Composite vortex spun core-spun yarn and method for manufacturing the same

Abstract

The application relates to a composite vortex spinning core yarn and a preparation method thereof, and belongs to the technical field of textiles; a high-molecular antistatic agent is prepared, the high-molecular antistatic agent can be coated on the surface of nano titanium dioxide, and a core-shell microphase structure is formed. After the nano titanium dioxide-high-molecular antistatic agent core-shell dispersion liquid is used for modifying spandex fibers, due to the influence of thermodynamic driving force, a microphase arrangement of the nano titanium dioxide as the core, the high-molecular antistatic agent as the interface phase and the spandex fibers as the continuous phase will be formed in the modified spandex fibers to minimize the interfacial tension, the arrangement mode effectively reduces the modulus mutation between the microphases, effectively improves the interfacial stress transmission efficiency between the microphases in the modified spandex fibers, significantly improves the initial modulus of the modified spandex fibers, and inhibits the stress relaxation and creep of the modified spandex fibers, so that the tension fluctuation of the modified spandex fibers in the vortex spinning process is reduced.

Description

Technical Field

[0001] This invention belongs to the field of textile technology, specifically relating to a composite vortex-spun core-spun yarn and its preparation method. Background Technology

[0002] Vortex-spun core-spun yarn is a composite yarn formed by wrapping short fibers around the surface of continuous filaments using air-jet vortex spinning technology. The core filament provides structural strength and functionality, while the outer fibers determine the yarn's hand feel, appearance, and moisture absorption. Among these, vortex-spun elastic core-spun yarn, with spandex filament as the core and regenerated cellulose fiber as the outer fiber, has broad application prospects in underwear, casual wear, and sportswear due to its combination of comfortable elasticity, soft hand feel, and good moisture absorption.

[0003] In the actual production and application of spandex fiber in eddy spinning core-spun yarn, the volume resistivity of spandex is typically as high as 10⁻⁶. 10 ~10 12 Ω·cm, spandex is a typical high-insulation material. During the high-speed spinning process of eddy spinning, when spandex filaments are unwound from the yarn cake, they rub violently against metal parts such as guide hooks and guide rollers, generating and accumulating a large amount of static charge. This static charge is difficult for spandex to dissipate on its own, and the charged spandex filaments vibrate laterally due to the electric field force on the unwinding path, resulting in violent fluctuations in pre-tension tension; the charged filaments easily attract short fibers, fly ash, and dust from the workshop air, forming sudden yarn defects; at the inlet of the spinning nozzle, the charged core filaments disrupt the orderly aggregation of the outer short fiber slivers, causing disordered fiber arrangement and uneven wrapping, ultimately leading to serious defects in the finished yarn such as exposed core and hollow slub segments.

[0004] Furthermore, the yarn formation mechanism of jet vortex spinning dictates that the wrapping of the core yarn by the outer fiber is completed only within an extremely short nozzle, and the wrapping structure is a true twist structure consisting of a parallel core layer and a helical winding layer. This process requires the spandex core yarn to maintain highly stable tension and precise centering throughout its entire path from the feed roller nip to the nozzle. However, ordinary spandex has an extremely low initial modulus, and under continuous pre-drafting, the tension of the spandex yarn gradually decreases over time, resulting in poor dimensional stability and easy deviation from the geometric center of the fiber sliver. Once the core yarn is eccentric, the outer fiber cannot achieve symmetrical and uniform wrapping during vortex twisting, and the incidence of core-exposed defects increases sharply. To solve the above technical defects, this invention provides a composite vortex-spun core-spun yarn and its preparation method. Summary of the Invention

[0005] The purpose of this invention is to provide a composite vortex-spun core-spun yarn and its preparation method, in order to solve the problems mentioned in the background art.

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

[0007] A method for preparing composite vortex-spun core-spun yarn includes the following steps:

[0008] Step 1: Mix 2-chloroethyl acrylate, 4,7-dihydroxy-1,10-phenanthroline, potassium carbonate, and N,N-dimethylacetamide in a reaction vessel and react at 80-120℃ for 2-4 hours. After the reaction is completed, cool the reaction solution to room temperature and pour it into deionized water to precipitate. After filtering and separating the precipitate, wash the precipitate with deionized water and dry it to obtain the antistatic agent precursor.

[0009] The reaction process is as follows:

[0010]

[0011] The second step involves mixing the antistatic agent precursor, phosphorus oxychloride, and triethylamine in a reaction vessel and reacting them at 60–90°C for 2–6 hours. After the reaction is complete, the reaction solution is cooled to room temperature and poured into deionized water to precipitate. The precipitate is then separated by filtration, washed with deionized water, and dried to obtain the antistatic agent.

[0012] The reaction process is as follows:

[0013]

[0014] The third step involves mixing the antistatic agent, polymeric monomer, initiator, and N,N-dimethylacetamide in a reaction vessel under nitrogen protection and reacting at 70–90°C for 3–6 hours to obtain a polymeric antistatic agent. Then, nano-titanium dioxide is added to the system and the reaction continues at 70–90°C for 1–2 hours. After the reaction is completed, the reaction solution is cooled to room temperature to obtain a nano-titanium dioxide-polymeric antistatic agent core-shell dispersion.

[0015] Step 4: Mix the nano-titanium dioxide-polymer antistatic agent core-shell dispersion and spandex spinning solution and obtain modified spandex fiber by dry spinning;

[0016] Step 5: Using modified spandex fiber as the core yarn and regenerated cellulose fiber as the outer yarn, the modified spandex fiber is pre-stretched and then spun through a vortex spinning process to obtain a composite vortex-spun core-spun yarn.

[0017] Furthermore, the polymerizable monomer is one or a mixture of poly(ethylene glycol) methyl ether methacrylate, poly(propylene glycol) methyl ether acrylate, butyl acrylate, ethyl acrylate, methyl methacrylate, and ethylhexyl acrylate.

[0018] Furthermore, the initiator is one or a mixture of azobisisobutyronitrile and benzoyl peroxide.

[0019] Furthermore, the spandex spinning solution contains the following raw materials in parts by weight: 40-60 parts of polytetramethylene ether glycol, 20-35 parts of 4,4'-diphenylmethane diisocyanate, 4-10 parts of 1,3-propanediamine, 0.5-1.5 parts of n-butanol, and 150-250 parts of N,N-dimethylacetamide.

[0020] Furthermore, the parameters for the dry spinning process are as follows: spinning tunnel temperature 200–250℃, spinning speed 350–600 m / min, and winding draw ratio 1.5–2.0.

[0021] Furthermore, the regenerated cellulose fiber is at least one of viscose fiber, modal fiber, and lyocell fiber.

[0022] Furthermore, the pre-stretching parameters are: pre-stretching ratio 2.5 to 4.0, and feed tension 0.05 to 0.12 cN / dtex.

[0023] Furthermore, the parameters of the vortex spinning process are as follows: spinning nozzle air pressure 0.55-0.75 MPa, short fiber sliver weight 13-16 g / 5m, spinning speed 380-550 m / min, and draft ratio 150-250.

[0024] Furthermore, the mass ratio of 2-chloroethyl acrylate, 4,7-dihydroxy-1,10-phenanthroline, potassium carbonate, and N,N-dimethylacetamide used is 2.6:4.1-5.7:2.8-5.6:28-36.

[0025] Furthermore, the mass ratio of the antistatic agent precursor, phosphorus oxychloride, and triethylamine used is 5:15-21:1.6-2.4.

[0026] Furthermore, the mass ratio of the antistatic agent, polymeric monomer, initiator, N,N-dimethylacetamide, and nano-titanium dioxide used is 1–1.5: 8–15: 0.05–0.15: 30–50: 2–5.

[0027] Furthermore, the mass ratio of the nano-titanium dioxide-polymer antistatic agent core-shell dispersion and the spandex spinning solution used is 5-15:100.

[0028] Furthermore, the mass ratio of modified spandex fiber to regenerated cellulose fiber used is 5–15:85–95.

[0029] The present invention also provides a composite vortex-spun core-spun yarn prepared by the above steps.

[0030] In summary, the present invention has at least the following beneficial effects:

[0031] 1) This invention prepares a polymeric antistatic agent that can form a dual anchoring effect of covalent and coordinate bonds on the surface of matting agent nano-titanium dioxide, thereby coating the nano-titanium dioxide and ultimately forming an inorganic-organic core-shell microphase structure. Furthermore, the polymeric antistatic agent of this invention has a polyacrylate backbone structure, and polyacrylate has excellent compatibility with spandex fibers. Based on this, the nano-titanium dioxide-polymeric antistatic agent core-shell dispersion structure constructed in this invention effectively solves the problem of nano-titanium dioxide agglomeration in spinning solution and fibers.

[0032] 2) The polymeric antistatic agent prepared in this invention can coat the surface of nano-titanium dioxide and form a core-shell microphase structure. The polymeric antistatic agent is fixed to the surface of nano-titanium dioxide, forming a permanent ion-conducting shell without migration loss. Furthermore, the high dielectric environment of the nano-titanium dioxide surface can more effectively promote the polarization and dissociation of the conductive matrix in the polymeric antistatic agent, increasing the concentration of ion carriers. The coordination bonds formed between the polymeric antistatic agent and the nano-titanium dioxide surface can further promote interfacial charge transfer between the nano-titanium dioxide phase and the polymeric antistatic agent phase, reducing interfacial contact resistance. Based on this, the nano-titanium dioxide-polymeric antistatic agent core-shell dispersion structure constructed in this invention effectively improves the antistatic properties of modified spandex fibers.

[0033] 3) The polymeric antistatic agent prepared in this invention can coat the surface of nano-titanium dioxide and form a core-shell microphase structure. After modifying spandex fibers using this nano-titanium dioxide-polymeric antistatic agent core-shell dispersion, due to the influence of thermodynamic driving force, a microphase arrangement will be formed in the modified spandex fibers, with nano-titanium dioxide as the core, polymeric antistatic agent as the interface phase, and spandex fiber as the continuous phase, to minimize interfacial tension. This arrangement effectively reduces the modulus abrupt change between microphases and effectively improves the interfacial stress transfer efficiency between the microphases inside the modified spandex fiber. On this basis, the antistatic agent monomer in the prepared polymeric antistatic agent can further improve the physical interaction force between spandex fiber and polymeric antistatic agent. Improving the physical interaction force between spandex fiber and polymeric antistatic agent can enhance the physical crosslinking points between the spandex fiber molecular network, thereby significantly improving the initial modulus of the modified spandex fiber and inhibiting the stress relaxation and creep of the modified spandex fiber, thus reducing the tension fluctuation of the modified spandex fiber during eddy spinning. Based on this, the microphase arrangement constructed in this invention, with nano-titanium dioxide as the core, polymeric antistatic agent as the interface phase, and spandex fiber as the continuous phase, effectively stabilizes the tension change of modified spandex fiber during eddy spinning, reduces the offset of modified spandex fiber during eddy spinning, and thus improves the coverage rate of outer fiber on the surface of modified spandex fiber, significantly reducing defects on the surface of finished yarn caused by core exposure and uneven wrapping.

[0034] 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

[0035] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0036] In a specific embodiment of the present invention, the spandex spinning solution is prepared by the following steps:

[0037] S1. By mass, 40-60 parts of polytetramethylene ether glycol with a molecular weight of 1800-2200 and 20-35 parts of 4,4'-diphenylmethane diisocyanate are mixed and reacted at a temperature of 70-85°C for 2-3 hours to obtain an isocyanate-terminated prepolymer.

[0038] S2. By mass, add 30-50% of N,N-dimethylacetamide (150-250 parts) to the isocyanate-terminated prepolymer obtained in S1 for dilution and dissolution. Then, add 4-10 parts of 1,3-propanediamine and 0.5-1.5 parts of n-butanol to the system. Control the system temperature within the range of 15-25°C and react at this temperature for 1-2 hours to obtain a polyurethane urea solution.

[0039] S3. By mass fraction, add the remaining N,N-dimethylacetamide to the polyurethane urea solution obtained in S2 and mature it at a temperature of 40-60℃ for 4-8 hours. After vacuum degassing, the spandex spinning solution is obtained.

[0040] In a specific embodiment of the present invention, the method for preparing the composite vortex-spun core-spun yarn includes the following steps:

[0041] Step 1: By mass, 2.6 parts of 2-chloroethyl acrylate, 4.1-5.7 parts of 4,7-dihydroxy-1,10-phenanthroline, 2.8-5.6 parts of potassium carbonate, and 28-36 parts of N,N-dimethylacetamide are mixed in a reaction vessel and reacted at 80-120℃ for 2-4 hours. After the reaction is completed, the reaction solution is cooled to room temperature and poured into deionized water to precipitate. After filtering to separate the precipitate, the precipitate is washed with deionized water and dried to obtain the antistatic agent precursor.

[0042] Step 2: According to the mass fraction, mix 5 parts of antistatic agent precursor, 15-21 parts of phosphorus oxychloride, and 1.6-2.4 parts of triethylamine in a reaction vessel and react at a temperature of 60-90℃ for 2-6 hours. After the reaction is completed, cool the reaction solution to room temperature and pour it into deionized water to precipitate. After filtering and separating the precipitate, wash the precipitate with deionized water and dry it to obtain the antistatic agent.

[0043] The antistatic agent prepared by this invention has acrylate structure, phenanthroline structure, phosphoric acid structure and ether bond structure. The phosphoric acid structure in the antistatic agent of this invention can ionize to release protons, which is an excellent ion-conducting carrier. It also has reactive double bonds, which can be copolymerized with polymeric monomers under the action of an initiator to form a polymeric antistatic agent with polyacrylate as the backbone.

[0044] Step 3: By mass, under nitrogen protection, mix 1-1.5 parts of antistatic agent, 8-15 parts of polymeric monomer, 0.05-0.15 parts of initiator, and 30-50 parts of N,N-dimethylacetamide in a reaction vessel and react at 70-90℃ for 3-6 hours to obtain a polymeric antistatic agent. Then, add 2-5 parts of nano-titanium dioxide to the system and continue the reaction at 70-90℃ for 1-2 hours. After the reaction is completed, cool the reaction solution to room temperature to obtain a nano-titanium dioxide-polymeric antistatic agent core-shell dispersion.

[0045] The phosphate structure in the polymeric antistatic agent prepared by this invention can react with the hydroxyl groups on the surface of nano-titanium dioxide to form a stable covalent bond as the first anchoring. Meanwhile, the dinitrogen structure of the phenanthroline structure can form a stable five-membered ring chelate coordination bond with the titanium atoms on the surface of nano-titanium dioxide as the second anchoring. This dual anchoring method can more effectively deconstruct nano-titanium dioxide aggregates, improve the dispersibility of nano-titanium dioxide, reduce the number of defects between nano-titanium dioxide and polymeric antistatic agent, and finally form a core-shell microphase structure with nano-titanium dioxide as the core and polymeric antistatic agent as the shell.

[0046] Step 4: Mix 5-15 parts by weight of nano-titanium dioxide-polymer antistatic agent core-shell dispersion and 100 parts by weight of spandex spinning solution and feed them into a dry spinning system. Spin at a tunnel temperature of 200-250℃ to obtain modified spandex fiber. Dry spinning parameters: spinning speed 350-600m / min, winding draw ratio 1.5-2.0.

[0047] The modified spandex fiber produced by this invention contains a core-shell microphase system composed of a polymeric antistatic agent and nano-titanium dioxide. The anchoring effect of nano-titanium dioxide on the polymeric antistatic agent can effectively prevent the migration and loss of the polymeric antistatic agent. In addition, the high dielectric environment on the surface of nano-titanium dioxide can more effectively promote the polarization and dissociation of phosphate groups in the polymeric antistatic agent, increasing the concentration of ion carriers. The phenanthroline structure in the polymeric antistatic agent itself has a highly delocalized π electron cloud. After forming coordinate bonds with titanium atoms on the surface of nano-titanium dioxide, the coordinate bonds can act as channels for electron coupling to further promote the interfacial charge transfer between the nano-titanium dioxide phase and the polymeric antistatic agent phase, reducing the interfacial contact resistance. The synergistic effect of phosphate groups and phenanthroline structure effectively improves the antistatic properties of the modified spandex fiber.

[0048] The polymeric antistatic agent prepared in this invention can coat the surface of nano-titanium dioxide and form a core-shell microphase structure. After modifying spandex fibers using this nano-titanium dioxide-polymeric antistatic agent core-shell dispersion, due to the influence of thermodynamic driving forces, a microphase arrangement will form in the modified spandex fibers, with nano-titanium dioxide as the core, the polymeric antistatic agent as the interface phase, and spandex fiber as the continuous phase, minimizing interfacial tension. This arrangement effectively reduces the modulus abrupt change between microphases and effectively improves the interfacial stress transfer efficiency between the microphases within the modified spandex fiber. Furthermore, the rigid large π-plane of the phenanthroline structure in the antistatic agent can generate π-π stacking with the spandex hard segments, which also contain benzene rings, while the phosphoric acid in the antistatic agent... The structure is also a very strong hydrogen bond donor, which can form strong hydrogen bond interactions with carbonyl and ether oxygen atoms in the hard and soft segments of polyurethane. Under the synergistic effect of these two groups, the physical interaction force between the polymeric antistatic agent and the spandex fiber is significantly improved. Improving the physical interaction force between the spandex fiber and the polymeric antistatic agent can enhance the physical cross-linking points between the spandex fiber molecular network, thereby effectively improving the initial modulus of the modified spandex fiber. Furthermore, these physical cross-linking points can also act as sacrificial bonds to dissipate energy during the stretching process, inhibit the stress relaxation and creep of the modified spandex fiber, and reduce the tension fluctuation of the modified spandex fiber during the eddy spinning process.

[0049] Step 5: Using 5-15 parts by weight of modified spandex fiber as the core yarn and 85-95 parts by weight of regenerated cellulose fiber as the outer yarn, the yarn is spun using an air-jet vortex spinning machine. The modified spandex fiber is unwound from the core yarn feeding device, passes through the tension device and the yarn guide, and enters the front roller nip. The feeding tension is 0.05-0.12 cN / dtex, and the pre-draft ratio is 2.5-4.0. After being drawn by the drafting mechanism, the regenerated cellulose fiber merges with the modified spandex fiber at the front roller nip and is sucked into the nozzle, exiting from the yarn guide channel to obtain a composite vortex spun core-spun yarn. The spinning nozzle air pressure is 0.55-0.75 MPa, the short fiber sliver weight is 13-16 g / 5m, the spinning speed is 380-550 m / min, and the draft ratio is 150-250.

[0050] To better understand the technical content of this invention, specific embodiments are provided below to further illustrate the invention. The substances used in these embodiments are commercially available.

[0051] Example 1

[0052] A method for preparing composite vortex-spun core-spun yarn includes the following steps:

[0053] Step 1: According to the mass fraction, 2.6 parts of 2-chloroethyl acrylate, 4.1 parts of 4,7-dihydroxy-1,10-phenanthroline, 2.8 parts of potassium carbonate, and 28 parts of N,N-dimethylacetamide were mixed in a reaction vessel and reacted at 80°C for 4 hours. After the reaction was completed, the reaction solution was cooled to room temperature and poured into deionized water to precipitate. After filtering to separate the precipitate, the precipitate was washed with deionized water and dried to obtain the antistatic agent precursor.

[0054] Step 2: According to the mass fraction, mix 5 parts of antistatic agent precursor, 15 parts of phosphorus oxychloride and 1.6 parts of triethylamine in a reaction vessel and react at 60°C for 6 hours. After the reaction is completed, cool the reaction solution to room temperature and pour it into deionized water to precipitate. After filtering and separating the precipitate, wash the precipitate with deionized water and dry it to obtain the antistatic agent.

[0055] Step 3: By mass, under nitrogen protection, 1 part antistatic agent, 4 parts poly(ethylene glycol) methyl ether methacrylate, 1 part poly(propylene glycol) methyl ether acrylate, 3 parts butyl acrylate, 0.05 parts azobisisobutyronitrile, and 30 parts N,N-dimethylacetamide are mixed in a reaction vessel and reacted at 70°C for 6 hours to obtain a polymeric antistatic agent. Then, 2 parts nano-titanium dioxide are added to the system and the reaction is continued at 70°C for 2 hours. After the reaction is completed, the reaction solution is cooled to room temperature to obtain a nano-titanium dioxide-polymeric antistatic agent core-shell dispersion.

[0056] Step 4: By mass, mix 5 parts of nano-titanium dioxide-polymer antistatic agent core-shell dispersion and 100 parts of spandex spinning solution and feed them into a dry spinning system. Spin at a tunnel temperature of 200℃ to obtain modified spandex fiber. Dry spinning parameters: spinning speed 350m / min, winding draw ratio 2.0.

[0057] Step 5: Using 5 parts by weight of modified spandex fiber as the core yarn and 95 parts by weight of viscose fiber as the outer yarn, a jet vortex spinning machine is used for spinning. The modified spandex fiber is unwound from the core yarn feeding device, passes through the tension device and the yarn guide, and enters the front roller nip. The feeding tension is 0.05 cN / dtex, and the pre-draft ratio is 2.5. After being drawn by the drafting mechanism, the viscose fiber merges with the modified spandex fiber at the front roller nip and is sucked into the nozzle, and output from the yarn guide channel to obtain a composite vortex spun core-spun yarn. The spinning nozzle air pressure is 0.75 MPa, the short fiber sliver weight is 16 g / 5 m, the spinning speed is 550 m / min, and the draft ratio is 150.

[0058] The spandex spinning solution used in this embodiment is prepared by the following steps:

[0059] S1. By mass, 40 parts of polytetramethylene ether glycol with a molecular weight specification of 1800 and 20 parts of 4,4'-diphenylmethane diisocyanate are mixed and reacted at 70°C for 3 hours to obtain an isocyanate-terminated prepolymer.

[0060] S2. By mass, add 75 parts of N,N-dimethylacetamide to the isocyanate-terminated prepolymer obtained in S1 to dilute and dissolve it. Then add 4 parts of 1,3-propanediamine and 0.5 parts of n-butanol to the system. Control the system temperature within the range of 15°C and react under this temperature condition for 2 hours to obtain a polyurethane urea solution.

[0061] S3. By mass, add 75 parts of N,N-dimethylacetamide (total 150 parts) to the polyurethane urea solution obtained in S2 and mature at 40°C for 8 hours. After vacuum degassing, the spandex spinning solution is obtained.

[0062] A composite vortex-spun core-spun yarn prepared by the above steps.

[0063] Example 2

[0064] A method for preparing composite vortex-spun core-spun yarn includes the following steps:

[0065] Step 1: According to the mass fraction, 2.6 parts of 2-chloroethyl acrylate, 4.9 parts of 4,7-dihydroxy-1,10-phenanthroline, 4.2 parts of potassium carbonate, and 32 parts of N,N-dimethylacetamide were mixed in a reaction vessel and reacted at 80℃ for 4 hours. After the reaction was completed, the reaction solution was cooled to room temperature and poured into deionized water to precipitate. After filtering to separate the precipitate, the precipitate was washed with deionized water and dried to obtain the antistatic agent precursor.

[0066] Step 2: According to the mass fraction, mix 5 parts of antistatic agent precursor, 18 parts of phosphorus oxychloride and 2.0 parts of triethylamine in a reaction vessel and react at 75°C for 4 hours. After the reaction is completed, cool the reaction solution to room temperature and pour it into deionized water to precipitate. After filtering and separating the precipitate, wash the precipitate with deionized water and dry it to obtain the antistatic agent.

[0067] Step 3: By mass, under nitrogen protection, 1.2 parts of antistatic agent, 5 parts of methyl methacrylate, 3 parts of ethyl acrylate, 2 parts of butyl acrylate, 0.10 parts of benzoyl peroxide, and 40 parts of N,N-dimethylacetamide are mixed in a reaction vessel and reacted at 80°C for 4.5 h to obtain a polymeric antistatic agent. Then, 3.5 parts of nano-titanium dioxide are added to the system and the reaction is continued at 80°C for 1.5 h. After the reaction is completed, the reaction solution is cooled to room temperature to obtain a nano-titanium dioxide-polymeric antistatic agent core-shell dispersion.

[0068] Step 4: By mass, mix 10 parts of nano-titanium dioxide-polymer antistatic agent core-shell dispersion and 100 parts of spandex spinning solution and feed them into a dry spinning system. Spin at a tunnel temperature of 225℃ to obtain modified spandex fiber. Dry spinning parameters: spinning speed 500m / min, winding draw ratio 1.75.

[0069] Step 5: Using 10 parts by weight of modified spandex fiber as the core yarn and 90 parts by weight of modal fiber as the outer yarn, a jet vortex spinning machine is used for spinning. The modified spandex fiber is unwound from the core yarn feeding device, passes through the tension device and the yarn guide, and enters the front roller nip. The feeding tension is 0.08 cN / dtex, and the pre-draft ratio is 3.2. After being drafted by the drafting mechanism, the modal fiber merges with the modified spandex fiber at the front roller nip and is sucked into the nozzle, and output from the yarn guide channel to obtain a composite vortex spun core-spun yarn. The spinning nozzle air pressure is 0.65 MPa, the short fiber sliver weight is 14 g / 5 m, the spinning speed is 460 m / min, and the draft ratio is 200.

[0070] The spandex spinning solution used in this embodiment is prepared by the following steps:

[0071] S1. By mass, 50 parts of polytetramethylene ether glycol with a molecular weight specification of 2000 and 28 parts of 4,4'-diphenylmethane diisocyanate are mixed and reacted at 78°C for 2.5 h to obtain an isocyanate-terminated prepolymer.

[0072] S2. By mass, add 80 parts of N,N-dimethylacetamide to the isocyanate-terminated prepolymer obtained in S1 to dilute and dissolve it. Then add 7 parts of 1,3-propanediamine and 1.0 part of n-butanol to the system, control the system temperature within the range of 20°C, and react at this temperature for 1.5 h to obtain a polyurethane urea solution.

[0073] S3. By mass, add 120 parts of N,N-dimethylacetamide (total 200 parts) to the polyurethane urea solution obtained in S2 and mature at 50°C for 6 hours. After vacuum degassing, the spandex spinning solution is obtained.

[0074] A composite vortex-spun core-spun yarn prepared by the above steps.

[0075] Example 3

[0076] A method for preparing composite vortex-spun core-spun yarn includes the following steps:

[0077] Step 1: According to the mass fraction, 2.6 parts of 2-chloroethyl acrylate, 5.7 parts of 4,7-dihydroxy-1,10-phenanthroline, 5.6 parts of potassium carbonate, and 36 parts of N,N-dimethylacetamide were mixed in a reaction vessel and reacted at 120℃ for 2 hours. After the reaction was completed, the reaction solution was cooled to room temperature and poured into deionized water to precipitate. After filtering to separate the precipitate, the precipitate was washed with deionized water and dried to obtain the antistatic agent precursor.

[0078] Step 2: According to the mass fraction, mix 5 parts of antistatic agent precursor, 21 parts of phosphorus oxychloride and 2.4 parts of triethylamine in a reaction vessel and react at 90°C for 2 hours. After the reaction is completed, cool the reaction solution to room temperature and pour it into deionized water to precipitate. After filtering and separating the precipitate, wash the precipitate with deionized water and dry it to obtain the antistatic agent.

[0079] Step 3: By mass percentage, under nitrogen protection, 1.5 parts of antistatic agent, 9 parts of ethylhexyl acrylate, 3 parts of poly(propylene glycol) methyl ether acrylate, 3 parts of butyl acrylate, 0.15 parts of benzoyl peroxide, and 50 parts of N,N-dimethylacetamide are mixed in a reaction vessel and reacted at 90°C for 3 hours to obtain a polymeric antistatic agent. Then, 5 parts of nano-titanium dioxide are added to the system and the reaction is continued at 90°C for 1 hour. After the reaction is completed, the reaction solution is cooled to room temperature to obtain a nano-titanium dioxide-polymeric antistatic agent core-shell dispersion.

[0080] Step 4: By mass, mix 15 parts of nano-titanium dioxide-polymer antistatic agent core-shell dispersion and 100 parts of spandex spinning solution and feed them into a dry spinning system. Spin at a tunnel temperature of 250℃ to obtain modified spandex fiber. Dry spinning parameters: spinning speed 600m / min, winding draw ratio 1.5.

[0081] Step 5: By weight, 15 parts modified spandex fiber are used as the core yarn and 85 parts lyocell fiber are used as the outer yarn. Spinning is performed using an air-jet vortex spinning machine. The modified spandex fiber is unwound from the core yarn feeding device, passes through the tension device and the yarn guide, and enters the front roller nip. The feeding tension is 0.12 cN / dtex, and the pre-draft ratio is 4.0. After being drafted by the drafting mechanism, the lyocell fiber merges with the modified spandex fiber at the front roller nip and is sucked into the nozzle. It is output from the yarn guide channel to obtain a composite vortex spun core-spun yarn. The spinning nozzle air pressure is 0.55 MPa, the short fiber sliver weight is 13 g / 5 m, the spinning speed is 380 m / min, and the draft ratio is 250.

[0082] The spandex spinning solution used in this embodiment is prepared by the following steps:

[0083] S1. By mass, 60 parts of polytetramethylene ether glycol with a molecular weight specification of 2200 and 35 parts of 4,4'-diphenylmethane diisocyanate are mixed and reacted at 85°C for 2 hours to obtain an isocyanate-terminated prepolymer.

[0084] S2. By mass, add 75 parts of N,N-dimethylacetamide to the isocyanate-terminated prepolymer obtained in S1 to dilute and dissolve it. Then add 10 parts of 1,3-propanediamine and 1.5 parts of n-butanol to the system. Control the system temperature within the range of 25°C and react at this temperature for 1 hour to obtain a polyurethane urea solution.

[0085] S3. By mass, add 175 parts of N,N-dimethylacetamide (total 250 parts) to the polyurethane urea solution obtained in S2 and mature at 60°C for 4 hours. After vacuum degassing, the spandex spinning solution is obtained.

[0086] A composite vortex-spun core-spun yarn prepared by the above steps.

[0087] Comparative Example 1

[0088] The difference between this comparative example and Example 2 is that the antistatic agent of the present invention is no longer added when preparing the polymeric antistatic agent.

[0089] A method for preparing composite vortex-spun core-spun yarn includes the following steps:

[0090] Step 1: By mass, 5 parts of methyl methacrylate, 3 parts of ethyl acrylate, 2 parts of butyl acrylate, 0.10 parts of benzoyl peroxide, and 40 parts of N,N-dimethylacetamide were mixed in a reaction vessel under nitrogen protection and reacted at 80°C for 4.5 h to obtain a polymeric antistatic agent. Then, 3.5 parts of nano-titanium dioxide were added to the system and the reaction was continued at 80°C for 1.5 h. After the reaction was completed, the reaction solution was cooled to room temperature to obtain a nano-titanium dioxide-polymeric antistatic agent core-shell dispersion.

[0091] Step 2: By mass fraction, 10 parts of nano-titanium dioxide-polymer antistatic agent core-shell dispersion and 100 parts of spandex spinning solution are mixed and fed into a dry spinning system. Modified spandex fiber is obtained by spinning at a tunnel temperature of 225℃. Dry spinning parameters: spinning speed 500m / min, winding draw ratio 1.75.

[0092] Step 3: By weight, 10 parts modified spandex fiber are used as the core yarn and 90 parts modal fiber are used as the outer yarn. Spinning is carried out using an air-jet vortex spinning machine. The modified spandex fiber is unwound from the core yarn feeding device, passes through the tension device and the yarn guide, and enters the front roller nip. The feeding tension is 0.08 cN / dtex, and the pre-draft ratio is 3.2. After being drafted by the drafting mechanism, the modal fiber merges with the modified spandex fiber at the front roller nip and is sucked into the nozzle. It is output from the yarn guide channel to obtain a composite vortex spun core-spun yarn. The air pressure of the spinning nozzle is 0.65 MPa, the short fiber sliver weight is 14 g / 5m, the spinning speed is 460 m / min, and the draft ratio is 200.

[0093] The spandex spinning solution used in this embodiment is prepared by the following steps:

[0094] S1. By mass, 50 parts of polytetramethylene ether glycol with a molecular weight specification of 2000 and 28 parts of 4,4'-diphenylmethane diisocyanate are mixed and reacted at 78°C for 2.5 h to obtain an isocyanate-terminated prepolymer.

[0095] S2. By mass, add 80 parts of N,N-dimethylacetamide to the isocyanate-terminated prepolymer obtained in S1 to dilute and dissolve it. Then add 7 parts of 1,3-propanediamine and 1.0 part of n-butanol to the system, control the system temperature within the range of 20°C, and react at this temperature for 1.5 h to obtain a polyurethane urea solution.

[0096] S3. By mass, add 120 parts of N,N-dimethylacetamide (total 200 parts) to the polyurethane urea solution obtained in S2 and mature at 50°C for 6 hours. After vacuum degassing, the spandex spinning solution is obtained.

[0097] A composite vortex-spun core-spun yarn prepared by the above steps.

[0098] Comparative Example 2

[0099] The difference between this comparative example and Example 2 is that a monomer (2-hydroxyethyl acrylate) without a phenanthroline structure was used to replace the antistatic agent precursor in the preparation of the antistatic agent.

[0100] A method for preparing composite vortex-spun core-spun yarn includes the following steps:

[0101] Step 1: According to the mass fraction, 5 parts of 2-hydroxyethyl acrylate, 18 parts of phosphorus oxychloride and 5.0 parts of triethylamine are mixed in a reaction vessel and reacted at 75°C for 4 hours. After the reaction is completed, the reaction solution is cooled to room temperature and poured into deionized water. The organic layer is separated by extraction with ethyl acetate, and the solvent is removed by rotary evaporation and then dried to obtain the antistatic agent.

[0102] Step 2: By mass percentage, under nitrogen protection, 1.2 parts of antistatic agent, 5 parts of methyl methacrylate, 3 parts of ethyl acrylate, 2 parts of butyl acrylate, 0.10 parts of benzoyl peroxide, and 40 parts of N,N-dimethylacetamide are mixed in a reaction vessel and reacted at 80°C for 4.5 h to obtain a polymeric antistatic agent. Then, 3.5 parts of nano-titanium dioxide are added to the system and the reaction is continued at 80°C for 1.5 h. After the reaction is completed, the reaction solution is cooled to room temperature to obtain a nano-titanium dioxide-polymeric antistatic agent core-shell dispersion.

[0103] The third step involves mixing 10 parts by weight of nano-titanium dioxide-polymer antistatic agent core-shell dispersion and 100 parts by weight of spandex spinning solution and feeding them into a dry spinning system. Modified spandex fiber is obtained by spinning at a tunnel temperature of 225℃. The dry spinning parameters are: spinning speed 500m / min and winding draw ratio 1.75.

[0104] Step 4: By weight, 10 parts modified spandex fiber are used as the core yarn and 90 parts modal fiber are used as the outer yarn. Spinning is carried out using an air-jet vortex spinning machine. The modified spandex fiber is unwound from the core yarn feeding device, passes through the tension device and the yarn guide, and enters the front roller nip. The feeding tension is 0.08 cN / dtex, and the pre-draft ratio is 3.2. After being drafted by the drafting mechanism, the modal fiber merges with the modified spandex fiber at the front roller nip and is sucked into the nozzle. It is output from the yarn guide channel to obtain a composite vortex spun core-spun yarn. The air pressure of the spinning nozzle is 0.65 MPa, the short fiber sliver weight is 14 g / 5m, the spinning speed is 460 m / min, and the draft ratio is 200.

[0105] The spandex spinning solution used in this embodiment is prepared by the following steps:

[0106] S1. By mass, 50 parts of polytetramethylene ether glycol with a molecular weight specification of 2000 and 28 parts of 4,4'-diphenylmethane diisocyanate are mixed and reacted at 78°C for 2.5 h to obtain an isocyanate-terminated prepolymer.

[0107] S2. By mass, add 80 parts of N,N-dimethylacetamide to the isocyanate-terminated prepolymer obtained in S1 to dilute and dissolve it. Then add 7 parts of 1,3-propanediamine and 1.0 part of n-butanol to the system, control the system temperature within the range of 20°C, and react at this temperature for 1.5 h to obtain a polyurethane urea solution.

[0108] S3. By mass, add 120 parts of N,N-dimethylacetamide (total 200 parts) to the polyurethane urea solution obtained in S2 and mature at 50°C for 6 hours. After vacuum degassing, the spandex spinning solution is obtained.

[0109] A composite vortex-spun core-spun yarn prepared by the above steps.

[0110] Experimental Example 1

[0111] The modified spandex fibers and composite eddy-spun core-spun yarns obtained in Examples 1-3 and Comparative Examples 1-2 were subjected to performance tests. The volume resistivity of each component spandex fiber was tested according to the national standard GB / T 14342-2015 "Test Method for Specific Resistance of Short Chemical Fibers". The initial modulus and breaking elongation of each component spandex fiber were tested according to the national standard GB / T 14344-2022 "Test Method for Tensile Properties of Long Chemical Fibers". The stress relaxation rate of each component spandex fiber was tested according to the national standard FZ / T 5007-2012 "Test Method for Elasticity of Spandex Yarn". The number of yarn defects of each component eddy-spun core-spun yarn was tested according to the national standard FZ / T 01050-2024 "Classification and Inspection Method for Yarn Defects - Capacitive Method". The core exposure of each component eddy-spun core-spun yarn was inspected by dyeing method, and the coverage rate was calculated. The test results are shown in Table 1.

[0112] Table 1

[0113] As shown in Table 1, the modified spandex fibers obtained in Examples 1-3 have lower volume resistivity and higher initial modulus, as well as lower stress relaxation rate. Using this modified spandex fiber, eddy-spun core-spun yarn with higher coverage and fewer defects can be produced. In Comparative Example 2, a monomer without phenanthroline structure was used to prepare the antistatic agent. It can be seen that the antistatic improvement effect of the single phosphate structure on spandex core yarn is not as good as that of Example 2, where phosphate and phenanthroline structures work synergistically. In addition, due to the lack of rigidity enhancement effect of phenanthroline structure, the modulus of the polymeric antistatic agent interface phase is significantly reduced, weakening the modulus buffering effect of the polymeric antistatic agent between nano-titanium dioxide and spandex fiber. As a result, the elongation at break of the spandex fiber in Comparative Example 2 is not as good as that in Example 2.

[0114] The descriptions of the above embodiments are merely illustrative of the methods and core ideas of the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing composite vortex-spun core-spun yarn, characterized in that, Includes the following steps: Step 1: 2-Chloroethyl acrylate, 4,7-dihydroxy-1,10-phenanthroline, potassium carbonate, and N,N-dimethylacetamide are mixed in a reaction vessel and reacted at a temperature of 80–120°C to obtain an antistatic agent precursor; The second step involves mixing the antistatic agent precursor, phosphorus oxychloride, and triethylamine in a reaction vessel and reacting them at a temperature of 60–90°C to obtain the antistatic agent. The third step involves mixing the antistatic agent, polymeric monomer, initiator, and N,N-dimethylacetamide in a reaction vessel under nitrogen protection and reacting at 70–90°C for 3–6 hours to obtain a polymeric antistatic agent. Then, nano-titanium dioxide is added to the system and the reaction continues at 70–90°C to obtain a nano-titanium dioxide-polymeric antistatic agent core-shell dispersion. Step 4: Mix the nano-titanium dioxide-polymer antistatic agent core-shell dispersion and spandex spinning solution and obtain modified spandex fiber by dry spinning; Step 5: Using modified spandex fiber as the core yarn and regenerated cellulose fiber as the outer yarn, the modified spandex fiber is pre-stretched and then spun through a vortex spinning process to obtain a composite vortex-spun core-spun yarn.

2. The method for preparing a composite vortex-spun core-spun yarn according to claim 1, characterized in that, The polymer monomer is one or a mixture of poly(ethylene glycol) methyl ether methacrylate, poly(propylene glycol) methyl ether acrylate, butyl acrylate, ethyl acrylate, methyl methacrylate, and ethylhexyl acrylate.

3. The method for preparing a composite vortex-spun core-spun yarn according to claim 1, characterized in that, The initiator is one or a mixture of azobisisobutyronitrile and benzoyl peroxide.

4. The method for preparing a composite vortex-spun core-spun yarn according to claim 1, characterized in that, The spandex spinning solution contains the following raw materials in parts by weight: 40-60 parts of polytetramethylene ether glycol, 20-35 parts of 4,4'-diphenylmethane diisocyanate, 4-10 parts of 1,3-propanediamine, 0.5-1.5 parts of n-butanol, and 150-250 parts of N,N-dimethylacetamide.

5. The method for preparing a composite vortex-spun core-spun yarn according to claim 1, characterized in that, The parameters for the dry spinning process are as follows: spinning tunnel temperature 200–250℃, spinning speed 350–600 m / min, and winding draw ratio 1.5–2.

0.

6. The method for preparing a composite vortex-spun core-spun yarn according to claim 1, characterized in that, The regenerated cellulose fiber is at least one of viscose fiber, modal fiber, and lyocell fiber.

7. The method for preparing a composite vortex-spun core-spun yarn according to claim 1, characterized in that, The pre-drafting parameters are: pre-draft ratio 2.5–4.0, feed tension 0.05–0.12 cN / dtex; and the vortex spinning process parameters are: spinning nozzle air pressure 0.55–0.75 MPa, short fiber sliver weight 13–16 g / 5m, spinning speed 380–550 m / min, and draft ratio 150–250.

8. The method for preparing a composite vortex-spun core-spun yarn according to claim 1, characterized in that, The mass ratio of 2-chloroethyl acrylate, 4,7-dihydroxy-1,10-phenanthroline, potassium carbonate, and N,N-dimethylacetamide used is 2.6:4.1-5.7:2.8-5.6:28-36. The mass ratio of antistatic agent precursor, phosphorus oxychloride, and triethylamine used is 5:15-21:1.6-2.

4. The mass ratio of antistatic agent, polymer monomer, initiator, N,N-dimethylacetamide, and nano-titanium dioxide used is 1-1.5:8-15:0.05-0.15:30-50:2-5. The mass ratio of nano-titanium dioxide-polymer antistatic agent core-shell dispersion and spandex spinning solution used is 5-15:

100.

9. The method for preparing a composite vortex-spun core-spun yarn according to claim 1, characterized in that, The mass ratio of modified spandex fiber to regenerated cellulose fiber used is 5-15:85-95.

10. The composite vortex-spun core-spun yarn obtained by the preparation method according to claim 1.

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