A uniform conductive spandex fiber and its preparation method

Abstract

The present invention relates to the technical field of functional textiles, and particularly relates to a uniform conductive spandex fiber and a preparation method thereof. The preparation method is as follows: a conductive agent is added during the preparation process of the spandex fiber polymerization stock solution, and then the initial spandex fiber is obtained by dry spinning. The particle size of the conductive agent is 50 nm - 1000 nm; after the initial spandex fiber is soaked in an Fe<supgt;3+< / supgt; aqueous solution, it is then soaked in a mixed aqueous solution containing a conductive organic polymer monomer and p-toluenesulfonic acid for in-situ polymerization reaction. During the soaking process of the initial spandex fiber in the mixed aqueous solution, a stretching operation is performed; after the soaking is completed, washing, drying, and stretching and shaping are carried out to obtain the conductive spandex fiber. The fabric made of the conductive spandex fiber of the present invention has good antistatic performance, has great application potential in wearable intelligent fabrics such as health movement monitoring, and has a broad market prospect.

Description

Technical Field

[0001] The present invention relates to a uniform conductive spandex fiber and a preparation method thereof, belonging to the technical field of functional textiles. Background Art

[0002] With the rapid development of synthetic fibers, their application proportion in chemical fibers is getting higher and higher. However, synthetic fibers are prone to static electricity accumulation in practical applications. Spandex is an elastic fiber with an alternating arrangement of hard and soft segments, having a high resilience rate, excellent weather resistance and strength. At present, spandex is widely used in clothing and medical products, but it also has the problem of static electricity accumulation.

[0003] Traditional chemical fibers, natural fibers, etc. are non-conductive, so appropriate methods need to be adopted to add conductive components to improve the conductive performance of the fibers. Currently, the materials added to conductive fibers include carbon nanomaterials, metal materials and conductive polymer materials. Nano-carbon materials include carbon nanotubes (CNTs), carbon black (CB), and graphene oxide (GO); metal materials include silver nanowires, nano-gold and liquid metals; conductive polymer materials include polyaniline (PANl), polypyrrole (PPY) and polythiophene and its derivatives (PEDOT, PSS). Among them, adding metal materials has disadvantages such as high cost, poor blending process and poor fatigue resistance; while polyaniline, polypyrrole and polythiophene are usually complexed on the fiber surface, and their anti-washing effect is poor, and the resistance will gradually increase and finally lose the antistatic effect.

[0004] A preparation method of a conductive spandex filament or cotton fabric disclosed in the patent application with the publication number CN106436288A is modified by a dopamine silane coupling agent and then conductive metal silver is added to enhance its conductivity. This method is expensive and not suitable for daily wear. A patent application with the publication number CN115928256A discloses a preparation method of a spandex fiber with low resistance, which is characterized in that conductive nanoparticles are added to the spandex spinning dope, and finally 40D low-resistance conductive fibers are prepared by dry spinning. Its method steps are cumbersome, it can be antistatic, but the elongation elastic recovery force is poor. Summary of the Invention

[0005] In view of the deficiencies of the existing technology, the present invention provides a uniform conductive spandex fiber and a preparation method thereof. The spandex dope is modified by adding a conductive agent, and the spandex conductive fiber is obtained through dry spinning technology. Then, the conductive performance is further improved by post-treating the fiber with a conductive polymer material. Due to the coordination effect between the conductive layer and the coating layer, its antistatic effect is greatly enhanced, and spandex fibers with more excellent conductive effects are obtained, and the preparation method is simple.

[0006] The technical solution for the present invention to solve the above technical problems is as follows: A preparation method of a uniform conductive spandex fiber, and the preparation method is as follows:

[0007] S1. Preparation of initial spandex fiber:

[0008] During the preparation of the spandex fiber polymerization stock solution, a conductive agent is added, and then the initial spandex fiber is obtained by dry spinning. The particle size of the conductive agent is 50 nm - 1000 nm;

[0009] S2. Post-treatment operation:

[0010] The initial spandex fiber is soaked in an Fe 3+ aqueous solution, and then soaked in a mixed aqueous solution containing a conductive organic polymer monomer and p-toluenesulfonic acid for in-situ polymerization reaction. The initial spandex fiber is subjected to a stretching operation during the soaking process in the mixed aqueous solution;

[0011] After the soaking is completed, washing, drying, and stretching and shaping are carried out to obtain the conductive spandex fiber.

[0012] Further, the specific operation of step S1 is as follows:

[0013] S1.1. Under the protection of an inert gas, polytetramethylene ether glycol and 4,4-diphenylmethane diisocyanate are stirred and mixed to form a prepolymer;

[0014] S1.2. DMAC is added to the prepolymer for dilution, and then a chain extender and a chain terminator are added to obtain an extended solution;

[0015] S1.3. An antioxidant, an anti-ultraviolet agent, an anti-yellowing agent, and a conductive agent are added to the extended solution and stirred to obtain a modified spandex fiber polymerization stock solution;

[0016] S1.4. The modified spandex fiber polymerization stock solution is filtered, DMAC is removed through a channel, and spinning is carried out to obtain the initial spandex fiber.

[0017] Further, the chain extender is a diamine; the terminator is a monoamine;

[0018] The antioxidant is at least one of BHT and BHA;

[0019] The anti-ultraviolet agent is at least one of Tinuvin 328 and Tinuvin 234;

[0020] The anti-yellowing agent is at least one of Tinuvin 622 and Irganox 1010;

[0021] The conductive agent is at least one of single-walled carbon nanotubes, multi-walled carbon nanotubes, carbon black, and graphene oxide. The conductive agent is used after being treated by high-pressure microfluidization.

[0022] Further, by weight parts, 50 - 75 parts of polytetramethylene ether glycol, 20 - 30 parts of 4,4 - diphenylmethane diisocyanate, 2 - 5 parts of chain extender, 1 - 1.5 parts of chain terminator, 0.1 - 1 part of antioxidant, 0.1 - 1 part of ultraviolet absorber, 0.1 - 1 part of anti - yellowing agent, 0.1 - 1 part of conductive agent.

[0023] Further, when preparing the prepolymer in step S1.1, control the temperature at 60 - 95 °C and the stirring time at 1 - 2 h;

[0024] When preparing the chain - extending solution in step S1.2, control the temperature at 5 - 15 °C and the viscosity at 3000 - 6000 poise;

[0025] When preparing the spandex fiber polymerization dope in step S1.3, control the temperature at 60 - 85 °C and the viscosity at 1500 - 3000 poise.

[0026] Further, the conditions for dry spinning are: the inlet air temperature is 38 - 42 °C, the upper return air temperature is 48 - 52 °C, the spinning temperature is 226 - 234 °C, and the spinning speed is 235 - 245 m / min.

[0027] Further, the Fe 3+ concentration of Fe in the aqueous solution is 0.05 - 0.6 mol / L, and the ratio of the concentration of Fe in the Fe 3+ aqueous solution to the concentration of the conductive organic polymer monomer in the mixed aqueous solution is 1:(1 - 3); the ratio of the concentration of the conductive organic polymer monomer in the mixed aqueous solution to the concentration of p - toluenesulfonic acid is 1:(0.95 - 1.05). 3+ aqueous solution of Fe 3+ Further, the draw ratio during the drawing operation of the initial spandex fiber during soaking in the mixed aqueous solution is 1.1 - 1.5;

[0028] The temperature of the in - situ polymerization reaction is 0 - 5 °C, and the reaction time is 60 - 240 min.

[0029] Further, the conductive organic polymer monomer is at least one of aniline and pyrrole;

[0030] The drying temperature is 40 - 60 °C, and the drying time is 1 - 3 hours.

[0031] The present invention also discloses a uniform conductive spandex fiber, and the conductive spandex fiber is prepared according to the preparation method described in the present invention.

[0032] The beneficial effects of the present invention are:

[0033] The beneficial effects of the present invention are:

[0034] The present invention discloses a uniform conductive spandex fiber. By adding a conductive agent to the spinning dope and then in-situ polymerizing a conductive polymer on the outside, there is a synergistic effect between the conductive agent and the outer conductive polymer, greatly enhancing its antistatic effect. This enables the spandex fiber, an elastic fiber, to have high electrical conductivity while maintaining high elongation and high resilience. The fabric made of the conductive spandex fiber of the present invention has good antistatic performance and has great application potential in wearable smart fabrics such as health movement monitoring, and has a broad market prospect.

[0035] In the preparation process of the spandex fiber spinning dope of the present invention, a conductive agent with a suitable particle size treated by high-pressure microfluidization is added, so that the conductive agent is uniformly dispersed in the spandex fiber. Thus, while the spandex fiber maintains good strength, the conductive agent is evenly distributed on the surface of the initial spandex fiber, which is more conducive to the in-situ polymerization of conductive organic polymer monomers on the surface of the initial spandex fiber. Coupled with a suitable drawing operation during the in-situ polymerization process, the conductive polymer is uniformly and stably attached to the conductive spandex fiber. The conductive spandex fiber has excellent mechanical strength and electrical conductivity, and the conductive polymer will not fall off after being subjected to external stretching, friction or solvent erosion, significantly enhancing the durability of the conductive spandex fiber. At the same time, the addition of the conductive agent in the conductive spandex fiber and the conductive polymer layer attached to the surface cooperate with each other, making the electrical conductivity of the conductive spandex fiber more continuous. The synergistic effect between the two greatly enhances its antistatic effect, and at the same time can effectively improve the flexibility and recoverable deformation and other properties of the spandex fiber. The preparation process of this method is simple and the cost is low. Brief Description of the Drawings

[0036] Figure 1 It is a micrograph of the conductive spandex fiber prepared in Example 1. Detailed Description of the Invention

[0037] The following makes a detailed description of the specific embodiments of the present invention. The present invention can be implemented in many other ways different from those described herein. Those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used are only for describing specific embodiments and do not limit the present invention.

[0039] A method for preparing a uniform conductive spandex fiber, the preparation method is as follows:

[0040] S1. Preparation of initial spandex fiber:

[0041] During the preparation of the polyurethane elastic fiber polymerization stock solution, a conductive agent is added, and then the initial polyurethane elastic fiber is obtained by dry spinning. The particle size of the conductive agent is 50nm - 1000nm;

[0042] S2. Post-treatment operation:

[0043] The initial polyurethane elastic fiber is soaked in an aqueous solution of Fe 3+ After that, it is soaked in a mixed aqueous solution containing a conductive organic polymer monomer and p-toluenesulfonic acid for in-situ polymerization reaction. During the soaking process of the initial polyurethane elastic fiber in the mixed aqueous solution, a stretching operation is carried out;

[0044] After the soaking is completed, washing, drying, and stretching and shaping are carried out to obtain the conductive polyurethane elastic fiber.

[0045] Specifically, the specific operation of step S1 is as follows:

[0046] S1.1. Under the protection of an inert gas, polytetramethylene ether glycol (PTMEG) and 4,4-diphenylmethane diisocyanate (MDI) are stirred and mixed to form a prepolymer;

[0047] S1.2. DMAC is added to the prepolymer for dilution, and then a chain extender and a chain terminator are added to obtain an extended solution;

[0048] S1.3. An antioxidant, an anti-ultraviolet agent, an anti-yellowing agent, and a conductive agent are added to the extended solution and stirred to obtain a modified polyurethane elastic fiber polymerization stock solution;

[0049] S1.4. The modified polyurethane elastic fiber polymerization stock solution is filtered, DMAC is removed through a channel, and then spun to obtain the initial polyurethane elastic fiber.

[0050] Specifically, the chain extender is a diamine; the terminator is a monoamine;

[0051] The antioxidant is at least one of BHT (2,6-di-tert-butyl-p-cresol) and BHA (butylated hydroxyanisole);

[0052] The anti-ultraviolet agent is at least one of Tinuvin 328 and Tinuvin 234;

[0053] The anti-yellowing agent is at least one of Tinuvin 622 and Irganox 1010;

[0054] The conductive agent is at least one of single-walled carbon nanotubes, multi-walled carbon nanotubes, carbon black, and graphene oxide. The conductive agent is used after being treated by high-pressure microfluidization.

[0055] More specifically, the high-pressure microfluidization treatment conditions are: conductive agent concentration of 0.5-1wt%, pressure of 100-300 MPa, temperature of 40-60°C, and 3-5 cycles.

[0056] More specifically, the diamine is selected from one or more of ethylenediamine, propylenediamine, butylenediamine, pentanediamine and isomers thereof;

[0057] The monoamine is selected from one or more of diethylamine, dipropylamine, dibutylamine, cyclohexylamine and ethanolamine.

[0058] Specifically, according to the weight parts, polytetramethylene ether glycol is 50-75 parts, 4,4-diphenylmethane diisocyanate is 20-30 parts, chain extender is 2-5 parts, chain terminator is 1-1.5 parts, antioxidant is 0.1-1 parts, anti-ultraviolet agent is 0.1-1 parts, anti-yellowing agent is 0.1-1 parts, and conductive agent is 0.1-1 parts.

[0059] More specifically, the weight average molecular weight of the polytetramethylene ether glycol used in the embodiments of the present invention is 1700-2000.

[0060] Specifically, when preparing the prepolymer in step S1.1, the temperature is controlled to be 60-95° C. and the stirring time is 1-2 h;

[0061] Step S1.2: When preparing the chain extension solution, the temperature is controlled at 5-15°C, and the viscosity is controlled at 3000-6000 poise (viscosity data tested at 25°C);

[0062] In step S1.3, when preparing the spandex fiber polymerization stock solution, the temperature is controlled at 60-85° C., and the viscosity is controlled at 1500-3000 poise (viscosity data tested at 25° C.).

[0063] Specifically, the dry spinning conditions are: inlet air temperature is 38-42°C, upper return air temperature is 48-52°C, spinning temperature is 226-234°C, and spinning speed is 235-245 m / min.

[0064] More specifically, in the embodiment of the present invention, the initial spandex fiber prepared in step S1.4 is 40 denier yarn.

[0065] Specifically, the Fe 3+ Fe in aqueous solution 3+ The concentration is 0.05-0.6 mol / L, Fe 3+ Fe in aqueous solution 3+ The ratio of the concentration of the conductive organic polymer monomer in the mixed aqueous solution to the concentration of the conductive organic polymer monomer in the mixed aqueous solution is 1: (1-3); the ratio of the concentration of the conductive organic polymer monomer in the mixed aqueous solution to the concentration of p-toluenesulfonic acid is 1: (0.95-1.05).

[0066] To increase the conductivity of a conductive organic polymer, some defects must be introduced into the conjugated structure of the organic polymer, that is, electrons are removed (oxidation) or inserted (reduction) from the polymer chain. This process is called doping. Therefore, the key to its conductivity lies in doping. The essence of doping is the charge transfer or redox reaction between the polymer chain with a conjugated structure and the dopant. Generally, oxidizing dopants, such as metal salts (FeCl 3 ), have a charge transfer doping mechanism. When using such a dopant to dope a conductive polymer, the polymer chain donates or accepts electrons, and at this time, the dopant is reduced or oxidized, and the formed dopant ions form a complex with the conductive polymer chain to maintain electrical neutrality.

[0067] Taking the preparation of polypyrrole using iron(III) chloride (FeCl 3 ) as an oxidant as an example, the reaction proceeds according to the following equation, and a conductive polymer is formed through charge transfer.

[0068] .

[0069] Specifically, the draw ratio of the initial spandex fiber during the soaking process in the mixed aqueous solution is 1.1 - 1.5;

[0070] The temperature of the in-situ polymerization reaction is 0 - 5 °C, and the reaction time is 60 - 240 min.

[0071] Specifically, the conductive organic polymer monomer is at least one of aniline and pyrrole;

[0072] The drying temperature is 40 - 60 °C, and the drying time is 1 - 3 hours.

[0073] A uniform conductive spandex fiber, wherein the conductive spandex fiber is prepared according to the preparation method described in the present invention.

[0074] Example 1

[0075] S1. Preparation of the initial spandex fiber:

[0076] S1.1. Under nitrogen protection, 50 kg of polytetramethylene ether glycol and 25 kg of diphenylmethane diisocyanate are stirred and reacted at 60 °C for 1 h to obtain a prepolymer PPS;

[0077] S1.2. Transfer PPS to a dissolver, add 100 kg of DMAC, cool the temperature to 10 °C during this period, pour it into a reaction kettle, and dropwise add a mixed amine solution containing 2 kg of ethylenediamine and 1.5 kg of diethylamine for chain extension reaction and chain termination reaction to obtain a chain-extended solution.

[0078] S1.3. Add 1 kg of antioxidant (BHT), 0.5 kg of UV absorber (Tinuvin 328), 0.5 kg of anti-yellowing agent (Tinuvin 622), and 1 kg of conductive agent (carbon black after high-pressure microfluidization treatment, 50 nm - 1000 nm) to DMAC for grinding, then add it to the chain extension solution. After reacting and curing at 60 °C for 8 h, filter to obtain the polyurethane fiber polymerization stock solution. Remove DMAC through a channel and obtain the initial polyurethane fiber by dry spinning; the dry spinning conditions are an inlet air temperature of 40 °C, an upper return air temperature of 50 °C, a spinning temperature of 230 °C, and a spinning speed of 240 m / min.

[0079] S2. Post-treatment operation:

[0080] Dissolve FeCl 3 in water to prepare an aqueous solution of Fe 3+ with a concentration of 0.05 mol / L. Immerse the initial polyurethane fiber in the Fe 3+ aqueous solution and oscillate for 1 hour to allow the initial polyurethane fiber to absorb Fe 3+ ;

[0081] Dissolve the conductive organic polymer monomer (pyrrole) and p-toluenesulfonic acid in distilled water to obtain a mixed aqueous solution, where the concentration of the conductive organic polymer monomer is 0.15 mol / L and the concentration of p-toluenesulfonic acid is 0.15 mol / L. Put the initial polyurethane fiber soaked in the Fe 3+ aqueous solution into the mixed aqueous solution for soaking, soak at 4 °C for 1 h, and carry out an in-situ polymerization reaction, and the draw ratio during the soaking process is 1.2 times.

[0082] Wash with distilled water, dry and stretch and shape. The drying temperature is 50 °C and the drying time is 2 h to finally obtain the conductive polyurethane fiber.

[0083] Example 2

[0084] S1. Preparation of the initial polyurethane fiber:

[0085] S1.1. Under nitrogen protection, add 55 kg of polytetramethylene ether glycol and 20 kg of diphenylmethane diisocyanate, and stir and react at 60 °C for 1 h to obtain the prepolymer PPS;

[0086] Transfer PPS to a dissolver, add 100 kg of DMAC, cool the temperature to 15 °C during this period, pour it into a reaction kettle, and dropwise add a mixed amine solution containing 2 kg of ethylenediamine and 1 kg of diethylamine for chain extension reaction and chain termination reaction to obtain a chain extension solution.

[0087] S1.3. Add 1 kg of antioxidant (BHA), 0.5 kg of UV absorber (Tinuvin 234), 0.5 kg of anti-yellowing agent (Irganox 1010), and 0.5 kg of conductive agent (single-walled carbon nanotubes after high-pressure microfluidization treatment, 50 nm - 1000 nm) to DMAC for grinding, and then add it to the chain extension solution. After reacting and curing at 60 °C for 8 h, filter to obtain the polyurethane fiber polymerization stock solution. Remove DMAC through the duct and obtain the initial polyurethane fiber by dry spinning; the dry spinning conditions are an inlet air temperature of 42 °C, an upper return air temperature of 52 °C, a spinning temperature of 234 °C, and a spinning speed of 245 m / min.

[0088] S2. Post-treatment operation:

[0089] Dissolve FeCl 3 in water to prepare an aqueous solution of Fe with a concentration of 0.4 mol / L. Immerse the initial polyurethane fiber in the Fe 3+ aqueous solution and oscillate for 1 hour to allow the initial polyurethane fiber to absorb Fe 3+ ; 3+

[0090] Dissolve the conductive organic polymer monomer (aniline) and p-toluenesulfonic acid in distilled water to obtain a mixed aqueous solution, where the concentration of the conductive organic polymer monomer is 0.4 mol / L and the concentration of p-toluenesulfonic acid is 0.6 mol / L. Immerse the initial polyurethane fiber soaked in the Fe 3+ aqueous solution into the mixed aqueous solution and soak it at 4 °C for 1 h for in-situ polymerization reaction, and the draw ratio during the soaking process is 1.5 times.

[0091] Wash with distilled water, dry, and stretch and shape. The drying temperature is 60 °C and the drying time is 1 h to finally obtain the conductive polyurethane fiber.

[0092] Example 3

[0093] S1. Preparation of the initial polyurethane fiber:

[0094] Under nitrogen protection, add 75 kg of polytetramethylene ether glycol and 30 kg of diphenylmethane diisocyanate, and stir and react at 95 °C for 1 h to obtain the prepolymer PPS;

[0095] Transfer PPS to a dissolver, add 120 kg of DMAC, cool the temperature to 5 °C during this period, pour it into the reaction kettle, and dropwise add a mixed amine solution containing 5 kg of butanediamine and 1.2 kg of dipropylamine for chain extension reaction and chain termination reaction to obtain the chain extension solution.

[0096] ​S1.3. Add 0.1 kg of antioxidant (BHA), 1 kg of UV absorber (Tinuvin 328), 1 kg of anti-yellowing agent (Irganox 1010), and 0.1 kg of conductive agent (graphene oxide after high-pressure microfluidization treatment, 50 nm - 1000 nm) to DMAC for grinding, and then add it to the chain extension solution. After reacting and curing at 85 °C for 6 h, filter to obtain the polyurethane fiber polymerization stock solution. Remove DMAC through the channel and obtain the initial polyurethane fiber by dry spinning; the dry spinning conditions are an inlet air temperature of 38 °C, an upper return air temperature of 48 °C, a spinning temperature of 226 °C, and a spinning speed of 235 m / min.

[0097] S2. Post-treatment operation:

[0098] Dissolve FeCl 3 in water to prepare an aqueous solution of Fe with a concentration of 0.6 mol / L. Immerse the initial polyurethane fiber in the aqueous solution of Fe 3+ and oscillate for 1 hour to allow the initial polyurethane fiber to absorb Fe 3+ ; 3+

[0099] Dissolve the conductive organic polymer monomer (pyrrole) and p-toluenesulfonic acid in distilled water to obtain a mixed aqueous solution, where the concentration of the conductive organic polymer monomer is 0.6 mol / L and the concentration of p-toluenesulfonic acid is 0.6 mol / L. Put the initial polyurethane fiber soaked in the aqueous solution of Fe 3+ into the mixed aqueous solution for soaking, soak at 5 °C for 1 h for in-situ polymerization reaction, and the draw ratio during the soaking process is 1.1 times.

[0100] Wash with distilled water, dry and stretch and shape. The drying temperature is 40 °C and the drying time is 3 h to finally obtain the conductive polyurethane fiber.

[0101] Example 4

[0102] S1. Preparation of the initial polyurethane fiber:

[0103] S1.1. Under nitrogen protection, add 60 kg of polytetramethylene ether glycol and 25 kg of diphenylmethane diisocyanate, and stir and react at 80 °C for 1 h to obtain the prepolymer PPS;

[0104] S1.2. Transfer PPS to a dissolver, add 100 kg of DMAC, cool the temperature to 10 °C during this period, pour it into the reaction kettle, and dropwise add a mixed amine solution containing 3 kg of propanediamine and 1.2 kg of dibutylamine for chain extension reaction and chain termination reaction to obtain the chain extension solution.

[0105] S1.3. Add 0.5 kg of antioxidant (BHT), 0.1 kg of UV absorber (Tinuvin 328), 0.1 kg of anti-yellowing agent (Irganox 1010), and 0.5 kg of conductive agent (multi-walled carbon nanotubes after high-pressure microfluidization treatment, 50 nm - 1000 nm) into DMAC for grinding, and then add it to the chain extender solution. After reacting and curing at 80 °C for 8 h, filter to obtain the polyurethane fiber polymerization stock solution. Remove DMAC through the duct and obtain the initial polyurethane fiber by dry spinning; the dry spinning conditions are an inlet air temperature of 40 °C, an upper return air temperature of 50 °C, a spinning temperature of 230 °C, and a spinning speed of 240 m / min.

[0106] S2. Post-treatment operation:

[0107] Dissolve FeCl 3 in water to prepare an aqueous solution of Fe with a concentration of 0.2 mol / L. Immerse the initial polyurethane fiber in the aqueous solution of Fe 3+ and oscillate for 1 hour to allow the initial polyurethane fiber to absorb Fe 3+ ; 3+ ;

[0108] Dissolve the conductive organic polymer monomer (pyrrole) and p-toluenesulfonic acid in distilled water to obtain a mixed aqueous solution, where the concentration of the conductive organic polymer monomer is 0.2 mol / L and the concentration of p-toluenesulfonic acid is 0.2 mol / L. Put the initial polyurethane fiber soaked in the aqueous solution of Fe 3+ into the mixed aqueous solution for soaking, soak at 0 °C for 4 h, and carry out in-situ polymerization reaction, and the draw ratio during the soaking process is 1.3 times.

[0109] Wash with distilled water, dry and stretch and shape. The drying temperature is 50 °C and the drying time is 2 h to finally obtain the conductive polyurethane fiber.

[0110] Comparative Example 1

[0111] Prepare the initial polyurethane fiber by the same method as in Example 1, but in this Comparative Example 1, no post-treatment operation is performed on the initial polyurethane fiber.

[0112] Comparative Example 2

[0113] Prepare the conductive polyurethane fiber by the same method as in Example 1. The difference is that when preparing the initial polyurethane fiber in this Comparative Example 2, no conductive agent is added.

[0114] Comparative Example 3

[0115] Prepare the conductive polyurethane fiber by the same method as in Example 1. The difference is that in this Comparative Example 3, no drawing operation is performed during the soaking process when carrying out the in-situ polymerization reaction.

[0116] Comparative Example 4

[0117] The conductive spandex fibers were prepared by the same method as in Example 1, except that in this Comparative Example 4, the conductive agent used was not subjected to high-pressure microfluidization treatment.

[0118] Comparative Example 5

[0119] The conductive spandex fibers were prepared by the same method as in Example 1, except that in this Comparative Example 6, the spinning temperature in this Comparative Example 5 was 245 °C (higher than the temperature conditions defined in the present invention).

[0120] The conductive spandex fibers prepared in the above examples and comparative examples were subjected to performance tests. The specific test results are shown in Table 1 below, and the test methods involved are as follows.

[0121] Test for the conductivity of conductive spandex fibers: At 25 °C, the two ends of the conductive spandex fibers were fixed by pressing with a metal plate and left for 24 h. Then, the resistance of the fiber bundle was measured with a resistivity measuring instrument, and the conductivity of the conductive spandex fibers was obtained by dividing the resistance by the distance between the probes.

[0122] Tensile strength and elongation tests of conductive spandex fibers: The conductive spandex fibers were placed in a tensile testing machine and pulled at a speed of 20 cm / min. The strength and elongation at the moment of fracture of the conductive spandex fibers were recorded. The elongation at break = maximum elongation length / length at the time of measurement. Observe whether there is a problem of powder shedding of the fibers during the tensile test.

[0123] Table 1 Performance test data of conductive spandex fibers

[0124]

[0125] It can be seen from the data in Table 1 above that the conductive spandex fibers prepared by the preparation methods described in Examples 1 - 4 of the present invention have both good conductive properties and strength properties, and there is no problem of powder shedding. By adding a conductive agent to the spinning dope and then in-situ polymerizing a layer of conductive polymer on the outside, there is a synergistic effect between the conductive agent and the outer conductive polymer, greatly enhancing its antistatic effect. This enables the elastic spandex fibers to have high conductivity while maintaining high elongation and high resilience. The fabric made of the conductive spandex fibers described in the present invention has good antistatic properties and has great application potential in wearable smart fabrics such as health movement monitoring, and has a broad market prospect. Figure 1 is the microscopic morphology diagram of the conductive spandex fibers prepared in Example 1. From Figure 1 it can be seen that: The surface of the conductive spandex fibers prepared by the preparation method described in the present invention is very uniform and has good application properties.

[0126] It can be seen from the data comparison between Comparative Example 1 and Example 1 that if no post-treatment operation is carried out during the preparation of conductive spandex fibers, the conductivity of the fibers will decrease significantly, and the strength performance will also show a downward trend.

[0127] It can be seen from the data comparison between Comparative Example 2 and Example 1 that if no conductive agent is added during the preparation of conductive spandex fibers, both the conductivity and strength performance of the fibers will decrease, and there will be a small amount of powder dropping problem during the stretching process. In the preparation method of the present invention, a conductive agent with a suitable particle size treated by high-pressure microfluidization is added during the preparation of the spandex fiber polymerization dope, so that the conductive agent is evenly distributed on the surface of the initial spandex fiber, which not only enables the spandex fiber to maintain good strength, but also facilitates the in-situ polymerization of the conductive organic polymer monomer on the surface of the initial spandex fiber. Coupled with the appropriate stretching operation during the in-situ polymerization process, the conductive polymer is uniformly and stably attached to the conductive spandex fiber, and the conductive spandex fiber has excellent mechanical strength and conductivity. The conductive polymer will not fall off after being subjected to external stretching, friction or solvent erosion, significantly enhancing the durability of the conductive spandex fiber.

[0128] It can be seen from the data comparison between Comparative Example 3 and Example 1 that if no stretching operation is carried out during the soaking process during the in-situ polymerization reaction, the conductivity will decrease, and it will be accompanied by a decrease in tensile strength and elongation at break.

[0129] It can be seen from the data comparison between Comparative Example 4 and Example 1 that if the conductive agent is not treated by high-pressure microfluidization, the conductive agent is poorly dispersed and agglomerated, resulting in a significant decrease in conductivity, and at the same time accompanied by a decrease in tensile strength and elongation at break.

[0130] It can be seen from the data comparison between Comparative Example 5 and Example 1 that if the spinning temperature is increased to 245 °C, it will affect the properties of the filaments, and further affect the tensile strength and elongation at break.

[0131] The technical features of the above-mentioned embodiments can be combined arbitrarily. For the sake of brevity of description, all possible combinations of the various technical features in the above-mentioned embodiments are not exhaustively listed. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.

[0132] For those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. The protection scope of the present invention shall be subject to the appended claims.

Claims

1. A method for preparing a uniform conductive spandex fiber, characterized in that: The preparation method is: S1. Preparation of initial spandex fiber: A conductive agent is added during the preparation of the spandex fiber polymerization solution, and then the initial spandex fiber is obtained by dry spinning, wherein the particle size of the conductive agent is 50nm-1000nm; The conductive agent is at least one of single-layer carbon nanotubes, multi-layer carbon nanotubes, carbon black, and graphene oxide, and the conductive agent is used after being treated with high-voltage microfluidization; S2. Post-processing operations: The initial spandex fiber was soaked in Fe 3+ aqueous solution, and then immersed in a mixed aqueous solution containing a conductive organic polymer monomer and p-toluenesulfonic acid to carry out an in-situ polymerization reaction, wherein the initial spandex fiber is subjected to a drafting operation during the immersion in the mixed aqueous solution; After the soaking is completed, the conductive spandex fiber is washed, dried, stretched and shaped to obtain the conductive spandex fiber.

2. The method for preparing a uniform conductive spandex fiber according to claim 1, characterized in that: The specific operations of step S1 are: S1.

1. Under the protection of inert gas, polytetramethylene ether glycol and 4,4-diphenylmethane diisocyanate are stirred and mixed to prepare a prepolymer; S1.2, adding DMAC to the prepolymer for dilution, and then adding a chain extender and a chain terminator to obtain a chain extension solution; S1.3, adding an antioxidant, an anti-ultraviolet agent, an anti-yellowing agent and a conductive agent to the chain extension solution and stirring to obtain a modified spandex fiber polymerization stock solution; S1.4, filtering the modified spandex fiber polymerization stock solution, removing DMAC through a channel, spinning, and obtaining initial spandex fibers.

3. The method for preparing a uniform conductive spandex fiber according to claim 2, characterized in that: The chain extender is a diamine; the terminator is a monoamine; The antioxidant is at least one of BHT and BHA; The anti-ultraviolet agent is at least one of Tinuvin 328 and Tinuvin 234; The anti-yellowing agent is at least one of Tinuvin 622 and Irganox 1010.

4. The method for preparing a uniform conductive spandex fiber according to claim 2, characterized in that: Calculated by weight, the ingredients include 50-75 parts of polytetramethylene ether glycol, 20-30 parts of 4,4-diphenylmethane diisocyanate, 2-5 parts of chain extender, 1-1.5 parts of chain terminator, 0.1-1 parts of antioxidant, 0.1-1 parts of anti-ultraviolet agent, 0.1-1 parts of anti-yellowing agent and 0.1-1 parts of conductive agent.

5. The method for preparing a uniform conductive spandex fiber according to claim 2, characterized in that: When preparing the prepolymer in step S1.1, the temperature is controlled at 60-95°C and the stirring time is 1-2h; In step S1.2, when preparing the chain extension solution, the temperature is controlled at 5-15°C and the viscosity is controlled at 3000-6000 poise; In step S1.3, when preparing the spandex fiber polymerization stock solution, the temperature is controlled at 60-85° C. and the viscosity is controlled at 1500-3000 poise.

6. The method for preparing a uniform conductive spandex fiber according to claim 1, characterized in that: The dry spinning conditions are: inlet air temperature is 38-42°C, upper return air temperature is 48-52°C, spinning temperature is 226-234°C, and spinning speed is 235-245m / min.

7. The method for preparing a uniform conductive spandex fiber according to claim 1, characterized in that: The Fe 3+ Fe in aqueous solution 3+ The concentration is 0.05-0.6 mol / L, Fe 3+ Fe in aqueous solution 3+ The ratio of the concentration of the conductive organic polymer monomer in the mixed aqueous solution to the concentration of the conductive organic polymer monomer in the mixed aqueous solution is (1-3):1; the ratio of the concentration of the conductive organic polymer monomer in the mixed aqueous solution to the concentration of p-toluenesulfonic acid is 1:(1-1.5).

8. The method for preparing a uniform conductive spandex fiber according to claim 1, characterized in that: The drafting ratio of the initial spandex fiber during the drafting operation during the soaking in the mixed aqueous solution is 1.1-1.5; The temperature of the in-situ polymerization reaction is 0-5°C, and the reaction time is 60-240min.

9. The method for preparing a uniform conductive spandex fiber according to claim 1, characterized in that: The conductive organic polymer monomer is at least one of aniline and pyrrole; The drying temperature is 40-60° C., and the drying time is 1-3 hours.

10. A uniform conductive spandex fiber, characterized in that: The conductive spandex fiber is prepared according to the preparation method according to any one of claims 1 to 9.

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