Flame-retardant low-temperature-resistant cable for ships and preparation method thereof

Abstract

The invention discloses a flame-retardant low-temperature-resistant cable for ships and warships and a preparation method thereof, and relates to the technical field of cables. The flame-retardant modifier is prepared from diethyl hydroxymethylphosphonate and 4-vinyl benzene sulfonyl chloride, polypropylene is modified by the flame-retardant modifier and 1, 7-divinyl-octamethyltetrasiloxane together, and P, S and Si elements are introduced, so that the flame-retardant property of polypropylene is improved, and the flame-retardant effect of the cable is further improved; and the compatibility and dispersity of the flame retardant in methyl phenyl vinyl silicone rubber raw rubber can also be improved, so that the flame retardant effect is improved, and meanwhile, the flame retardant has good mechanical properties and low-temperature-resistant effects. In the preparation process of the modified polypropylene, the modified ethylene propylene diene monomer nano powder is also added as a nucleating agent and a reinforcing agent, so that the rigidity, the cold-resistant effect and the flame-retardant effect of the modified polypropylene can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of cables, and in particular to a flame-retardant and low-temperature-resistant cable for ships and a preparation method thereof. Background Art

[0002] With the development of my country's economy, there have been great progress in the fields of communication technology, radio and television, railway transportation, petrochemical industry, construction, etc. Various wires and cables, communication cables, etc. are widely used in these fields and have become one of the indispensable components. However, facilities in high-altitude cold areas or cold environmental conditions have put forward higher requirements on the flame retardancy, low temperature resistance, service life, quality and applicability of such products.

[0003] Cables used in places where humans often move, such as buildings or rail transit, are required to have excellent flame retardancy. In order to reduce the incidence of fire and the mortality rate when a fire occurs, it is very important to improve the flame retardancy of cables. Usually, a large amount of flame retardants are added to the cable covering to overcome its flammable defects, including inorganic flame retardants, organic halogen flame retardants, organic phosphorus flame retardants, intumescent flame retardants, etc. Organic halogen flame retardants will produce toxic and corrosive gases when burned, which will cause harm to human health and the ecological environment. With the improvement of environmental awareness, more and more flame retardants are developing in the direction of high efficiency, low smoke, halogen-free and environmentally friendly. Summary of the invention

[0004] The object of the present invention is to provide a flame-retardant and low-temperature-resistant cable for ships and a preparation method thereof, so as to solve the problems existing in the prior art.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: A flame-retardant and low-temperature resistant cable for ships, comprising a cable core, a cushion layer, a wrapped shielding layer, and a sheath layer, wherein the cable core comprises seven twisted insulating cores, and the insulating core comprises a conductor and an insulating layer;

[0006] The insulating layer comprises, by weight: 60 to 75 parts of modified polypropylene, 30 to 50 parts of methylphenyl vinyl silicone rubber, 5 to 10 parts of epoxy soybean oil, 5 to 10 parts of methyl silicone oil, 0.5 to 2 parts of diisopropyl peroxide, 0.5 to 2 parts of triallyl isocyanurate, and 1 to 3 parts of stearic acid;

[0007] The sheath layer comprises, by weight: 60 to 70 parts of methylphenyl vinyl silicone rubber, 40 to 55 parts of modified polypropylene, 10 to 20 parts of epoxy soybean oil, 5 to 10 parts of methyl silicone oil, 3 to 5 parts of diisopropylbenzene peroxide, 1 to 3 parts of triallyl isocyanurate, and 1 to 3 parts of stearic acid.

[0008] Furthermore, the wrapped shielding layer is an aluminum foil wrapped shielding layer; and the cushion layer is a buffer cushion layer, specifically a soft rubber sleeve.

[0009] Furthermore, the conductor is a silver-plated copper wire with a diameter of 0.1 mm.

[0010] Furthermore, the phenyl content of the methylphenyl vinyl silicone rubber is 6-10%, and the vinyl content is 0.15-0.25%.

[0011] Furthermore, the viscosity of the methyl silicone oil at 25° C. is 50 mPa.s; and the epoxy group mass content of the epoxy soybean oil is 5.8-6.4% of the mass of the epoxy soybean oil.

[0012] Furthermore, the preparation method of the modified polypropylene is: a flame retardant modifier and 1,7-divinyl-octamethyltetrasiloxane are grafted onto polypropylene under the catalysis of a photoinitiator and ultraviolet light to obtain pre-modified polypropylene; then the modified EPDM rubber powder and the pre-modified polypropylene are mixed in a mass ratio of 1:10, and extruded and granulated at 180-230°C and a screw speed of 180-200r / min.

[0013] Furthermore, the polypropylene refers to a homopolymer or copolymer grade polypropylene resin having a melt index greater than 8.0 g / 10 min.

[0014] Furthermore, the preparation method of the flame retardant modifier is as follows: at 10°C, add diethyl hydroxymethylphosphonate, triethylamine, toluene, and 4-vinylbenzenesulfonyl chloride in sequence, heat to 20°C, stir at 60rpm for 12h, wash the filtrate once with 70mL of water, wash three times with 70mL of saturated sodium carbonate solution in sequence, dry at 80°C for 2h, vacuum distill, collect at 150°C / 2~3mmHg, and obtain the flame retardant modifier.

[0015] Furthermore, the ratio of diethyl hydroxymethylphosphonate, triethylamine, toluene and 4-vinylbenzenesulfonyl chloride is 50 g: 6-8 g: 210 mL: 60-80 g.

[0016] Furthermore, the modified EPDM rubber powder is prepared by modifying EPDM rubber powder with vermiculite powder and graphite powder.

[0017] Furthermore, the particle size of the EPDM rubber powder is 200 meshes.

[0018] Furthermore, the particle sizes of the vermiculite powder and graphite powder are both 20-50 nm.

[0019] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0020] The insulating material and the sheath material in the cable of the present invention adopt the same composition, both of which use methylphenyl vinyl silicone rubber raw rubber and modified polypropylene as the main base materials, thereby improving the low temperature resistance and flame retardant effect of the cable and having excellent mechanical properties.

[0021] The flame retardant modifier of the invention uses diethyl hydroxymethylphosphonate as a raw material, wherein the hydroxyl group of the hydroxyl group is combined with the sulfonyl chloride group of 4-vinylbenzenesulfonyl chloride, and then the double bond is used to modify polypropylene with 1,7-divinyl-octamethyltetrasiloxane, and P, S and Si elements are introduced to improve the flame retardant property of polypropylene, thereby improving the flame retardant effect of the cable, and the introduction of organic silicon can improve the compatibility and dispersibility with methylphenyl vinyl silicone rubber raw rubber, thereby having good mechanical properties and low temperature resistance while improving the flame retardant effect.

[0022] In the process of preparing modified polypropylene, the present invention further adds modified EPDM nano powder as a nucleating agent and a reinforcing agent. Since the modified EPDM rubber powder has the characteristics of small size and easy dispersion, it can be evenly dispersed in the polypropylene matrix, effectively increasing the number of nucleation and spherulites of polypropylene, and effectively improving the rigidity and cold resistance of the modified polypropylene. The modified EPDM nano powder in the present invention is prepared by composite modification of vermiculite powder and graphite powder, so that the modified EPDM nano powder has excellent mechanical properties and flame retardant properties, and works together with the flame retardant modifier to improve the flame retardant properties and mechanical properties of polypropylene, thereby optimizing the cold resistance and flame retardant effects of the cable. DETAILED DESCRIPTION

[0023] 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 making creative work are within the scope of protection of the present invention.

[0024] Embodiment 1: A flame-retardant and low-temperature-resistant cable for ships, comprising a cable core, a soft rubber sleeve, an aluminum foil wrapped shielding layer, and a sheath layer, wherein the cable core comprises seven twisted insulated wire cores, and the insulated wire core comprises a silver-plated copper wire with a diameter of 0.1 mm and an insulating layer;

[0025] The insulating layer comprises, by weight: 60 parts of modified polypropylene, 30 parts of methylphenyl vinyl silicone rubber, 5 parts of epoxy soybean oil, 5 parts of methyl silicone oil, 0.5 parts of diisopropyl peroxide, 0.5 parts of triallyl isocyanurate, and 1 part of stearic acid;

[0026] The sheath layer comprises, by weight: 60 parts of methylphenyl vinyl silicone rubber, 40 parts of modified polypropylene, 10 parts of epoxy soybean oil, 5 parts of methyl silicone oil, 3 parts of diisopropylbenzene peroxide, 1 part of triallyl isocyanurate, and 1 part of stearic acid;

[0027] The preparation method of the insulating layer and the sheath layer is as follows: adding the raw materials in proportion into a vacuum kneader and kneading for 10 minutes, then extruding and coating the cable surface in sequence, and vulcanizing at 180° C. for 10 hours to obtain the insulating layer and the sheath layer;

[0028] The preparation method of the modified polypropylene is:

[0029] (1) At 10°C, diethyl hydroxymethylphosphonate, triethylamine, toluene, and 4-vinylbenzenesulfonyl chloride were added in the ratio of 50 g: 6 g: 210 mL: 60 g in sequence, the temperature was raised to 20°C, and the mixture was stirred at 60 rpm for 12 h. The filtrate was washed once with 70 mL of water and three times with 70 mL of saturated sodium carbonate solution in sequence, dried at 80°C for 2 h, and vacuum distilled. The mixture was collected at 150°C / 2-3 mmHg to obtain a flame retardant modifier.

[0030] (2) Benzophenone, flame retardant modifier, 1,7-divinyl-octamethyltetrasiloxane, and acetone were mixed at a mass ratio of 0.5:3:1:30 to obtain a modified liquid. Polypropylene and the modified liquid were mixed at a mass ratio of 1:10. The wavelength was 365 nm and the light intensity was 45 mW / cm 2 The ultraviolet lamp was used as the light source for 6 minutes of irradiation. After the irradiation, the polypropylene was ultrasonically shaken at 20°C, 20kHz, and 400W for 6 hours. The polypropylene was taken out and washed with pure water and anhydrous ethanol for 5 times each, and dried at 70°C for 12 hours to obtain pre-modified polypropylene.

[0031] (3) 0.5 kg of vermiculite powder with a particle size of 40 nm, 0.5 kg of graphite powder with a particle size of 40 nm, and 15 L of a 2% vinyltriethoxysilane solution, wherein the solvent of the silane coupling agent solution is a mixture of water and ethanol in a mass ratio of 9:1; after stirring for 30 minutes, filtering to obtain a composite filler;

[0032] (4) Add EPDM rubber powder to a flask containing xylene at 50°C and stir until completely dissolved. Then, add composite filler and azobisisobutyronitrile in sequence at 65°C in a nitrogen atmosphere and stir to react for 4 hours, wherein the mass ratio of EPDM rubber, composite filler and azobisisobutyronitrile is 1:0.1:0.005. Precipitate with acetone, extract with N,N-dimethylformamide, and dry in vacuum to obtain modified EPDM rubber powder.

[0033] (5) Then, the modified EPDM rubber powder and the pre-modified polypropylene are mixed in a mass ratio of 1:10 and extruded into granules.

[0034] Embodiment 2: A flame-retardant and low-temperature-resistant cable for ships, comprising a cable core, a soft rubber sleeve, an aluminum foil wrapped shielding layer, and a sheath layer, wherein the cable core comprises seven twisted insulated wire cores, and the insulated wire core comprises a silver-plated copper wire with a diameter of 0.1 mm and an insulating layer;

[0035] The insulating layer comprises, by weight: 70 parts of modified polypropylene, 40 parts of methylphenyl vinyl silicone rubber, 8 parts of epoxy soybean oil, 8 parts of methyl silicone oil, 1.2 parts of dicumyl peroxide, 1.2 parts of triallyl isocyanurate, and 2 parts of stearic acid;

[0036] The sheath layer comprises, by weight: 65 parts of methylphenyl vinyl silicone rubber, 48 parts of modified polypropylene, 15 parts of epoxy soybean oil, 8 parts of methyl silicone oil, 4 parts of diisopropylbenzene peroxide, 2 parts of triallyl isocyanurate, and 2 parts of stearic acid;

[0037] The preparation method of the insulating layer and the sheath layer is as follows: adding the raw materials in proportion into a vacuum kneader and kneading for 10 minutes, then extruding and coating the cable surface in sequence, and vulcanizing at 180° C. for 10 hours to obtain the insulating layer and the sheath layer;

[0038] The preparation method of the modified polypropylene is:

[0039] (1) At 10°C, diethyl hydroxymethylphosphonate, triethylamine, toluene, and 4-vinylbenzenesulfonyl chloride were added in the ratio of 50 g: 7 g: 210 mL: 70 g in sequence, the temperature was raised to 20°C, and the mixture was stirred at 60 rpm for 12 h. The filtrate was washed once with 70 mL of water and three times with 70 mL of saturated sodium carbonate solution in sequence, dried at 80°C for 2 h, and vacuum distilled. The mixture was collected at 150°C / 2-3 mmHg to obtain a flame retardant modifier.

[0040] (2) Benzophenone, flame retardant modifier, 1,7-divinyl-octamethyltetrasiloxane, and acetone were mixed evenly at a mass ratio of 0.5:3.5:1.5:35 to obtain a modified liquid. Polypropylene and the modified liquid were mixed evenly at a mass ratio of 1:10. The wavelength was 365 nm and the light intensity was 45 mW / cm 2 The ultraviolet lamp was used as the light source for 8 minutes of irradiation. After the irradiation, the polypropylene was ultrasonically shaken at 25°C, 20kHz, and 500W for 7 hours. The polypropylene was taken out and washed with pure water and anhydrous ethanol for 5 times each, and dried at 70°C for 12 hours to obtain pre-modified polypropylene.

[0041] (3) 0.5 kg of vermiculite powder with a particle size of 40 nm, 0.5 kg of graphite powder with a particle size of 40 nm, and 15 L of a 2% vinyltriethoxysilane solution, wherein the solvent of the silane coupling agent solution is a mixture of water and ethanol in a mass ratio of 9:1; after stirring for 30 minutes, filtering to obtain a composite filler;

[0042] (4) Add EPDM rubber powder to a flask containing xylene at 55°C and stir until completely dissolved. Then, add composite filler and azobisisobutyronitrile in sequence at 60°C in a nitrogen atmosphere and stir to react for 4 hours, wherein the mass ratio of EPDM rubber, composite filler and azobisisobutyronitrile is 1:0.1:0.005. Precipitate with acetone, extract with N,N-dimethylformamide, and dry in vacuum to obtain modified EPDM rubber powder.

[0043] (5) Then, the modified EPDM rubber powder and the pre-modified polypropylene are mixed in a mass ratio of 1:10 and extruded into granules.

[0044] Embodiment 3: A flame-retardant and low-temperature-resistant cable for ships, comprising a cable core, a soft rubber sleeve, an aluminum foil wrapped shielding layer, and a sheath layer, wherein the cable core comprises seven twisted insulated wire cores, and the insulated wire core comprises a silver-plated copper wire with a diameter of 0.1 mm and an insulating layer;

[0045] The insulating layer comprises, by weight: 75 parts of modified polypropylene, 50 parts of methylphenyl vinyl silicone rubber, 10 parts of epoxy soybean oil, 10 parts of methyl silicone oil, 2 parts of diisopropylbenzene peroxide, 2 parts of triallyl isocyanurate, and 3 parts of stearic acid;

[0046] The sheath layer comprises, by weight: 70 parts of methylphenyl vinyl silicone rubber, 55 parts of modified polypropylene, 20 parts of epoxy soybean oil, 10 parts of methyl silicone oil, 5 parts of diisopropylbenzene peroxide, 3 parts of triallyl isocyanurate, and 3 parts of stearic acid;

[0047] The preparation method of the insulating layer and the sheath layer is as follows: adding the raw materials in proportion into a vacuum kneader and kneading for 10 minutes, then extruding and coating the cable surface in sequence, and vulcanizing at 180° C. for 10 hours to obtain the insulating layer and the sheath layer;

[0048] The preparation method of the modified polypropylene is:

[0049] (1) At 10°C, diethyl hydroxymethylphosphonate, triethylamine, toluene, and 4-vinylbenzenesulfonyl chloride were added in the ratio of 50 g: 8 g: 210 mL: 80 g in sequence, the temperature was raised to 20°C, and the mixture was stirred at 60 rpm for 12 h. The filtrate was washed once with 70 mL of water and three times with 70 mL of saturated sodium carbonate solution in sequence, dried at 80°C for 2 h, and vacuum distilled. The mixture was collected at 150°C / 2-3 mmHg to obtain a flame retardant modifier.

[0050] (2) Benzophenone, flame retardant modifier, 1,7-divinyl-octamethyltetrasiloxane, and acetone were mixed at a mass ratio of 0.5:4:2:40 to obtain a modified liquid. Polypropylene and the modified liquid were mixed at a mass ratio of 1:10. The wavelength was 365 nm and the light intensity was 45 mW / cm 2 The ultraviolet lamp was used as the light source for 8 minutes of irradiation. After the irradiation, the polypropylene was ultrasonically shaken at 30°C, 20kHz, and 600W for 8 hours. The polypropylene was taken out and washed with pure water and anhydrous ethanol for 5 times each, and dried at 70°C for 12 hours to obtain pre-modified polypropylene.

[0051] (3) 0.5 kg of vermiculite powder with a particle size of 40 nm, 0.5 kg of graphite powder with a particle size of 40 nm, and 15 L of a 2% vinyltriethoxysilane solution, wherein the solvent of the silane coupling agent solution is a mixture of water and ethanol in a mass ratio of 9:1; after stirring for 30 minutes, filtering to obtain a composite filler;

[0052] (4) Add EPDM rubber powder to a flask containing xylene at 60°C and stir until completely dissolved. Then, add composite filler and azobisisobutyronitrile in sequence at 75°C in a nitrogen atmosphere and stir to react for 4 hours, wherein the mass ratio of EPDM rubber, composite filler and azobisisobutyronitrile is 1:0.1:0.005. Precipitate with acetone, extract with N,N-dimethylformamide, and dry in vacuum to obtain modified EPDM rubber powder.

[0053] (5) Then, the modified EPDM rubber powder and the pre-modified polypropylene are mixed in a mass ratio of 1:10 and extruded into granules.

[0054] Comparative Example 1; The difference between Comparative Example 1 and Example 1 is that the flame retardant modifier is only diethyl hydroxymethylphosphonate, and the remaining preparation steps and components are the same as Example 1.

[0055] Comparative Example 2; The difference between Comparative Example 1 and Example 1 is that the flame retardant modifier is only 4-vinylbenzenesulfonyl chloride, and the remaining preparation steps and components are the same as Example 1.

[0056] Comparative Example 3; The difference between Comparative Example 3 and Example 1 is that 1,7-divinyl-octamethyltetrasiloxane is not added in the preparation of pre-modified polypropylene, and the remaining preparation steps and components are the same as Example 1.

[0057] Comparative Example 4: The difference between Comparative Example 4 and Example 1 is that modified EPDM rubber powder is not added, and the remaining preparation steps and components are the same as Example 1.

[0058] Comparative Example 5; The difference between Comparative Example 5 and Example 1 is that no vermiculite powder is added in the preparation of the modified EPDM rubber powder, and the remaining preparation steps and components are the same as Example 1.

[0059] Comparative Example 6: The difference between Comparative Example 6 and Example 1 is that no graphite powder is added in the preparation of the modified EPDM rubber powder, and the remaining preparation steps and components are the same as Example 1.

[0060] Effect example

[0061] Table 1 below shows the performance analysis results of the cables using Examples 1 to 3 of the present invention and Comparative Examples 1 to 6.

[0062] Table 1

[0063]

[0064] From the comparison of the test data of the embodiment and the comparative example, it can be found that the flame retardant modifier of the present invention is prepared from diethyl hydroxymethylphosphonate and 4-vinylbenzenesulfonyl chloride, and is used together with 1,7-divinyl-octamethyltetrasiloxane to modify polypropylene, introduce P, S, and Si elements, improve the flame retardant properties of polypropylene, and then improve the flame retardant effect of the cable, and can also improve the compatibility and dispersibility with methylphenylvinyl silicone rubber raw rubber, so that while improving the flame retardant effect, it has good mechanical properties and low temperature resistance. In the process of preparing modified polypropylene, the present invention also adds modified ethylene propylene diene monomer nanopowder as a nucleating agent and a reinforcing agent, which can effectively improve the rigidity, cold resistance and flame retardant effect of the modified polypropylene.

[0065] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and scope of the equivalent elements of the claims be included in the invention. Any marking in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A flame-retardant and low-temperature resistant cable for ships, comprising a cable core, a cushion layer, a wrapped shielding layer, and a sheath layer, characterized in that: The cable core comprises seven twisted insulated wire cores, and the insulated wire core comprises a conductor and an insulating layer; The insulating layer comprises, by weight: 60 to 75 parts of modified polypropylene, 30 to 50 parts of methylphenyl vinyl silicone rubber, 5 to 10 parts of epoxy soybean oil, 5 to 10 parts of methyl silicone oil, 0.5 to 2 parts of diisopropyl peroxide, 0.5 to 2 parts of triallyl isocyanurate, and 1 to 3 parts of stearic acid; The sheath layer comprises, by weight: 60 to 70 parts of methylphenyl vinyl silicone rubber, 40 to 55 parts of modified polypropylene, 10 to 20 parts of epoxy soybean oil, 5 to 10 parts of methyl silicone oil, 3 to 5 parts of diisopropylbenzene peroxide, 1 to 3 parts of triallyl isocyanurate, and 1 to 3 parts of stearic acid.

2. A flame-retardant and low-temperature-resistant cable for ships according to claim 1, characterized in that: The phenyl content in the methylphenyl vinyl silicone rubber is 6-10%, and the vinyl content is 0.15-0.25%.

3. The flame-retardant and low-temperature-resistant cable for ships according to claim 1, characterized in that: The preparation method of the modified polypropylene comprises the following steps: a flame retardant modifier and 1,7-divinyl-octamethyltetrasiloxane are grafted onto polypropylene under the catalysis of a photoinitiator and by ultraviolet light to obtain pre-modified polypropylene; then modified EPDM rubber powder and pre-modified polypropylene are mixed in a mass ratio of 1:10, and extruded and granulated at 180-230° C. and a screw speed of 180-200 r / min.

4. A flame-retardant and low-temperature-resistant cable for ships according to claim 3, characterized in that: The polypropylene refers to a homopolymer or copolymer grade polypropylene resin having a melt index greater than 8.0 g / 10 min.

5. The flame-retardant and low-temperature-resistant cable for ships according to claim 3, characterized in that: The preparation method of the flame retardant modifier is as follows: at 10°C, diethyl hydroxymethylphosphonate, triethylamine, toluene, and 4-vinylbenzenesulfonyl chloride are added in sequence, the temperature is raised to 20°C, and the mixture is stirred at 60 rpm for 12 hours. The filtrate is washed once with 70 mL of water and three times with 70 mL of saturated sodium carbonate solution in sequence, dried at 80°C for 2 hours, vacuum distilled, and collected at 150°C / 2-3 mmHg to obtain the flame retardant modifier.

6. The flame-retardant and low-temperature-resistant cable for ships according to claim 5, characterized in that: The ratio of diethyl hydroxymethylphosphonate, triethylamine, toluene and 4-vinylbenzenesulfonyl chloride is 50g:6-8g:210mL:60-80g.

7. The flame-retardant and low-temperature-resistant cable for ships according to claim 3, characterized in that: The modified EPDM rubber powder is prepared by modifying EPDM rubber powder with vermiculite powder and graphite powder.

8. The flame-retardant and low-temperature-resistant cable for ships according to claim 7, characterized in that: The particle size of the EPDM rubber powder is 200 meshes.

9. The flame-retardant and low-temperature-resistant cable for ships according to claim 7, characterized in that: The particle sizes of the vermiculite powder and graphite powder are both 20-50 nm.

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