Cable capable of rapidly conducting heat and retarding flame and preparation method thereof

Abstract

The invention discloses a cable capable of rapidly conducting heat and retarding flame and a preparation method thereof, and belongs to the technical field of cables. The preparation method comprises the following steps: mixing and stirring 60-70 parts of high-density polyethylene, 20-30 parts of polypropylene, 15-25 parts of a heat-conducting filler, 10-15 parts of an ethylene-vinyl acetate copolymer, 8-15 parts of a flame retardant, 6-10 parts of a polyolefin elastomer, 5-8 parts of glass fibers, 3-5 parts of a compatilizer, 1-3 parts of a coupling agent, 0.5-1.2 parts of an antioxidant, 0.5-1.2 parts of an ultraviolet light absorber and 0.05-0.1 part of a cross-linking agent; and performing melt extrusion on the cable material, coating the periphery of a copper wire with the cable material, and cooling the cable material to obtain the cable. A spatial network structure is formed among the flame retardant containing flame-retardant elements of nitrogen, phosphorus and silicon, the heat-conducting filler, the glass fiber and the matrix resin, so that the raw materials such as the flame retardant and the like can fully play roles, and the cable has excellent and stable flame-retardant effect, heat-conducting property and mechanical property.

Description

Technical Field

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

[0002] Wires and cables include bare wires, wires and cables for electrical equipment, power cables, communication cables, optical cables, and winding wires. Cable material is the common name for plastics used for insulation and sheathing of wires and cables. The polymer materials used mainly include polyvinyl chloride, polyethylene, polypropylene, fluoroplastics, chlorinated polyethers, and polyamides. These polymer materials are light, resistant to chemical corrosion, easy to process and shape, have excellent electrical insulation properties, and have excellent mechanical and fatigue resistance properties. However, the thermal conductivity of these materials is very low, generally 0.1-0.3W / (m·K), which is almost a thermal insulator. It has poor heat dissipation effect and cannot dissipate the heat in the wires and cables in time, thus creating a short circuit risk, which is not conducive to the safe operation of the cable.

[0003] In addition, the arc generated by the cable's own fault and the fire nearby are likely to cause cable fires. After the cable catches fire, the fire burns along the cable in a linear manner. When halogen and low-halogen cable materials burn, they will produce toxic and harmful gases and smoke, which not only pollute the environment but also endanger human life. Therefore, it is urgent to design and prepare a cable that can quickly conduct heat and has an efficient and safe flame retardant effect to ensure the safe operation of the cable. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a fast heat-conducting and flame-retardant cable and a preparation method thereof.

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

[0006] A method for preparing a fast heat-conducting and flame-retardant cable comprises the following steps:

[0007] Weigh 60-70 parts of high-density polyethylene, 20-30 parts of polypropylene, 15-25 parts of thermal conductive filler, 10-15 parts of ethylene-vinyl acetate copolymer, 8-15 parts of flame retardant, 6-10 parts of polyolefin elastomer, 5-8 parts of glass fiber, 3-5 parts of compatibilizer, 1-3 parts of coupling agent, 0.5-1.2 parts of antioxidant, 0.5-1.2 parts of ultraviolet absorber and 0.05-0.1 parts of cross-linking agent by weight and mix them evenly, then heat up to 60-80°C and stir for 1 hour, then put into a twin-screw extruder for extrusion and granulation to obtain cable material, then melt the cable material, extrude it, and coat it on the side of the copper wire. After cooling and solidification, a cable with rapid thermal conductivity and flame retardancy is obtained.

[0008] Furthermore, the thermally conductive filler is one or more of silicon nitride, boron nitride, magnesium oxide, and aluminum oxide.

[0009] Thermally conductive fillers can quickly transfer heat, help cables dissipate heat effectively in high-temperature environments, prevent overheating, thereby reducing the risk of short circuits and ensuring the safe operation of cables; thermally conductive fillers can optimize the overall structure of cables, enhance their tensile strength and pressure resistance, alleviate vibration and pressure during cable operation, and improve their overall stability; thermally conductive fillers can also provide protection for cables, resist external moisture, corrosive chemicals and oxidation processes, and extend the service life of cables.

[0010] Furthermore, the flame retardant is prepared by the following steps:

[0011] S1. Add 11-dodecenol and tetrahydrofuran to a dry three-necked flask, stir evenly, then add phosphorus oxychloride and pyridine, place the flask in an ice-water bath at 0°C for 1 hour, centrifuge the product for separation after the reaction, and then dry at 80°C for 12 hours to obtain intermediate 1; the amount ratio of phosphorus oxychloride, 11-dodecenol, pyridine and tetrahydrofuran is 14mL: 56.2g: 25mL: 200mL;

[0012] In an ice-water bath, pyridine is used as an acid-binding agent, and the dosage ratio of phosphorus oxychloride to 11-dodecenol is controlled to be 1:2-2.05, then phosphorus oxychloride and 11-dodecenol undergo an esterification reaction, and the reaction process is as follows:

[0013]

[0014] S2, nitrogen gas was blown into a dry three-necked flask to expel air and moisture in the flask, and then intermediate 1, triethylamine and dimethyl sulfoxide were added, and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane was added after stirring and dissolving, and the reaction was stirred at room temperature for 2 hours. After the reaction was completed, reduced pressure distillation was performed to obtain intermediate 2; the amount ratio of intermediate 1, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, triethylamine and dimethyl sulfoxide was 48.5 g: 27.6 mL: 16 mL: 200 mL;

[0015] Triethylamine is used as an acid binding agent, and the molar ratio of intermediate 1 and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane is controlled to be 1.05-1.1:1 at room temperature, so that intermediate 1 and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane undergo a substitution reaction, and the reaction process is as follows:

[0016]

[0017] S3. Blow nitrogen through a dry three-necked flask to expel air and moisture from the flask, then add intermediate 2, triethylamine and DMF (N,N-dimethylformamide), stir and heat to 50°C, then slowly add 2-chloro-4,6-diamino-1,3,5-triazine, and keep the temperature to react for 3 hours. After the reaction is completed, perform reduced pressure distillation to obtain a flame retardant; the amount ratio of intermediate 2, 2-chloro-4,6-diamino-1,3,5-triazine, triethylamine and DMF is 57 g:11.6 g:13 mL:240 mL.

[0018] Triethylamine is used as an acid binding agent, and the molar ratio of intermediate 2 and 2-chloro-4,6-diamino-1,3,5-triazine is controlled to be 1.05-1.1:1 under heating, so that intermediate 2 and 2-chloro-4,6-diamino-1,3,5-triazine undergo a nucleophilic substitution reaction, and the reaction process is as follows:

[0019]

[0020] Flame retardants contain rich nitrogen, phosphorus, and silicon flame retardant elements, and do not contain any halogen. The synergistic effect of nitrogen, phosphorus, and silicon elements gives cables an efficient and safe flame retardant effect. Phosphorus provides an acid source, reacts with polymer materials, and promotes the formation of carbonized products; nitrogen provides a gas source, which can make the system expand and foam, and also promotes the formation of a carbonized layer, forming porous foam carbon; silicon generates an inorganic heat-insulating protective layer containing -Si-0 bonds and -Si-C- bonds during combustion, which not only prevents the decomposition products generated by combustion from escaping, but also inhibits the thermal decomposition of polymer materials, achieving the purpose of high flame retardancy, low smoke emission, and low harmfulness.

[0021] The flame retardant contains long methyl chains that can stretch and rotate freely, which makes the cable tough and soft, and has a high resilience. Adding flame retardants to cable materials can improve the mechanical properties of the cable.

[0022] The flame retardant contains terminal carbon-carbon double bonds, which can produce chemical reactions with unreacted carbon-carbon double bonds in the matrix resin under the action of a cross-linking agent and during the melting process, and can also produce chemical reactions with carbon-carbon double bonds in a coupling agent grafted on the surface of a thermally conductive filler and glass fiber. Flame retardant molecules are then grafted onto the macromolecular chain of the matrix resin, and are cross-linked with the thermally conductive filler and the glass fiber. Thus, a spatial network structure is formed between the flame retardant, the thermally conductive filler, the glass fiber and the matrix resin. The flame retardant, the thermally conductive filler and the glass fiber are all stably present in the cable and can fully exert their effects. Therefore, the cable of the present invention has efficient and safe flame retardant effects, excellent and stable thermal conductivity and mechanical properties, etc.

[0023] Furthermore, the compatibilizer is one or both of maleic anhydride grafted polypropylene and maleic anhydride grafted polyethylene.

[0024] Furthermore, the coupling agent is one or more of vinyltrimethoxysilane, vinyltriethoxysilane, and 3-(methacryloyloxy)propyltrimethoxysilane.

[0025] Under the action of the silaneoxy group of the coupling agent, the coupling agent is grafted onto the surface of the thermal conductive filler and the glass fiber, thereby improving the dispersion of the thermal conductive filler and the glass fiber, and increasing the compatibility of the two with organic raw materials such as polyethylene and polypropylene, so that the two can fully play their role and effectively improve the thermal conductivity and mechanical properties of the cable.

[0026] Furthermore, the antioxidant is one or more of antioxidant 1076, antioxidant 1010, antioxidant 1098, antioxidant 168, and antioxidant DLTP.

[0027] Furthermore, the ultraviolet absorber is one or more of ultraviolet absorber UV-P, ultraviolet absorber UV-9, ultraviolet absorber UV-531, light stabilizer AM-101, and light stabilizer GW-540.

[0028] Furthermore, the cross-linking agent is one or more of benzoyl peroxide, dicumyl peroxide, and di-tert-butyl peroxide.

[0029] The invention also discloses a fast heat-conducting and flame-retardant cable, which is prepared according to the method for preparing the fast heat-conducting and flame-retardant cable.

[0030] Beneficial effects of the present invention: the flame retardant contains rich halogen-free flame retardant elements such as nitrogen, phosphorus and silicon, and there is a chemical reaction between the flame retardant and the thermal conductive filler, glass fiber and matrix resin, thereby forming a spatial network structure. Therefore, the flame retardant, thermal conductive filler and glass fiber of the present invention can all be stably present in the cable and fully play their roles. Therefore, the cable of the present invention has efficient and safe flame retardant effect, excellent and stable thermal conductivity and mechanical properties, etc. DETAILED DESCRIPTION

[0031] 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.

[0032] Example 1

[0033] The flame retardant is prepared in the following steps:

[0034] S1. Add 56.2 g of 11-dodecenol and 200 mL of tetrahydrofuran into a 500 mL dry three-necked flask, stir evenly, add 14 mL of phosphorus oxychloride and 25 mL of pyridine, place the flask in an ice water bath at 0°C for 1 h, and after the reaction is completed, centrifuge the product for separation by centrifugal sedimentation, and then dry at 80°C for 12 h to obtain intermediate 1;

[0035] S2, nitrogen was blown into a 500 mL dry three-necked flask to expel air and moisture in the flask, and then 48.5 g of intermediate 1, 16 mL of triethylamine and 200 mL of dimethyl sulfoxide were added, and after stirring and dissolving, 27.6 mL of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane was added, and the reaction was stirred at room temperature for 2 h. After the reaction was completed, the reaction was distilled under reduced pressure to obtain intermediate 2;

[0036] S3. Blow nitrogen into a 500 mL dry three-necked flask to expel air and moisture from the flask, add 57 g of intermediate 2, 13 mL of triethylamine and 240 mL of DMF, stir and heat to 50°C, slowly add 11.6 g of 2-chloro-4,6-diamino-1,3,5-triazine, and react at this temperature for 3 h. After the reaction is completed, perform distillation under reduced pressure to obtain a flame retardant.

[0037] Example 2

[0038] The specific steps for preparing a cable that can conduct heat quickly and is flame retardant are as follows:

[0039] 60 parts of high-density polyethylene, 20 parts of polypropylene, 15 parts of silicon nitride, 10 parts of ethylene-vinyl acetate copolymer, 8 parts of the flame retardant prepared in Example 1, 6 parts of polyolefin elastomer, 5 parts of glass fiber, 3 parts of maleic anhydride grafted polypropylene, 1 part of vinyl trimethoxy silane, 0.5 parts of antioxidant 1076, 0.5 parts of ultraviolet absorber UV-P, and 0.05 parts of di-tert-butyl peroxide were weighed and mixed uniformly, then the temperature was raised to 60°C and stirred for 1 hour, and then put into a twin-screw extruder for extrusion granulation to obtain a cable material, and then the cable material was melted, extruded, and coated on the side of the copper wire. After cooling and solidification, a cable with rapid thermal conductivity and flame retardancy was obtained.

[0040] Example 3

[0041] The specific steps for preparing a cable that can conduct heat quickly and is flame retardant are as follows:

[0042] 68 parts of high-density polyethylene, 27 parts of polypropylene, 11 parts of boron nitride, 10 parts of magnesium oxide, 13 parts of ethylene-vinyl acetate copolymer, 12 parts of the flame retardant prepared in Example 1, 8 parts of polyolefin elastomer, 7 parts of glass fiber, 4 parts of maleic anhydride grafted polyethylene, 2 parts of vinyl triethoxy silane, 0.8 parts of antioxidant 1010, 0.2 parts of antioxidant 168, 0.8 parts of ultraviolet absorber UV-9, 0.2 parts of light stabilizer AM-101, and 0.08 parts of diisopropyl peroxide were weighed and mixed uniformly, then the temperature was raised to 70°C and stirred for 1 hour, and then put into a twin-screw extruder for extrusion granulation to obtain a cable material, and then the cable material was melted, extruded, and coated on the side of the copper wire. After cooling and solidification, a cable with rapid thermal conductivity and flame retardancy was obtained.

[0043] Example 4

[0044] The specific steps for preparing a cable that can conduct heat quickly and is flame retardant are as follows:

[0045] 70 parts of high-density polyethylene, 30 parts of polypropylene, 6 parts of silicon nitride, 7 parts of boron nitride, 6 parts of magnesium oxide, 6 parts of aluminum oxide, 15 parts of ethylene-vinyl acetate copolymer, 15 parts of the flame retardant prepared in Example 1, 10 parts of polyolefin elastomer, 8 parts of glass fiber, 2.5 parts of maleic anhydride grafted polypropylene, 2.5 parts of maleic anhydride grafted polyethylene, 1 part of vinyl trimethoxy silane, 2 parts of 3-(methacryloyloxy)propyl trimethoxy silane, 0.8 parts of antioxidant 1098, 0.4 parts of antioxidant DLTP, 0.8 parts of ultraviolet absorber UV-531, 0.4 parts of light stabilizer GW-540, and 0.1 parts of benzoyl peroxide were weighed and mixed uniformly, then the temperature was raised to 80° C. and stirred for 1 hour, and then put into a twin-screw extruder for extrusion granulation to obtain a cable material, and then the cable material was melted, extruded, and coated on the side of the copper wire. After cooling and solidification, a cable with rapid thermal conductivity and flame retardancy was obtained.

[0046] Comparative Example 1

[0047] Prepare the cable. The specific steps are as follows:

[0048] The remaining steps remain unchanged, only the flame retardant in Example 2 is removed to prepare the cable.

[0049] Comparative Example 2

[0050] Prepare the cable. The specific steps are as follows:

[0051] The remaining steps remained unchanged, except that the flame retardant in Example 2 was replaced by the flame retardant K-600 produced by Suzhou Jiayi Chemical Co., Ltd. to prepare a cable.

[0052] Comparative Example 3

[0053] Prepare the cable. The specific steps are as follows:

[0054] The remaining steps remained unchanged, except that the vinyltrimethoxysilane in Example 2 was replaced by 3-aminopropyltrimethoxysilane to prepare a cable.

[0055] Performance Testing

[0056] The cable materials obtained after extrusion granulation of Examples 2-4 and Comparative Examples 1-3 were injection molded into the required standard test specimens (injection molding temperature was 180° C., mold temperature was room temperature), and the following performance tests were performed:

[0057] (1) The tensile properties refer to GB / T 1040.3-2006, the tensile rate is 50 mm / min, and the tensile strength is tested using a UTM4204 electronic tensile testing machine;

[0058] (2) Thermal conductivity test was performed according to ASTM-D5470 using a DRL-III thermal conductivity tester;

[0059] (3) The oxygen index test shall be carried out using the method specified in GB / T 2406.2;

[0060] The test results of all items are shown in Table 1 below:

[0061] Table 1

[0062]

[0063]

[0064] The cables prepared in Examples 2-4 and Comparative Examples 1-3 were made into corresponding samples according to different test standards and the following performance tests were carried out. The test results are shown in Table 2 below:

[0065] Table 2

[0066] Test items Fire resistance test Smoke density Flame retardant grade Test standards EN 50200 GB / T 8323 IEC 60332 Example 2 pass 53 A Example 3 pass 51 A Example 4 pass 50 A Comparative Example 1 Not passed 193 D Comparative Example 2 pass 75 B Comparative Example 3 pass 62 B

[0067] 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.

[0068] 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 method for preparing a fast heat-conducting and flame-retardant cable, characterized in that: The following steps are involved: Weigh 60-70 parts of high-density polyethylene, 20-30 parts of polypropylene, 15-25 parts of thermal conductive filler, 10-15 parts of ethylene-vinyl acetate copolymer, 8-15 parts of flame retardant, 6-10 parts of polyolefin elastomer, 5-8 parts of glass fiber, 3-5 parts of compatibilizer, 1-3 parts of coupling agent, 0.5-1.2 parts of antioxidant, 0.5-1.2 parts of ultraviolet absorber, and 0.05-0.1 parts of cross-linking agent by weight and mix them evenly, heat to 60-80°C and stir for 1h, put into a twin-screw extruder for extrusion and granulation to obtain a cable material, then melt the cable material, extrude it, and coat it on the side of the copper wire, and after cooling and solidification, obtain a cable with rapid thermal conductivity and flame retardancy; Wherein, the flame retardant is prepared by the following steps: S1. Add 11-dodecenol and tetrahydrofuran into a flask, add phosphorus oxychloride and pyridine with stirring, react at 0°C for 1 hour, centrifuge, and dry to obtain intermediate 1; S2, after nitrogen blowing into the flask, add intermediate 1, triethylamine and dimethyl sulfoxide, add 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane with stirring, react at room temperature for 2h, and distill under reduced pressure to obtain intermediate 2; S3. After nitrogen is blown into the flask, intermediate 2, triethylamine and DMF are added, the temperature is raised to 50°C with stirring, 2-chloro-4,6-diamino-1,3,5-triazine is added, the reaction is carried out for 3 hours, and the flame retardant is obtained by distillation under reduced pressure.

2. The method for preparing a fast heat-conducting and flame-retardant cable according to claim 1, characterized in that: The amount ratio of phosphorus oxychloride, 11-dodecenol, pyridine and tetrahydrofuran in step S1 is 14mL:56.2g:25mL:200mL; the amount ratio of intermediate 1, 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, triethylamine and dimethyl sulfoxide in step S2 is 48.5g:27.6mL:16mL:200mL; the amount ratio of intermediate 2, 2-chloro-4,6-diamino-1,3,5-triazine, triethylamine and DMF in step S3 is 57g:11.6g:13mL:240mL.

3. The method for preparing a fast heat-conducting and flame-retardant cable according to claim 1, characterized in that: The thermal conductive filler is one or more of silicon nitride, boron nitride, magnesium oxide and aluminum oxide.

4. The method for preparing a fast heat-conducting and flame-retardant cable according to claim 1, characterized in that: The compatibilizer is one or both of maleic anhydride grafted polypropylene and maleic anhydride grafted polyethylene.

5. The method for preparing a fast heat-conducting and flame-retardant cable according to claim 1, characterized in that: The coupling agent is one or more of vinyl trimethoxy silane, vinyl triethoxy silane and 3-(methacryloyloxy)propyl trimethoxy silane.

6. The method for preparing a fast heat-conducting and flame-retardant cable according to claim 1, characterized in that: The antioxidant is one or more of antioxidant 1076, antioxidant 1010, antioxidant 1098, antioxidant 168, and antioxidant DLTP.

7. The method for preparing a fast heat-conducting and flame-retardant cable according to claim 1, characterized in that: The ultraviolet absorber is one or more of the ultraviolet absorber UV-P, ultraviolet absorber UV-9, ultraviolet absorber UV-531, light stabilizer AM-101, and light stabilizer GW-540.

8. The method for preparing a fast heat-conducting and flame-retardant cable according to claim 1, characterized in that: The cross-linking agent is one or more of benzoyl peroxide, dicumyl peroxide and di-tert-butyl peroxide.

9. A fast heat-conducting and flame-retardant cable, characterized in that: The cable is prepared according to the method for preparing a fast heat-conducting and flame-retardant cable according to any one of claims 1 to 8.

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