Tensile flame-retardant cable

Abstract

The invention discloses a tensile flame-retardant cable, and belongs to the technical field of cables. The cable is composed of an outer sheath, a metal armor layer, an insulating layer and conductors. The steel wire armor layer is added in the cable, so that the tensile property of the cable can be enhanced; the outer sheath material takes polyvinyl chloride as a matrix, so that the cable is endowed with excellent mechanical property and certain flame retardant property; thermoplastic polyurethane is added into the material of the outer sheath, so that the tensile property of the cable can be enhanced; the self-made flame retardant is added into the outer sheath material, and the flame retardant contains various flame-retardant components, so that the flame-retardant property of the cable can be remarkably enhanced, the performance is stable, and the influence on the mechanical property of the cable is relatively small; therefore, the cable prepared by the invention is excellent in tensile property, also has stable and efficient flame retardant property, and has important application value in the technical field of cables.

Description

Technical Field

[0001] The present invention belongs to the technical field of cables, and specifically relates to a tensile and flame-retardant cable. Background Art

[0002] A cable is a conductive medium, usually a rope-like cable formed by stranding several or several groups of wires (at least two wires in each group). The wires in each group are insulated from each other and are often twisted around a center, and the whole is covered with a highly insulating covering layer. The cable has the characteristics of conducting electricity inside and being insulated outside. It is widely used in various fields such as petrochemical industry, computers, and national defense.

[0003] For the power transmission of equipment such as reel machines, conveyors, lifting electromagnets, electric flat cars, various cranes, and large reclaimers, since the cable needs to withstand the effects of tension, torsion, friction, etc., there is a great demand for the tensile performance of the cable. And the most influential on the cable performance is its outermost protective layer. The commonly used material for the protective layer is polyvinyl chloride material. The polyvinyl chloride material has good rigidity, high strength, flame retardancy, corrosion resistance, good electrical insulation, etc.; and it has good processing performance and low price, and is widely used in the cable industry. The polyvinyl chloride material itself has a certain flame retardancy, but when it is used as the protective layer material, a series of additives such as plasticizers, antioxidants, stabilizers, and processing aids are usually added. These additives will reduce the flame retardancy of the polyvinyl chloride material, and the polyvinyl chloride material will produce harmful HCl gas to the human body when burning. HCl also has a strong corrosive effect on metals. In addition to generating toxic gases, a large amount of smoke will also be generated due to incomplete combustion of some gases, seriously affecting people's lives and property safety. Therefore, it is urgent to solve the above problems to meet the higher requirements in the cable technology field. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a tensile and flame-retardant cable.

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

[0006] A tensile and flame-retardant cable sequentially includes an outer sheath, a metal armor layer, an insulating layer, and a conductor from outside to inside.

[0007] Further, the material of the conductor is copper.

[0008] Further, the material of the insulating layer is polyvinyl chloride.

[0009] Further, the material of the metal armor layer is steel wire.

[0010] Further, the material of the outer sheath is prepared by the following steps:

[0011] After drying the polyvinyl chloride resin and thermoplastic polyurethane, the flame retardant, antioxidant, initiator and processing aid are added to a mixer. After stirring and mixing evenly, they are put into a twin-screw extruder, melted and blended, and then extruded to obtain the material for the outer sheath.

[0012] Further, the raw materials are as follows by weight: 80 - 100 parts of polyvinyl chloride resin, 15 - 25 parts of thermoplastic polyurethane, 6 - 18 parts of flame retardant, 4 - 6 parts of antioxidant, 0.1 - 0.3 parts of initiator, and 3 - 5 parts of processing aid.

[0013] Further, the drying conditions are drying in an oven at 80 - 90 °C for 8 - 12 h.

[0014] Further, the initiator is one of diisopropyl peroxydicarbonate and dicyclohexyl peroxydicarbonate.

[0015] Further, the antioxidant is a hindered phenol antioxidant.

[0016] Further, the processing aid is one of magnesium stearate and zinc stearate.

[0017] Adding thermoplastic polyurethane to the raw materials, thermoplastic polyurethane is a good elastomer and has a large use temperature range, which can improve the tensile property of the outer sheath.

[0018] Further, the flame retardant is prepared through the following steps:

[0019] A1. Add piperazine to a flask, then add N,N-dimethylformamide (DMF), stir to completely dissolve piperazine, and then sequentially add allyl chloride and triethylamine to the device using a constant pressure dropping funnel. Then place the device in a water bath, control the temperature at 50 °C, react for 3 h. After the reaction is completed, distill off the solvent under reduced pressure, and wash with distilled water 3 - 4 times. After drying, intermediate 1 is obtained; the dosage ratio of piperazine, N,N-dimethylformamide, allyl chloride, and triethylamine is 9.7 g:100 mL:7.6 g:10 mL;

[0020] Under the action of triethylamine, piperazine and allyl chloride undergo a nucleophilic substitution reaction. By controlling the molar ratio of the two to be close to 1:1 and piperazine being slightly in excess, intermediate 1 is obtained; the specific reaction process is as follows:

[0021]

[0022] A2. Add dichlorophenylphosphine, intermediate 1, and N,N-dimethylformamide into a flask. After stirring and mixing evenly, add triethylamine to the reaction system using a constant-pressure dropping funnel. After the addition is complete, place the device in a water bath and control the reaction temperature at 55 °C. Stir the reaction for 4 h. After the reaction is complete, purify by column chromatography and rotary evaporation to remove the eluent to obtain intermediate 2. The dosage ratio of dichlorophenylphosphine, intermediate 1, N,N-dimethylformamide, and triethylamine is 19.4 g: 12.6 g: 100 mL: 10 mL;

[0023] Under the action of triethylamine, dichlorophenylphosphine and intermediate 1 undergo a nucleophilic substitution reaction. By controlling the molar ratio of the two to be close to 1:1 and dichlorophenylphosphine being slightly in excess, intermediate 2 is obtained. The specific reaction process is as follows:

[0024]

[0025] A3. Place 4-hydroxybenzeneboronic acid in a flask, then add N,N-dimethylformamide to dissolve 4-hydroxybenzeneboronic acid. Stir under ice bath conditions and slowly add triethylamine. Then dissolve intermediate 2 in N,N-dimethylformamide and slowly add it to the reaction system using a constant-pressure dropping funnel. After reacting at 0 °C for 1 h, place it in a water bath and control the temperature at 50 °C. Stir the reaction for 5 h. After the reaction is complete, centrifuge to obtain the supernatant, and slowly add it dropwise to deionized water to produce a precipitate. Filter by suction, then wash with deionized water and dry in an oven to obtain the flame retardant. The dosage ratio of 4-hydroxybenzeneboronic acid, N,N-dimethylformamide, triethylamine, and intermediate 2 is 13.8 g: 100 mL: 10 mL: 28.4 g;

[0026]

[0027] The prepared flame retardant contains three flame retardant components: organic phosphorus, organic nitrogen, and organic boron. On the one hand, when organic phosphorus decomposes upon heating, it generates non-combustible gases, thereby diluting the concentration of combustible gases and oxygen in the flame region, achieving the effect of self-extinguishing the polyvinyl chloride matrix. On the other hand, the PO - free radicals generated by the thermal decomposition of organic phosphorus can capture H - and OH -Active free radicals are generated, thereby terminating the combustion chain reaction and achieving the purpose of flame retardancy. Additionally, the flame retardancy mechanism of organic nitrogen is generally a gas-phase flame retardancy mechanism. That is, during combustion, the nitrogen-based flame retardant decomposes upon heating, and this decomposition consumes a large amount of heat in the combustion system, causing the temperature on the surface of the polymer matrix to drop below the ignition temperature of the matrix, ultimately playing a role in flame retardancy. At the same time, when the nitrogen-based flame retardant decomposes upon heating, it generates non-combustible gases such as ammonia, water vapor, and nitrogen. These non-combustible gases dilute the concentrations of oxygen and combustible gases in the flame region, enabling the matrix to achieve self-extinguishing, and thus playing a role in preventing the material from continuing to burn. Furthermore, organic boron is a condensed-phase flame retardant. When organic borides burn, they generate boric anhydride or boric acid, which form a glassy molten covering during pyrolysis, promoting the direct oxidation of the material into CO2, reducing the generation of CO. At the same time, the generated covering hinders the overflow of combustible gases. Moreover, the boric acid structure forms a boron-oxygen six-membered ring network structure upon heating. Further heating results in the formation of a B-O-C carbon layer covering the surface of the epoxy resin, reducing heat transfer and inhibiting the diffusion of combustible decomposition products, promoting carbonization. By introducing three flame retardant components, they can synergistically enhance the flame retardancy performance of the matrix. Finally, the prepared flame retardant molecules contain unsaturated carbon-carbon double bonds, which can crosslink with the polyvinyl chloride matrix under the action of an initiator, not only enhancing the stability of the flame retardant but also reducing the impact of the flame retardant on the mechanical properties of the matrix.

[0028] Advantages of the present invention:

[0029] 1. Adding a steel wire armor layer to the cable prepared by the present invention can enhance the tensile performance of the cable;

[0030] 2. The outer sheath material uses polyvinyl chloride as the matrix, endowing the cable with excellent mechanical properties and a certain degree of flame retardancy;

[0031] 3. Adding thermoplastic polyurethane to the outer sheath material can enhance the tensile performance of the cable;

[0032] 4. Adding a self-made flame retardant to the outer sheath material. The flame retardant contains multiple flame retardant components, which can significantly enhance the flame retardancy performance of the cable, and has stable performance with little impact on the mechanical properties of the cable;

[0033] Therefore, the cable prepared by the present invention has excellent tensile performance and also has stable and efficient flame retardancy performance, possessing important application value in the field of cable technology. Specific embodiments

[0034] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0035] Example 1

[0036] Preparation of flame retardant:

[0037] A1. Add 9.7 g of piperazine into a flask, then add 100 mL of N,N-dimethylformamide, stir to completely dissolve the piperazine, and then sequentially add 7.6 g of allyl chloride and 10 mL of triethylamine into the device with a constant pressure dropping funnel. Then place the device in a water bath, control the temperature at 50 °C, react for 3 h. After the reaction is completed, remove the solvent by vacuum distillation, and then wash with distilled water 3 - 4 times. After drying, obtain intermediate 1;

[0038] A2. Add 19.4 g of phenylphosphonic dichloride, 12.6 g of intermediate 1 and 100 mL of N,N-dimethylformamide into a flask. After stirring and mixing evenly, add 10 mL of triethylamine into the reaction system with a constant pressure dropping funnel. After the dropping is completed, place the device in a water bath, control the reaction temperature at 55 °C, stir and react for 4 h. After the reaction is completed, purify by column chromatography (the eluent uses a mixed solvent of benzene / ethyl acetate, and the volume ratio of the two is 2:3), and rotary evaporate to remove the eluent to obtain intermediate 2;

[0039] A3. Place 13.8 g of 4-hydroxybenzeneboronic acid in a flask, then add 100 mL of N,N-dimethylformamide to dissolve 4-hydroxybenzeneboronic acid. Stir under ice bath conditions and slowly add 10 mL of triethylamine. Then dissolve 28.4 g of intermediate 2 in N,N-dimethylformamide, and slowly add it into the reaction system with a constant pressure dropping funnel. After reacting at 0 °C for 1 h, place it in a water bath, control the temperature at 50 °C, stir and react for 5 h. After the reaction is completed, centrifuge to take the supernatant, and slowly drip it into deionized water to generate a precipitate. Filter by suction, then wash with deionized water, and dry in an oven to obtain the flame retardant.

[0040] Example 2

[0041] Preparation of flame retardant:

[0042] A1. Add 19.4 g of piperazine into a flask, then add 200 mL of N,N-dimethylformamide, stir to completely dissolve the piperazine. Then, sequentially add 15.2 g of allyl chloride and 20 mL of triethylamine into the device using a constant pressure dropping funnel. Next, place the device in a water bath and control the temperature at 50 °C. React for 3 h. After the reaction is completed, remove the solvent by vacuum distillation, wash with distilled water 3 times, and dry to obtain intermediate 1.

[0043] A2. Add 38.8 g of phenylphosphonic dichloride, 25.2 g of intermediate 1, and 200 mL of N,N-dimethylformamide into a flask. After stirring and mixing evenly, add 20 mL of triethylamine into the reaction system using a constant pressure dropping funnel. After the dropping is completed, place the device in a water bath and control the reaction temperature at 55 °C. Stir and react for 4 h. After the reaction is completed, purify by column chromatography (the eluent uses a mixed solvent of benzene / ethyl acetate, and the volume ratio of the two is 2:3), and rotary evaporate to remove the eluent to obtain intermediate 2.

[0044] A3. Place 27.6 g of 4-hydroxybenzeneboronic acid in a flask, then add 200 mL of N,N-dimethylformamide to dissolve 4-hydroxybenzeneboronic acid. Stir under ice bath conditions and slowly add 20 mL of triethylamine. Then dissolve 56.8 g of intermediate 2 in N,N-dimethylformamide and slowly add it to the reaction system using a constant pressure dropping funnel. React at 0 °C for 1 h, then place it in a water bath and control the temperature at 50 °C. Stir and react for 5 h. After the reaction is completed, centrifuge to take the supernatant and slowly drip it into deionized water to produce a precipitate. Filter by suction, wash with deionized water, and dry in an oven to obtain the flame retardant.

[0045] Example Three

[0046] Materials for preparing the outer sheath:

[0047] Put 80 g of polyvinyl chloride resin and 15 g of thermoplastic polyurethane in an 80 °C drying oven and dry for 8 h. Then add 6 g of the flame retardant prepared in Example One, 4 g of antioxidant 1076, 0.1 g of diisopropyl peroxydicarbonate, and 3 g of magnesium stearate into a mixer, stir and mix evenly, and then put it into a twin-screw extruder. After melt blending, extrude to obtain the materials for the outer sheath.

[0048] Example Four

[0049] Materials for preparing the outer sheath:

[0050] 90 g of polyvinyl chloride resin and 20 g of thermoplastic polyurethane were dried in an oven at 85 °C for 10 h, and then 12 g of the flame retardant prepared in Example 1, 5 g of antioxidant 1076, 0.2 g of dicyclohexyl peroxydicarbonate, and 4 g of zinc stearate were added to a mixer. After stirring and mixing evenly, they were put into a twin-screw extruder. After melt blending, extrusion was carried out to obtain the material for the outer sheath.

[0051] Example 5

[0052] Preparation of the material for the outer sheath:

[0053] 100 g of polyvinyl chloride resin and 25 g of thermoplastic polyurethane were dried in an oven at 90 °C for 12 h, and then 18 g of the flame retardant prepared in Example 1, 6 g of antioxidant 1076, 0.3 g of dicyclohexyl peroxydicarbonate, and 5 g of zinc stearate were added to a mixer. After stirring and mixing evenly, they were put into a twin-screw extruder. After melt blending, extrusion was carried out to obtain the material for the outer sheath.

[0054] Example 6

[0055] Copper was used as the conductor, and polyvinyl chloride was extruded on the conductor to form an insulating layer. Then, steel wires were helically stranded on the insulating layer of the cable to form a metal armor layer; 100 g of polyvinyl chloride resin and 25 g of thermoplastic polyurethane were dried in an oven at 90 °C for 12 h, and then 18 g of the flame retardant prepared in Example 1, 6 g of antioxidant 1076, 0.3 g of dicyclohexyl peroxydicarbonate, and 5 g of zinc stearate were added to a mixer. After stirring and mixing evenly, they were put into a twin-screw extruder. After melt blending, extrusion was carried out to coat the surface of the metal armor layer to obtain a tensile flame-retardant cable.

[0056] Comparative Example 1

[0057] A commercially available organophosphorus flame retardant of the same mass was used to replace the flame retardant in Example 5, and the remaining steps were the same as those in Example 5.

[0058] Comparative Example 2

[0059] Commercially available polyvinyl chloride cable material was used.

[0060] Examples 3, 4, and 5, and Comparative Examples 1 and 2 were made into corresponding test shapes according to different test standards for the following performance tests:

[0061] The tensile properties were measured according to the national standard GB / T 1040.2 "Determination of tensile properties of plastics - Part 2: Test conditions for moulding and extrusion plastics".

[0062] The limiting oxygen index was measured using the national standard GB / T 2406 "Test Method for Flammability of Plastics"; after the samples of Examples 3, 4, 5 and Comparative Example 1 were placed at room temperature for 100 days, the limiting oxygen index was measured again.

[0063] The smoke density was measured using the national standard GB / T 8323.2 "Plastics - Smoke Generation - Part 2: Determination of Smoke Density by the Single Chamber Method".

[0064] The measured results are shown in the following table:

[0065]

[0066] As can be seen from the above table, the flame retardant performance of the outer sheath material prepared in the examples of the present invention is much higher than that of the comparative example, and the self-made flame retardant of the present invention has little influence on the mechanical properties of the material, with stable performance, and has important application value in the field of cable technology.

[0067] In the description of the specification, the description with reference to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0068] The above content is only an example and explanation of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the described specific embodiments or use similar ways to replace them. As long as they do not deviate from the invention or exceed the scope defined by the claims of the present invention, they should fall within the protection scope of the present invention.

Claims

1. A tensile and flame-retardant cable, which sequentially includes an outer sheath, a metal armor layer, an insulating layer, and a conductor from outside to inside, is characterized in that, The material of the outer sheath comprises the following raw materials in parts by weight: 80-100 parts of polyvinyl chloride resin, 15-25 parts of thermoplastic polyurethane, 6-18 parts of flame retardant, 4-6 parts of antioxidant, 0.1-0.3 part of initiator, and 3-5 parts of processing aid.

2. The tensile and flame-retardant cable according to claim 1, characterized in that, The flame retardant is prepared through the following steps: A1. Add piperazine into a flask, then add N,N-dimethylformamide, stir to completely dissolve piperazine, then successively add allyl chloride and triethylamine, place the device in a water bath, control the temperature at 50 °C, react for 3 h, after the reaction is completed, perform vacuum distillation, washing, and drying to obtain intermediate 1; A2. Add phenylphosphonic dichloride, intermediate 1, and N,N-dimethylformamide into a flask, stir and mix evenly, then add triethylamine, after the dropping is completed, place the device in a water bath, control the reaction temperature at 55 °C, stir and react for 4 h, after the reaction is completed, perform column chromatography purification and rotary evaporation to obtain intermediate 2; A3. Place 4-hydroxyphenylboronic acid in a flask, add N,N-dimethylformamide to dissolve 4-hydroxyphenylboronic acid, stir under ice bath conditions, and slowly add triethylamine, then dissolve intermediate 2 in N,N-dimethylformamide, slowly add it to the reaction system, react at 0 °C for 1 h, then place it in a water bath, control the temperature at 50 °C, stir and react for 5 h, after the reaction is completed, centrifuge to take the supernatant, drop it into deionized water to generate precipitation, perform suction filtration, wash with deionized water, and dry to obtain the flame retardant.

3. The tensile and flame-retardant cable according to claim 2, wherein In step A1, the dosage ratio of piperazine, N,N-dimethylformamide, allyl chloride, and triethylamine is 9.7 g:100 mL:7.6 g:10 mL.

4. The tensile and flame-retardant cable according to claim 2, wherein In step A2, the dosage ratio of phenylphosphonic dichloride, intermediate 1, N,N-dimethylformamide, and triethylamine is 19.4 g:12.6 g:100 mL:10 mL.

5. The tensile and flame-retardant cable according to claim 2, characterized in that, In step A3, the dosage ratio of 4-hydroxyphenylboronic acid, N,N-dimethylformamide, triethylamine, and intermediate 2 is 13.8 g:100 mL:10 mL:28.4 g.

6. A tensile and flame-retardant cable according to claim 1, wherein The initiator is one of diisopropyl peroxydicarbonate and dicyclohexyl peroxydicarbonate.

7. The tensile and flame-retardant cable according to claim 1, wherein The antioxidant is a hindered phenol antioxidant.

8. A tensile and flame-retardant cable according to claim 1, characterized in that, The processing aid is one of magnesium stearate and zinc stearate.

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