Flexible control cable

Abstract

The application belongs to the technical field of control cable, and discloses a flexible control cable.The flexible control cable comprises an insulating wire core, a shielding layer and a sheath layer.The insulating wire core is formed by extruding an insulating layer on a conductor, the conductor is formed by twisting a plurality of tinned copper wires, and the insulating layer is a polyperfluoroethylene propylene insulating layer.The shielding layer is obtained by braiding a nickel-plated copper wire.The sheath layer is made of a sheath material, and the sheath material is prepared from a flame retardant, isophorone diisocyanate, tetrahydrofuran, furfurylamine, modified nanofiber dispersion liquid and linear polyurethane solution.The linear polyurethane solution is prepared from polytetrahydrofuran diol, isophorone diisocyanate, dibutyltin dilaurate, tetrahydrofuran and a chain extender.The introduction of the chain extender, the flame retardant and the modified nanofiber effectively improves the tensile strength, the flame retardancy, the wear resistance, the bending resistance and the toughness at low temperature of the flexible control cable.Therefore, the application has a wider application prospect.

Description

Technical Field

[0001] This invention belongs to the field of control cable technology, and specifically relates to a flexible control cable. Background Technology

[0002] Flexible control cables are a type of special cable whose core function is to transmit control signals and implement equipment action commands. They also possess high flexibility and bend resistance, and are mainly used in electrical systems that require frequent movement, bending, or vibration. They ensure stable transmission of control signals and prevent cable damage or signal interruption due to mechanical stress. Flexible control cables consist of, from the inside out, a conductor, an insulation layer, a shielding layer, a filler layer, and a sheath layer. The sheath layer, which directly contacts the external environment, must simultaneously meet the requirements of flexibility, abrasion resistance, and environmental resistance.

[0003] However, in practical applications, the sheath of flexible control cables is still prone to wear, leading to scratches, peeling, and even exposure of the internal shielding and insulation layers. Furthermore, flexibility decreases under extreme temperatures or harsh environments, and tensile strength, flame retardancy, and bending resistance remain relatively poor. Therefore, the tensile strength, flame retardancy, abrasion resistance, bending resistance, and low-temperature toughness of existing flexible control cables still need improvement. Summary of the Invention

[0004] To address the shortcomings mentioned in the background section, the present invention aims to provide a flexible control cable that solves the following technical problems:

[0005] Existing flexible control cables still suffer from poor tensile strength, flame retardancy, abrasion resistance, bending resistance, and low-temperature toughness.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A flexible control cable includes an insulated core, a shielding layer, and a sheathing layer. The insulated core is a conductor with an extruded insulation layer. The conductor is formed by stranding multiple tin-plated copper wires. The insulation layer is a polytetrafluoroethylene (PTFE) insulation layer. The shielding layer is woven from nickel-plated copper wires.

[0008] The sheath layer is made of a sheath material, which includes the following raw materials: flame retardant, isophorone diisocyanate, tetrahydrofuran, furfural amine, modified nanofiber dispersion, and linear polyurethane solution.

[0009] The flame retardant is prepared from phenylphosphonic dichloride, 1,4-butanediol, triethylamine, and tetrahydrofuran;

[0010] The modified nanofiber dispersion is a tetrahydrofuran dispersion of lanthanum-coordinated modified terthiophene nanofibers.

[0011] The linear polyurethane solution is prepared from polytetrahydrofuran diol, isophorone diisocyanate, dibutyltin dilaurate, tetrahydrofuran, and a chain extender. The chain extender is prepared by reacting maleic anhydride and furan through an addition reaction, followed by a reaction with 3-amino-1,2-propanediol.

[0012] Preferably, the flame retardant is prepared by the following method:

[0013] Benzophosphonyl dichloro was dissolved in tetrahydrofuran 1 and a mixed solution of 1,4-butanediol, triethylamine and tetrahydrofuran 2 was added dropwise at 0-4℃. After stirring for 1-1.5 h, the mixture was refluxed at 66℃ for 24-25 h. After filtration and rotary evaporation to remove tetrahydrofuran, the residue was dissolved in dichloromethane, and anhydrous sodium sulfate was added. After standing for 12-15 h and filtration, dichloromethane was removed again by rotary evaporation to obtain the flame retardant.

[0014] Preferably, the ratio of phenylphosphonic dichloro, tetrahydrofuran 1, 1,4-butanediol, triethylamine, tetrahydrofuran 2, dichloromethane, and anhydrous sodium sulfate is 19.5-23.4g: 100-120mL: 11.12-13.34g: 20.3-24.3g: 50-60mL: 40-48mL: 5-6g.

[0015] Preferably, the modified nanofiber dispersion is prepared as follows:

[0016] A1: Dissolve lanthanum nitrate hexahydrate in anhydrous ethanol to obtain a lanthanum nitrate solution;

[0017] A2: Dissolve terthiophene in chloroform, then add lanthanum nitrate solution dropwise and react at 40℃ for 12-14 h. After centrifugation and washing of the precipitate, disperse it in tetrahydrofuran and sonicate for 1-2 h to obtain a modified nanofiber dispersion.

[0018] Preferably, the ratio of lanthanum nitrate hexahydrate to anhydrous ethanol in A1 is 2.2-2.6 g: 20-24 mL;

[0019] The ratio of the amounts of terthiophene, chloroform, lanthanum nitrate solution, and tetrahydrofuran described in A2 is 1.5-1.8g: 50-60mL: 20-24mL: 100-120mL.

[0020] Preferably, the linear polyurethane solution is prepared as follows:

[0021] B1: Dissolve maleic anhydride in ethyl acetate, add furan and stir for 24-26 h, then filter, wash the precipitate and vacuum dry to obtain white crystals;

[0022] B2: Dissolve 3-amino-1,2-propanediol in anhydrous ethanol to obtain a 3-amino-1,2-propanediol solution;

[0023] B3: Disperse the white crystals in anhydrous ethanol, then add 3-amino-1,2-propanediol solution dropwise while stirring and react at 83-85℃ for 6-7h. After cooling to 25-35℃ and standing for 12-15h, centrifuge, wash the precipitate, and vacuum dry to obtain the crude product.

[0024] B4: Under a nitrogen atmosphere, the crude product is added to toluene and reacted at 110°C for 8-9 hours. After cooling to 70-80°C, it is refrigerated at 0-4°C for 12-15 hours. After filtration, washing of the precipitate, and vacuum drying, the chain extender is obtained.

[0025] B5: Under a nitrogen atmosphere, polytetrahydrofuran diol, isophorone diisocyanate and dibutyltin dilaurate are mixed and reacted at 78-80℃ for 2-2.5h. After cooling to 55-65℃, tetrahydrofuran is added and stirred for 10-20min. Then, a chain extender is added and reacted at 63-65℃ for 6-7h to obtain a linear polyurethane solution.

[0026] Preferably, the ratio of maleic anhydride, ethyl acetate, and furan in B1 is 98.1-117.7g: 1000-1200mL: 88.5-106.2g;

[0027] The ratio of 3-amino-1,2-propanediol to anhydrous ethanol in B2 is 28.3-34 g: 50-60 mL;

[0028] The ratio of the white crystals, anhydrous ethanol, and 3-amino-1,2-propanediol solution described in B3 is 50-60g: 100-120mL: 45-54g;

[0029] The ratio of crude product to toluene described in B4 is 10-12g: 400-480mL;

[0030] The ratio of polytetrahydrofuran diol, isophorone diisocyanate, dibutyltin dilaurate, tetrahydrofuran, and chain extender in B5 is 10-12g: 4.47-5.36g: 0.1-0.12g: 40-48mL: 1.71-2.06g.

[0031] Preferably, the sheath material is prepared by the following method:

[0032] Under a nitrogen atmosphere, flame retardant and isophorone diisocyanate are mixed and reacted at 78-80℃ for 2-2.5h. After cooling to 55-65℃, tetrahydrofuran is added and stirred for 10-20min. Then, furfurylamine is added at 25-35℃ and reacted for 30-40min. Modified nanofiber dispersion is then added and stirred for 15-20min. Linear polyurethane solution is then added and stirred at 65℃ for 2-3h. Finally, the mixture is poured into a mold and vacuum dried. After demolding, it is pulverized, passed through a 300-mesh sieve, and vacuum dried to obtain the sheath material.

[0033] Preferably, the ratio of the flame retardant, isophorone diisocyanate, tetrahydrofuran, furfuralamine, modified nanofiber dispersion, and linear polyurethane solution is 5-6g: 2.23-2.68g: 10-12mL: 0.97-1.16g: 56-72mL: 51.6-61.9g.

[0034] Preferably, the flexible control cable is prepared as follows:

[0035] S1: Twist 5-10 tin-plated copper wires with a diameter of 0.1mm together to form a conductor;

[0036] S2: Use an extruder to extrude insulating material onto the surface of the conductor to form a 0.1-0.3mm thick polytetrafluoroethylene propylene insulation layer, thus obtaining an insulated wire core;

[0037] S3: A shielding layer with a braiding density of 85%-90% is formed on the surface of the insulated core using nickel-plated copper wire with a diameter of 0.08-0.1mm. After forming the shielding layer, a sheathing material is extruded on the outer surface to form a sheathing layer with a thickness of 0.2-0.4mm, thus obtaining a flexible control cable.

[0038] The beneficial effects of this invention are:

[0039] This invention provides a flexible control cable, which effectively improves the tensile strength, flame retardancy, abrasion resistance, bending resistance and low-temperature toughness of the flexible control cable through the following methods.

[0040] (1) The rigid six-membered ring in the chain extender of this invention restricts the free sliding of the molecular chain and improves the chain rigidity; at the same time, the polar groups in the molecule can form hydrogen bonds with the urea and ester groups in the polyurethane, enhancing the intermolecular forces; in addition, the branched structure can increase the reaction sites with isophorone diisocyanate, indirectly increasing the crosslinking density, thereby significantly improving the tensile strength. The six-membered ring structure in the chain extender has a high carbon content, and it is easy to form a dense carbon layer through "cyclization-crosslinking" during combustion; at the same time, the polar heteroatoms can also promote gas phase flame retardancy during combustion, further improving the flame retardancy. The rigid ring structure in the chain extender can improve the material hardness and elastic modulus, make the molecular chain more compact, and make the cable less prone to plastic deformation during friction, thereby improving wear resistance.

[0041] (2) The flame retardant of this invention contains a rigid benzene ring, which can form rigid reinforcing points in the polyurethane matrix and restrict the sliding of molecular chains; the polar phosphoryl group in the flame retardant can form hydrogen bonds with the urethane bonds of the hard segments of polyurethane, enhancing the intermolecular forces; the phosphorus group in the flame retardant can promote slight cross-linking of the matrix during the reaction process, further improving the structural stability, thereby significantly improving the tensile strength of the sheath material. During combustion, the phosphorus element in the flame retardant can be converted into a molten phosphate ester coating layer, which isolates oxygen and heat and prevents the matrix from burning further; during combustion, the flame retardant can also capture free radicals in the combustion chain reaction and interrupt the combustion process. The rigid benzene ring in the flame retardant can improve the overall hardness of the material and reduce the surface deformation during wear; the polar phosphoryl group and ester bond enhance the intermolecular forces, making the matrix structure more compact and reducing the probability of abrasive particles embedding into the surface; the good compatibility between the flame retardant and the polyurethane matrix can also avoid the aggravation of wear due to phase interface peeling during wear, further improving wear resistance.

[0042] (3) The modified nanofiber dispersion of the present invention has an extremely high specific surface area, and lanthanum ions can form coordination bonds with the urethane bonds of polyurethane in the sheath matrix. At the same time, the conjugated structure of terthiophene has van der Waals forces with the polymer molecular chain, which greatly enhances the interfacial bonding force between the nanofiber and the polyurethane, flame retardant and other matrices, and reduces stress concentration during stretching. The linear fiber structure of the modified nanofiber can form a micro-reinforcing skeleton in the matrix, which can effectively transfer external forces during stretching, avoid local fracture of the matrix, and thus improve the overall tensile strength. During combustion, lanthanum ions will react with the oxygen-containing functional groups generated by the combustion of the matrix to generate a dense lanthanum oxide or lanthanide composite oxide coating, which covers the surface of the material, isolates oxygen and combustible gases, and prevents the spread of flame. The conjugated structure of terthiophene is prone to cross-linking and carbonization at high temperature, forming a continuous dense carbon layer, blocking heat transfer, reducing the release of combustible volatiles, and forming a double barrier with the lanthanum oxide coating, further improving the flame retardant ability. Lanthanum ions can also inhibit the generation of smoke and toxic gases during combustion, further optimizing the flame retardant performance. When the sheath surface is subjected to friction, the high-hardness modified nanofibers can directly bear the frictional stress as wear-resistant particles, reducing direct wear on the matrix. The modified nanofibers can form a microscopic continuous network within the matrix, dispersing localized frictional stress over a wider area and preventing localized wear-through caused by stress concentration at friction points. Simultaneously, the strong interfacial bonding between the nanofibers and the matrix prevents the fibers from detaching from the matrix, further extending the wear-resistant life. The modified nanofibers can prevent significant stress concentration at the interface during bending, thus preventing the initiation of cracks during bending. The modified nanofibers themselves can undergo slight bending deformation; when the cable bends, the nanofibers can absorb bending energy through their own deformation, simultaneously driving the matrix molecular chains to deform in tandem, reducing bending fracture caused by excessive rigidity in the matrix and further improving bending resistance. Lanthanum ions have a large radius and moderate charge density, which can form weak coordination with oxygen atoms in polyurethane molecular chains, breaking the rigid aggregation of molecular chains at low temperatures, promoting local movement of molecular chains, and reducing the low-temperature brittleness of the matrix. When the material deforms at low temperatures, the modified nanofibers can absorb impact energy through fiber slippage and slight fracture. When microcracks are generated inside the material, the cracks will deflect when they encounter nanofibers, increasing the energy consumption for crack propagation and thus improving low-temperature toughness. The molecular-level compatibility between the modified nanofibers and the polyurethane matrix can avoid interfacial peeling brittleness caused by poor interfacial compatibility at low temperatures, further improving the toughness of the cable at low temperatures.

[0043] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Detailed Implementation

[0044] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0045] In the description of this invention, it should be understood that the terms "opening", "upper", "lower", "thickness", "top", "middle", "length", "inner", "around", etc., which indicate orientation or positional relationship, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this invention.

[0046] Unless otherwise specified, the following information pertains to some of the raw materials used in the following embodiments and comparative examples of this invention:

[0047] The polytetrafluoroethylene propylene resin was purchased from Hubei Xinhongli Chemical Co., Ltd., item number: XHL1494; the polytetrahydrofuran diol was purchased from Shandong Jining Huakai Resin Co., Ltd., with a number average molecular weight of 1000 g / mol.

[0048] Example 1: A method for preparing a flexible control cable is as follows:

[0049] S1: Dissolve 98.1g of maleic anhydride in 1000mL of ethyl acetate, add 88.5g of furan and stir for 24h. Then filter, wash the precipitate three times with ethyl acetate, and dry under vacuum at 40℃ for 2h to obtain white crystals.

[0050] S2: Dissolve 28.3 g of 3-amino-1,2-propanediol in 50 mL of anhydrous ethanol to obtain a 3-amino-1,2-propanediol solution;

[0051] S3: Disperse 50g of white crystals in 100mL of anhydrous ethanol, then add 45g of 3-amino-1,2-propanediol solution dropwise while stirring and react at 83℃ for 6h. After cooling to 25℃ and standing for 12h, centrifuge to separate the precipitate. Wash the precipitate three times with anhydrous ethanol and dry it under vacuum at 55℃ for 4h to obtain the crude product.

[0052] S4: Under a nitrogen atmosphere, 10g of crude product was added to 400mL of toluene and reacted at 110℃ for 8h. After cooling to 70℃, it was refrigerated at 0℃ for 12h. Then, it was filtered and the precipitate was washed twice with toluene at 0℃. After vacuum drying at 75℃ for 6h, the chain extender was obtained.

[0053] S5: Dissolve 19.5g of phenylphosphonic dichloro in 100mL of tetrahydrofuran and slowly add 11.12g of 1,4-butanediol, 20.3g of triethylamine and 50mL of tetrahydrofuran solution at 0℃ and stir for 1h. Then reflux at 66℃ for 24h, filter to remove the precipitate and rotary evaporate the filtrate to remove tetrahydrofuran. Dissolve the residue in 40mL of dichloromethane, add 5g of anhydrous sodium sulfate, let stand for 12h and filter. Then rotary evaporate again to remove dichloromethane to obtain the flame retardant.

[0054] S6: Under a nitrogen atmosphere, 10g of dehydrated polytetrahydrofuran diol, 4.47g of isophorone diisocyanate and 0.1g of dibutyltin dilaurate were mixed and reacted at 78°C for 2h. After cooling to 55°C, 40mL of tetrahydrofuran was added and stirred for 10min. Then, 1.71g of chain extender was added and reacted at 63°C for 6h to obtain a linear polyurethane solution.

[0055] S7: Dissolve 2.2g of lanthanum nitrate hexahydrate in 20mL of anhydrous ethanol to obtain a lanthanum nitrate solution;

[0056] S8: Dissolve 1.5g of terthiophene in 50mL of chloroform, then add 20mL of lanthanum nitrate solution and react at 40℃ for 12h. Centrifuge to separate the precipitate and wash it three times with a chloroform and ethanol mixture with a volume ratio of 1:1. Then disperse it in 100mL of tetrahydrofuran and sonicate for 1h to obtain a modified nanofiber dispersion.

[0057] S9: Under a nitrogen atmosphere, 5g of flame retardant and 2.23g of isophorone diisocyanate were mixed and reacted at 78℃ for 2h. After cooling to 55℃, 10mL of tetrahydrofuran was added and stirred for 10min. Then, 0.97g of furfurylamine was added at 25℃ and reacted for 30min. Next, 56mL of modified nanofiber dispersion was added and stirred for 15min. Then, 51.6g of linear polyurethane solution was added and stirred at 65℃ for 2h. Finally, the mixture was poured into a mold and vacuum dried at 75℃ for 48h. After demolding, the mixture was pulverized, passed through a 300-mesh sieve, and vacuum dried at 75℃ for 6h to obtain the sheath material.

[0058] S10: Five tin-plated copper wires with a diameter of 0.1 mm are twisted together to form a conductor;

[0059] S11: Use an extruder to extrude insulating material (polytetrafluoroethylene propylene resin) onto the surface of the conductor to form a 0.1mm thick polytetrafluoroethylene propylene insulation layer, thus obtaining an insulated wire core;

[0060] S12: A shielding layer with a braiding density of 85% is formed on the surface of the insulated core using nickel-plated copper wire with a diameter of 0.08mm. After forming the shielding layer, a sheathing material is extruded on the outer surface to form a 0.2mm thick sheathing layer, thus obtaining a flexible control cable.

[0061] Example 2: A method for preparing a flexible control cable is as follows:

[0062] S1: Dissolve 107.9g of maleic anhydride in 1100mL of ethyl acetate, add 97.3g of furan and stir for 25h. Then filter, wash the precipitate 4 times with ethyl acetate, and dry under vacuum at 40℃ for 2.5h to obtain white crystals.

[0063] S2: Dissolve 31.1 g of 3-amino-1,2-propanediol in 55 mL of anhydrous ethanol to obtain a 3-amino-1,2-propanediol solution.

[0064] S3: 55g of white crystals were dispersed in 110mL of anhydrous ethanol, and then 49.5g of 3-amino-1,2-propanediol solution was added dropwise while stirring and reacted at 84℃ for 6.5h. After cooling to 30℃ and standing for 13h, the mixture was centrifuged and the precipitate was washed 4 times with anhydrous ethanol and then dried under vacuum at 58℃ for 56h to obtain the crude product.

[0065] S4: Under a nitrogen atmosphere, 11 g of crude product was added to 440 mL of toluene and reacted at 110 °C for 8.9 h. After cooling to 75 °C, it was refrigerated at 2 °C for 13 h. Then, it was filtered and the precipitate was washed three times with toluene at 2 °C. After vacuum drying at 78 °C for 7 h, the chain extender was obtained.

[0066] S5: Dissolve 21.5g phenylphosphonic dichloro in 110mL tetrahydrofuran and slowly add 12.23g of 1,4-butanediol, 22.3g of triethylamine and 55mL tetrahydrofuran solution dropwise at 2℃ and stir for 1.3h. Then reflux at 66℃ for 24.5h, filter to remove the precipitate and rotary evaporate the filtrate to remove tetrahydrofuran. Dissolve the residue in 44mL dichloromethane, add 5.5g anhydrous sodium sulfate, let stand for 13h and filter. Then rotary evaporate again to remove dichloromethane to obtain the flame retardant.

[0067] S6: Under a nitrogen atmosphere, 11g of dehydrated polytetrahydrofuran diol, 4.92g of isophorone diisocyanate and 0.11g of dibutyltin dilaurate were mixed and reacted at 79℃ for 2.3h. After cooling to 60℃, 44mL of tetrahydrofuran was added and stirred for 15min. Then, 1.88g of chain extender was added and reacted at 64℃ for 6.5h to obtain a linear polyurethane solution.

[0068] S7: Dissolve 2.4 g of lanthanum nitrate hexahydrate in 22 mL of anhydrous ethanol to obtain a lanthanum nitrate solution;

[0069] S8: Dissolve 1.65g of terthiophene in 55mL of chloroform, then add 22mL of lanthanum nitrate solution and react at 40℃ for 13h. Centrifuge to separate the precipitate and wash it 4 times with a chloroform and ethanol mixture with a volume ratio of 1:1. Then disperse it in 110mL of tetrahydrofuran and sonicate for 1.5h to obtain a modified nanofiber dispersion.

[0070] S9: Under a nitrogen atmosphere, 5.5g of flame retardant and 2.45g of isophorone diisocyanate were mixed and reacted at 79℃ for 2.3h. After cooling to 60℃, 11mL of tetrahydrofuran was added and stirred for 15min. Then, 1.07g of furfurylamine was added at 30℃ and reacted for 35min. Next, 61.6mL of modified nanofiber dispersion was added and stirred for 18min. Then, 56.8g of linear polyurethane solution was added and stirred at 65℃ for 2.5h. Finally, the mixture was poured into a mold and vacuum dried at 78℃ for 49h. After demolding, the mixture was pulverized, passed through a 300-mesh sieve, and vacuum dried at 78℃ for 7h to obtain the sheath material.

[0071] S10: Seven tin-plated copper wires with a diameter of 0.1 mm are twisted together to form a conductor;

[0072] S11: Use an extruder to extrude insulating material (polytetrafluoroethylene propylene resin) onto the surface of the conductor to form a 0.2mm thick polytetrafluoroethylene propylene insulation layer, thus obtaining an insulated wire core;

[0073] S12: A shielding layer with a braiding density of 88% is formed on the surface of the insulated core using nickel-plated copper wire with a diameter of 0.09mm. After forming the shielding layer, a sheathing material is extruded on the outer surface to form a 0.3mm thick sheathing layer, thus obtaining a flexible control cable.

[0074] Example 3: A method for preparing a flexible control cable is as follows:

[0075] S1: Dissolve 117.7g of maleic anhydride in 1200mL of ethyl acetate, add 106.2g of furan and stir for 26h. Then filter, wash the precipitate 5 times with ethyl acetate, and dry under vacuum at 40℃ for 3h to obtain white crystals.

[0076] S2: Dissolve 34g of 3-amino-1,2-propanediol in 60mL of anhydrous ethanol to obtain a 3-amino-1,2-propanediol solution.

[0077] S3: Disperse 60g of white crystals in 120mL of anhydrous ethanol, then add 54g of 3-amino-1,2-propanediol solution dropwise while stirring and react at 85℃ for 7h. After cooling to 35℃ and standing for 15h, centrifuge to separate the precipitate. Wash the precipitate 5 times with anhydrous ethanol and dry it under vacuum at 60℃ for 6h to obtain the crude product.

[0078] S4: Under a nitrogen atmosphere, 12g of crude product was added to 480mL of toluene and reacted at 110℃ for 9h. After cooling to 80℃, it was refrigerated at 4℃ for 15h. Then, it was filtered and the precipitate was washed 4 times with toluene at 4℃. After vacuum drying at 80℃ for 8h, the chain extender was obtained.

[0079] S5: Dissolve 23.4g of phenylphosphonic dichloro in 120mL of tetrahydrofuran and slowly add 13.34g of 1,4-butanediol, 24.3g of triethylamine and 60mL of tetrahydrofuran solution at 4℃ and stir for 1.5h. Then reflux at 66℃ for 25h, filter to remove the precipitate and remove tetrahydrofuran by rotary evaporation of the filtrate. Dissolve the residue in 48mL of dichloromethane, add 6g of anhydrous sodium sulfate, let stand for 15h and filter. Remove dichloromethane by rotary evaporation again to obtain the flame retardant.

[0080] S6: Under a nitrogen atmosphere, 12g of dehydrated polytetrahydrofuran diol, 5.36g of isophorone diisocyanate and 0.12g of dibutyltin dilaurate were mixed and reacted at 80℃ for 2.5h. After cooling to 65℃, 48mL of tetrahydrofuran was added and stirred for 20min. Then, 2.06g of chain extender was added and reacted at 65℃ for 7h to obtain a linear polyurethane solution.

[0081] S7: Dissolve 2.6g of lanthanum nitrate hexahydrate in 24mL of anhydrous ethanol to obtain a lanthanum nitrate solution;

[0082] S8: Dissolve 1.8g of terthiophene in 60mL of chloroform, then add 24mL of lanthanum nitrate solution and react at 40℃ for 14h. Centrifuge to separate the precipitate and wash it 5 times with a chloroform and ethanol mixture with a volume ratio of 1:1. Then disperse it in 120mL of tetrahydrofuran and sonicate for 2h to obtain a modified nanofiber dispersion.

[0083] S9: Under a nitrogen atmosphere, 6g of flame retardant and 2.68g of isophorone diisocyanate were mixed and reacted at 80℃ for 2.5h. After cooling to 65℃, 12mL of tetrahydrofuran was added and stirred for 20min. Then, 1.16g of furfurylamine was added at 35℃ and reacted for 40min. Next, 72mL of modified nanofiber dispersion was added and stirred for 20min. Then, 61.9g of linear polyurethane solution was added and stirred at 65℃ for 3h. Finally, the mixture was poured into a mold and vacuum dried at 80℃ for 50h. After demolding, the mixture was pulverized, passed through a 300-mesh sieve, and vacuum dried at 80℃ for 8h to obtain the sheath material.

[0084] S10: Ten tin-plated copper wires with a diameter of 0.1 mm are twisted together to form a conductor;

[0085] S11: Use an extruder to extrude insulating material (polytetrafluoroethylene propylene resin) onto the surface of the conductor to form a 0.3mm thick polytetrafluoroethylene propylene insulation layer, thus obtaining an insulated wire core;

[0086] S12: A shielding layer with a braiding density of 90% is formed on the surface of the insulated core using nickel-plated copper wire with a diameter of 0.1mm. After forming the shielding layer, a sheathing material is extruded on the outer surface to form a 0.4mm thick sheathing layer, thus obtaining a flexible control cable.

[0087] Comparative Example 1:

[0088] Compared with Example 1, this comparative example only replaces the "1.71g chain extender" added in the preparation process of S6 with "0.9g 1,4-butanediol". All other steps and parameters are the same, and will not be repeated in this comparative example. The final result is a flexible control cable.

[0089] Comparative Example 2:

[0090] Compared with Example 1, this comparative example only replaces the "5g flame retardant" added during the preparation of S9 with "5g polytetrahydrofuran diol". All other steps and parameters are the same, and will not be repeated in this comparative example. The final result is a flexible control cable.

[0091] Comparative Example 3:

[0092] Compared with Example 1, this comparative example only omits the addition of "modified nanofiber dispersion" during the preparation process of S9. All other steps and parameters are the same, and will not be repeated here. The final result is a flexible control cable.

[0093] Performance testing:

[0094] Determination of tensile strength:

[0095] Referring to GB / T 528-2009 standard, the sheath layer of the flexible control cable prepared in Examples 1-3 and Comparative Examples 1-3 of the present invention was measured at a tensile rate of 50 mm / min. The tensile strength (MPa) of the cable was measured at 23°C after being made into a sample with a size of 170 mm × 10 mm × 4 mm. The results are shown in Table 1.

[0096] Determination of flame retardancy:

[0097] Referring to GB / T 2408-2008 standard, the vertical flame retardancy rating of the sheath material of the flexible control cables prepared in Examples 1-3 and Comparative Examples 1-3 of this invention was determined, and the results are shown in Table 1.

[0098] Abrasion resistance testing:

[0099] Referring to GB / T 3960-2016 standard, the sheath material of the flexible control cable prepared in Examples 1-3 and Comparative Examples 1-3 of this invention was made into a specimen with a size of 30mm×7mm×6mm, and the wear mass (mg) after 1000 revolutions at 100 rpm under a 5N load was measured. The measurement results are shown in Table 1.

[0100] Determination of bending resistance:

[0101] According to GB / T 2951.21-2008 standard, repeated bending tests were conducted to determine the bending resistance (number of bends before fracture or sheath cracking) of the flexible control cables prepared in Examples 1-3 and Comparative Examples 1-3 of this invention after being made into specimens with a size of 125mm×13mm×0.4mm. The test results are shown in Table 1.

[0102] Low temperature resistance test:

[0103] Referring to GB / T 1043.1-2008 standard, the sheath material of the flexible control cables prepared in Examples 1-3 and Comparative Examples 1-3 of this invention was measured. After being prepared into type A notched specimens (notch bottom radius 0.25 mm) with dimensions of 80 mm × 10 mm × 4 mm and stored at -40°C for 24 h, the impact strength (kJ / m²) was determined under the conditions of -40°C and a pendulum energy of 2.75 J. 2 The measurement results are shown in Table 1.

[0104] Table 1: Performance test results of Examples 1-3 and Comparative Examples 1-3

[0105]

[0106] Data Analysis:

[0107] As can be seen from Table 1, the flexible control cable prepared according to the embodiments of the present invention has excellent tensile strength, flame retardancy, abrasion resistance, bending resistance and low-temperature toughness.

[0108] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above 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 one or more embodiments or examples.

[0109] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A flexible control cable, characterized in that, It includes an insulated core, a shielding layer, and a sheathing layer. The insulated core is a conductor with an extruded insulation layer. The conductor is formed by stranding multiple tin-plated copper wires. The insulation layer is a polytetrafluoroethylene (PTFE) insulation layer. The shielding layer is woven from nickel-plated copper wires. The sheath layer is made of a sheath material, which includes the following raw materials: flame retardant, isophorone diisocyanate, tetrahydrofuran, furfural amine, modified nanofiber dispersion, and linear polyurethane solution. The flame retardant is prepared from phenylphosphonic dichloride, 1,4-butanediol, triethylamine, and tetrahydrofuran; The modified nanofiber dispersion is a tetrahydrofuran dispersion of lanthanum-coordinated modified terthiophene nanofibers. The linear polyurethane solution is prepared from polytetrahydrofuran diol, isophorone diisocyanate, dibutyltin dilaurate, tetrahydrofuran, and a chain extender. The chain extender is prepared by reacting maleic anhydride and furan through an addition reaction, followed by a reaction with 3-amino-1,2-propanediol.

2. The flexible control cable according to claim 1, characterized in that, The flame retardant is prepared as follows: Benzophosphonyl dichloro was dissolved in tetrahydrofuran 1 and a mixed solution of 1,4-butanediol, triethylamine and tetrahydrofuran 2 was added dropwise at 0-4℃. After stirring for 1-1.5 h, the mixture was refluxed at 66℃ for 24-25 h. After filtration and rotary evaporation to remove tetrahydrofuran, the residue was dissolved in dichloromethane, and anhydrous sodium sulfate was added. After standing for 12-15 h and filtration, dichloromethane was removed again by rotary evaporation to obtain the flame retardant.

3. The flexible control cable according to claim 2, characterized in that, The ratio of the amounts of phenylphosphonic dichloride, tetrahydrofuran 1, 1,4-butanediol, triethylamine, tetrahydrofuran 2, dichloromethane, and anhydrous sodium sulfate is 19.5-23.4g: 100-120mL: 11.12-13.34g: 20.3-24.3g: 50-60mL: 40-48mL: 5-6g.

4. The flexible control cable according to claim 1, characterized in that, The modified nanofiber dispersion is prepared as follows: A1: Dissolve lanthanum nitrate hexahydrate in anhydrous ethanol to obtain a lanthanum nitrate solution; A2: Dissolve terthiophene in chloroform, then add lanthanum nitrate solution dropwise and react at 40℃ for 12-14 h. After centrifugation and washing of the precipitate, disperse it in tetrahydrofuran and sonicate for 1-2 h to obtain a modified nanofiber dispersion.

5. The flexible control cable according to claim 4, characterized in that, The ratio of lanthanum nitrate hexahydrate to anhydrous ethanol described in A1 is 2.2-2.6 g : 20-24 mL; The ratio of the amounts of terthiophene, chloroform, lanthanum nitrate solution, and tetrahydrofuran described in A2 is 1.5-1.8g: 50-60mL: 20-24mL: 100-120mL.

6. The flexible control cable according to claim 1, characterized in that, The preparation method of the linear polyurethane solution is as follows: B1: Dissolve maleic anhydride in ethyl acetate, add furan and stir for 24-26 h, then filter, wash the precipitate and vacuum dry to obtain white crystals; B2: Dissolve 3-amino-1,2-propanediol in anhydrous ethanol to obtain a 3-amino-1,2-propanediol solution; B3: Disperse the white crystals in anhydrous ethanol, then add 3-amino-1,2-propanediol solution dropwise while stirring and react at 83-85℃ for 6-7h. After cooling to 25-35℃ and standing for 12-15h, centrifuge, wash the precipitate, and vacuum dry to obtain the crude product. B4: Under a nitrogen atmosphere, the crude product is added to toluene and reacted at 110°C for 8-9 hours. After cooling to 70-80°C, it is refrigerated at 0-4°C for 12-15 hours. After filtration, washing of the precipitate, and vacuum drying, the chain extender is obtained. B5: Under a nitrogen atmosphere, polytetrahydrofuran diol, isophorone diisocyanate and dibutyltin dilaurate are mixed and reacted at 78-80℃ for 2-2.5h. After cooling to 55-65℃, tetrahydrofuran is added and stirred for 10-20min. Then, a chain extender is added and reacted at 63-65℃ for 6-7h to obtain a linear polyurethane solution.

7. The flexible control cable according to claim 6, characterized in that, The ratio of maleic anhydride, ethyl acetate, and furan in B1 is 98.1-117.7g: 1000-1200mL: 88.5-106.2g; The ratio of 3-amino-1,2-propanediol to anhydrous ethanol in B2 is 28.3-34 g: 50-60 mL; The ratio of the white crystals, anhydrous ethanol, and 3-amino-1,2-propanediol solution described in B3 is 50-60g: 100-120mL: 45-54g; The ratio of crude product to toluene described in B4 is 10-12g: 400-480mL; The ratio of polytetrahydrofuran diol, isophorone diisocyanate, dibutyltin dilaurate, tetrahydrofuran, and chain extender in B5 is 10-12g: 4.47-5.36g: 0.1-0.12g: 40-48mL: 1.71-2.06g.

8. The flexible control cable according to claim 1, characterized in that, The preparation method of the sheath material is as follows: Under a nitrogen atmosphere, flame retardant and isophorone diisocyanate are mixed and reacted at 78-80℃ for 2-2.5h. After cooling to 55-65℃, tetrahydrofuran is added and stirred for 10-20min. Then, furfurylamine is added at 25-35℃ and reacted for 30-40min. Modified nanofiber dispersion is then added and stirred for 15-20min. Linear polyurethane solution is then added and stirred at 65℃ for 2-3h. Finally, the mixture is poured into a mold and vacuum dried. After demolding, it is pulverized, passed through a 300-mesh sieve, and vacuum dried to obtain the sheath material.

9. The flexible control cable according to claim 8, characterized in that, The ratio of the flame retardant, isophorone diisocyanate, tetrahydrofuran, furfural amine, modified nanofiber dispersion, and linear polyurethane solution is 5-6g: 2.23-2.68g: 10-12mL: 0.97-1.16g: 56-72mL: 51.6-61.9g.

10. The flexible control cable according to claim 1, characterized in that, The method for manufacturing the flexible control cable is as follows: S1: Twist 5-10 tin-plated copper wires together to form a conductor; S2: Use an extruder to extrude insulating material onto the surface of the conductor to form a 0.1-0.3mm thick polytetrafluoroethylene propylene insulation layer, thus obtaining an insulated wire core; S3: A shielding layer is woven on the surface of the insulated core using nickel-plated copper wire. After forming the shielding layer, a sheath material is extruded onto the outer surface to form a 0.2-0.4mm thick sheath layer, resulting in a flexible control cable.

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