Military special flame-retardant wear-resistant flexible cable material

Abstract

The invention discloses a military special flame-retardant wear-resistant flexible cable material, which belongs to the technical field of cable material processing, is used for solving the technical problem that the flame-retardant performance and the wear-resistant performance of the cable material in the prior art need to be further improved, and specifically comprises an insulating rubber layer, a wrapping layer and a sheath layer which are sequentially arranged from inside to outside, the insulating rubber layer is composed of a wire core and rubber, wherein the wire core is composed of a plurality of metal alloy wires which are mutually twisted, and the rubber wraps the wire core. The flame-retardant modified polyurethane is obtained by preparing a flame-retardant chain extender containing nitrogen and phosphorus and further taking polyethylene glycol as a soft segment, diphenylmethane diisocyanate as a hard segment, the flame-retardant chain extender as a chain extender and acrylic acid-2-hydroxyethyl ester as an end-capping reagent, so that the flame retardance and the wear resistance of the cable material are improved, and the flame retardance of the cable material is improved. The mechanical property is also improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cable material processing, in particular to a military special anti-delay-burning and wear-resistant soft cable material. BACKGROUND

[0002] With the increasing performance requirements of modern military equipment on information transmission and power supply systems, military special cable materials not only need to have excellent electrical properties, but also need to have softness, anti-delay-burning, wear resistance and environmental adaptability.

[0003] Among them, the development focus of soft cable material is to improve its reliability in high temperature, strong friction and flammable environment. The commonly used flexible cable sheath base materials include low smoke zero halogen polyolefin (LSZH), thermoplastic polyurethane (TPU), ethylene-vinyl acetate copolymer (EVA), etc. In order to improve the flame retardant properties and mechanical strength of the material, the commonly used modification methods in the research include: introducing halogen-substituted inorganic flame retardant or phosphorus-nitrogen reaction type flame retardant, and surface modification / micro-nano composite filler technology, etc. These methods improve the flame retardancy and wear resistance of the material to a certain extent, and preliminarily meet the requirements of anti-delay-burning and mechanical strength in military field.

[0004] In the prior art, there are still certain technical bottlenecks in the high flame retardancy and wear resistance of soft cable material. First, although a large amount of traditional inorganic flame-retardant fillers can improve the flame retardancy, the poor interfacial compatibility between the flame-retardant fillers and the flexible matrix easily causes problems such as material hardening, decrease of breaking elongation and decrease of wear resistance, thereby reducing the softness and service life of the cable material. Secondly, some added phosphorus or nitrogen flame retardants have strong migration in the processing process, which easily leads to the decline of flame-retardant effect after long-term service. Thirdly, some modified magnesium carbonate inorganic fillers easily form agglomeration in the polymer matrix due to uneven particle size or too strong surface polarity, which forms stress concentration points and causes material wear and cracking or mechanical property decrease under complex stress environment.

[0005] In view of the technical defects in this aspect, a solution is proposed. SUMMARY

[0006] The purpose of the present application is to provide a military special anti-delay-burning and wear-resistant soft cable material, which solves the technical problem that the delay-burning performance and wear resistance of the cable material in the prior art need to be further improved.

[0007] The purpose of the present application can be achieved by the following technical scheme: a military special anti-delay-burning and wear-resistant soft cable material, comprising an insulating rubber layer, a wrapping layer and a sheath layer arranged in sequence from inside to outside.

[0008] The insulating rubber layer is composed of a core of a plurality of metal alloy wires twisted with each other and rubber coated outside the core;

[0009] The sheath layer comprises the following raw materials by weight parts: 40-60 parts of flame-retardant modified polyurethane, 10-20 parts of polyvinyl chloride, 3-4 parts of ethylene-vinyl acetate copolymer, 15-20 parts of modified magnesium carbonate and 8-10 parts of auxiliary additives;

[0010] The auxiliary additives are composed of initiator, light stabilizer, antioxidant, lubricant and plasticizer in a mass ratio of 0.5:2:1:2:5.

[0011] Further, the metal alloy wire is silver-plated copper wire, the rubber is one or more of styrene butadiene rubber, ethylene-propylene rubber and chloroprene rubber, and the wrapping layer is one or more of polyester tape and aluminum metal tape.

[0012] Further, the flame-retardant modified polyurethane is prepared by the following steps:

[0013] A1, polyethylene glycol, dibutyltin dilaurate and N, N-dimethylformamide are placed in a reaction kettle protected by nitrogen atmosphere and stirred, and a calculated amount of diphenylmethane diisocyanate is added, the reaction kettle is heated to 80-90 DEG C, and the reaction is kept for 1-2 h to obtain a prepolymer solution;

[0014] A2, the prepolymer solution and the flame-retardant chain extender are placed in a reaction kettle protected by nitrogen atmosphere and stirred, the reaction kettle is heated to 100-120 DEG C, and the reaction is kept for 15-30 min, and 2-hydroxyethyl acrylate is added, and the flame-retardant modified polyurethane is obtained after treatment.

[0015] The preparation reaction formula of the flame-retardant modified polyurethane is:

[0016]

[0017] In the formula: .

[0018] The preparation reaction principle of the flame-retardant modified polyurethane is:

[0019] During the reaction, under the action of heating and catalyst, the hydroxyl group of polyethylene glycol reacts with the isocyanate group of diphenylmethane diisocyanate by nucleophilic reaction, the addition amount of diphenylmethane diisocyanate is controlled, the isocyanate-terminated prepolymer is obtained, the flame-retardant chain extender and the blocking agent 2-hydroxyethyl acrylate are further added, and the olefin-terminated flame-retardant modified polyurethane is obtained.

[0020] Further, in step A1, the ratio of the amount of polyethylene glycol, dibutyltin dilaurate and N,N-dimethylformamide is 4-6 g:0.1-0.2 g:50-80 mL, and the amount of diphenylmethane diisocyanate added is 0.55 times the molar amount of the hydroxyl group of polyethylene glycol; in step A2, the ratio of the amount of the prepolymer solution, the flame-retardant chain extender and 2-hydroxyethyl acrylate is 40-60 mL:2-4 g:0.5-1 g, and the post-treatment step includes: after the reaction is completed, the reaction kettle is heated to 130-140℃, and distilled under reduced pressure until no liquid is collected, to obtain the flame-retardant modified polyurethane.

[0021] Further, the flame-retardant chain extender is prepared by the following steps:

[0022] B1, 2,5-dihydroxybenzaldehyde, triethylamine and tetrahydrofuran are placed in a reaction kettle and stirred, cooled to 0-5℃ by ice bath, and slowly added with phenylphosphonic dichloride, and incubated for 0.5-1 h, and the flame-retardant chain extender precursor is obtained after post-treatment;

[0023] B2, the flame-retardant chain extender precursor, triethylamine, hydroxylamine hydrochloride and methanol are placed in a reaction kettle and stirred, incubated for 0.5-1 h, and the flame-retardant chain extender is obtained after post-treatment.

[0024] The preparation reaction formula of the flame-retardant chain extender is:

[0025]

[0026] The preparation reaction principle of the flame-retardant chain extender is:

[0027] During the reaction, the phenolic hydroxyl group of 2,5-dihydroxybenzaldehyde attacks the phosphoryl chloride group of phenylphosphonic dichloride as a nucleophile, and the chloride ion is removed to react with triethylamine to form a hydrochloride salt, to obtain the flame-retardant chain extender precursor, and further, hydroxylamine hydrochloride attacks the aldehyde group of the flame-retardant chain extender precursor to undergo condensation reaction, to obtain the flame-retardant chain extender containing oxime.

[0028] Further, in step B1, the ratio of the amounts of 2,5-dihydroxybenzaldehyde, triethylamine, tetrahydrofuran and benzene phosphonic dichloride is 2-4 g:2-4 g:60-80 mL:1-2 g, and the post-treatment step comprises: after the reaction is completed, the reaction system is allowed to return to room temperature, filtration is performed, 4-6 mL of deionized water is added to the filtrate to quench the reaction, 60-80 mL of ethyl acetate is added to wash the reaction 2-4 times, and the organic phase is transferred to a rotary evaporator with a temperature of 70-80 DEG C, and the rotary evaporation is performed until no liquid is produced, thereby obtaining the flame-retardant chain extender precursor; in step B2, the ratio of the amounts of the flame-retardant chain extender precursor, triethylamine, hydroxylamine hydrochloride and methanol is 3-5 g:1-2 g:0.5-1 g:80-100 mL, and the post-treatment step comprises: after the reaction is completed, the reaction kettle is heated to 50-60 DEG C, and the reaction is distilled under reduced pressure until no liquid is produced, the reaction liquid is allowed to return to room temperature, 80-100 mL of ethyl acetate and 80-100 mL of deionized water are added to wash the reaction 2-4 times, and the organic phase is transferred to a rotary evaporator with a temperature of 80-90 DEG C, and the rotary evaporation is performed until no liquid is produced, thereby obtaining the flame-retardant chain extender.

[0029] Further, the modified magnesium carbonate is prepared by the following steps:

[0030] C1, deionized water, succinic acid and L-aspartic acid are placed in a reaction kettle and stirred, and sodium carbonate aqueous solution is slowly added until the reaction liquid is dissolved, thereby obtaining a mixed liquid;

[0031] C2, the mixed liquid and magnesium chloride hexahydrate are placed in a reaction kettle and stirred, and hydrothermal reaction is performed for 2-4 h, and the modified magnesium carbonate precursor is obtained after post-treatment;

[0032] The reaction principle for preparing the modified magnesium carbonate precursor is as follows:

[0033] During the reaction, succinic acid and L-aspartic acid are organic ligands, which can form a complex with Mg²⁺ in the reaction, and control the crystal growth; under the alkaline conditions provided by sodium carbonate, succinic acid and L-aspartic acid lose protons and show negative electricity, magnesium chloride hexahydrate provides Mg²⁺, and under the alkaline and high-temperature conditions, the Mg²⁺ reacts with CO3²⁻ provided by sodium carbonate to generate magnesium carbonate; succinic acid is coordinated with magnesium ions through its double carboxyl groups, thereby limiting the crystal growth along a specific direction, and obtaining regular and small particles; L-aspartic acid contains amino and carboxyl groups, which can produce electrostatic and steric hindrance effects on the surface of the crystal nucleus, thereby further inhibiting the particle agglomeration and introducing surface polar functional groups, and thus the modified magnesium carbonate precursor with good dispersity, large specific surface area and stronger interfacial activity is obtained.

[0034] C3, the modified magnesium carbonate precursor, ethanol, deionized water and gamma-methacryloyloxypropyltrimethoxysilane are placed in a reaction kettle and stirred, the reaction kettle is heated to 50-60 DEG C, and the reaction is maintained for 2-4 h, and the modified magnesium carbonate is obtained after post-treatment.

[0035] The preparation reaction principle of the modified magnesium carbonate is:

[0036] During the reaction, under the conditions of deionized water and heating, the silicon-oxygen bond of the gamma-methacryloxypropyl trimethoxysilane is hydrolyzed into silanol, and the silanol further condenses with the hydroxyl groups on the surface of the modified magnesium carbonate precursor to obtain the modified magnesium carbonate modified by the olefin unsaturated silane coupling agent.

[0037] Further, in step C1, the use amount ratio of the deionized water, succinic acid and L-aspartic acid is 50-70 mL:0.2-0.5 g:0.3-0.6 g, and the concentration of the sodium carbonate aqueous solution is 1-2 mol / L; in step C2, the use amount ratio of the mixed solution and the magnesium chloride hexahydrate is 60-80 mL:2-4 g, and the post-processing step includes: after the reaction is completed, the reaction system is cooled to room temperature, and then filtered, the filter cake is washed with deionized water for 2-4 times, and then transferred to an oven with a temperature of 50-60℃, and dried to constant weight to obtain the modified magnesium carbonate precursor.

[0038] Further, in step C3, the use amount ratio of the modified magnesium carbonate precursor, ethanol, deionized water and gamma-methacryloxypropyl trimethoxysilane is 2-4 g:30-50 mL:4-8 mL:0.5-1 g, and the post-processing step includes: after the reaction is completed, the reaction system is cooled to room temperature, and then filtered, the filter cake is washed with deionized water and ethanol for 2-4 times, and then transferred to an oven with a temperature of 50-60℃, and dried to constant weight, ground, and then passed through a 2500 mesh sieve to obtain the modified magnesium carbonate.

[0039] Further, the operation steps of the hydrothermal reaction include: transferring the reaction solution to a hydrothermal reaction kettle, heating to 180-200℃, and keeping the temperature for 2-4 h, and then post-processing to obtain the modified magnesium carbonate.

[0040] Further, the preparation method of the cable material is: adding the flame-retardant modified polyurethane, the ethylene-vinyl acetate copolymer, the modified magnesium carbonate and the auxiliary additive into a double-screw extruder, and melt-extruding and coating outside the wrapping layer to obtain the cable material.

[0041] The preparation reaction principle of the cable material is:

[0042] During the reaction, under the initiation of dicumyl peroxide, the flame-retardant modified polyurethane, the modified magnesium carbonate and the ethylene-vinyl acetate copolymer undergo a free radical polymerization reaction to obtain the cable material.

[0043] Further, the auxiliary additive is composed of initiators, light stabilizers, antioxidants, lubricants and plasticizers in a mass ratio of 0.5:2:1:2:5, the initiator is dicumyl peroxide, the light stabilizer is one or more of 2-hydroxy-4-n-octyloxybenzophenone, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole and p-tert-butyl phenyl salicylate, the antioxidant is one or more of N,N'-diphenyl-p-phenylenediamine, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite and dioctadecyl thiodipropionate, the lubricant is one or more of oleic acid, fatty acid amide and polyethylene wax, and the plasticizer is one or more of dibutyl phthalate, dioctyl sebacate and dioctyl adipate;

[0044] The temperature of the eight temperature zones of the twin-screw extruder from the feeding port to the discharging port is 160 DEG C, 165 DEG C, 170 DEG C, 170 DEG C, 175 DEG C, 175 DEG C, 180 DEG C and 180 DEG C in sequence, and the main motor speed of the twin-screw extruder is 80-120 rpm, and the pressure is 100-150 bar.

[0045] The present application has the following advantages:

[0046] 1、The present application is to use succinic acid and L-aspartic acid as modifiers, using the carboxyl structure in the molecule to chelate magnesium ions, adsorb on the magnesium carbonate microcrystalline, change the crystal polymerization direction, and further modify by silane coupling agent to obtain modified magnesium carbonate, magnesium carbonate itself is an inorganic flame-retardant filler, which will absorb heat and decompose under high temperature conditions, release non-combustible gases such as water and carbon dioxide, play a role in diluting combustible gas and reducing heat release rate, thereby delaying the flame spread of cable material, through the introduction of organic ligands such as succinic acid and L-aspartic acid in the precursor stage, a good organic-inorganic hybrid structure is formed, which improves the dispersibility and surface activity of the particles while maintaining the thermal stability of the inorganic phase, and further surface modification is carried out by using gamma-methacryloxypropyl trimethoxysilane, so that the magnesium carbonate has stronger polar affinity, and under the initiation of the initiator, the interfacial compatibility of the polyurethane matrix and the ethylene-vinyl acetate copolymer blending system is significantly improved, effectively avoiding the mechanical property deterioration problem caused by the agglomeration of inorganic fillers, in addition, the modified magnesium carbonate can also be used as a physical reinforcing phase, and can also improve the wear resistance and mechanical properties of the cable material, meet the long-term service requirements under high-strength dragging, complex climate and vibration conditions in military scenarios. Synergistic effect with the flame-retardant chain extender used at the same time, forming a phosphorus-nitrogen-magnesium carbonate composite flame-retardant system, which can promote the formation of carbon layer during combustion, improve the carbonization stability and heat shielding performance of the cable sheath, and improve the flame retardant performance of the cable material.

[0047] 2、The application is to prepare a flame-retardant chain extender containing nitrogen and phosphorus, further using polyethylene glycol as a soft segment, using diphenyl methane diisocyanate as a hard segment, using the flame-retardant chain extender as a chain extender, and using acrylic acid-2-hydroxyethyl ester as a capping agent to obtain a flame-retardant modified polyurethane, the phosphine group, aromatic ring and hydroxamic acid structure are introduced into the molecule of the flame-retardant chain extender, these functional groups provide excellent flame-retardant performance on the one hand, and have active sites participating in the chain extension or crosslinking reaction of polyurethane on the other hand, in the flame environment, the phosphine group can release phosphoric acid free radicals to capture active free radicals generated in the combustion process, inhibit the thermal cracking chain reaction, and at the same time promote the formation of a carbon layer to form a dense protective carbon shell, effectively improving the thermal barrier capacity of the cable material, the hydroxyl and hydroxamic acid in the molecule of the flame-retardant chain extender react with the isocyanate group to further improve the molecular chain regularity and crosslinking degree, so that the polyurethane matrix has better mechanical strength. The flame-retardant modified polyurethane uses polyethylene glycol and diisocyanate as the basis, realizes the ordered regulation and functionalization of the polyurethane chain structure by introducing the flame-retardant chain extender and acrylic acid-2-hydroxyethyl ester for co-reaction, so that the obtained polyurethane not only has good flexibility and mechanical properties, but also has high flame retardant performance. The flame-retardant modified polyurethane is blended with ethylene-vinyl acetate copolymer, and is blended and granulated with modified magnesium carbonate and other additives to form a composite cable material, which improves the overall synergistic flame retardant, wear-resistant and mechanical properties of the material. BRIEF DESCRIPTION OF DRAWINGS

[0048] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0049] Figure 1 It is a schematic diagram of the overall three-dimensional structure of the present application.

[0050] In the figure: 1, insulating rubber layer; 2, wrapping layer; 3, sheath layer. DETAILED DESCRIPTION

[0051] The technical solutions of the present application will be described below in conjunction with the embodiments, obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0052] The average molecular weight of the ethylene-vinyl acetate copolymer used in the present application is 2000, and the density is 0.92-0.98 g / cm³.

[0053] The polyethylene glycol used in the present application has an average molecular weight of 400 and a density of 1.13 g / cm3.

[0054] Example 1

[0055] The present embodiment provides a preparation method of modified magnesium carbonate for military special anti-flame and wear-resistant soft cable material, comprising the following steps:

[0056] Step I, preparation of mixed solution

[0057] Take: 500 mL of deionized water, 2 g of succinic acid and 3 g of L-aspartic acid are placed in a reaction kettle for stirring, and 1 mol / L sodium carbonate aqueous solution is slowly added until the reaction solution is dissolved to obtain a mixed solution.

[0058] Step II, preparation of modified magnesium carbonate precursor

[0059] Take: 600 mL of mixed solution and 20 g of magnesium chloride hexahydrate are placed in a reaction kettle for stirring, and the reaction solution is transferred to a hydrothermal reaction kettle, heated to 180℃, and kept for 2 h. After the reaction is completed, the reaction system is cooled to room temperature, filtered, the filter cake is washed with deionized water for 2 times, transferred to an oven with a temperature of 50℃, and dried to constant weight to obtain a modified magnesium carbonate precursor.

[0060] Step III, preparation of modified magnesium carbonate

[0061] Take: 20 g of modified magnesium carbonate precursor, 300 mL of ethanol, 40 mL of deionized water and 5 g of γ-methacryloxypropyltrimethoxysilane are placed in a reaction kettle for stirring, the reaction kettle is heated to 50℃, and kept for 2 h. After the reaction is completed, the reaction system is cooled to room temperature, filtered, the filter cake is washed with deionized water and ethanol for 2 times, transferred to an oven with a temperature of 50℃, and dried to constant weight, ground, and passed through a 2500 mesh sieve to obtain modified magnesium carbonate.

[0062] Example 2

[0063] The present embodiment provides a preparation method of modified magnesium carbonate for military special anti-flame and wear-resistant soft cable material, comprising the following steps:

[0064] Step I, preparation of mixed solution

[0065] Take: 600 mL of deionized water, 3.5 g of succinic acid and 4.5 g of L-aspartic acid are placed in a reaction kettle for stirring, and 1.5 mol / L sodium carbonate aqueous solution is slowly added until the reaction solution is dissolved to obtain a mixed solution.

[0066] Step II, preparation of modified magnesium carbonate precursor

[0067] Weighing: 700 mL of mixed solution and 30 g of magnesium chloride hexahydrate are placed in a reaction kettle for stirring, and the reaction solution is transferred to a hydrothermal reaction kettle, the temperature is raised to 190 DEG C, and the reaction is kept for 3 h. After the reaction is completed, the reaction system is cooled to room temperature, filtered, the filter cake is washed with deionized water for 3 times, and then transferred to an oven with a temperature of 55 DEG C for drying until the weight is constant to obtain the modified magnesium carbonate precursor.

[0068] Step III, preparation of modified magnesium carbonate

[0069] Weighing: 30 g of modified magnesium carbonate precursor, 400 mL of ethanol, 600 mL of deionized water and 7 g of gamma-methacryloxypropyl trimethoxysilane are placed in a reaction kettle for stirring, the reaction kettle is heated to 55 DEG C, and the reaction is kept for 3 h. After the reaction is completed, the reaction system is cooled to room temperature, filtered, the filter cake is washed with deionized water and ethanol for 3 times, and then transferred to an oven with a temperature of 55 DEG C for drying until the weight is constant, ground, and then passed through a 2500 mesh sieve to obtain the modified magnesium carbonate.

[0070] Example 3

[0071] The embodiment provides a preparation method of modified magnesium carbonate for military special anti-flame and wear-resistant soft cable material, which comprises the following steps:

[0072] Step I, preparation of mixed solution

[0073] Weighing: 700 mL of deionized water, 5 g of succinic acid and 6 g of L-aspartic acid are placed in a reaction kettle for stirring, and 2 mol / L sodium carbonate aqueous solution is slowly added until the reaction solution is dissolved to obtain a mixed solution.

[0074] Step II, preparation of modified magnesium carbonate precursor

[0075] Weighing: 800 mL of mixed solution and 40 g of magnesium chloride hexahydrate are placed in a reaction kettle for stirring, and the reaction solution is transferred to a hydrothermal reaction kettle, the temperature is raised to 200 DEG C, and the reaction is kept for 4 h. After the reaction is completed, the reaction system is cooled to room temperature, filtered, the filter cake is washed with deionized water for 4 times, and then transferred to an oven with a temperature of 60 DEG C for drying until the weight is constant to obtain the modified magnesium carbonate precursor.

[0076] Step III, preparation of modified magnesium carbonate

[0077] Weighing: 40 g of modified magnesium carbonate precursor, 500 mL of ethanol, 80 mL of deionized water and 10 g of gamma-methacryloxypropyl trimethoxysilane are placed in a reaction kettle for stirring, the reaction kettle is heated to 60 DEG C, and the reaction is kept for 4 h. After the reaction is completed, the reaction system is cooled to room temperature, filtered, the filter cake is washed with deionized water and ethanol for 4 times, and then transferred to an oven with a temperature of 60 DEG C for drying until the weight is constant, ground, and then passed through a 2500 mesh sieve to obtain the modified magnesium carbonate.

[0078] Example 4

[0079] The embodiment provides a preparation method of a flame-retardant chain extender for a flame-retardant modified polyurethane used for a military special anti-flame-retardant wear-resistant soft cable material, and the method comprises the following steps:

[0080] Step 1, preparing a flame-retardant chain extender precursor

[0081] Take 2,5-dihydroxybenzaldehyde 20 g, triethylamine 20 g and tetrahydrofuran 600 mL, stir in a reaction kettle, cool to 0 DEG C in an ice bath, slowly add benzene phosphonic dichloride 10 g, and keep the reaction for 0.5 h; after the reaction is completed, the reaction system is restored to room temperature, filtration is carried out, 40 mL of deionized water is added to the filtrate for quenching, 600 mL of ethyl acetate is added for washing and extraction twice, the organic phase is transferred to a rotary evaporator with a temperature of 70 DEG C, and liquid is extracted until no liquid is obtained, so that the flame-retardant chain extender precursor is obtained.

[0082] Step 2, preparing a flame-retardant chain extender

[0083] Take the flame-retardant chain extender precursor 30 g, triethylamine 10 g, hydroxylamine hydrochloride 5 g and methanol 800 mL, stir in a reaction kettle, and react at room temperature for 0.5 h; after the reaction is completed, the reaction kettle is heated to 50 DEG C, and distilled under reduced pressure until no liquid is obtained; after the reaction liquid is cooled to room temperature, 800 mL of ethyl acetate and 800 mL of deionized water are added for washing and extraction twice, the organic phase is transferred to a rotary evaporator with a temperature of 80 DEG C, and liquid is extracted until no liquid is obtained, so that the flame-retardant chain extender is obtained.

[0084] Example 5

[0085] The embodiment provides a preparation method of a flame-retardant chain extender for a flame-retardant modified polyurethane used for a military special anti-flame-retardant wear-resistant soft cable material, and the method comprises the following steps:

[0086] Step 1, preparing a flame-retardant chain extender precursor

[0087] Take 2,5-dihydroxybenzaldehyde 30 g, triethylamine 30 g and tetrahydrofuran 700 mL, stir in a reaction kettle, cool to 3 DEG C in an ice bath, slowly add benzene phosphonic dichloride 15 g, and keep the reaction for 1 h; after the reaction is completed, the reaction system is restored to room temperature, filtration is carried out, 50 mL of deionized water is added to the filtrate for quenching, 700 mL of ethyl acetate is added for washing and extraction three times, the organic phase is transferred to a rotary evaporator with a temperature of 75 DEG C, and liquid is extracted until no liquid is obtained, so that the flame-retardant chain extender precursor is obtained.

[0088] Step 2, preparing a flame-retardant chain extender

[0089] Take: 40g of flame-retardant chain extender precursor, 15g of triethylamine, 7g of hydroxylamine hydrochloride and 900mL of methanol are placed in the reaction kettle for stirring, room temperature reaction for 1h, after the reaction is completed, the reaction kettle is heated to 55℃, reduced pressure distillation until no liquid is collected, when the reaction liquid is cooled to room temperature, 900mL of ethyl acetate and 900mL of deionized water are added and washed with 3 times, the organic phase is transferred to the rotary evaporator with the temperature of 85℃, and the liquid is collected until no liquid is collected, to obtain the flame-retardant chain extender.

[0090] Example 6

[0091] The embodiment provides a preparation method of a flame-retardant chain extender for a flame-retardant modified polyurethane used for a military special anti-flame and wear-resistant soft cable material, and the method comprises the following steps:

[0092] Step 1, preparing a flame-retardant chain extender precursor

[0093] Take: 40g of 2,5-dihydroxybenzaldehyde, 40g of triethylamine and 800mL of tetrahydrofuran are placed in the reaction kettle for stirring, the temperature is reduced to 5℃ in the ice bath, 20g of benzenephosphonic dichloride is slowly added, and the reaction is kept for 1h; after the reaction is completed, the reaction system is restored to room temperature, filtration is carried out, 60mL of deionized water is added to quench the reaction, 800mL of ethyl acetate is added and washed with 4 times, the organic phase is transferred to the rotary evaporator with the temperature of 80℃, and the liquid is collected until no liquid is collected, to obtain the flame-retardant chain extender precursor.

[0094] Step 2, preparing a flame-retardant chain extender

[0095] Take: 50g of the flame-retardant chain extender precursor, 20g of triethylamine, 10g of hydroxylamine hydrochloride and 1000mL of methanol are placed in the reaction kettle for stirring, room temperature reaction for 1h, after the reaction is completed, the reaction kettle is heated to 60℃, reduced pressure distillation until no liquid is collected, when the reaction liquid is cooled to room temperature, 1000mL of ethyl acetate and 1000mL of deionized water are added and washed with 4 times, the organic phase is transferred to the rotary evaporator with the temperature of 90℃, and the liquid is collected until no liquid is collected, to obtain the flame-retardant chain extender.

[0096] Example 7

[0097] The embodiment provides a preparation method of a flame-retardant modified polyurethane for a military special anti-flame and wear-resistant soft cable material, and the method comprises the following steps:

[0098] Step 1, preparing a prepolymer liquid

[0099] Take: 40g of polyethylene glycol, 1g of dibutyltin dilaurate and 500mL of N,N-dimethylformamide are placed in the reaction kettle under the protection of nitrogen atmosphere for stirring, 0.55 times of the hydroxyl molar amount of polyethylene glycol is added to diphenylmethane diisocyanate, the reaction kettle is heated to 80℃, and the reaction is kept for 1h, to obtain the prepolymer liquid.

[0100] Step 2, preparation of flame-retardant modified polyurethane

[0101] Prepolymer solution 400 mL and flame-retardant chain extender prepared in Example 4 20 g were placed in a reaction kettle under nitrogen atmosphere protection and stirred, the reaction kettle was heated to 100℃, and kept for 150 min. Acrylic acid-2-hydroxyethyl ester 5 g was added. After the reaction was completed, the reaction kettle was heated to 130℃, and distilled under reduced pressure until no liquid was collected. Flame-retardant modified polyurethane was obtained.

[0102] Example 8

[0103] The present example provides a preparation method of flame-retardant modified polyurethane for military special anti-flame and wear-resistant soft cable material, comprising the following steps:

[0104] Step 1, preparation of prepolymer solution

[0105] Polyethylene glycol 50 g, dibutyltin dilaurate 1.5 g and N,N-dimethylformamide 600 mL were weighed and placed in a reaction kettle under nitrogen atmosphere protection and stirred. Diphenylmethane diisocyanate was added at 0.55 times the molar amount of the hydroxyl group of polyethylene glycol. The reaction kettle was heated to 85℃, and kept for 1.5 h. Prepolymer solution was obtained.

[0106] Step 2, preparation of flame-retardant modified polyurethane

[0107] Prepolymer solution 500 mL and flame-retardant chain extender prepared in Example 5 30 g were placed in a reaction kettle under nitrogen atmosphere protection and stirred. The reaction kettle was heated to 110℃, and kept for 20 min. Acrylic acid-2-hydroxyethyl ester 7 g was added. After the reaction was completed, the reaction kettle was heated to 135℃, and distilled under reduced pressure until no liquid was collected. Flame-retardant modified polyurethane was obtained.

[0108] Example 9

[0109] The present example provides a preparation method of flame-retardant modified polyurethane for military special anti-flame and wear-resistant soft cable material, comprising the following steps:

[0110] Step 1, preparation of prepolymer solution

[0111] Polyethylene glycol 60 g, dibutyltin dilaurate 2 g and N,N-dimethylformamide 800 mL were weighed and placed in a reaction kettle under nitrogen atmosphere protection and stirred. Diphenylmethane diisocyanate was added at 0.55 times the molar amount of the hydroxyl group of polyethylene glycol. The reaction kettle was heated to 90℃, and kept for 2 h. Prepolymer solution was obtained.

[0112] Step 2, preparation of flame-retardant modified polyurethane

[0113] Prepolymer solution 600 mL and flame-retardant chain extender 40 g prepared in Example 6 were placed in a reaction kettle under the protection of nitrogen atmosphere and stirred, the reaction kettle was heated to 120℃, and kept for 30 min, then 2-hydroxyethyl acrylate 10 g was added, after the reaction was completed, the reaction kettle was heated to 140℃, and distilled under reduced pressure until no liquid was collected, to obtain the flame-retardant modified polyurethane.

[0114] Example 10

[0115] The embodiment provides a preparation method of a military special flame-retardant wear-resistant soft cable material, including the following steps:

[0116] The dicumyl peroxide, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, dilauryl thiodipropionate, polyethylene wax and dioctyl adipate were uniformly mixed according to the mass ratio of 0.5:2:1:2:5 to obtain an auxiliary additive, which was reserved;

[0117] The silver-plated copper wires were twisted into a wire core, and then placed in parallel, and then the ethylene-propylene rubber was used to extrude and coat the wire core to form an insulating rubber layer 1, and then an aluminum metal belt was used to wrap the insulating rubber layer 1 to form a wrapping layer 2.

[0118] The flame-retardant modified polyurethane 40 parts prepared in Example 7, polyvinyl chloride 10 parts, ethylene-vinyl acetate copolymer 3 parts, modified magnesium carbonate 15 parts prepared in Example 1 and auxiliary additive 8 parts were added into a double-screw extruder, and then melt-extruded and coated outside the wrapping layer 2 to obtain the cable material.

[0119] The eight temperature zones of the double-screw extruder from the feeding port to the discharging port are 160℃, 165℃, 170℃, 170℃, 175℃, 175℃, 180℃ and 180℃ in sequence, the main motor speed of the double-screw extruder is 80 rpm, and the pressure is 100 bar.

[0120] Example 11

[0121] The embodiment provides a preparation method of a military special flame-retardant wear-resistant soft cable material, including the following steps:

[0122] The dicumyl peroxide, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, dilauryl thiodipropionate, polyethylene wax and dioctyl adipate were uniformly mixed according to the mass ratio of 0.5:2:1:2:5 to obtain an auxiliary additive, which was reserved;

[0123] The silver-plated copper wires were twisted into a wire core, and then placed in parallel, and then the ethylene-propylene rubber was used to extrude and coat the wire core to form an insulating rubber layer 1, and then an aluminum metal belt was used to wrap the insulating rubber layer 1 to form a wrapping layer 2.

[0124] The flame-retardant modified polyurethane prepared in Example 8, 15 parts of polyvinyl chloride, 3.5 parts of ethylene-vinyl acetate copolymer, 17 parts of the modified magnesium carbonate prepared in Example 2 and 9 parts of auxiliary additives are added into a double-screw extruder to be melt-extruded and wrapped outside the outer layer 2 to obtain a cable material;

[0125] The eight temperature zones of the double-screw extruder from the feeding port to the discharging port are 160℃, 165℃, 170℃, 170℃, 175℃, 175℃, 180℃ and 180℃, respectively, the main motor speed of the double-screw extruder is 100 rpm, and the pressure is 125 bar.

[0126] Example 12

[0127] The present embodiment provides a preparation method of a military special flame-retardant wear-resistant soft cable material, comprising the following steps:

[0128] The dicumyl peroxide, 2-(2'-hydroxy-3', 5'-di-tert-butylphenyl)-5-chlorobenzotriazole, dioctyl sulfide dipropionate, polyethylene wax and dioctyl adipate are uniformly mixed in a mass ratio of 0.5:2:1:2:5 to obtain auxiliary additives for standby;

[0129] The silver-plated copper wires are twisted into a wire core, and then the ethylene-propylene rubber is used to extrude and wrap an insulating rubber layer 1 outside the wire core, and then an aluminum metal belt is used to wind and form a wrapping layer 2 outside the insulating rubber layer 1;

[0130] The flame-retardant modified polyurethane prepared in Example 9, 20 parts of polyvinyl chloride, 4 parts of ethylene-vinyl acetate copolymer, 20 parts of the modified magnesium carbonate prepared in Example 3 and 10 parts of auxiliary additives are added into a double-screw extruder to be melt-extruded and wrapped outside the wrapping layer 2 to obtain a cable material;

[0131] The eight temperature zones of the double-screw extruder from the feeding port to the discharging port are 160℃, 165℃, 170℃, 170℃, 175℃, 175℃, 180℃ and 180℃, respectively, the main motor speed of the double-screw extruder is 20 rpm, and the pressure is 150 bar.

[0132] Comparative Example 1

[0133] The difference between the present comparative example and Example 12 is that the preparation of the mixed solution in step I does not add succinic acid and L-aspartic acid.

[0134] Comparative Example 2

[0135] The difference between the present comparative example and Example 12 is that the modified magnesium carbonate precursor is used instead of the modified magnesium carbonate in the preparation of the cable material.

[0136] Comparative Example 3

[0137] The difference between the present comparative example and Example 12 is that the flame-retardant chain extender is not added when preparing the flame-retardant modified polyurethane in step 2.

[0138] Performance test:

[0139] The tensile strength and vertical burning grade of the cable material prepared in Examples 10-12 and Comparative Examples 1-3 were determined according to the standard GB / T 32129-2015 “Halogen-free low-smoke flame-retardant cable material for wire and cable”.

[0140] The softness of the cable material prepared in Examples 10-12 and Comparative Examples 1-3 was determined according to the standard JB / T 10696.3-2007 “Wire and cable mechanical and physical properties test methods Part 3: bending test”.

[0141] The abrasion resistance test of the cable material prepared in Examples 10-12 and Comparative Examples 1-3 was carried out according to the standard GB / T 17737.324-2018 “Coaxial communication cable Part 1-324: mechanical test method Cable abrasion resistance test”, and the abrasion resistance of the cable sheath layer sample was defined by the number of cycles of the sample with the blade to break the cable sheath layer, and the specific test results are shown in Table 1.

[0142] Table 1. Performance test data table of the sample

[0143]

[0144] Data analysis:

[0145] Comparative analysis of the data in Table 1, the tensile strength of the military special flame-retardant and abrasion-resistant flexible cable material prepared by the present application is 15.3 MPa, the number of winding turns is 7, the vertical burning grade is V-0 and the number of cycles reaches 81 times; then the present application uses succinic acid and L-aspartic acid as a modifier, uses the carboxyl structure in the molecule to chelate magnesium ions and adsorb on magnesium carbonate microcrystals, changes the crystal polymerization direction, further modifies by a silane coupling agent to obtain modified magnesium carbonate, prepares a flame-retardant chain extender containing nitrogen and phosphorus, further uses polyethylene glycol as a soft segment, diphenyl methane diisocyanate as a hard segment, a flame-retardant chain extender as a chain extender, and 2-hydroxyethyl acrylate as an end-capping agent to obtain a flame-retardant modified polyurethane, which not only improves the flame-retardant and abrasion-resistant properties of the cable material, but also improves its mechanical properties.

[0146] The preferred embodiments of the application disclosed above are only to facilitate the elucidation of the application. The preferred embodiments do not describe all the details of the application and limit the application to the specific embodiments. Obviously, many modifications and variations can be made in light of the teachings above. The description is chosen and described in order to provide the best illustration of the application and its practical application to those skilled in the art and to enable those skilled in the art to utilize the application in its best mode. The application is only limited by the claims and their full scope and equivalents.

Claims

1. A military-grade special flame-retardant and wear-resistant flexible cable material, characterized in that, It includes an insulating rubber layer (1), a wrapping layer (2), and a sheath layer (3) arranged sequentially from the inside out; The insulating rubber layer (1) consists of a core composed of several intertwined metal alloy wires and rubber covering the core. The sheath layer (3) comprises the following raw materials in parts by weight: 40-60 parts flame-retardant modified polyurethane, 10-20 parts polyvinyl chloride, 3-4 parts ethylene-vinyl acetate copolymer, 15-20 parts modified magnesium carbonate and 8-10 parts auxiliary additives. The auxiliary additives consist of an initiator, a light stabilizer, an antioxidant, a lubricant, and a plasticizer in a mass ratio of 0.5:2:1:2:

5.

2. The military-grade special flame-retardant and wear-resistant flexible cable material according to claim 1, characterized in that, The metal alloy wire is silver-plated copper wire, the rubber is one or more of styrene-butadiene rubber, ethylene propylene rubber, and chloroprene rubber, and the wrapping layer is one or more of polyester tape and aluminum metal tape.

3. The military-grade special flame-retardant and wear-resistant flexible cable material according to claim 1, characterized in that, The flame-retardant modified polyurethane is prepared by the following steps: A1. Place polyethylene glycol, dibutyltin dilaurate and N,N-dimethylformamide in a reaction vessel under nitrogen atmosphere and stir. Add a calculated amount of diphenylmethane diisocyanate. Heat the reaction vessel to 80-90℃ and keep it at this temperature for 1-2 hours to obtain a prepolymer solution. A2. Place the prepolymer liquid and flame retardant chain extender in a reaction vessel under nitrogen atmosphere and stir. Heat the reaction vessel to 100-120℃ and keep it at that temperature for 15-30 minutes. Add 2-hydroxyethyl acrylate and perform post-treatment to obtain flame retardant modified polyurethane.

4. The military-grade special flame-retardant and wear-resistant flexible cable material according to claim 3, characterized in that, In step A1, the ratio of polyethylene glycol, dibutyltin dilaurate, and N,N-dimethylformamide is 4-6g:0.1-0.2g:50-80mL, and diphenylmethane diisocyanate is added at 0.55 times the molar amount of hydroxyl groups in polyethylene glycol; in step A2, the ratio of prepolymer solution, flame retardant chain extender, and 2-hydroxyethyl acrylate is 40-60mL:2-4g:0.5-1g.

5. The military-grade special flame-retardant and wear-resistant flexible cable material according to claim 3, characterized in that, The flame-retardant chain extender is prepared by the following steps: B1. Place 2,5-dihydroxybenzaldehyde, triethylamine and tetrahydrofuran in a reaction vessel and stir. Cool to 0-5℃ in an ice bath, slowly add phenylphosphonic dichloride, and react at room temperature for 0.5-1h. Post-treatment yields the flame retardant chain extender precursor. B2. Place the flame retardant chain extender precursor, triethylamine, hydroxylamine hydrochloride and methanol in a reaction vessel and stir. React at room temperature for 0.5-1 h, and then perform post-treatment to obtain the flame retardant chain extender.

6. The military-grade special flame-retardant and wear-resistant flexible cable material according to claim 5, characterized in that, In step B1, the ratio of 2,5-dihydroxybenzaldehyde, triethylamine, tetrahydrofuran, and phenylphosphonic dichloroacetate is 2-4g:2-4g:60-80mL:1-2g; in step B2, the ratio of the flame retardant chain extender precursor, triethylamine, hydroxylamine hydrochloride, and methanol is 3-5g:1-2g:0.5-1g:80-100mL.

7. The military-grade special flame-retardant and wear-resistant flexible cable material according to claim 1, characterized in that, The modified magnesium carbonate is prepared by the following steps: C1. Place deionized water, succinic acid and L-aspartic acid in a reaction vessel and stir. Slowly add sodium carbonate aqueous solution until the reaction solution is dissolved to obtain a mixture. C2. Place the mixture and magnesium chloride hexahydrate in a reaction vessel and stir. Perform a hydrothermal reaction for 2-4 hours. After post-treatment, obtain the modified magnesium carbonate precursor. C3. The modified magnesium carbonate precursor, ethanol, deionized water and γ-methacryloyloxypropyltrimethoxysilane were placed in a reaction vessel and stirred. The reaction vessel was heated to 50-60℃ and kept at that temperature for 2-4 hours. The modified magnesium carbonate was then obtained after post-treatment.

8. The military-grade special flame-retardant and wear-resistant flexible cable material according to claim 7, characterized in that, In step C1, the ratio of deionized water, succinic acid, and L-aspartic acid is 50-70 mL: 0.2-0.5 g: 0.3-0.6 g, and the concentration of sodium carbonate aqueous solution is 1-2 mol / L; in step C2, the ratio of the mixture to magnesium chloride hexahydrate is 60-80 mL: 2-4 g; in step C3, the ratio of modified magnesium carbonate precursor, ethanol, deionized water, and γ-methacryloyloxypropyltrimethoxysilane is 2-4 g: 30-50 mL: 4-8 mL: 0.5-1 g.

Images