Fire-resistant light cable of safe harbor returning system for ship and processing method of fire-resistant light cable

Abstract

The invention relates to the field of cables, and discloses a fire-resistant light cable for a safety harbor-returning system for a ship and a processing method thereof.The cable comprises a guide core, a fire-resistant layer, an insulating layer, a cabling layer, an inner sheath layer, an armor layer and an outer sheath layer which are sequentially arranged from inside to outside, and the inner sheath layer and the outer sheath layer are prepared by extruding sheath layer materials; the sheath layer is made of low-density polyethylene, nitrile rubber, ethylene-tetrafluoroethylene copolymer, functional additives, composite filler and auxiliaries; the functional additive is prepared by the following steps: reacting 3, 5-di-tert-butyl-4-hydroxybenzoyl chloride with 2-chloro-4, 6-diamino-1, 3, 5-triazine to obtain a modified hindered phenol component, and then reacting 1, 4-p-xylylene dichloride with 10-(2, 5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide to obtain a product, and continuously reacting the product with the modified hindered phenol component; the composite filler is prepared by modifying vermiculite with titanium dioxide and zinc oxide pillared. The cable prepared by the invention has excellent mechanical properties, flame retardance and aging resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of cables, and in particular relates to a fire-resistant light cable for a ship's safe return to port system and a processing method thereof. Background Art

[0002] Fire-resistant shipboard power cables refer to fire-resistant power cables used in ship electrical systems. Ships, as a special working environment, have a high risk of fire. Therefore, shipboard cables need to have good flame retardant properties to ensure that the spread of fire can be slowed down and the losses caused by fire can be reduced in the event of a fire. Among them, the sheath material is an important component of the cable. Its performance will affect the service life of the entire cable and whether the system can operate normally. Low-density polyethylene is a general-purpose plastic with a wide range of uses, but its molecular structure is relatively simple. The high saturation of its hydrocarbon backbone results in a low limiting oxygen index, which cannot achieve self-extinguishing. During the combustion process, low-density polyethylene will release heat violently, accompanied by the release of large amounts of toxic gases and the production of molten droplets, which can easily cause secondary fires. In addition, its molecular structure is sensitive to high temperatures and ultraviolet rays. Long-term exposure to high temperatures or ultraviolet rays is prone to oxidative degradation, causing molecular chain breakage and cross-linking, resulting in a significant decrease in mechanical properties, which seriously limits the service life of shipboard cables. Summary of the Invention

[0003] In order to solve the deficiencies mentioned in the above background technology, the purpose of the present invention is to provide a fire-resistant lightweight cable for a safe return to port system for ships and a processing method thereof. The prepared cable has excellent mechanical properties, flame retardant properties and aging resistance.

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] A fire-resistant lightweight cable for a safe return-to-port system for ships, comprising, arranged in order from the inside out, a conductor core, a fire-resistant layer, an insulating layer, a cabling layer, an inner sheath layer, an armor layer, and an outer sheath layer. The inner and outer sheath layers are prepared by drawing a sheath layer material through an extrusion device on the outsides of the cabling layer and the armor layer. The sheath layer material comprises the following components in parts by weight: 40-70 parts of low-density polyethylene, 10-20 parts of nitrile rubber, 10-15 parts of ethylene-tetrafluoroethylene copolymer, 2-6 parts of a functional additive, 5-12 parts of a composite filler, 3.5-6 parts of dicumyl peroxide, 2-5.5 parts of triallyl isocyanurate, 1-3 parts of a plasticizer, and 0.1-0.5 parts of a lubricant.

[0006] The functional additive is prepared by an acylation reaction between 3,5-di-tert-butyl-4-hydroxybenzoyl chloride and 2-chloro-4,6-diamino-1,3,5-triazine to obtain a modified hindered phenol component, and then a substitution reaction is carried out between 1,4-p-dichlorobenzyl and 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, and then the obtained product is further subjected to a substitution reaction with the modified hindered phenol component. The composite filler is prepared by using vermiculite as a raw material and using titanium dioxide and zinc oxide pillared to modify the vermiculite.

[0007] Preferably, the plasticizer is one or more combinations of dioctyl adipate, dimethyl phthalate, dioctyl phthalate, and diisodecyl phthalate; and the lubricant is polyethylene wax or oxidized polyethylene wax.

[0008] Preferably, the preparation method of the sheath layer material includes the following steps: weighing each component by weight, uniformly mixing low-density polyethylene, nitrile rubber, ethylene-tetrafluoroethylene copolymer, composite filler, functional additives, diisopropylbenzene peroxide, triallyl isocyanurate, plasticizer and lubricant, and then putting them into a twin-screw extruder for extrusion molding to prepare the sheath layer material.

[0009] Preferably, the preparation method of the functional additive comprises the following steps:

[0010] A. Take 3,5-di-tert-butyl-4-hydroxybenzoic acid in a reactor, add chloroform, raise the temperature to 45-55°C, then add distilled thionyl chloride dropwise, stir and react for 4-6 hours, and after the reaction is completed, remove the solvent by rotary evaporation to prepare 3,5-di-tert-butyl-4-hydroxybenzoyl chloride;

[0011] B. 2-chloro-4,6-diamino-1,3,5-triazine was placed in a reactor, tetrahydrofuran was added, nitrogen was passed through the reaction, triethylamine was added dropwise under ice-water bath conditions, and after stirring and mixing, a mixture of 3,5-di-tert-butyl-4-hydroxybenzoyl chloride and tetrahydrofuran was added, and the mixture was placed at 45-60° C. for 6-8 hours. After the reaction was completed, the mixture was filtered, washed, and dried to prepare a modified hindered phenol component;

[0012] C. Disperse 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide in N,N-dimethylformamide, pass nitrogen through the reaction, stir evenly at 75-80°C, then add sodium hydroxide and stir for 0.5-1h, then add 1,4-dichlorobenzyl, stir and react for 6-8h, then add the modified hindered phenol component and continue stirring for 6-8h. After the reaction is completed, filter, wash and dry to prepare a functional additive.

[0013] Preferably, in step B, the molar ratio of 2-chloro-4,6-diamino-1,3,5-triazine to 3,5-di-tert-butyl-4-hydroxybenzoyl chloride is 1:2-2.1; and in step C, the molar ratio of 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, 1,4-dichlorobenzyl and modified hindered phenol component is 2:1:2-2.1.

[0014] Preferably, the preparation method of the composite filler comprises the following steps:

[0015] (1) Vermiculite was dispersed in an ethanol solution, and then a dispersion of tetrabutyl titanate and ethanol was added, stirred for 5-6 hours, and then slowly added dropwise to deionized water. The mixture was allowed to stand at room temperature for 20-24 hours. The suspension was then centrifuged, washed with ethanol, freeze-dried, and finally calcined at 480-525°C for 4-6 hours to prepare modified vermiculite.

[0016] (2) The modified vermiculite was added to the zinc acetate solution and stirred at room temperature to obtain a homogeneous dispersion. The dispersion was then centrifuged, freeze-dried, and finally calcined at 480-525°C for 4-6 hours to prepare a composite filler.

[0017] Preferably, the mass ratio of vermiculite to tetrabutyl titanate in step (1) is 1:0.1-0.15; the concentration of the zinc acetate solution in step (2) is 0.1-0.3 mol / L; and the addition ratio of the modified vermiculite to the zinc acetate solution is 1 g:5-10 mL.

[0018] A method for processing a fire-resistant lightweight cable for a ship's safe return to port system comprises the following steps:

[0019] S1. Use cable drawing equipment to Z-draw 6mm round copper rods, then pass through annealing equipment to obtain qualified bare copper wire conductors, which are then twisted in one go through a stranding machine and a pressing die to obtain a conductor core.

[0020] S2. Wrap a fire-resistant layer around the outer side of the conductor core, and then extrude a cross-linked polyethylene insulation layer around the outer side of the fire-resistant layer using an extruder;

[0021] S3. Use 0.04mm non-open mesh PP filling rope to fill the outside of the insulation layer to form a cable layer;

[0022] S4, extruding the sheath material on the outer side of the cabling layer to form an inner sheath layer;

[0023] S5. Tinned copper wire is braided on the outside of the inner sheath layer with a braiding density of ≥90% to form an armor layer;

[0024] S6. Extruding a sheath layer material on the outside of the armor layer to form an outer sheath layer, thereby preparing a fire-resistant light cable for a safe return to port system for ships.

[0025] Preferably, the refractory layer is wrapped in the same direction with a double layer of calcined mica tape, and the overlap rate of the mica tape is controlled at 30-40%. The specific operation steps are: first, a layer of calcined mica tape is overlapped and wrapped on the outside of the conductor core, and then impregnated with a nano-ceramic suspension. After impregnation, it is placed at 190-205°C for drying, and then a second layer of calcined mica tape is overlapped and wrapped.

[0026] Preferably, the nano-scale ceramic suspension comprises, by mass fraction, 45-55% La2Zr2O7, 15-25% Y2O3, 15-20% mSiO2·nH2O, and the remainder is water.

[0027] Beneficial effects of the present invention:

[0028] The invention uses a hindered phenol antioxidant 3,5-di-tert-butyl-4-hydroxybenzoic acid for chlorination treatment, then uses the prepared 3,5-di-tert-butyl-4-hydroxybenzoyl chloride to carry out an acylation reaction with the amino group in 2-chloro-4,6-diamino-1,3,5-triazine to prepare a modified hindered phenol component, and then uses 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, 1,4-dichlorobenzyl and the modified hindered phenol component as raw materials, firstly uses the chlorine atoms at both ends of 1,4-dichlorobenzyl to carry out a substitution reaction with the hydroxyl group at one end of 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, and then further uses the ungrafted chlorine atoms in the modified hindered phenol component to carry out a substitution reaction with the remaining hydroxyl groups to prepare a functional additive. The functional additive incorporates a triazine compound, 2-chloro-4,6-diamino-1,3,5-triazine, which releases non-flammable gases during combustion through its nitrogen element, thereby synergistically improving the flame retardant properties of the material with the flame-retardant phosphorus element in the modified additive. The introduced triazine ring structure also exhibits significant UV absorption, providing additional light-stabilizing protection for the material. Furthermore, the introduced hindered phenol antioxidant provides the material with excellent high-temperature aging resistance. Furthermore, the present invention utilizes vermiculite as a raw material and uses titanium dioxide and zinc oxide pillars to modify the vermiculite to prepare a composite filler. The titanium dioxide pillars the interlayers of the vermiculite, facilitating the dispersion and loading of zinc oxide in the vermiculite. Adding the composite filler to the matrix improves the mechanical properties of the material.

[0029] The present invention first uses a layer of calcined mica tape to overlap and wrap the outer side of the conductor core, and then impregnates it with a nano-ceramic suspension. After impregnation, it is dried online so that the nano-ceramic layer is coated on the surface of the inner mica tape. At the same time, a second layer of mica tape is overlapped and wrapped, which can prevent the applied nano-ceramic coating from falling off. The nano-ceramic coating can not only increase the insulation performance of the two layers of mica tape, but also prevent spray water from penetrating into the inner mica tape and causing electrical breakdown. The fire-resistant layer formed by this process can not only work normally under flame burning conditions, but also continue to work after the fire protection system is activated and fire water drops fall on the cable surface, thereby maximally meeting the performance requirements under actual fire conditions.

[0030] The present invention ensures that the bending radius of the cable meets the requirement of 6D and the conductor resistance meets the requirements specified by the standard through specific conductor twisting. The fire-resistant layer is wrapped and coated to ensure excellent fire resistance. Cross-linked polyethylene is used as the insulation layer material to ensure the excellent insulation resistance performance of the cable. The cabling layer is filled with 0.04mm non-open mesh PP filling rope, which is more suitable for the narrow installation and laying environment of ships and offshore platforms. The armor layer protects the insulated core of the cable from damage by external forces. At the same time, it has strong voltage resistance and can resist the voltage superposition caused by high-order harmonics in the frequency conversion system. The inner and outer sheath layers are made of sheath materials with excellent mechanical properties, flame retardant properties and aging resistance. The cable prepared by the present invention does not short-circuit or open-circuit within 180 minutes (accumulated 36 impact vibrations) under 830°C flame burning + impact vibration (impact vibration interval does not exceed 5 minutes), achieving high performance and high quality of the cable and meeting the strict requirements of the ship electrical system for cables. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0032] Figure 1 It is a structural schematic diagram of the fire-resistant light cable of the ship's safe return to port system of the present invention.

[0033] In the figure: 1- conductor core, 2- fire-resistant layer, 3- insulation layer, 4- cabling layer, 5- inner sheath layer, 6- armor layer, 7- outer sheath layer. DETAILED DESCRIPTION

[0034] 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 embodiments described 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 any creative efforts shall fall within the scope of protection of the present invention.

[0035] like Figure 1 As shown, a fire-resistant light cable for a safe return to port system for ships includes a core 1, a fire-resistant layer 2, an insulating layer 3, a cabling layer 4, an inner sheath layer 5, an armor layer 6, and an outer sheath layer 7, which are arranged in sequence from the inside to the outside.

[0036] Example 1 A method for preparing a functional additive comprises the following steps:

[0037] A. Take 2.5 g of 3,5-di-tert-butyl-4-hydroxybenzoic acid in a reactor, add 30 mL of chloroform, raise the temperature to 50°C, then add 2 mL of distilled thionyl chloride dropwise, stir and react for 5 hours, and after the reaction is completed, remove the solvent by rotary evaporation to prepare 3,5-di-tert-butyl-4-hydroxybenzoyl chloride;

[0038] B. Take 1.5g of 2-chloro-4,6-diamino-1,3,5-triazine in a reactor, add 50mL of tetrahydrofuran, purge the reaction with nitrogen, add 3mL of triethylamine dropwise under ice-water bath conditions, stir and mix, add a mixture of 5.5g of 3,5-di-tert-butyl-4-hydroxybenzoyl chloride and 50mL of tetrahydrofuran, place at 55°C for 8h, and after completion of the reaction, filter, wash, and dry to prepare a modified hindered phenol component;

[0039] C. Take 3.3g of 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide and disperse it in 50mL of N,N-dimethylformamide. The reaction is purged with nitrogen and stirred at 80°C. Then, 1g of sodium hydroxide is added and stirred for 1h. Then, 0.87g of 1,4-dichlorobenzyl is added and stirred for 8h. Subsequently, 6.1g of modified hindered phenol component is added and stirring is continued for 6h. After the reaction is completed, the functional additive is prepared by filtration, washing and drying.

[0040] Example 2 A method for preparing a composite filler comprises the following steps:

[0041] (1) 1 g of vermiculite was dispersed in a 5% ethanol solution, and then a dispersion of 0.12 g of tetrabutyl titanate and 10 mL of ethanol was added. The mixture was stirred for 6 h, and then slowly added dropwise to 100 mL of deionized water. The mixture was allowed to stand at room temperature for 24 h. The suspension was then centrifuged, washed with ethanol, and freeze-dried. Finally, the suspension was calcined at 500 °C for 5 h at a heating rate of 10 °C / min to prepare modified vermiculite.

[0042] (2) Take 1 g of modified vermiculite and add it to 8 mL of 0.2 mol / L zinc acetate solution. Stir and mix at room temperature to obtain a homogeneous dispersion. Then, the dispersion is centrifuged and freeze-dried. Finally, it is calcined at 500 °C for 5 h at a heating rate of 10 °C / min to prepare a composite filler.

[0043] Example 3 A sheath layer material includes the following components in parts by weight: 42 parts of low-density polyethylene, 10 parts of nitrile rubber, 10 parts of ethylene-tetrafluoroethylene copolymer, 2 parts of the functional additive prepared in Example 1, 5.5 parts of the composite filler prepared in Example 2, 3.5 parts of diisopropylbenzene peroxide, 2.5 parts of triallyl isocyanurate, 1 part of plasticizer dioctyl adipate, and 0.1 part of lubricant polyethylene wax.

[0044] The preparation method of the above-mentioned sheath layer material includes the following steps: weighing each component by weight, mixing low-density polyethylene, nitrile rubber, ethylene-tetrafluoroethylene copolymer, composite filler, functional additives, dicumyl peroxide, triallyl isocyanurate, plasticizer and lubricant evenly, and then putting it into a twin-screw extruder for extrusion molding to prepare the sheath layer material.

[0045] A method for processing a fire-resistant lightweight cable for a ship's safe return to port system comprises the following steps:

[0046] S1. Use cable drawing equipment to Z-draw 6mm round copper rods, then pass through annealing equipment to obtain qualified bare copper wire conductors, which are then twisted in one go through a stranding machine and a pressing die to obtain a conductor core.

[0047] S2. A layer of calcined mica tape is first wrapped around the outer side of the conductor core and impregnated with a nano-ceramic suspension. After impregnation, the conductor core is dried at 200°C. A second layer of calcined mica tape is then wrapped around the outer side of the conductor core. The nano-ceramic suspension comprises, by mass, 50% La2Zr2O7, 20% Y2O3, 17% mSiO2·nH2O, and the remainder water. A cross-linked polyethylene insulation layer is then extruded onto the outer side of the refractory layer using an extruder.

[0048] S3. Use 0.04mm non-open mesh PP filling rope to fill the outside of the insulation layer to form a cable layer;

[0049] S4, extruding the sheath material on the outer side of the cabling layer to form an inner sheath layer;

[0050] S5. Tinned copper wire is braided on the outside of the inner sheath layer with a braiding density of 90% to form an armor layer;

[0051] S6. Extruding a sheath layer material on the outside of the armor layer to form an outer sheath layer, thereby preparing a fire-resistant light cable for a safe return to port system for ships.

[0052] Example 4 A sheath layer material includes the following components in parts by weight: 55 parts of low-density polyethylene, 14 parts of nitrile rubber, 12 parts of ethylene-tetrafluoroethylene copolymer, 3.5 parts of the functional additive prepared in Example 1, 9 parts of the composite filler prepared in Example 2, 4.5 parts of diisopropyl benzene peroxide, 3.5 parts of triallyl isocyanurate, 2 parts of plasticizer dimethyl phthalate, and 0.2 parts of lubricant oxidized polyethylene wax.

[0053] The preparation method of the above-mentioned sheath layer material is the same as that of Example 3.

[0054] The processing method of a fire-resistant lightweight cable for a safe return to port system for ships is the same as that of Example 3.

[0055] Example 5 A sheath layer material includes the following components in parts by weight: 67 parts of low-density polyethylene, 18 parts of nitrile rubber, 14 parts of ethylene-tetrafluoroethylene copolymer, 5 parts of the functional additive prepared in Example 1, 11 parts of the composite filler prepared in Example 2, 5 parts of diisopropylbenzene peroxide, 5 parts of triallyl isocyanurate, 2.5 parts of plasticizer dioctyl phthalate, and 0.4 parts of lubricant oxidized polyethylene wax.

[0056] The preparation method of the above-mentioned sheath layer material is the same as that of Example 3.

[0057] The processing method of a fire-resistant lightweight cable for a safe return to port system for ships is the same as that of Example 3.

[0058] Comparative Example 1 A method for preparing a functional additive comprises the following steps:

[0059] C. Take 3.3 g of 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide and disperse it in 50 mL of N,N-dimethylformamide. Purify the reaction with nitrogen and stir evenly at 80°C. Then, add 1 g of sodium hydroxide and stir for 1 hour. Then, add 0.87 g of 1,4-dichlorobenzyl and stir the reaction for 8 hours. After the reaction is completed, filter, wash and dry to prepare a functional additive.

[0060] Comparative Example 2 A method for preparing a composite filler comprises the following steps:

[0061] 1 g of vermiculite was added to 8 mL of 0.2 mol / L zinc acetate solution, stirred and mixed at room temperature to obtain a homogeneous dispersion, then the dispersion was centrifuged and freeze-dried, and finally calcined at 500°C for 5 h at a heating rate of 10°C / min to prepare a composite filler.

[0062] Comparative Example 3 A sheath layer material includes the following components in parts by weight: 67 parts of low-density polyethylene, 18 parts of nitrile rubber, 14 parts of ethylene-tetrafluoroethylene copolymer, 5 parts of the functional additive prepared in Comparative Example 1, 11 parts of the composite filler prepared in Example 2, 5 parts of dicumyl peroxide, 5 parts of triallyl isocyanurate, 2.5 parts of plasticizer dioctyl phthalate, and 0.4 parts of lubricant oxidized polyethylene wax.

[0063] The preparation method of the above-mentioned sheath layer material is the same as that of Example 3.

[0064] The processing method of a fire-resistant lightweight cable for a safe return to port system for ships is the same as that of Example 3.

[0065] Comparative Example 4 A sheath layer material includes the following components in parts by weight: 67 parts of low-density polyethylene, 18 parts of nitrile rubber, 14 parts of ethylene-tetrafluoroethylene copolymer, 11 parts of the composite filler prepared in Example 2, 5 parts of dicumyl peroxide, 5 parts of triallyl isocyanurate, 2.5 parts of plasticizer dioctyl phthalate, and 0.4 parts of lubricant oxidized polyethylene wax.

[0066] The preparation method of the above-mentioned sheath layer material is the same as that of Example 3.

[0067] The processing method of a fire-resistant lightweight cable for a safe return to port system for ships is the same as that of Example 3.

[0068] Comparative Example 5 A sheath layer material includes the following components in parts by weight: 67 parts of low-density polyethylene, 18 parts of nitrile rubber, 14 parts of ethylene-tetrafluoroethylene copolymer, 5 parts of the functional additive prepared in Example 1, 11 parts of the composite filler prepared in Comparative Example 2, 5 parts of dicumyl peroxide, 5 parts of triallyl isocyanurate, 2.5 parts of plasticizer dioctyl phthalate, and 0.4 parts of lubricant oxidized polyethylene wax.

[0069] The preparation method of the above-mentioned sheath layer material is the same as that of Example 3.

[0070] The processing method of a fire-resistant lightweight cable for a safe return to port system for ships is the same as that of Example 3.

[0071] Comparative Example 6 A sheath layer material includes the following components in parts by weight: 67 parts of low-density polyethylene, 18 parts of nitrile rubber, 14 parts of ethylene-tetrafluoroethylene copolymer, 5 parts of the functional additive prepared in Example 1, 11 parts of a composite filler, 5 parts of dicumyl peroxide, 5 parts of triallyl isocyanurate, 2.5 parts of a plasticizer, dioctyl phthalate, and 0.4 parts of a lubricant, oxidized polyethylene wax, wherein the composite filler is a simple mixture of vermiculite, titanium dioxide, and zinc oxide in a mass ratio of 1:0.12:0.29.

[0072] The preparation method of the above-mentioned sheath layer material is the same as that of Example 3.

[0073] The processing method of a fire-resistant lightweight cable for a safe return to port system for ships is the same as that of Example 3.

[0074] Performance testing

[0075] A. The cables prepared in Examples 3-5 were subjected to 830°C flame burning + impact vibration (impact vibration interval not exceeding 5 minutes) according to IEC60331-2 and EN50200 standards. No short circuit or open circuit occurred within 180 minutes (accumulated 36 times of impact vibration).

[0076] B. The performance of the sheath layer materials prepared in Examples 3-5 and Comparative Examples 3-6 was tested:

[0077] (1) Flame retardant performance test: The sheath layer material is made into a test sample with a specification of 100mm×7mm×4mm. The flame retardant performance of the sample is evaluated with reference to the limiting oxygen index of the test sample in GB / T 2406.2-2009. Generally speaking, the larger the limiting oxygen index, the better the flame retardant performance, and vice versa. The data results are shown in Table 1.

[0078] Table 1 Flame retardant performance test results of samples

[0079]

[0080] The data in Table 1 demonstrate that the jacket layer materials prepared in Examples 3-5 and Comparative Examples 5-6 exhibit excellent flame retardancy. Comparative Example 3, in which the functional additives were added without the introduction of a modified hindered phenol component, exhibited a lower limiting oxygen index than that of Examples 3-5. This is because the nitrogen in the modified hindered phenol component further enhances the flame retardancy of the material. Comparative Example 4, in which no functional additives were added, exhibited a significantly lower limiting oxygen index than that of Examples 3-5, demonstrating that the addition of the modified additives significantly enhanced the flame retardancy of the material.

[0081] (2) Mechanical property testing: The sheath layer material was subjected to a tensile property test using a universal mechanical testing machine in accordance with GB / T 1040.2-2022; and after aging at 110°C for 24 h, its tensile strength and elongation at break were tested to evaluate the high temperature aging resistance of the sample; and after cumulative irradiation with a 40W UV lamp (wavelength 290~400nm) at 60°C for 72 h (turning over for 36 h in the middle to ensure uniform irradiation), its tensile strength and elongation at break were tested, with the distance between the sample and the lamp tube being 254 mm, to evaluate the UV aging resistance of the sample; and the tear strength test was carried out in accordance with GB / T 529-2008, and the data results are shown in Table 2.

[0082] Table 2 Test results of mechanical properties and aging resistance of samples

[0083]

[0084] It can be seen from the data in Table 2 that the sheath layer materials prepared in Examples 3-5 of the present invention have high tensile strength and are not easy to break. After high-temperature aging and UV aging, they still have high tensile strength and elongation at break, and have excellent aging resistance. Among them, the functional additives added in Comparative Example 3 did not introduce a modified hindered phenol component, and no functional additives were added in Comparative Example 4. The tensile strength and elongation at break of Comparative Example 3-4 after high-temperature aging and ultraviolet aging were significantly lower than those of Examples 3-5. The reason is that the hindered phenol component and triazine ring structure introduced in the functional additives improved the material's resistance to high-temperature aging and ultraviolet aging. The composite filler added in Comparative Example 5 did not utilize the interlayer of titanium dioxide pillared vermiculite. The composite filler added in Comparative Example 6 was simply mixed with vermiculite, titanium dioxide and zinc oxide. The mechanical properties of Comparative Examples 5-6 were lower than those of Examples 3-5. The possible reason was that the agglomeration of nanoparticles led to a decrease in mechanical properties. In addition, the tensile strength and elongation at break of Comparative Example 5 after ultraviolet aging were significantly lower than those of Examples 3-5, indicating that the introduction of titanium dioxide improved the material's resistance to ultraviolet aging to a certain extent.

[0085] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0086] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and modifications fall within the scope of the invention as claimed.

Claims

1. A fire-resistant light cable for a ship's safe return to port system, characterized in that: The invention comprises a conductor core, a fire-resistant layer, an insulating layer, a cabling layer, an inner sheath layer, an armor layer, and an outer sheath layer, which are sequentially arranged from the inside to the outside. The inner sheath layer and the outer sheath layer are prepared by drawing a sheath layer material on the outside of the cabling layer and the armor layer through an extrusion device. The sheath layer material comprises the following components in parts by weight: 40-70 parts of low-density polyethylene, 10-20 parts of nitrile rubber, 10-15 parts of ethylene-tetrafluoroethylene copolymer, 2-6 parts of functional additives, 5-12 parts of composite fillers, 3.5-6 parts of dicumyl peroxide, 2-5.5 parts of triallyl isocyanurate, 1-3 parts of plasticizer, and 0.1-0.5 parts of lubricant. The functional additive is prepared by an acylation reaction between 3,5-di-tert-butyl-4-hydroxybenzoyl chloride and 2-chloro-4,6-diamino-1,3,5-triazine to obtain a modified hindered phenol component, and then a substitution reaction is carried out between 1,4-p-dichlorobenzyl and 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, and then the obtained product is further subjected to a substitution reaction with the modified hindered phenol component. The composite filler is prepared by using vermiculite as a raw material and using titanium dioxide and zinc oxide pillared to modify the vermiculite.

2. The fire-resistant light cable for a ship's safe return to port system according to claim 1, characterized in that: The plasticizer is one or more combinations of dioctyl adipate, dimethyl phthalate, dioctyl phthalate, and diisodecyl phthalate; and the lubricant is polyethylene wax or oxidized polyethylene wax.

3. The fire-resistant light cable for a ship's safe return to port system according to claim 1, characterized in that: The preparation method of the sheath layer material comprises the following steps: weighing each component by weight, uniformly mixing low-density polyethylene, nitrile rubber, ethylene-tetrafluoroethylene copolymer, composite filler, functional additives, dicumyl peroxide, triallyl isocyanurate, plasticizer and lubricant, and then placing the mixture into a twin-screw extruder for extrusion molding to prepare the sheath layer material.

4. The fire-resistant light cable for a ship's safe return to port system according to claim 1, characterized in that: The preparation method of the functional additive comprises the following steps: A. Take 3,5-di-tert-butyl-4-hydroxybenzoic acid in a reactor, add chloroform, raise the temperature to 45-55°C, then add distilled thionyl chloride dropwise, stir and react for 4-6 hours, and after the reaction is completed, remove the solvent by rotary evaporation to prepare 3,5-di-tert-butyl-4-hydroxybenzoyl chloride; B. 2-chloro-4,6-diamino-1,3,5-triazine was placed in a reactor, tetrahydrofuran was added, nitrogen was passed through the reaction, triethylamine was added dropwise under ice-water bath conditions, and after stirring and mixing, a mixture of 3,5-di-tert-butyl-4-hydroxybenzoyl chloride and tetrahydrofuran was added, and the mixture was placed at 45-60° C. for 6-8 hours. After the reaction was completed, the mixture was filtered, washed, and dried to prepare a modified hindered phenol component; C. Disperse 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide in N,N-dimethylformamide, pass nitrogen through the reaction, stir evenly at 75-80°C, then add sodium hydroxide and stir for 0.5-1h, then add 1,4-dichlorobenzyl, stir and react for 6-8h, then add the modified hindered phenol component and continue stirring for 6-8h. After the reaction is completed, filter, wash and dry to prepare a functional additive.

5. The fire-resistant light cable for a ship's safe return to port system according to claim 4, characterized in that: In step B, the molar ratio of 2-chloro-4,6-diamino-1,3,5-triazine to 3,5-di-tert-butyl-4-hydroxybenzoyl chloride is 1:2-2.1; and in step C, the molar ratio of 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, 1,4-dichlorobenzyl and modified hindered phenol component is 2:1:2-2.

1.

6. The fire-resistant light cable for a ship's safe return to port system according to claim 1, characterized in that: The preparation method of the composite filler comprises the following steps: (1) Vermiculite was dispersed in an ethanol solution, and then a dispersion of tetrabutyl titanate and ethanol was added, stirred for 5-6 hours, and then slowly added dropwise to deionized water. The mixture was allowed to stand at room temperature for 20-24 hours. The suspension was then centrifuged, washed with ethanol, freeze-dried, and finally calcined at 480-525°C for 4-6 hours to prepare modified vermiculite. (2) The modified vermiculite was added to the zinc acetate solution and stirred at room temperature to obtain a homogeneous dispersion. The dispersion was then centrifuged, freeze-dried, and finally calcined at 480-525°C for 4-6 hours to prepare a composite filler.

7. The fire-resistant light cable for a ship's safe return to port system according to claim 6, characterized in that: The mass ratio of vermiculite to tetrabutyl titanate in step (1) is 1:0.1-0.15; the concentration of the zinc acetate solution in step (2) is 0.1-0.3 mol / L; and the addition ratio of the modified vermiculite to the zinc acetate solution is 1 g:5-10 mL.

8. A method for processing a fire-resistant lightweight cable for a ship's safe return to port system according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Use cable drawing equipment to Z-draw 6mm round copper rods, then pass through annealing equipment to obtain qualified bare copper wire conductors, which are then twisted in one go through a stranding machine and a pressing die to obtain a conductor core. S2. Wrap a fire-resistant layer around the outer side of the conductor core, and then extrude a cross-linked polyethylene insulation layer around the outer side of the fire-resistant layer using an extruder; S3. Use 0.04mm non-open mesh PP filling rope to fill the outside of the insulation layer to form a cable layer; S4, extruding the sheath material on the outer side of the cabling layer to form an inner sheath layer; S5. Tinned copper wire is braided on the outside of the inner sheath layer with a braiding density of ≥90% to form an armor layer; S6. Extruding a sheath layer material on the outside of the armor layer to form an outer sheath layer, thereby preparing a fire-resistant light cable for a safe return to port system for ships.

9. The method for processing a fire-resistant lightweight cable for a ship's safe return to port system according to claim 8, characterized in that: The refractory layer is wrapped in the same direction with two layers of calcined mica tape, and the overlap rate of the mica tape is controlled at 30-40%. The specific operation steps are: first, a layer of calcined mica tape is overlapped and wrapped on the outside of the conductor core, and then impregnated with nano-ceramic suspension liquid. After impregnation, it is placed in a drying temperature of 190-205°C, and then a second layer of calcined mica tape is overlapped and wrapped.

10. The method for processing the fire-resistant light cable for the ship's safe return to port system according to claim 9, characterized in that: The nano-scale ceramic suspension comprises, by mass fraction, 45-55% La2Zr2O7, 15-25% Y2O3, 15-20% mSiO2·nH2O, and the remainder is water.

Images