cable for wind power generation and a preparation method thereof. Background Art

[0002] Renewable energy includes solar energy, hydropower, wind energy, biomass energy, wave energy, tidal energy, ocean temperature difference energy, geothermal energy, etc. Among them, wind energy is a kind of usable energy provided to humans by air flow, and the total reserve of resources is very huge.

[0003] The utilization of wind energy is inseparable from wind power generation equipment, and wind power generation equipment is inseparable from the supporting power cables. Wind power generation equipment is often set up in areas with harsh environments such as high altitudes, so there are high requirements for the performance of cables. The composition of the cable can be generally divided into three main structural components: conductor, insulation layer and protective sheath. Since the outermost layer of the cable is the protective sheath, which is in direct contact with the external environment, the performance of the sheath determines whether the performance of the cable is excellent; common cable sheath materials include polypropylene, polyethylene, cross-linked polyethylene, polyvinyl chloride, etc., among which polypropylene is a thermoplastic synthetic resin with excellent performance, chemical resistance, heat resistance, electrical insulation, high-strength mechanical properties and good high wear resistance processing performance, and is a very high-quality protective sheath material. However, polypropylene has poor low-temperature resistance and is prone to brittleness in environments such as high altitudes; in addition, polypropylene has a low oxygen index and poor flame retardant properties. It is easy to burn when encountering open flames. Not only that, the atmosphere in high-altitude areas is thin and the ultraviolet intensity is high. The cable is exposed to long-term irradiation, resulting in loss of mechanical properties and cracking of the cable, which seriously affects the safety of cable use. Therefore, it is urgent to solve the above problems to meet the higher demands in the field of power cable technology. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a flame retardant power cable for wind power generation and a preparation method thereof.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A flame-retardant power cable for wind power generation consists of a conductor, an insulating layer and a protective sheath which are arranged in sequence from the inside to the outside.

[0007] Furthermore, the conductor material is pure copper.

[0008] Furthermore, the insulating layer material is mica tape.

[0009] The insulation layer is mica tape, which can enhance the flame retardant performance of the cable to a certain extent.

[0010] A method for preparing a flame-retardant power cable for wind power generation comprises the following steps:

[0011] After the insulating layer is coated on the outside of the conductor, the protective sheath material is extruded and coated on the outer surface of the insulating layer to obtain a flame-retardant power cable for wind power generation.

[0012] Furthermore, the material of the protective cover is prepared by the following steps:

[0013] The polypropylene resin and nitrile rubber are dried in a drying oven at 80°C for 12 hours, the dried polypropylene resin and nitrile rubber are added into a mixer with a multi-effect flame retardant, an initiator and a lubricant and stirred for 15 minutes, and then added into a twin-screw extruder, melt-blended and extruded to obtain the material of the protective cover.

[0014] Furthermore, the raw materials are calculated in parts by weight as follows: 80-100 parts of polypropylene resin, 20-30 parts of nitrile rubber, 8-24 parts of multi-effect flame retardant, 0.1-0.3 parts of initiator, and 3-5 parts of lubricant.

[0015] Furthermore, the lubricant is one of magnesium stearate and zinc stearate.

[0016] Furthermore, the initiator is one of diisopropyl peroxydicarbonate and dicyclohexyl peroxydicarbonate.

[0017] The prepared protective cover material is based on polypropylene, which gives the material excellent mechanical properties and electrical insulation properties; the added nitrile rubber can greatly improve the material's low-temperature resistance.

[0018] Furthermore, the multi-effect flame retardant is prepared by the following steps:

[0019] S1. Add diethylphosphoacetic acid, 1,3-bis(aminopropyl)tetramethyldisiloxane, dicyclohexylcarbodiimide (DCC, dehydrating agent) and N,N-dimethylformamide (DMF) to a three-necked flask equipped with a stirring device, stir and mix well, place in a 50°C water bath, heat in a water bath for 6 hours, filter after the reaction, and remove the solvent by distillation under reduced pressure to obtain intermediate 1; the ratio of diethylphosphoacetic acid, 1,3-bis(aminopropyl)tetramethyldisiloxane, dicyclohexylcarbodiimide and N,N-dimethylformamide is 19.6 g:28.4 g:20.6 g:150 mL;

[0020] Under the action of dicyclohexylcarbodiimide, 1,3-bis(aminopropyl)tetramethyldisiloxane and diethylphosphoacetic acid undergo amidation reaction, and the intermediate 1 is obtained by controlling the molar ratio of the two to be close to 1:1 and the 1,3-bis(aminopropyl)tetramethyldisiloxane to be slightly excessive. The specific reaction process is as follows:

[0021]

[0022] S2. At room temperature, under nitrogen protection, in a three-necked flask equipped with a stirring device, the intermediate 1, 2-hydroxy-5-chlorobenzophenone, triethylamine and N,N-dimethylformamide were mixed and stirred uniformly, the reaction temperature was controlled to 70°C, and the reaction was kept warm for 8 hours. After the reaction was completed, it was filtered, and part of the solvent was removed by vacuum distillation, and then purified by column chromatography (the eluent was a mixed solvent of petroleum ether / ethyl acetate, and the volume ratio of the two was 4:1), and the eluent was removed by rotary evaporation to obtain intermediate 2; the ratio of the amount of intermediate 1, 2-hydroxy-5-chlorobenzophenone, triethylamine, and N,N-dimethylformamide was 42.6 g:23.2 g:15 mL:150 mL;

[0023] Intermediate 1 undergoes nucleophilic substitution with 2-hydroxy-5-chlorobenzophenone, and triethylamine removes hydrogen chloride generated by the reaction to obtain intermediate 2. The specific reaction process is as follows:

[0024]

[0025] S3. After the intermediate 2, triethylamine and N,N-dimethylformamide are stirred and mixed evenly in a three-necked flask, allyl chloride is added dropwise to the reaction system while stirring. After the addition is completed, the temperature is raised to 75°C and the reaction is kept warm for 8 hours. After the reaction is completed, the mixture is filtered and purified by column chromatography (the eluent is a mixed solvent of petroleum ether / ethyl acetate in a volume ratio of 5:1), and the eluent is removed by rotary evaporation to obtain a multi-effect flame retardant; the ratio of the intermediate 2, triethylamine, N,N-dimethylformamide and allyl chloride is 62.2g:15mL:150mL:7.6g;

[0026] Intermediate 2 reacts with allyl chloride, and triethylamine acts as an acid binding agent to promote the reaction to obtain a multi-effect flame retardant. The specific reaction process is as follows:

[0027]

[0028] The prepared multi-effect flame retardant molecule contains phosphate, -Si-O-Si-chain segment, benzophenone and carbon-carbon double bond structure, among which phosphate is a flame retardant with good flame retardant performance, and its flame retardant effect is mainly achieved through gas phase flame retardant mechanism and condensed phase flame retardant mechanism, and can enhance the flame retardant performance of polypropylene matrix; in addition, the introduced Si-O-Si-chain segment is a good flame retardant and smoke suppression component, which can synergize with phosphate and greatly enhance the flame retardant and smoke suppression performance of the matrix; the introduction of benzophenone ultraviolet absorber can consume the ultraviolet radiation energy absorbed by the matrix through keto-enol tautomerism phenomenon, which greatly improves the anti-ultraviolet performance of the matrix; finally, the multi-effect flame retardant molecule also contains carbon-carbon double bond, which can produce chemical bonding with the matrix, which not only improves the compatibility of the multi-effect flame retardant and the matrix, so that the performance of the multi-effect flame retardant can be fully exerted, but also improves the migration resistance and exudation resistance of the auxiliary agent, and ensures the long-term stability of the multi-effect flame retardant.

[0029] Beneficial effects of the present invention:

[0030] 1. The cable insulation layer material prepared by the present invention is mica tape, which can enhance the flame retardant performance of the cable to a certain extent;

[0031] 2. The protective sheath material is based on polypropylene, which gives the cable excellent mechanical properties and electrical insulation properties;

[0032] 3. The added nitrile rubber can enhance the low temperature resistance of the cable;

[0033] 4. The various groups in the prepared multi-effect flame retardant molecules can play a synergistic role, significantly enhancing the flame retardant, smoke suppression and UV resistance of the cable, and the performance is stable and not easy to fall off;

[0034] Therefore, the cable prepared by the present invention has excellent low temperature resistance and mechanical properties, and also has stable and efficient flame retardant, smoke suppression and UV resistance, and is halogen-free and environmentally friendly, and has important application value in the field of power cable technology. DETAILED DESCRIPTION

[0035] 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.

[0036] Embodiment 1

[0037] Preparation of multi-effect flame retardant:

[0038] S1. Add 19.6 g of diethylphosphoacetic acid, 28.4 g of 1,3-bis(aminopropyl)tetramethyldisiloxane, 20.6 g of dicyclohexylcarbodiimide and 150 mL of N,N-dimethylformamide into a three-necked flask equipped with a stirring device, stir and mix evenly, place in a 50° C. water bath, heat in a water bath for 6 h, filter after the reaction is completed, and remove the solvent by distillation under reduced pressure to obtain intermediate 1;

[0039] S2. At room temperature, 42.6 g of intermediate 1, 23.2 g of 2-hydroxy-5-chlorobenzophenone, 15 mL of triethylamine and 150 mL of N,N-dimethylformamide were mixed and stirred evenly in a three-necked flask equipped with a stirring device under nitrogen protection. The reaction temperature was controlled to 70° C. and the reaction was kept warm for 8 hours. After the reaction was completed, the mixture was filtered and partially distilled off under reduced pressure. The mixture was then purified by column chromatography (the eluent was a mixed solvent of petroleum ether / ethyl acetate in a volume ratio of 4:1), and the eluent was removed by rotary evaporation to obtain intermediate 2.

[0040] S3. In a three-necked flask, stir and mix 62.2 g of intermediate 2, 15 mL of triethylamine and 150 mL of N,N-dimethylformamide, and then add 7.6 g of allyl chloride dropwise to the reaction system while stirring. After the addition is complete, raise the temperature to 75°C and keep the reaction for 8 hours. After the reaction is complete, filter and purify by column chromatography (the eluent is a mixed solvent of petroleum ether / ethyl acetate in a volume ratio of 5:1), remove the eluent by rotary evaporation, and obtain a multi-effect flame retardant.

[0041] Embodiment 2

[0042] Preparation of multi-effect flame retardant:

[0043] S1. Add 39.2 g of diethylphosphoacetic acid, 56.8 g of 1,3-bis(aminopropyl)tetramethyldisiloxane, 41.2 g of dicyclohexylcarbodiimide and 300 mL of N,N-dimethylformamide into a three-necked flask equipped with a stirring device, stir and mix evenly, place in a 50° C. water bath, heat in a water bath for 6 h, filter after the reaction is completed, and remove the solvent by distillation under reduced pressure to obtain intermediate 1;

[0044] S2. At room temperature, under nitrogen protection, 85.2 g of intermediate 1, 46.4 g of 2-hydroxy-5-chlorobenzophenone, 30 mL of triethylamine and 300 mL of N,N-dimethylformamide were mixed and stirred evenly in a three-necked flask equipped with a stirring device. The reaction temperature was controlled to 70° C. and the reaction was kept warm for 8 hours. After the reaction was completed, the mixture was filtered and part of the solvent was removed by distillation under reduced pressure. The mixture was then purified by column chromatography (the eluent was a mixed solvent of petroleum ether / ethyl acetate in a volume ratio of 4:1), and the eluent was removed by rotary evaporation to obtain intermediate 2.

[0045] S3. In a three-necked flask, stir and mix 124.4 g of intermediate 2, 30 mL of triethylamine and 300 mL of N,N-dimethylformamide, and then drop 15.2 g of allyl chloride into the reaction system while stirring. After the addition is complete, raise the temperature to 75°C and keep the reaction for 8 hours. After the reaction is complete, filter and purify by column chromatography (the eluent is a mixed solvent of petroleum ether / ethyl acetate in a volume ratio of 5:1), remove the eluent by rotary evaporation, and obtain a multi-effect flame retardant.

[0046] Embodiment 3

[0047] 80g of polypropylene resin and 20g of nitrile rubber were dried in an oven at 80°C for 12h, and the dried polypropylene resin and nitrile rubber, 8g of the multi-effect flame retardant prepared in Example 1, 0.1g of diisopropyl peroxydicarbonate and 3g of magnesium stearate were added to a mixer and stirred for 15min, and then added to a twin-screw extruder, melt-blended, and extruded to obtain the material of the protective cover.

[0048] Embodiment 4

[0049] 90 g of polypropylene resin and 25 g of nitrile rubber were dried in an oven at 80° C. for 12 h, and the dried polypropylene resin and nitrile rubber, 16 g of the multi-effect flame retardant prepared in Example 2, 0.2 g of dicyclohexyl peroxydicarbonate and 4 g of zinc stearate were added to a mixer and stirred for 15 min, and then added to a twin-screw extruder, melt-blended, and extruded to obtain the material of the protective cover.

[0050] Embodiment 5

[0051] 100 g of polypropylene resin and 30 g of nitrile rubber were dried in an oven at 80° C. for 12 h, and the dried polypropylene resin and nitrile rubber, 24 g of the multi-effect flame retardant prepared in Example 2, 0.3 g of dicyclohexyl peroxydicarbonate and 5 g of zinc stearate were added to a mixer and stirred for 15 min, and then added to a twin-screw extruder, melt-blended, and extruded to obtain the material of the protective cover.

[0052] Embodiment 6

[0053] A mica tape is coated on a pure copper conductor to form an insulating layer; 100 g of polypropylene resin and 30 g of nitrile rubber are dried in a drying oven at 80° C. for 12 h, the dried polypropylene resin and nitrile rubber, 24 g of the multi-effect flame retardant prepared in Example 2, 0.3 g of dicyclohexyl peroxydicarbonate and 5 g of zinc stearate are added to a mixer and stirred for 15 min, and then added to a twin-screw extruder, melt-blended, and extruded and coated on the surface of the insulating layer through an extruder to obtain a flame-retardant power cable for wind power generation.

[0054] Comparative Example 1

[0055] The multi-effect flame retardant in Example 5 is replaced by a commercially available halogen-containing flame retardant of equal quality, and the remaining steps are the same as those in Example 5 to obtain the material of the protective cover.

[0056] Comparative Example 2

[0057] Commercially available polypropylene cable material was used.

[0058] Embodiments 3, 4, 5, and comparative examples 1 and 2 were made into corresponding shapes to be tested according to different test standards, and the following performance tests were performed:

[0059] The tensile properties were measured using the national standard GB / T 1040.2-2006 "Determination of tensile properties of plastics Part 2: Test conditions for molded and extruded plastics"; the specimens were then placed in an environment of -50°C, and after 3 days, the tensile properties were measured using the same standard;

[0060] The sample was placed in a xenon lamp aging test chamber for accelerated aging for 30 days. The aging conditions were air atmosphere, xenon lamp wavelength 280-800nm, and irradiation intensity 550W / m 2 , test the tensile strength of the sample after aging (GB / T 1040.2-2006), and calculate the tensile strength retention rate; tensile strength retention rate = tensile strength after test / tensile strength before test × 100%;

[0061] The smoke density is measured using the national standard GB / T 8323.2-2008 "Plastic smoke generation Part 2: Single chamber method for determination of smoke density test method";

[0062] The national standard GB / T 2406-2008 "Test method for combustion performance of plastics" is used to measure the limiting oxygen index of the sample before and after being placed at room temperature for 180 days;

[0063] The measured results are shown in the following table:

[0064]

[0065] It can be seen from the above table that the protective sheath material prepared in the embodiment of the present invention has higher low temperature resistance, flame retardancy, smoke suppression and UV resistance than the control example, and the multi-effect flame retardant has little effect on the mechanical properties of the protective sheath material. Using it for cables can enhance the corresponding performance of the cables. Therefore, the present invention has important application value in the field of power cable technology.

[0066] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0067] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A flame-retardant power cable for wind power generation, comprising a conductor, an insulating layer and a protective sheath arranged in sequence from the inside to the outside, characterized in that: The material of the protective cover includes the following raw materials in parts by weight: 80-100 parts of polypropylene resin, 20-30 parts of nitrile rubber, 8-24 parts of multi-effect flame retardant, 0.1-0.3 parts of initiator, and 3-5 parts of lubricant; Wherein, the multi-effect flame retardant is prepared by the following steps: S1. After diethylphosphoacetic acid, 1,3-bis(aminopropyl)tetramethyldisiloxane, dicyclohexylcarbodiimide and N,N-dimethylformamide were stirred and mixed evenly, the mixture was placed in a water bath at 50°C and heated in the water bath for 6 hours. After the reaction was completed, the mixture was filtered and distilled under reduced pressure to obtain intermediate 1; the ratio of diethylphosphoacetic acid, 1,3-bis(aminopropyl)tetramethyldisiloxane, dicyclohexylcarbodiimide and N,N-dimethylformamide was 19.6 g:28.4 g:20.6 g:150 mL; S2. At room temperature, under nitrogen protection, the intermediate 1, 2-hydroxy-5-chlorobenzophenone, triethylamine and N,N-dimethylformamide were mixed and stirred evenly, and reacted at 70°C for 8 hours. After the reaction was completed, the mixture was filtered, distilled under reduced pressure, purified by column chromatography, and rotary evaporated to obtain intermediate 2; the ratio of the amount of intermediate 1, 2-hydroxy-5-chlorobenzophenone, triethylamine and N,N-dimethylformamide was 42.6 g: 23.2 g: 15 mL: 150 mL; S3. After stirring and mixing the intermediate 2, triethylamine and N,N-dimethylformamide evenly, add allyl chloride dropwise to the reaction system while stirring. After the addition is completed, raise the temperature to 75°C and keep the reaction for 8 hours. After the reaction is completed, filter, purify by column chromatography, and rotary evaporate to obtain a multi-effect flame retardant; the usage ratio of intermediate 2, triethylamine, N,N-dimethylformamide, and allyl chloride is 62.2g:15mL:150mL:7.6g.

2. A flame-retardant power cable for wind power generation according to claim 1, characterized in that: The material of the conductor is pure copper.

3. A flame-retardant power cable for wind power generation according to claim 1, characterized in that: The material of the insulating layer is mica tape.

4. A flame-retardant power cable for wind power generation according to claim 1, characterized in that: The lubricant is one of magnesium stearate and zinc stearate.

5. The flame-retardant power cable for wind power generation according to claim 1, characterized in that: The initiator is one of diisopropyl peroxydicarbonate and dicyclohexyl peroxydicarbonate.

6. A flame-retardant power cable for wind power generation according to claim 1, characterized in that: After the insulating layer is coated on the outside of the conductor, the protective sheath material is extruded and coated on the outer surface of the insulating layer to obtain a flame-retardant power cable for wind power generation.

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