A coated yarn and preparation method thereof

Abstract

The present invention belongs to the field of textile technology, and particularly relates to a coated yarn and a preparation method thereof. The coated yarn is obtained by weaving a first outer coated yarn and a second outer coated yarn onto the outside of a core yarn, wherein the first outer coated yarn is a phase-change temperature-regulating polyester fiber, which uses an organic low-temperature phase-change compound as a phase-change heat storage material and an acrylic polymer as a wall material, and phase-change microspheres are prepared by suspension polymerization. The phase-change temperature-regulating microsphere finishing liquid is obtained by mixing with an inorganic powder modified with a silane coupling agent and then surface-modifying the microspheres with a thermosensitive polymer, and then coating the microspheres on the polyester fiber. The second outer coated yarn is an antibacterial cotton fiber, and the core yarn is a nylon stretch yarn. The prepared coated yarn has good mechanical properties, deodorizing properties, and antibacterial properties.

Description

Technical Field

[0001] The invention belongs to the technical field of textiles, and particularly relates to a coated yarn and a preparation method thereof. Background Art

[0002] In recent years, people have begun to pay more attention to the quality of life, and the demand for functional textiles has continued to grow. They are no longer satisfied with basic warmth and decorative features. Covered yarn, also known as wrapped yarn, is a new type of yarn structure. It uses a filament or staple fiber as the core yarn, which is covered with another filament or staple fiber yarn. The outer yarn is wrapped in a spiral pattern around the core yarn. The purpose of developing this yarn is to simultaneously utilize the properties of two or more fiber components. Currently, the functional textiles on the market mainly have functions such as antibacterial and deodorizing, anti-adhesion, hydrophobic and oleophobic, UV resistance, far infrared resistance, negative ionization, fire retardancy, electrical conductivity, and high water absorbency.

[0003] The Chinese patent publication number CN114622316B discloses a polylactic acid bio-based functional coated yarn for sweaters and a preparation method thereof, comprising a core yarn and an outer covering yarn, wherein the core yarn is an elastic yarn, and the outer covering yarn comprises a first outer covering yarn and a second outer covering yarn, wherein the first outer covering yarn is a metal microfilament and the second outer covering yarn is a PLA bio-based filament. The addition of the metal microfilament enhances the biodegradability of the sweater and improves the skin-friendliness of the sweater. The addition of wool fiber ensures the warmth retention of the sweater while reducing the Low sweater processing costs; Chinese patent publication number CN118932576A discloses a process for manufacturing soft, ultrafine covered yarn. The modified polyurethane obtained is spun to produce modified spandex filaments. The modified spandex filaments are then spirally wrapped around the core yarn with outer covering yarns to produce soft, ultrafine covered yarns. The covered yarn obtained by the method of the present invention is relatively fine and has excellent softness, antistatic properties, UV resistance, mechanical properties, and thermal insulation. The resulting product is more dense and lighter. However, in daily life, the temperature fluctuates rapidly in inclement weather, and improving the comfort of consumers in these harsh environments has become a focus of attention. Summary of the Invention

[0004] In response to the problems existing in the prior art, the present invention provides a covered yarn and a preparation method thereof, which is obtained by weaving a first outer covering yarn and a second outer covering yarn wrapped around the outside of a core yarn, wherein the first outer covering yarn is a phase change temperature-regulating polyester fiber, the second outer covering yarn is an antibacterial cotton fiber, and the core yarn is a nylon stretch yarn. The prepared covered yarn has good mechanical properties, deodorizing properties and antibacterial properties.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A covered yarn, comprising a core yarn and an outer covering yarn, wherein the outer covering yarn comprises a first outer covering yarn and a second outer covering yarn; the core yarn is a nylon stretch yarn, the first outer covering yarn is a phase-change temperature-regulating polyester fiber, and the second outer covering yarn is an antibacterial cotton fiber;

[0007] The preparation method of the phase-change temperature-regulating polyester fiber comprises: using an organic low-temperature phase-change compound as a phase-change heat storage material and an acrylic polymer as a wall material, preparing phase-change microspheres through suspension polymerization, mixing the phase-change microspheres with an inorganic powder modified with a silane coupling agent, and then surface-modifying the microspheres with a temperature-sensitive polymer to obtain a phase-change temperature-regulating microsphere finishing liquid, which is then coated on polyester fibers to obtain the phase-change temperature-regulating polyester fiber;

[0008] The preparation method of the antibacterial cotton fiber comprises: modifying the cotton fiber with a water-soluble high molecular polymer binder and then introducing an inorganic antibacterial agent to obtain the antibacterial cotton fiber.

[0009] Covered yarn is a kind of yarn composed of two or more fibers. Compared with ordinary yarn, it can give full play to the advantages of different fibers and make up for the shortcomings. Nylon has good wear resistance, elasticity and elastic recovery, but its heat resistance and light resistance are relatively poor. Therefore, it is used as the core yarn in the present invention to avoid direct contact with heat sources and direct light. Polyester has good wear resistance, high temperature resistance and dimensional stability, but it is inelastic and has poor hygroscopicity. Therefore, it is surface-coated and modified using phase change thermostatic materials, inorganic adsorption materials and thermosensitive polymers to improve elasticity while giving it a certain intelligent thermostatic effect, thereby improving comfort. Cotton fiber has good hygroscopicity and heat preservation properties. Therefore, it is used as the second outer covering yarn to cooperate with polyester to improve the hygroscopicity and air permeability of the fabric. Further introduction of inorganic antibacterial particles can make the prepared yarn have good antibacterial properties.

[0010] Furthermore, the preparation method of the phase change temperature regulating polyester fiber is specifically as follows:

[0011] S1. Mix n-octadecane, butyl stearate, methyl methacrylate, a crosslinking agent and an initiator, and then ultrasonically disperse them for 10-20 minutes. Then add an emulsifier solution, raise the temperature to 30-40°C, stir and disperse for 10-20 minutes, then raise the temperature to 80-90°C and stir for 6-10 hours. After separation by suction filtration, washing and drying, phase change microspheres are obtained; wherein the crosslinking agent is pentaerythritol tetraacrylate or ethylene glycol dimethacrylate, the initiator is any one of azobisisobutyronitrile, azobisisoheptanenitrile, dimethyl azobisisobutyrate, azobisisobutyramidine hydrochloride, and azobisisobutylimidazoline hydrochloride, or a mixture thereof, and the emulsifier is any one of sodium lauryl sulfate, monoglyceride laurate, glyceryl stearate, and cetyl palmitate or a mixture thereof;

[0012] Phase change materials can store or release large amounts of heat during temperature changes, providing a buffering effect in inclement weather and offering consumers prolonged thermal comfort. n-Octadecane and butyl stearate have phase transition temperatures close to the human body's comfort temperature. They share the same long-chain alkyl groups and can form a eutectic mixture. By properly blending them, the phase transition temperature can be adjusted to within the human comfort range (15-35°C). Polymethacrylic acid is a highly transparent plastic with high chemical stability, excellent mechanical properties, and biocompatibility. It is non-toxic and harmless to the human body, making it an ideal wall material for preparing microspheres. Therefore, in this invention, n-Octadecane and butyl stearate are used as the phase change core materials, while polymethyl methacrylate is used as the wall material. Phase change microspheres are prepared via suspension polymerization. By encapsulating the phase change material within the microspheres, the microspheres are protected and prevented from leaking during the reaction.

[0013] S2. Add the pretreated opal powder to water, ultrasonically disperse it to obtain a suspension, then add the silane coupling agent solution thereto, raise the temperature to 30-45° C. and stir for 6-8 hours, then add the phase change microspheres thereto, continue stirring for 3-5 hours, centrifuge, and dry to obtain silane coupling agent-modified opal-coated phase change microspheres; wherein the pretreatment process of the opal powder is as follows: place the opal powder in a ball mill, add water and a dispersant, and then ball mill; the ball-to-material mass ratio is 3-6:1, the ball mill revolution speed is 200-300 r / min, the grinding time is 2-5 hours, and the mass ratio of the opal powder, water, and dispersant is 20-40:5-8:0.25-0.32;

[0014] In everyday life, unpleasant body odor is unavoidable after exercise or in hot weather. Deodorants absorb or neutralize body odor, largely eliminating existing odor and acting as a passive adsorbent to reduce body odor. Opal, primarily composed of silica, has numerous microporous structures and a large surface area, which facilitates adsorption and is therefore commonly used as an adsorbent. To ensure that opal meets textile requirements, it is ultrafinely processed using a planetary ball mill. Because opal powder is subject to static electricity and is prone to agglomeration and even caking, wet grinding is employed. Dispersants are added during the grinding process to provide electrostatic stabilization, ensuring thorough grinding of the powder. To further promote the dispersion of the ground opal powder, the surface is modified with a silane coupling agent. Silane coupling agents react with the hydroxyl groups on the surface of inorganic particles, forming chemical bonds and coating the surface with an organic coating. This creates a steric barrier between the inorganic particles, effectively preventing aggregation and improving dispersibility in the medium. In addition, one end of the organic functional group in the silane coupling agent can react with the organic material, namely polymethyl methacrylate, or produce a strong intermolecular force, so that the silane coupling agent forms a strong bond between the inorganic opal powder and the surface of the phase change microspheres, further enhancing the bonding effect between the opal powder and the phase change microspheres. A layer of opal powder is covered on the surface of the phase change microspheres. On the one hand, the adsorption effect of the opal powder can absorb odors, and on the other hand, it can improve the mechanical properties of the phase change microspheres.

[0015] S3. Ultrasonic dispersion of the silane coupling agent-modified opal-coated phase change microspheres in water, and addition of N-isopropylacrylamide, acrylamide, and potassium persulfate. Under a nitrogen atmosphere, the temperature is raised to 70-85° C. and stirred for reaction for 4-8 hours. After the reaction, the phase change microspheres are washed by centrifugation with deionized water and dried to obtain phase change temperature-regulating microspheres modified with a thermosensitive polymer surface.

[0016] Isopropyl acrylamide is a temperature-responsive polymer with a lower critical temperature of 32-33°C. After surface modification, the polymer chains undergo a conformational transition from contraction to extension in aqueous solution in response to changes in ambient temperature. When the temperature is above its lower critical temperature, the polymer chains contract, and when the temperature is below it, the polymer chains extend, thus achieving reversible temperature response. Therefore, in this step, N-isopropyl acrylamide and acrylamide copolymer are used as thermosensitive polymers to coat silane coupling agent-modified opal-coated phase change microspheres to achieve surface temperature control. After exercise or in hot weather, the human body temperature rises and sweat is secreted, inevitably emitting unpleasant sweat odor. When the temperature exceeds the lower critical temperature of the thermosensitive polymer, the polymer chains contract, exposing the opal adsorbent coated on the surface of the phase change microspheres, which facilitates the adsorption of sweat or body odor.

[0017] S4. Add phase-change temperature-regulating microspheres modified with a thermosensitive polymer surface, ethylene-vinyl acetate copolymer and sodium carboxymethyl cellulose into water, stir evenly to obtain a phase-change temperature-regulating microsphere finishing solution, add polyester fiber thereto for impregnation, and after impregnation, take out and dry to obtain the phase-change temperature-regulating polyester fiber.

[0018] In this step, the phase change temperature regulating microspheres are mixed with the adhesive ethylene-vinyl acetate copolymer and the thickener sodium carboxymethyl cellulose to prepare a phase change temperature regulating microsphere finishing liquid, which is then impregnated into the polyester fiber. Due to the addition of the adhesive and the thickener, the phase change temperature regulating microspheres can be more firmly bonded to the polyester fiber.

[0019] Furthermore, the preparation method of the antibacterial cotton fiber is specifically as follows:

[0020] A1. Immerse the pretreated cotton fiber in a polyacrylic acid oligomer solution for 20-30 minutes, then heat the solution to 160-180° C. for 5-10 minutes, wash, and dry the solution to obtain polyacrylic acid-coated cotton fiber; wherein the drying conditions are: drying at 75-85° C. for 1-3 hours;

[0021] A2. Immersing the polyacrylic acid-coated cotton fiber in a silver nitrate solution, stirring at 20-30° C. for 10-20 minutes, and then drying, immersing the fiber in a NaBH4 solution again, stirring at 20-30° C. for 10-20 minutes, washing, and drying to obtain the antibacterial cotton fiber; wherein the drying conditions are: drying at 75-85° C. for 1-3 hours;

[0022] Cotton fabric has good water absorption, air permeability, is therefore usually used in textile products, its structure is porous state, so the surface very easily absorbs microorganisms, the perspiration on human skin surface, dander and the stain that adheres to the cotton fabric surface all may provide nutrition to health errors, make microorganism be easy to grow at the cotton fabric surface breeding especially, may cause human body to receive pathogen infection.Therefore in this step, at first utilize the hydroxyl generation esterification on polyacrylic acid oligomer and cotton fiber surface, cotton fiber surface is modified, again it is immersed in the silver nitrate solution, by the carboxyl on the polyacrylic acid oligomer and the coordination of silver ion, nano silver particle can be firmly loaded on the cotton fiber surface, thereby make cotton fiber have good antimicrobial property.

[0023] A method for preparing a covered yarn comprises the following steps: drawing a core yarn from the core of a hollow spindle, performing a drafting process, then wrapping a first outer covering yarn around the core yarn in an S-twist wrapping direction with a twist of 800-1000 twists / m, then wrapping a second outer covering yarn around the first outer covering yarn in a Z-twist wrapping direction with a twist of 60%-75% of the first covering twist, and then drawing and winding the yarn after twisting to obtain the covered yarn. The drafting process has a draft ratio of 3.4-3.8.

[0024] The present invention has the following beneficial effects:

[0025] The present invention uses nylon stretch yarn as the core yarn, phase-change temperature-regulating polyester fiber as the first outer covering yarn, and antibacterial cotton fiber as the second outer covering yarn. The first outer covering yarn is wrapped around the core yarn in an S-twist direction, and then the second outer covering yarn is wrapped around the first outer covering yarn in a Z-twist direction. After twisting, the yarn is drawn out and reeled up. The phase-change temperature-regulating polyester fiber is prepared by suspension polymerization using n-octadecane and butyl stearate as the phase-change core material and polymethyl methacrylate as the wall material. Phase-change microspheres are then coated and modified with a silane coupling agent and further coated with a thermosensitive polymer. These microspheres can store or release large amounts of heat when the temperature changes, adjusting the wearer's comfort. They can also absorb unpleasant odors after exercise or in hot weather. In the preparation process of antibacterial cotton fiber, polyacrylic acid oligomers are first used to undergo esterification reaction with the hydroxyl groups on the surface of the cotton fiber, and then it is immersed in a silver nitrate solution. Through the coordination effect between the carboxyl groups on the polyacrylic acid oligomers and the silver ions, the nanosilver particles can be firmly loaded on the surface of the cotton fiber, thus giving the cotton fiber good antibacterial properties. DETAILED DESCRIPTION

[0026] The following will be combined with the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0027] The n-octadecane (melting point 28.18°C, specification: 99%), butyl stearate (melting point 27°C, specification: chemically pure, 98%), and silane coupling agent (Lushi, ≥98.0%) used in the present invention were purchased from Sinopharm Chemical Reagent Company, methyl methacrylate (AR), pentaerythritol tetraacrylate (AR), azobisisobutyronitrile (AR), and sodium lauryl sulfate (AR) were purchased from Shanghai MacLean Biochemical Technology Co., Ltd., opal powder (1250 mesh, provided by Heilongjiang Enterprise Shanghai, produced from Nenjiang opal shale), dispersant is sodium polyphosphate, N-isopropylacrylamide, acrylamide, Sodium sulfate was purchased from Sigma-Aldrich, USA. Ethylene-vinyl acetate copolymer (P301637), sodium carboxymethyl cellulose (C104986), polyacrylic acid oligomer (50%), silver nitrate (99%), and sodium borohydride (99%) were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. Nylon stretch yarn (70D nylon stretch yarn) was purchased from Jiaxing Jinxu New Materials Technology Co., Ltd. Polyester stretch yarn (75D polyester stretch yarn) was purchased from Shaoxing Xineng Textile Technology Co., Ltd. Cotton fiber was purchased from Dezhou Caishihe Textile Co., Ltd. All raw materials and reagents were commercially available. The ball mill used in the present invention was an XQM-4 planetary ball mill.

[0028] Example 1

[0029] A covered yarn, comprising a core yarn and an outer covering yarn, wherein the outer covering yarn comprises a first outer covering yarn and a second outer covering yarn; the core yarn is a nylon stretch yarn, the first outer covering yarn is a phase-change temperature-regulating polyester fiber, and the second outer covering yarn is an antibacterial cotton fiber;

[0030] The preparation method of phase-change temperature-regulating polyester fiber includes: using an organic low-temperature phase-change compound as a phase-change heat storage material and an acrylic polymer as a wall material, preparing phase-change microspheres through suspension polymerization, mixing the phase-change microspheres with an inorganic powder modified with a silane coupling agent, and then surface-modifying the microspheres with a temperature-sensitive polymer to obtain a phase-change temperature-regulating microsphere finishing liquid, which is then coated on polyester fiber to obtain the phase-change temperature-regulating polyester fiber;

[0031] The preparation method of the antibacterial cotton fiber comprises the following steps: modifying the cotton fiber with a water-soluble high molecular polymer binder and then introducing an inorganic antibacterial agent to obtain the antibacterial cotton fiber.

[0032] The preparation method of phase change temperature regulating polyester fiber is specifically as follows:

[0033] S1. 12 parts by weight of n-octadecane, 8 parts by weight of butyl stearate, 25 parts by weight of methyl methacrylate, 4 parts by weight of crosslinking agent pentaerythritol tetraacrylate and 1 part by weight of initiator azobisisobutyronitrile were mixed uniformly and ultrasonically dispersed for 15 minutes, and then 45 parts by weight of emulsifier sodium lauryl sulfate solution was added thereto. The temperature was raised to 35° C. and stirred and dispersed at a speed of 800 r / min for 15 minutes. After that, the temperature was raised to 85° C. and stirred at a speed of 600 r / min for 8 hours. The mixture was separated by suction filtration, washed repeatedly with ethanol and deionized water for 3 times, and dried in an oven at 50° C. for 24 hours to obtain phase change microspheres; wherein the preparation method of the sodium lauryl sulfate solution is as follows: sodium lauryl sulfate is dissolved in deionized water and mixed uniformly; the amount of sodium lauryl sulfate in deionized water is 0.05 g / mL;

[0034] S2. Add 10 parts by weight of pretreated opal powder to 100 parts by weight of water, ultrasonically disperse for 25 minutes to obtain a suspension, add 5 parts by weight of silane coupling agent KH550 solution thereto, raise the temperature to 40° C. and stir for 7 hours, then add 15 parts by weight of phase change microspheres thereto, continue stirring for 4 hours, centrifuge, and dry in an oven at 45° C. for 4 hours to obtain silane coupling agent-modified opal-coated phase change microspheres; wherein the pretreatment process of the opal powder is as follows: Opal powder was placed in a ball mill, and water and a dispersant were added before ball milling. The ball-to-material mass ratio was 4:1, the ball mill revolution speed was 250 r / min, the milling time was 3 hours, and the mass ratio of opal powder, water, and dispersant was 35:6.5:0.3. The silane coupling agent KH550 solution was prepared by dispersing the silane coupling agent KH550 in the aqueous solution and mixing uniformly. The amount of the silane coupling agent KH550 in the water was 0.05 g / mL.

[0035] S3, dispersing 12 parts by weight of silane coupling agent-modified opal-coated phase change microspheres in 180 parts by weight of water by ultrasonication for 25 minutes, adding 15 parts by weight of N-isopropylacrylamide, 4 parts by weight of acrylamide and 0.8 parts by weight of potassium persulfate, raising the temperature to 80° C. under a nitrogen atmosphere, stirring and reacting for 6 hours, and after the reaction, centrifugally washing with deionized water three times, and vacuum drying at 65° C. for 18 hours to obtain phase change temperature-regulating microspheres modified with a thermosensitive polymer surface;

[0036] S4. Add 35 parts by weight of phase-change temperature-regulating microspheres modified with a thermosensitive polymer surface, 45 parts by weight of ethylene-vinyl acetate copolymer and 5 parts by weight of sodium carboxymethyl cellulose to 55 parts by weight of water, stir for 6 hours to mix evenly to obtain a phase-change temperature-regulating microsphere finishing liquid, add 35 parts by weight of polyester fiber thereto for impregnation, take out after impregnation for 6 hours, and dry at 80°C for 30 minutes to obtain a phase-change temperature-regulating polyester fiber.

[0037] The preparation method of the antibacterial cotton fiber is specifically as follows:

[0038] A1. Immersing 10 parts by weight of pretreated cotton fibers in 100 parts by weight of a polyacrylic acid oligomer solution (1 wt%, pH=4) for 25 minutes, raising the temperature to 170°C and heating for 8 minutes, washing three times with deionized water, and drying in an oven at 80°C for 2 hours to obtain polyacrylic acid-coated cotton fibers; wherein the pretreatment process of the cotton fibers is as follows: placing 10 parts by weight of untreated cotton fibers in 100 parts by weight of an aqueous solution of sodium dodecyl sulfate, ultrasonically washing for 40 minutes, washing three times with deionized water, ultrasonically washing with anhydrous ethanol for 40 minutes, and washing three times with deionized water, and drying the resulting fibers in an oven at 75°C for 2 hours to obtain the polyacrylic acid-coated cotton fibers, wherein the concentration of the aqueous solution of sodium dodecyl sulfate is 2 wt%;

[0039] A2. 15 parts by weight of polyacrylic acid-coated cotton fibers were immersed in 100 parts by weight of silver nitrate solution, stirred at 25° C. for 15 min, dried at 80° C. for 2 h, and then immersed in 100 parts by weight of NaBH4 solution, stirred at 25° C. for 15 min, washed three times with deionized water, and dried at 80° C. for 2 h to obtain antibacterial cotton fibers; wherein the concentration of the silver nitrate solution was 0.47 mol / L, and the concentration of the NaBH4 solution was 0.94 mol / L;

[0040] A method for preparing a covered yarn comprises the following steps: drawing a core yarn nylon stretch yarn from the core of a hollow spindle in a covering machine, performing a drafting treatment through a drafting device with a drafting multiple of 3.6, then covering the outside of the core yarn with a first outer covering yarn in an S-twist covering direction with a twist of 900 twists / m, then covering the outside of the first outer covering yarn in a Z-twist covering direction with a twist of 65% of the first covering twist, and drawing and winding the yarn after twisting to obtain a covered yarn.

[0041] Example 2

[0042] Compared with the first embodiment, this embodiment has the following differences. For the rest, refer to the first embodiment.

[0043] In the preparation method of phase change temperature regulating polyester fiber:

[0044] In step S1, 10 parts by weight of n-octadecane, 6 parts by weight of butyl stearate, 22 parts by weight of methyl methacrylate, 2 parts by weight of a crosslinking agent pentaerythritol tetraacrylate, and 0.45 parts by weight of an initiator azobisisobutyronitrile are mixed uniformly and ultrasonically dispersed for 10 minutes. Then, 40 parts by weight of an emulsifier sodium lauryl sulfate solution is added thereto, the temperature is raised to 30° C., the mixture is stirred and dispersed for 10 minutes, and then the temperature is raised to 80° C. and stirred for 8 hours.

[0045] In step S2, 6.5 parts by weight of pretreated opal powder are added to 80 parts by weight of water, ultrasonically dispersed for 20 minutes to obtain a suspension, 3.5 parts by weight of a silane coupling agent KH550 solution are added thereto, the temperature is raised to 30° C. and stirred for 6 hours, and then 12 parts by weight of phase change microspheres are added thereto, and the mixture is stirred for 3 hours and then centrifuged; during the pretreatment of the opal powder, the ball-to-material mass ratio is 3:1, the ball mill revolution speed is 200 r / min, the grinding time is 2 hours, and the mass ratio of the opal powder, water, and dispersant is 20:5:0.25;

[0046] In step S3, 10 parts by weight of silane coupling agent-modified opal-coated phase change microspheres are dispersed in 150 parts by weight of water by ultrasonication for 20 minutes, and 12 parts by weight of N-isopropylacrylamide, 2 parts by weight of acrylamide, and 0.5 parts by weight of potassium persulfate are added. Under a nitrogen atmosphere, the temperature is raised to 70° C. and stirred for reaction for 4 hours.

[0047] In step S4, 30 parts by weight of phase change temperature-regulating microspheres modified with a thermosensitive polymer surface, 38 parts by weight of ethylene-vinyl acetate copolymer and 2 parts by weight of sodium carboxymethyl cellulose are added to 50 parts by weight of water, and the mixture is stirred for 5 hours to obtain a phase change temperature-regulating microsphere finishing liquid, to which 32 parts by weight of polyester fiber is added for impregnation.

[0048] In the preparation method of antibacterial cotton fiber:

[0049] In step A1, 8 parts by weight of pretreated cotton fibers are immersed in 88 parts by weight of a polyacrylic acid oligomer solution (1 wt%, pH=4) for 20 minutes, then heated to 160°C for 5 minutes, washed three times with deionized water, and dried in an oven at 75°C for 1 hour to obtain polyacrylic acid-coated cotton fibers;

[0050] In step A2, 12 parts by weight of polyacrylic acid-coated cotton fiber is immersed in 95 parts by weight of silver nitrate solution, stirred at 20°C for 10 minutes, and then dried at 75°C for 1 hour, and then immersed in 95 parts by weight of NaBH4 solution again, stirred at 20°C for 10 minutes, washed three times with deionized water, and dried at 75°C for 1 hour to obtain antibacterial cotton fiber;

[0051] In the preparation method of the covered yarn, the drawing multiple is 3.4, and then the first outer covering yarn is covered on the outside of the core yarn in an S-twist covering direction with a twist of 800 twists / m, and then the second outer covering yarn is covered on the outside of the first outer covering yarn in a Z-twist covering direction with a twist of 60% of the first covering twist.

[0052] Example 3

[0053] Compared with the first embodiment, this embodiment has the following differences. For the rest, refer to the first embodiment.

[0054] In the preparation method of phase change temperature regulating polyester fiber:

[0055] In step S1, 15 parts by weight of n-octadecane, 10 parts by weight of butyl stearate, 28 parts by weight of methyl methacrylate, 6 parts by weight of a crosslinking agent pentaerythritol tetraacrylate, and 1.2 parts by weight of an initiator azobisisobutyronitrile are mixed uniformly and ultrasonically dispersed for 20 minutes, and then 50 parts by weight of an emulsifier sodium lauryl sulfate solution is added thereto, the temperature is raised to 40° C., and the mixture is stirred and dispersed for 20 minutes, and then the temperature is raised to 90° C. and stirred for 10 hours;

[0056] In step S2, 12 parts by weight of pretreated opal powder are added to 120 parts by weight of water, ultrasonically dispersed for 30 minutes to obtain a suspension, 5.5 parts by weight of a silane coupling agent KH550 solution are added thereto, the temperature is raised to 45° C. and stirred for 8 hours, and then 18 parts by weight of phase change microspheres are added thereto, and the mixture is stirred for 5 hours and then centrifuged; during the pretreatment of the opal powder, the ball-to-material mass ratio is 6:1, the ball mill revolution speed is 300 r / min, the grinding time is 5 hours, and the mass ratio of the opal powder, water, and dispersant is 40:8:0.32;

[0057] In step S3, 15 parts by weight of silane coupling agent-modified opal-coated phase change microspheres are dispersed in 200 parts by weight of water by ultrasonication for 30 minutes, and 18 parts by weight of N-isopropylacrylamide, 6 parts by weight of acrylamide, and 1 part by weight of potassium persulfate are added. Under a nitrogen atmosphere, the temperature is raised to 85° C. and stirred for reaction for 8 hours.

[0058] In step S4, 40 parts by weight of phase change temperature-regulating microspheres modified with a thermosensitive polymer surface, 50 parts by weight of ethylene-vinyl acetate copolymer and 8 parts by weight of sodium carboxymethyl cellulose are added to 60 parts by weight of water, and the mixture is stirred for 8 hours to obtain a phase change temperature-regulating microsphere finishing liquid, to which 40 parts by weight of polyester fiber is added for impregnation.

[0059] In the preparation method of antibacterial cotton fiber:

[0060] In step A1, 12 parts by weight of pretreated cotton fibers were immersed in 120 parts by weight of a polyacrylic acid oligomer solution (1 wt%, pH = 4) for 30 minutes, and then the temperature was raised to 180°C and heated for 10 minutes. The fibers were then washed three times with deionized water and dried in an oven at 85°C for 3 hours to obtain polyacrylic acid-coated cotton fibers.

[0061] In step A2, 18 parts by weight of polyacrylic acid-coated cotton fiber is immersed in 120 parts by weight of silver nitrate solution, stirred at 30°C for 20 minutes, and then dried at 85°C for 3 hours. The fiber is then immersed in 120 parts by weight of NaBH4 solution again, stirred at 30°C for 20 minutes, washed three times with deionized water, and dried at 85°C for 3 hours to obtain antibacterial cotton fiber;

[0062] In the preparation method of the covered yarn, the drawing multiple is 3.8, and the first outer covering yarn is covered on the outside of the core yarn in an S-twist covering direction with a twist of 1000 twists / m, and then the second outer covering yarn is covered on the outside of the first outer covering yarn in a Z-twist covering direction with a twist of 75% of the first covering twist.

[0063] Comparative Example 1

[0064] Compared with Example 1, in the preparation process of the phase-change temperature-regulating polyester fiber, the phase-change microspheres are not coated with opal powder. The rest is referred to Example 1, specifically:

[0065] Among them, the preparation method of phase change temperature regulating polyester fiber is:

[0066] 12 parts by weight of phase change microspheres were dispersed in 180 parts by weight of water by ultrasonication for 25 minutes, and 15 parts by weight of N-isopropylacrylamide, 4 parts by weight of acrylamide and 0.8 parts by weight of potassium persulfate were added. The temperature was raised to 80°C under a nitrogen atmosphere and stirred for 6 hours. After the reaction, the mixture was washed three times with deionized water by centrifugation and dried in vacuum at 65°C for 18 hours to obtain phase change temperature-regulating microspheres modified with a thermosensitive polymer surface.

[0067] 35 parts by weight of phase change temperature-regulating microspheres modified with a thermosensitive polymer surface, 45 parts by weight of ethylene-vinyl acetate copolymer and 5 parts by weight of sodium carboxymethyl cellulose were added to 55 parts by weight of water, and the mixture was stirred for 6 hours to obtain a phase change temperature-regulating microsphere finishing liquid. 35 parts by weight of polyester fiber was added thereto for impregnation. After impregnation for 6 hours, the fiber was taken out and dried at 80°C for 30 minutes to obtain a phase change temperature-regulating polyester fiber.

[0068] The preparation method of the phase change microspheres refers to the preparation of the phase change microspheres in step S1 of the method for preparing phase change temperature-regulating polyester fibers in Example 1.

[0069] The preparation of the antibacterial cotton fiber and the coated yarn refers to the preparation process of the antibacterial cotton fiber and the coated yarn in Example 1.

[0070] Comparative Example 2

[0071] Compared with Example 1, in the preparation process of the phase-change temperature-regulating polyester fiber, the phase-change microspheres coated with the silane coupling agent-modified opal were not coated with the temperature-sensitive polymer. The rest of the steps were similar to those of Example 1, specifically:

[0072] Among them, the preparation method of phase change polyester fiber is: adding 35 parts by weight of silane coupling agent modified opal-coated phase change microspheres, 45 parts by weight of ethylene-vinyl acetate copolymer and 5 parts by weight of sodium carboxymethyl cellulose to 55 parts by weight of water, stirring for 6 hours to mix evenly to obtain a phase change microsphere finishing liquid, adding 35 parts by weight of polyester fiber thereto for impregnation, taking out after impregnation for 6 hours, and drying at 80°C for 30 minutes to obtain a phase change polyester fiber; wherein the silane coupling agent modified opal-coated phase change microspheres are prepared by referring to the silane coupling agent modified opal-coated phase change microspheres in Example 1.

[0073] The preparation of the antibacterial cotton fiber and the coated yarn refers to the preparation process of the antibacterial cotton fiber and the coated yarn in Example 1.

[0074] Comparative Example 3

[0075] Compared with Example 1, this comparative example does not modify the cotton fiber with polyacrylic acid oligomer during the preparation of the antibacterial cotton fiber. The rest is similar to Example 1, specifically:

[0076] The preparation of the antibacterial cotton fiber is as follows: 15 parts by weight of pretreated cotton fiber is immersed in 100 parts by weight of silver nitrate solution, stirred at 25°C for 15 minutes, and then dried at 80°C for 2 hours, and then immersed in 100 parts by weight of NaBH4 solution again, stirred at 25°C for 15 minutes, washed three times with deionized water, and dried at 80°C for 2 hours to obtain the antibacterial cotton fiber; wherein the concentration of the silver nitrate solution is 0.47 mol / L, and the concentration of the NaBH4 solution is 0.94 mol / L.

[0077] The preparation of the phase-change temperature-regulating polyester fiber and the coated yarn refers to the preparation process of the phase-change temperature-regulating polyester fiber and the coated yarn in Example 1.

[0078] Comparative Example 4

[0079] Compared with Example 1, in this comparative example, the cotton fibers were not subjected to antibacterial treatment, and the pretreated cotton fibers were directly used as the second outer covering yarn. The rest of the process was similar to that of Example 1.

[0080] Related tests:

[0081] Breaking strength: According to GB / T3916-2013 “Textiles, yarn from packages, single yarn - Determination of breaking strength and elongation (CRE method)”, the breaking strength of Examples 1 to 3 and Comparative Examples 1 to 4 was tested using a yarn strength and elongation meter.

[0082] Elongation at break: According to GB / T3916-2013 “Textiles, yarn from packages, and single yarn — Determination of breaking strength and elongation at break (CRE method)”, the elongation at break of Examples 1 to 3 and Comparative Examples 1 to 4 was tested using a yarn strength and elongation meter. The test results are shown in Table 1.

[0083] Table 1 Test results of breaking strength and breaking elongation

[0084]

[0085] It can be seen from the above test data that the overall mechanical properties of Examples 1 to 3 are better than those of Comparative Examples 1 to 4, and in particular, Example 1 has the best comprehensive mechanical properties.

[0086] Deodorization Performance Test: The coated yarns prepared in each example and comparative example were knitted into socks or underwear, and their deodorization performance was evaluated. The samples were cut into 10 cm x 10 cm pieces. A detector tube was used to measure the initial concentrations of ammonia and acetic acid in the enclosed space and the concentrations of ammonia and acetic acid two hours after the deodorizing sample was added. Deodorization performance tests were conducted according to the standards "GB / T 33610.1-2019 Textiles - Determination of Deodorization Performance - Part 1: General Principles" and "GB / T 33610.2-2017 Textiles - Determination of Deodorization Performance - Part 2: Detection Tube Method." The test results are shown in Table 2.

[0087] Table 2 Deodorization performance test results

[0088]

[0089] It can be seen from the above deodorization performance test results that the deodorization performance of Examples 1 to 3 is better than that of Comparative Examples 1 to 4 as a whole, among which Example 1 has the best deodorization performance; before washing with water, Comparative Examples 2 to 4 are not much different from Examples 1 to 3, but the deodorization performance of Comparative Example 1 (opal powder is not coated during the preparation process) is the worst. This is because opal powder as an adsorption material can effectively adsorb ammonia and acetic acid and effectively eliminate odor; but after washing with water 50 times, the ammonia elimination rate and acetic acid elimination rate of Comparative Example 2 (the silane coupling agent modified opal-coated phase change microspheres are not coated with thermosensitive polymers during the preparation process) are significantly reduced. This is because coating the modified opal-coated phase change microspheres with thermosensitive polymers can enhance the binding effect between opal powder and fibers to a certain extent.

[0090] Antibacterial Properties: The coated yarns prepared in each example and comparative example were knitted into socks or underwear, and their antibacterial properties were evaluated. The fabric samples and the control samples were cut into 5 mm x 5 mm pieces, and 0.75 g ± 0.05 g of each sample was weighed as a sample. The antibacterial properties were tested according to the standard "T / SZTI A 001-2020 Antibacterial Fibers and Textiles." The test results are shown in Table 3.

[0091] Table 3 Antibacterial performance test results

[0092]

[0093] It can be seen from the above antibacterial performance test results that the antibacterial performance of Examples 1 to 3 is better than that of Comparative Examples 1 to 4 as a whole, among which Example 1 has the best antibacterial performance; before washing, Comparative Examples 1 to 3 are not much different from Examples 1 to 3, but the antibacterial performance of Comparative Example 4 (no antibacterial treatment of the cotton fiber) is the worst. This is because the nanosilver particles are not loaded on the surface of the cotton fiber and the antibacterial effect cannot be achieved; but after washing 50 times, the antibacterial performance of Comparative Example 3 (the cotton fiber is not modified with polyacrylic acid oligomer) is significantly reduced. This is because the cotton fiber surface is not modified with polyacrylic acid, the binding force between the nanosilver particles and the cotton fiber surface is small, and its antibacterial performance is reduced after washing.

[0094] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0095] Although the embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A covered yarn, characterized in that: It comprises a core yarn and an outer covering yarn, wherein the outer covering yarn comprises a first outer covering yarn and a second outer covering yarn; the core yarn is nylon stretch yarn, the first outer covering yarn is phase change temperature regulating polyester fiber, and the second outer covering yarn is antibacterial cotton fiber; The preparation method of the phase-change temperature-regulating polyester fiber comprises: using n-octadecane and butyl stearate as phase-change core materials; using polymethyl methacrylate as wall material; preparing phase-change microspheres by suspension polymerization; mixing the phase-change microspheres with opal powder modified with a silane coupling agent; and then using N-isopropyl acrylamide and acrylamide copolymer as a thermosensitive polymer for surface modification to obtain a phase-change temperature-regulating microsphere finishing liquid; coating the microspheres on polyester fibers to obtain the phase-change temperature-regulating polyester fibers; The preparation method of the antibacterial cotton fiber comprises: modifying the cotton fiber with a water-soluble high molecular polymer binder and then introducing an inorganic antibacterial agent to obtain the antibacterial cotton fiber; The preparation method of the phase change temperature regulating polyester fiber is specifically as follows: S1. Mix n-octadecane, butyl stearate, methyl methacrylate, a crosslinking agent, and an initiator, and disperse them by ultrasonication for 10-20 minutes. Then, add the emulsifier solution, raise the temperature to 30-40° C., stir and disperse for 10-20 minutes, then raise the temperature to 80-90° C. and stir for 6-10 hours. After separation by suction filtration, washing, and drying, phase change microspheres are obtained. S2. Add the pretreated opal powder to water, disperse it by ultrasonication to obtain a suspension, add the silane coupling agent solution thereto, raise the temperature to 30-45° C., stir for 6-8 hours, add the phase change microspheres thereto, continue stirring for 3-5 hours, and then centrifuge and dry to obtain the silane coupling agent-modified opal-coated phase change microspheres; S3. Ultrasonic dispersion of the silane coupling agent-modified opal-coated phase change microspheres in water, and addition of N-isopropylacrylamide, acrylamide, and potassium persulfate. Under a nitrogen atmosphere, the temperature is raised to 70-85° C. and stirred for reaction for 4-8 hours. After the reaction, the phase change microspheres are washed by centrifugation with deionized water and dried to obtain phase change temperature-regulating microspheres modified with a thermosensitive polymer surface. S4. Add phase-change temperature-regulating microspheres modified with a thermosensitive polymer surface, ethylene-vinyl acetate copolymer and sodium carboxymethyl cellulose into water, stir evenly to obtain a phase-change temperature-regulating microsphere finishing solution, add polyester fiber thereto for impregnation, and after impregnation, take out and dry to obtain the phase-change temperature-regulating polyester fiber.

2. The covered yarn according to claim 1, characterized in that The pretreatment process of opal powder is as follows: placing the opal powder in a ball mill, adding water and a dispersant, and then ball milling; the ball-to-material mass ratio is 3-6:1, the ball mill revolution speed is 200-300 r / min, and the grinding time is 2-5 hours.

3. The covered yarn according to claim 1, characterized in that The crosslinking agent is pentaerythritol tetraacrylate or ethylene glycol dimethacrylate, the initiator is any one of azobisisobutyronitrile, azobisisoheptanenitrile, dimethyl azobisisobutyrate, azobisisobutyramidine hydrochloride, and azobisisobutylimidazoline hydrochloride, or a mixture thereof, and the emulsifier is any one of sodium lauryl sulfate, monoglyceride of laurate, glyceryl stearate, and cetyl palmitate, or a mixture thereof.

4. The covered yarn according to claim 1, characterized in that The preparation method of the antibacterial cotton fiber is specifically as follows: A1. Immersing the pretreated cotton fibers in a polyacrylic acid oligomer solution for 20-30 minutes, then heating the solution to 160-180° C. for 5-10 minutes, followed by washing and drying to obtain polyacrylic acid-coated cotton fibers. A2. Immerse the polyacrylic acid-coated cotton fiber in a silver nitrate solution, stir for 10-20 minutes at 20-30° C., and then dry it. Immerse it in a NaBH4 solution again, stir for 10-20 minutes at 20-30° C., and wash and dry it to obtain the antibacterial cotton fiber.

5. The covered yarn according to claim 4, characterized in that In steps A1 and A2, the drying conditions are: drying at 75-85° C. for 1-3 h.

6. The method for preparing the covered yarn according to any one of claims 1 to 5, characterized in that: The method comprises the following steps: drawing a core yarn from the core of a hollow spindle, performing a drafting process, then wrapping a first outer covering yarn around the core yarn in an S-twist wrapping direction with a twist of 800-1000 twists / m, then wrapping a second outer covering yarn around the first outer covering yarn in a Z-twist wrapping direction with a twist of 60%-75% of the first covering twist, and drawing and winding the yarn after twisting to obtain the covered yarn.

7. The method for preparing the covered yarn according to claim 6, wherein: When the drafting process is performed, the drafting ratio is 3.4-3.8.

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