Method for preparing moisture-absorbing and antistatic polyester filament from recycled polyester fiber

Abstract

The present invention discloses a method for preparing moisture-absorbing and antistatic polyester filaments from recycled polyester fibers, which relates to the technical field of recycled fiber filaments and is used to solve the technical problem that it is impossible to maintain the lasting moisture-absorbing performance and antistatic performance of polyester filaments through component improvement combined with hierarchical material improvement while ensuring mechanical properties. The steps of the preparation method include the preparation of recycled polyester chips, melt extrusion, spinning cooling, preparation of an antistatic bonding layer, preparation of a hydrophilic moisture-absorbing layer, and drying and winding; under the good dispersion and thickening effects of guar gum and polyvinylpyrrolidone, activated clay adsorbs quaternary ammonium salt of chitosan and graphene and then disperses in the melt of recycled polyester chips. After melt extrusion, a recycled polyester fiber strip with improved moisture-absorbing performance, antistatic performance, antibacterial performance and uniform component distribution is obtained; the three-layer structure of the composite antistatic bonding layer and the hydrophilic moisture-absorbing layer improves the stability and mechanical properties and maintains the lasting moisture-absorbing performance and antistatic performance.

Description

Technical Field

[0001] The present invention relates to the technical field of regenerated fiber filaments, and particularly to a method for preparing moisture-absorbing and antistatic polyester filaments from regenerated polyester fibers. Background Art

[0002] Polyester fiber is an important variety in synthetic fibers, mainly a synthetic fiber obtained by spinning polyester formed by polycondensation of organic dibasic acids and diols, and has advantages such as durability and wrinkle resistance. Polyester filament is a filament made of polyester and is widely used in fields such as textiles and interior building decoration. Regenerated polyester filaments can be obtained by chemical methods and physical methods, and the current main raw materials are polyester plastic bottles and polyester clothing.

[0003] The invention patent with publication number CN113279081B discloses a processing method of polyester filaments, including the following steps: mixing the raw materials of polyester filaments, drying after mixing evenly to obtain a dried mixture; melt-extruding the dried mixture, and obtaining an extruded polyester filament after filtration; obtaining polyester filaments after the extruded polyester filament undergoes distribution, spinning, cooling, post-treatment, drying, and winding; the raw materials of the polyester filaments include polyester chips, accelerator, semi-coke powder, zeolite powder, fly ash, and polyvinylpyrrolidone, and the polyester filaments obtained by this invention have the advantage of good air permeability. However, in the process of researching the preparation of composite polyester filaments from regenerated polyester fibers, it is found that it is impossible to maintain the long-lasting moisture absorption performance and antistatic performance of polyester filaments through component improvement combined with hierarchical material improvement while ensuring the mechanical properties. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for preparing moisture-absorbing and antistatic polyester filaments from regenerated polyester fibers, so as to solve the technical problem that in the prior art, it is impossible to maintain the long-lasting moisture absorption performance and antistatic performance of polyester filaments through component improvement combined with hierarchical material improvement while ensuring the mechanical properties.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] The present invention provides a method for preparing moisture-absorbing and antistatic polyester filaments from regenerated polyester fibers, including the following steps:

[0007] S1. Preparation of regenerated polyester chips: Cleaning, shredding, melting, alcoholysis, polycondensation, and cooling of PET-based bottle chips to obtain regenerated polyester chips with a molecular weight of 17,000 - 18,000, an intrinsic viscosity of 0.7 - 0.8 dl / g, a crystallinity of 28%, a melting point of 249 ± 2 °C, and a moisture content of less than 1200 ppm;

[0008] S2. Melt Extrusion: According to parts by weight, 85 - 100 parts of recycled polyester chips are mixed with 2 - 6 parts of quaternary ammonium salt of chitosan, 0.4 - 1.8 parts of graphene, 1 - 3 parts of activated clay, 0.2 - 0.8 parts of polyvinylpyrrolidone, and 5 - 11 parts of guar gum, and then melt extruded and filtered to obtain recycled polyester fiber strips;

[0009] S3. Spinning and Cooling: The recycled polyester fiber strips are distributed and then spun, with a spinning speed of 800 - 900 m / min, and blown to room temperature by air to obtain recycled polyester fiber filaments;

[0010] S4. Preparation of Antistatic Adhesive Layer: The recycled polyester fiber filaments are soaked and passed through the antistatic adhesive layer material, and dried and shaped to obtain recycled polyester fiber filaments wrapped with the antistatic adhesive layer;

[0011] S5. Preparation of Hydrophilic and Moisture - Absorbing Layer: The recycled polyester fiber filaments wrapped with the antistatic adhesive layer are soaked and passed through the hydrophilic and moisture - absorbing layer material, and dried and shaped to obtain recycled polyester fiber filaments wrapped with the hydrophilic and moisture - absorbing layer;

[0012] S6. Drying and Winding: The recycled polyester fiber filaments wrapped with the hydrophilic and moisture - absorbing layer are dried and wound to obtain moisture - absorbing and antistatic polyester staple fibers.

[0013] The preparation method of the moisture - absorbing and antistatic polyester staple fibers of the present invention includes steps of preparation of recycled polyester chips, melt extrusion, spinning and cooling, preparation of antistatic adhesive layer, preparation of hydrophilic and moisture - absorbing layer, and drying and winding; among them, the re - melting, alcoholysis, and polycondensation of PET - based bottle chips can decompose and polymerize the polyester bottle chips again to obtain recycled polyester chips with stable physical and chemical indexes and high purity. In the melt extrusion step, the recycled polyester chips are combined with quaternary ammonium salt of chitosan with good antibacterial property, film - forming property, cation adsorption property, moisture absorption and retention property, flocculation property, and antistatic property, graphene with good toughness and optical properties, activated clay with good decolorization and adsorption properties, polyvinylpyrrolidone with excellent film - forming property, adhesiveness, moisture absorption, and solubilization effect, and guar gum with antistatic and thickening effects; so that under the good dispersion and thickening effects of guar gum and polyvinylpyrrolidone, activated clay adsorbs quaternary ammonium salt of chitosan and graphene and then disperses in the melt of recycled polyester chips, and recycled polyester fiber strips with improved moisture absorption performance, antistatic performance, antibacterial performance and uniform composition distribution are obtained through melt extrusion; by soaking, passing through, drying and shaping, a three - layer structure with a composite antistatic adhesive layer and hydrophilic and moisture - absorbing layer is obtained, not only the hydrophilic and moisture - absorbing performance, antistatic performance, and antibacterial performance are improved, but also the composite structure improves the stability and mechanical properties, maintaining persistent moisture absorption performance and antistatic performance.

[0014] Further, the preparation method of the antistatic adhesive layer material includes the following steps:

[0015] Step 1: Add 1.5 g of multi-walled carbon nanotubes into a flask, then add 8 - 12 g of sodium lignosulfonate and 100 mL of deionized water. Disperse them by ultrasonic bath for 20 min, centrifuge at 8000 - 12000 rpm for 10 min, and then add 0.3 g of fatty alcohol polyoxyethylene ether. Mix and stir evenly to obtain an antistatic dispersion liquid.

[0016] Step 2: Weigh 80 g of rosin modified pentaerythritol ester, heat it to 120 - 130 °C to melt it. After complete melting, add 22 - 30 g of the antistatic dispersion liquid and stir evenly at a speed of 200 - 300 rpm to obtain an antistatic adhesive layer material.

[0017] Furthermore, the diameter of the multi-walled carbon nanotubes is 10 - 30 nm and the length is 1 - 2 μm; the softening point of the rosin modified pentaerythritol ester is 100 - 105 °C, and the maximum acid value is 30 mgKOH / g.

[0018] Furthermore, the preparation method of the hydrophilic moisture-absorbing layer material includes the following steps:

[0019] Step 1: Vacuum dehydrate the sodium polyacrylate solution with a moisture content of 80% at 80 - 90 °C, then raise the temperature to 120 - 130 °C, keep it warm for cross-linking for 30 min, crush, grind and sieve to obtain water-absorbing micropowders with a particle size of 10 - 20 μm. Add deionized water with a mass 5 times that of the water-absorbing micropowders and stir evenly to obtain a water-absorbing micropowder dispersion liquid.

[0020] Step 2: Weigh 60 g of rosin modified pentaerythritol ester, heat it to 120 - 130 °C to melt it. After complete melting, add 15 - 30 g of the water-absorbing micropowder dispersion liquid and stir evenly at a speed of 200 - 300 rpm to obtain a hydrophilic moisture-absorbing layer material.

[0021] Furthermore, the melting temperature in Step S1 is 270 - 280 °C, the alcoholysis is carried out by treating with ethylene glycol at 260 °C for 20 min, and the dosage of ethylene glycol is 1.5 times the mass of the PET bottle chips; the polycondensation is carried out at 280 °C to distill off ethylene glycol and trimethylolpropane.

[0022] Furthermore, in Step S2, the melt extrusion is carried out by a twin-screw extruder, the melting temperature is 285 °C, the screw speed is 120 rpm, and the filtration is carried out using a filter screen with a mesh size of 20 μm.

[0023] Furthermore, the temperature during spinning is 270 - 285 °C, the linear density of the regenerated polyester fiber filaments is 200 dtex, and the draw ratio is 3.5.

[0024] Furthermore, the temperature for drying and shaping in Step S4 is 85 - 95 °C and the time is 30 - 40 min; the temperature for drying and shaping in Step S5 is 80 - 90 °C and the time is 20 - 30 min.

[0025] The present invention has the following beneficial effects:

[0026] 1. In the preparation method of the moisture-absorbing and antistatic polyester filament of the present invention, in the good dispersion and thickening effect of guar gum and polyvinylpyrrolidone, activated clay adsorbs chitosan quaternary ammonium salt and graphene and then disperses in the melt of recycled polyester chips. After melt extrusion, a recycled polyester fiber strip with improved moisture-absorbing performance, antistatic performance, antibacterial performance and uniform composition distribution is obtained; through soaking, passing through and drying and shaping, a three-layer structure of a composite antistatic bonding layer and a hydrophilic moisture-absorbing layer is obtained. Not only the hydrophilic moisture-absorbing performance, antistatic performance and antibacterial performance are improved, but the composite structure also improves the stability and mechanical properties, and maintains the persistent moisture-absorbing performance and antistatic performance.

[0027] 2. The antistatic bonding layer material non-covalently modifies multi-walled carbon nanotubes with lignosulfonate, an anionic surfactant with dispersion and flocculation effects, and disperses to form an antistatic dispersion liquid under the emulsification of fatty alcohol polyoxyethylene ether; due to a large number of surface groups such as carboxyl groups and hydroxyl groups bonded to the surface of multi-walled carbon nanotubes, the P electrons on the carbon atoms form a large-range delocalized π bond, with significant conjugation effect and good electrical conductivity; under the coating and bonding effect of rosin-modified pentaerythritol ester, the water in the antistatic dispersion liquid evaporates and is wrapped, and after drying, it has dense mesh holes, obtaining an antistatic bonding layer with high structural strength, not easily removed by washing with water and having long-term antistatic performance.

[0028] 3. The hydrophilic moisture-absorbing layer material crosslinks, crushes, grinds and sieves sodium polyacrylate with high water absorbency to obtain a water-absorbing fine powder dispersion liquid with good fluidity. Under the coating and bonding effect of rosin-modified pentaerythritol ester, the water in the water-absorbing fine powder dispersion liquid evaporates and is coated, and after drying, it has dense mesh holes, obtaining a hydrophilic moisture-absorbing layer with high structural strength, not easily removed by washing with water and having long-term hydrophilic moisture-absorbing performance. Detailed implementation manners

[0029] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0030] Example 1

[0031] A method for preparing a moisture-absorbing and antistatic polyester filament from recycled polyester fibers in this example includes the following steps:

[0032] S1. Preparation of recycled polyester chips: Bottles made of PET material are washed, shredded, melted, alcoholyzed, polycondensed, and cooled to obtain recycled polyester chips with a molecular weight of 17,000 - 18,000, an intrinsic viscosity of 0.7 - 0.8 dl / g, a crystallinity of 28%, a melting point of 249 ± 2 °C, and a moisture content of less than 1200 ppm. Among them, the melting temperature is 276 °C, the alcoholysis is carried out by treating with ethylene glycol at 260 °C for 20 min, and the dosage of ethylene glycol is 1.5 times the mass of the PET material bottles. The polycondensation is carried out at 280 °C to distill off ethylene glycol and trimethylolpropane.

[0033] S2. Melting and extrusion: 890 g of recycled polyester chips are mixed with 42 g of quaternary ammonium salt of chitosan, 16 g of graphene, 26 g of activated clay, 7 g of polyvinylpyrrolidone, and 75 g of guar gum, and then melted and extruded and filtered to obtain recycled polyester fiber strips. Among them, the melting and extrusion is carried out using a twin-screw extruder, the melting temperature is 285 °C, the screw speed is 120 rpm, and the filtration is carried out using a filter screen with a mesh size of 20 μm.

[0034] S3. Spinning and cooling: The recycled polyester fiber strips are distributed and then spun, the spinning speed is 860 m / min, and they are cooled by blowing to room temperature to obtain recycled polyester fiber filaments. The temperature during spinning is 280 °C, the linear density of the recycled polyester fiber filaments is 200 dtex, and the draw ratio is 3.5.

[0035] S4. Preparation of antistatic adhesive layer: The recycled polyester fiber filaments are soaked and passed through the antistatic adhesive layer material, and then dried and shaped to obtain recycled polyester fiber filaments wrapped with the antistatic adhesive layer. Among them, the drying and shaping temperature is 88 °C, and the time is 40 min.

[0036] The preparation method of the antistatic adhesive layer material includes the following steps:

[0037] Step 1, Add 1.5 g of multi-walled carbon nanotubes into a flask, add 9 g of sodium lignosulfonate and 100 mL of deionized water, disperse by water bath ultrasonic for 20 min, centrifuge at 9000 rpm for 10 min, and add 0.3 g of fatty alcohol polyoxyethylene ether, and mix and stir evenly to obtain an antistatic dispersion liquid. The diameter of the multi-walled carbon nanotubes is 10 - 30 nm, and the length is 1 - 2 μm.

[0038] Step 2, Weigh 80 g of rosin-modified pentaerythritol ester, heat it to 125 °C to melt it, and after complete melting, add 28 g of the antistatic dispersion liquid, and stir evenly at a speed of 270 rpm to obtain the antistatic adhesive layer material. The softening point of the rosin-modified pentaerythritol ester is 100 - 105 °C, and the maximum acid value is 30 mgKOH / g.

[0039] S5. Preparation of hydrophilic moisture-absorbing layer: The regenerated polyester fiber filaments wrapped with the antistatic adhesive layer are soaked and passed through the hydrophilic moisture-absorbing layer material, and then dried and shaped to obtain the regenerated polyester fiber filaments wrapped with the hydrophilic moisture-absorbing layer; among them, the drying and shaping temperature is 86 °C and the time is 28 min.

[0040] The preparation method of the hydrophilic moisture-absorbing layer material includes the following steps:

[0041] Step 1, vacuum dehydrate the sodium polyacrylate solution with a moisture content of 80% at 86 °C, raise the temperature to 125 °C, keep warm and crosslink for 30 min, crush, grind and screen to obtain water-absorbing micropowders with a particle size of 10 - 20 μm, and add deionized water 5 times the mass of the water-absorbing micropowders, and stir evenly to obtain a water-absorbing micropowder dispersion.

[0042] Step 2, weigh 60 g of rosin-modified pentaerythritol ester, heat it to 125 °C to melt it, and after complete melting, add 26 g of the water-absorbing micropowder dispersion, and stir evenly at a rotation speed of 280 rpm to obtain the hydrophilic moisture-absorbing layer material; the softening point of the rosin-modified pentaerythritol ester is 100 - 105 °C, and the maximum acid value is 30 mgKOH / g.

[0043] S6. Drying and winding: The regenerated polyester fiber filaments wrapped with the hydrophilic moisture-absorbing layer are dried and wound to obtain moisture-absorbing and antistatic polyester staple fibers.

[0044] Example 2

[0045] A method for preparing moisture-absorbing and antistatic polyester staple fibers from regenerated polyester fibers in this example includes the following steps:

[0046] S1. Preparation of regenerated polyester chips: The PET material bottle flakes are washed, chopped, melted, alcoholyzed, polycondensed and cooled to obtain regenerated polyester chips with a molecular weight of 17000 - 18000, an intrinsic viscosity of 0.7 - 0.8 dl / g, a crystallinity of 28%, a melting point of 249 ± 2 °C, and a moisture content of less than 1200 ppm; among them, the melting temperature is 280 °C, the alcoholysis is carried out by treating with ethylene glycol at 260 °C for 20 min, and the dosage of ethylene glycol is 1.5 times the mass of the PET material bottle flakes; the polycondensation is to distill off ethylene glycol and trimethylolpropane at 280 °C.

[0047] S2. Melting and extrusion: After mixing 986 g of regenerated polyester chips with 32 g of chitosan quaternary ammonium salt, 9 g of graphene, 15 g of activated clay, 5 g of polyvinylpyrrolidone, and 92 g of guar gum, melt and extrude and filter to obtain regenerated polyester fiber strips; among them, the melting and extrusion is carried out by a twin-screw extruder, the melting temperature is 285 °C, the screw rotation speed is 120 rpm, and the filtration is carried out with a filter screen with a mesh size of 20 μm.

[0048] S3. Spinning and Cooling: After distributing the recycled polyester fiber strips, they are spun at a spinning speed of 900 m / min and cooled by air blowing to room temperature to obtain recycled polyester fiber filaments. The spinning temperature is 282 °C, the linear density of the recycled polyester fiber filaments is 200 dtex, and the draw ratio is 3.5;

[0049] S4. Preparation of Antistatic Adhesive Layer: The recycled polyester fiber filaments are soaked and passed through the antistatic adhesive layer material, and then dried and shaped to obtain recycled polyester fiber filaments wrapped with the antistatic adhesive layer. Among them, the drying and shaping temperature is 94 °C and the time is 38 min;

[0050] The preparation method of the antistatic adhesive layer material includes the following steps:

[0051] Step 1: Add 1.5 g of multi-walled carbon nanotubes into a flask, add 11 g of sodium lignosulfonate and 100 mL of deionized water, disperse them by water bath ultrasonic for 20 min, centrifuge at 11000 rpm for 10 min, and add 0.3 g of fatty alcohol polyoxyethylene ether, and mix and stir evenly to obtain an antistatic dispersion liquid. The diameter of the multi-walled carbon nanotubes is 10 - 30 nm and the length is 1 - 2 μm;

[0052] Step 2: Weigh 80 g of rosin-modified pentaerythritol ester, heat it to 130 °C to melt it, and after complete melting, add 28 g of the antistatic dispersion liquid, and stir evenly at a speed of 300 rpm to obtain the antistatic adhesive layer material. The softening point of the rosin-modified pentaerythritol ester is 100 - 105 °C, and the maximum acid value is 30 mgKOH / g;

[0053] S5. Preparation of Hydrophilic and Moisture-absorbing Layer: The recycled polyester fiber filaments wrapped with the antistatic adhesive layer are soaked and passed through the hydrophilic and moisture-absorbing layer material, and then dried and shaped to obtain recycled polyester fiber filaments wrapped with the hydrophilic and moisture-absorbing layer. Among them, the drying and shaping temperature is 87 °C and the time is 28 min;

[0054] The preparation method of the hydrophilic and moisture-absorbing layer material includes the following steps:

[0055] Step 1: Vacuum dehydrate the sodium polyacrylate solution with a moisture content of 80% at 90 °C, raise the temperature to 128 °C, keep it warm and crosslink for 30 min, crush, grind, and sieve to obtain water-absorbing micropowders with a particle size of 10 - 20 μm, and add deionized water 5 times the mass of the water-absorbing micropowders, and stir evenly to obtain a water-absorbing micropowder dispersion liquid;

[0056] Step 2: Weigh 60 g of rosin-modified pentaerythritol ester, heat it to 130 °C to melt it, and after complete melting, add 30 g of the water-absorbing micropowder dispersion liquid, and stir evenly at a speed of 300 rpm to obtain the hydrophilic and moisture-absorbing layer material. The softening point of the rosin-modified pentaerythritol ester is 100 - 105 °C, and the maximum acid value is 30 mgKOH / g;

[0057] S6. Drying and winding: The regenerated polyester fiber filaments wrapped with the hydrophilic and moisture-absorbing layer are dried and wound to obtain moisture-absorbing and antistatic polyester filament.

[0058] Example 3

[0059] A method for preparing moisture-absorbing and antistatic polyester filament from regenerated polyester fiber in this example includes the following steps:

[0060] S1. Preparation of regenerated polyester chips: The PET bottles are washed, shredded, melted, alcoholyzed, polycondensed, and cooled to obtain regenerated polyester chips with a molecular weight of 17,000 - 18,000, intrinsic viscosity of 0.7 - 0.8 dl / g, crystallinity of 28%, melting point of 249 ± 2 °C, and moisture content less than 1200 ppm; among them, the melting temperature is 280 °C, alcoholysis is carried out by treating with ethylene glycol at 260 °C for 20 min, and the dosage of ethylene glycol is 1.5 times the mass of the PET bottles; polycondensation is to distill off ethylene glycol and trimethylolpropane at 280 °C.

[0061] S2. Melting and extrusion: 920 g of regenerated polyester chips are mixed with 53 g of chitosan quaternary ammonium salt, 16 g of graphene, 15 g of activated clay, 3 g of polyvinylpyrrolidone, and 66 g of guar gum, then melted, extruded, and filtered to obtain regenerated polyester fiber strips; among them, melting and extrusion are carried out using a twin-screw extruder, the melting temperature is 285 °C, the screw speed is 120 rpm, and the filtration is carried out using a filter screen with a mesh size of 20 μm.

[0062] S3. Spinning and cooling: The regenerated polyester fiber strips are distributed and spun, the spinning speed is 830 m / min, and they are cooled by blowing to room temperature to obtain regenerated polyester fiber filaments; the temperature during spinning is 276 °C, the linear density of the regenerated polyester fiber filaments is 200 dtex, and the draw ratio is 3.5.

[0063] S4. Preparation of antistatic bonding layer: The regenerated polyester fiber filaments are soaked and passed through the antistatic bonding layer material, and then dried and shaped to obtain regenerated polyester fiber filaments wrapped with the antistatic bonding layer; among them, the temperature for drying and shaping is 95 °C, and the time is 34 min.

[0064] The preparation method of the antistatic bonding layer material includes the following steps:

[0065] Step 1, Add 1.5 g of multi-walled carbon nanotubes into a flask, add 12 g of sodium lignosulfonate and 100 mL of deionized water, disperse by water bath ultrasonic for 20 min, centrifuge at 12,000 rpm for 10 min, add 0.3 g of fatty alcohol polyoxyethylene ether, and mix and stir evenly to obtain an antistatic dispersion; the diameter of the multi-walled carbon nanotubes is 10 - 30 nm, and the length is 1 - 2 μm.

[0066] Step 2: Weigh 80 g of rosin-modified pentaerythritol ester, heat it to 123 °C to melt it, and after complete melting, add 30 g of antistatic dispersion liquid, and stir evenly at a rotation speed of 290 rpm to obtain an antistatic bonding layer material; the softening point of the rosin-modified pentaerythritol ester is 100 - 105 °C, and the maximum acid value is 30 mgKOH / g;

[0067] S5. Preparation of hydrophilic moisture-absorbing layer: Immerse and pass the regenerated polyester fiber filaments wrapped with the antistatic bonding layer through the hydrophilic moisture-absorbing layer material, and dry and shape it to obtain the regenerated polyester fiber filaments wrapped with the hydrophilic moisture-absorbing layer; among them, the drying and shaping temperature is 85 °C, and the time is 28 min;

[0068] The preparation method of the hydrophilic moisture-absorbing layer material includes the following steps:

[0069] Step 1: Vacuum dehydrate the sodium polyacrylate solution with a moisture content of 80% at 87 °C, raise the temperature to 122 °C, keep warm and crosslink for 30 min, crush, grind, and screen to obtain water-absorbing micropowders with a particle size of 10 - 20 μm, and add deionized water 5 times the mass of the water-absorbing micropowders, and stir evenly to obtain a water-absorbing micropowder dispersion liquid;

[0070] Step 2: Weigh 60 g of rosin-modified pentaerythritol ester, heat it to 130 °C to melt it, and after complete melting, add 18 g of the water-absorbing micropowder dispersion liquid, and stir evenly at a rotation speed of 280 rpm to obtain the hydrophilic moisture-absorbing layer material; the softening point of the rosin-modified pentaerythritol ester is 100 - 105 °C, and the maximum acid value is 30 mgKOH / g;

[0071] S6. Drying and winding: The regenerated polyester fiber filaments wrapped with the hydrophilic moisture-absorbing layer are dried and wound to obtain moisture-absorbing and antistatic polyester staple fibers.

[0072] Example 4

[0073] A method for preparing moisture-absorbing and antistatic polyester staple fibers from regenerated polyester fibers in this example includes the following steps:

[0074] S1. Preparation of regenerated polyester chips: Wash, cut, melt, alcoholyze, polycondense, and cool the PET material bottle chips to obtain regenerated polyester chips with a molecular weight of 17,000 - 18,000, an intrinsic viscosity of 0.7 - 0.8 dl / g, a crystallinity of 28%, a melting point of 249 ± 2 °C, and a moisture content of less than 1200 ppm; among them, the melting temperature is 277 °C, the alcoholysis is carried out by treating with ethylene glycol at 260 °C for 20 min, and the dosage of ethylene glycol is 1.5 times the mass of the PET material bottle chips; the polycondensation is to distill off ethylene glycol and trimethylolpropane at 280 °C;

[0075] S2. Melt Extrusion: After mixing 1000 g of recycled polyester chips with 60 g of quaternary ammonium salt of chitosan, 18 g of graphene, 28 g of activated clay, 7 g of polyvinylpyrrolidone, and 108 g of guar gum, melt extrusion and filtration are carried out to obtain recycled polyester fiber strips. Among them, melt extrusion is carried out using a twin-screw extruder, the melting temperature is 285 °C, the screw speed is 120 rpm, and filtration is carried out using a filter screen with a mesh size of 20 μm.

[0076] S3. Spinning and Cooling: The recycled polyester fiber strips are distributed and then spun. The spinning speed is 840 m / min, and they are cooled by blowing to room temperature to obtain recycled polyester fiber filaments. The temperature during spinning is 282 °C, the linear density of the recycled polyester fiber filaments is 200 dtex, and the draw ratio is 3.5.

[0077] S4. Preparation of Antistatic Adhesive Layer: The recycled polyester fiber filaments are soaked and passed through the antistatic adhesive layer material, and then dried and shaped to obtain recycled polyester fiber filaments wrapped with the antistatic adhesive layer. Among them, the temperature for drying and shaping is 90 °C, and the time is 38 min.

[0078] The preparation method of the antistatic adhesive layer material includes the following steps:

[0079] Step 1: Add 1.5 g of multi-walled carbon nanotubes into a flask, add 11 g of sodium lignosulfonate and 100 mL of deionized water, disperse by water bath ultrasonic for 20 min, centrifuge at 9500 rpm for 10 min, and add 0.3 g of fatty alcohol polyoxyethylene ether, and mix and stir evenly to obtain an antistatic dispersion liquid. The diameter of the multi-walled carbon nanotubes is 10 - 30 nm, and the length is 1 - 2 μm.

[0080] Step 2: Weigh 80 g of rosin-modified pentaerythritol ester, heat it to 128 °C to melt it, and after complete melting, add 25 g of the antistatic dispersion liquid, and stir evenly at a speed of 260 rpm to obtain the antistatic adhesive layer material. The softening point of the rosin-modified pentaerythritol ester is 100 - 105 °C, and the maximum acid value is 30 mgKOH / g.

[0081] S5. Preparation of Hydrophilic and Hygroscopic Layer: The recycled polyester fiber filaments wrapped with the antistatic adhesive layer are soaked and passed through the hydrophilic and hygroscopic layer material, and then dried and shaped to obtain recycled polyester fiber filaments wrapped with the hydrophilic and hygroscopic layer. Among them, the temperature for drying and shaping is 85 °C, and the time is 30 min.

[0082] The preparation method of the hydrophilic and hygroscopic layer material includes the following steps:

[0083] Step 1: Vacuum dehydrate the sodium polyacrylate solution with a moisture content of 80% at 87 °C, raise the temperature to 130 °C, keep it warm and crosslink for 30 min, crush, grind, and sieve to obtain water-absorbing micropowders with a particle size of 10 - 20 μm, and add deionized water 5 times the mass of the water-absorbing micropowders, and stir evenly to obtain a water-absorbing micropowder dispersion liquid.

[0084] Step 2: Weigh 60 g of rosin-modified pentaerythritol ester, heat it to 130 °C until it melts completely, and then add 26 g of water-absorbing micropowder dispersion liquid. Stir evenly at a speed of 230 rpm to obtain the hydrophilic moisture-absorbing layer material. The softening point of the rosin-modified pentaerythritol ester is 100 - 105 °C, and the maximum acid value is 30 mgKOH / g.

[0085] S6. Drying and winding: The regenerated polyester fiber filaments wrapped with the hydrophilic moisture-absorbing layer are dried and wound to obtain moisture-absorbing and antistatic polyester staple fibers.

[0086] Example 5

[0087] A method for preparing moisture-absorbing and antistatic polyester staple fibers from regenerated polyester fibers in this example includes the following steps:

[0088] S1. Preparation of regenerated polyester chips: Bottles made of PET are cleaned, shredded, melted, alcoholyzed, polycondensed, and cooled to obtain regenerated polyester chips with a molecular weight of 17,000 - 18,000, an intrinsic viscosity of 0.7 - 0.8 dl / g, a crystallinity of 28%, a melting point of 249 ± 2 °C, and a moisture content of less than 1200 ppm. Among them, the melting temperature is 274 °C, the alcoholysis is carried out by treating with ethylene glycol at 260 °C for 20 min, and the dosage of ethylene glycol is 1.5 times the mass of the PET bottles. The polycondensation is carried out at 280 °C to distill off ethylene glycol and trimethylolpropane.

[0089] S2. Melting and extrusion: Mix 885 g of regenerated polyester chips with 37 g of chitosan quaternary ammonium salt, 9 g of graphene, 16 g of activated clay, 5 g of polyvinylpyrrolidone, and 86 g of guar gum, and then melt and extrude and filter to obtain regenerated polyester fiber strips. Among them, the melting and extrusion is carried out using a twin-screw extruder, the melting temperature is 285 °C, the screw speed is 120 rpm, and the filtration is carried out using a filter screen with a mesh size of 20 μm.

[0090] S3. Spinning and cooling: Distribute the regenerated polyester fiber strips and then spin them. The spinning speed is 890 m / min, and they are cooled to room temperature by blowing air to obtain regenerated polyester fiber filaments. The temperature during spinning is 282 °C, the linear density of the regenerated polyester fiber filaments is 200 dtex, and the draw ratio is 3.5.

[0091] S4. Preparation of antistatic adhesive layer: Immerse the regenerated polyester fiber filaments in the antistatic adhesive layer material and pass them through, and then dry and shape them to obtain regenerated polyester fiber filaments wrapped with the antistatic adhesive layer. Among them, the temperature for drying and shaping is 95 °C, and the time is 36 min.

[0092] The preparation method of the antistatic adhesive layer material includes the following steps:

[0093] Step 1: Add 1.5 g of multi-walled carbon nanotubes into a flask, then add 9 g of sodium lignosulfonate and 100 mL of deionized water. Disperse them by ultrasonic bath for 20 min, centrifuge at 10600 rpm for 10 min, and then add 0.3 g of fatty alcohol polyoxyethylene ether. Mix and stir evenly to obtain an antistatic dispersion; the diameter of the multi-walled carbon nanotubes is 10 - 30 nm and the length is 1 - 2 μm;

[0094] Step 2: Weigh 80 g of rosin-modified pentaerythritol ester, heat it to 127 °C to melt it. After complete melting, add 27 g of the antistatic dispersion and stir evenly at a speed of 260 rpm to obtain an antistatic bonding layer material; the softening point of the rosin-modified pentaerythritol ester is 100 - 105 °C and the maximum acid value is 30 mgKOH / g;

[0095] S5. Preparation of the hydrophilic moisture-absorbing layer: Immerse the regenerated polyester fiber filaments wrapped with the antistatic bonding layer through the hydrophilic moisture-absorbing layer material, and then dry and shape them to obtain the regenerated polyester fiber filaments wrapped with the hydrophilic moisture-absorbing layer; among them, the temperature for drying and shaping is 86 °C and the time is 28 min;

[0096] The preparation method of the hydrophilic moisture-absorbing layer material includes the following steps:

[0097] Step 1: Vacuum dehydrate the sodium polyacrylate solution with a moisture content of 80% at 90 °C, raise the temperature to 128 °C, keep it warm and crosslink for 30 min, then crush, grind and screen to obtain water-absorbing micropowders with a particle size of 10 - 20 μm. Add deionized water 5 times the mass of the water-absorbing micropowders and stir evenly to obtain a water-absorbing micropowder dispersion;

[0098] Step 2: Weigh 60 g of rosin-modified pentaerythritol ester, heat it to 124 °C to melt it. After complete melting, add 30 g of the water-absorbing micropowder dispersion and stir evenly at a speed of 300 rpm to obtain the hydrophilic moisture-absorbing layer material; the softening point of the rosin-modified pentaerythritol ester is 100 - 105 °C and the maximum acid value is 30 mgKOH / g;

[0099] S6. Drying and winding: The regenerated polyester fiber filaments wrapped with the hydrophilic moisture-absorbing layer are dried and wound to obtain moisture-absorbing and antistatic polyester drawn yarns.

[0100] Comparative Example 1

[0101] A method for preparing moisture-absorbing and antistatic polyester drawn yarns from regenerated polyester fibers provided in this comparative example is different from that in Example 1 in that chitosan quaternary ammonium salt and graphene are not added in the melt extrusion step.

[0102] Comparative Example 2

[0103] A method for preparing moisture-absorbing and antistatic polyester drawn yarns from regenerated polyester fibers provided in this comparative example is different from that in Example 1 in that the step of preparing the antistatic bonding layer is cancelled.

[0104] Comparative Example 3

[0105] A method for preparing moisture-absorbing and antistatic polyester filament from recycled polyester fiber provided in this comparative example is different from that in Example 1 in that the step of preparing the hydrophilic moisture-absorbing layer is cancelled.

[0106] Comparative Example 4

[0107] A method for preparing moisture-absorbing and antistatic polyester filament from recycled polyester fiber provided in this comparative example is different from that in Example 1 in that drying and shaping are not carried out during the preparation of the hydrophilic moisture-absorbing layer.

[0108] Performance Test of Polyester Filament

[0109] For the moisture-absorbing and antistatic polyester filaments prepared from recycled polyester fiber in Examples 1-5 and Comparative Examples 1-4, the coefficient of variation of linear density, breaking strength and antibacterial rate after 20 times of washing were tested with reference to the standard DB35 / T 1058-2019 "General Technical Conditions for Antibacterial Polyester Filament", and the moisture-absorbing performance and antistatic performance were also tested;

[0110] Among them, for the moisture-absorbing performance test, the temperature was controlled at (20±2)°C and the relative humidity was controlled at (65±3)%. The filament was immersed in water for more than 2 h, then the filament was taken out and drained naturally, and finally put into a centrifuge to dehydrate at a speed of 1500 rpm for 10 min. The filament was taken out and quickly weighed on an electronic balance and marked as W1. Then the filament was dried to a constant weight in an electrothermal blast drying oven at (105±3)°C and quickly weighed on an electronic balance and marked as W0. The water retention rate was calculated using the following formula: Water retention rate = (W1 - W0) / W0 * 100%; The antistatic performance test was carried out with reference to the standard GB / T 12703.4-2010 to test the surface resistivity. The specific test results are shown in the following table:

[0111]

[0112]

[0113] As can be seen from the above table, for the polyester filaments prepared in the embodiments of the present invention, the coefficient of variation of linear density and the surface resistivity are less than those of the comparative examples, while the breaking strength, the antibacterial rate and the water retention rate after 20 washes are greater than those of the comparative examples. This shows that the linear density of the polyester filaments in the embodiments has a lower degree of dispersion, and the breaking strength, antibacterial property, moisture absorption and sweat discharge property, and antistatic property are better, making them suitable for further processing into sportswear fabrics with moisture absorption and sweat discharge and antistatic properties. In Comparative Example 1, since chitosan quaternary ammonium salt and graphene were not added in the melt extrusion step, it does not have the antibacterial and antistatic properties of chitosan quaternary ammonium salt and the toughness and optical properties of graphene, resulting in a decrease in breaking strength and a relatively obvious decrease in antibacterial rate, moisture absorption property and antistatic property. In Comparative Example 2, since the antistatic adhesive layer was removed, the overall structural strength and antistatic property of the polyester filaments were significantly reduced. In Comparative Example 3, since the hydrophilic moisture absorption layer was removed, the overall structural strength and moisture absorption property of the polyester filaments were significantly reduced. In Comparative Example 4, since the hydrophilic moisture absorption layer was not dried and shaped during preparation, the structure of the hydrophilic moisture absorption layer was not stable enough, and the hydrophilic components were not well combined with the polyester fibers, resulting in a decrease in breaking strength, moisture absorption property and antistatic property.

[0114] The above content is only an example and explanation of the structure of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the structure of the invention or exceed the scope defined by this claim book, they should fall within the protection scope of the present invention.

[0115] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only the specific embodiments. Obviously, according to the content of this specification, many modifications and changes can be made. This specification selects and specifically describes these embodiments to better explain the principle and practical application of the present invention, so that those skilled in the art can understand and utilize the present invention well. The present invention is only limited by the claim book and its full scope and equivalents.

Claims

1. Method for preparing moisture-absorbing and antistatic polyester filament from recycled polyester fiber, Characterized in that, It includes the following steps: S1. Preparation of recycled polyester chips: Bottles made of PET material are washed, shredded, melted, alcoholyzed, polycondensed, and cooled to obtain recycled polyester chips with a molecular weight of 17,000 - 18,000, intrinsic viscosity of 0.7 - 0.8 dl / g, crystallinity of 28%, melting point of 249 ± 2 °C, and moisture content less than 1200 ppm; S2. Melting and extrusion: According to parts by weight, 85 - 100 parts of recycled polyester chips are mixed with 2 - 6 parts of chitosan quaternary ammonium salt, 0.4 - 1.8 parts of graphene, 1 - 3 parts of activated clay, 0.2 - 0.8 parts of polyvinylpyrrolidone, and 5 - 11 parts of guar gum, then melted and extruded and filtered to obtain recycled polyester fiber strips; S3. Spinning and cooling: The recycled polyester fiber strips are distributed and spun, and the spinning speed is 800 - 900 m / min, and are cooled by blowing to room temperature to obtain recycled polyester fiber filaments; S4. Preparation of antistatic adhesive layer: The recycled polyester fiber filaments are soaked and passed through the antistatic adhesive layer material, and are dried and shaped to obtain recycled polyester fiber filaments wrapped with an antistatic adhesive layer; S5. Preparation of hydrophilic moisture-absorbing layer: The recycled polyester fiber filaments wrapped with an antistatic adhesive layer are soaked and passed through the hydrophilic moisture-absorbing layer material, and are dried and shaped to obtain recycled polyester fiber filaments wrapped with a hydrophilic moisture-absorbing layer; S6. Drying and winding: The recycled polyester fiber filaments wrapped with a hydrophilic moisture-absorbing layer are dried and wound to obtain moisture-absorbing and antistatic polyester filaments; The preparation method of the antistatic adhesive layer material includes the following steps: Step 1, Add 1.5 g of multi-walled carbon nanotubes into a flask, add 8 - 12 g of sodium lignosulfonate and 100 mL of deionized water, disperse by water bath ultrasonic for 20 min, centrifuge at 8000 - 12000 rpm for 10 min, add 0.3 g of fatty alcohol polyoxyethylene ether, and mix and stir evenly to obtain an antistatic dispersion; Step 2, Weigh 80 g of rosin-modified pentaerythritol ester, heat it to 120 - 130 °C to melt it, after complete melting, add 22 - 30 g of the antistatic dispersion, and stir evenly at a speed of 200 - 300 rpm to obtain the antistatic adhesive layer material.

2. The method for preparing moisture-absorbing and antistatic polyester filament from recycled polyester fiber according to claim 1, Characterized in that, The diameter of the multi-walled carbon nanotubes is 10 - 30 nm, and the length is 1 - 2 μm; the softening point of the rosin-modified pentaerythritol ester is 100 - 105 °C, and the maximum acid value is 30 mg KOH / g.

3. The method for preparing moisture-absorbing and antistatic polyester filament from recycled polyester fiber according to claim 1, Characterized in that, The preparation method of the hydrophilic moisture-absorbing layer material includes the following steps: Step 1, Vacuum dehydrate the sodium polyacrylate solution with a water content of 80% at 80 - 90 °C, raise the temperature to 120 - 130 °C, keep warm and crosslink for 30 min, crush, grind, and sieve to obtain water-absorbing micropowders with a particle size of 10 - 20 μm, add deionized water 5 times the mass of the water-absorbing micropowders, and stir evenly to obtain a water-absorbing micropowder dispersion; Step 2: Weigh 60 g of rosin-modified pentaerythritol ester, heat it to 120 - 130 °C until it melts completely, and then add 15 - 30 g of water-absorbing micropowder dispersion liquid. Stir evenly at a speed of 200 - 300 rpm to obtain the hydrophilic moisture-absorbing layer material.

4. The method for preparing moisture-absorbing and antistatic polyester filament from recycled polyester fiber according to claim 1, characterized in that, the melting temperature in step S1 is 270 - 280 °C, alcoholysis is carried out by treating with ethylene glycol at 260 °C for 20 min, and the dosage of ethylene glycol is 1.5 times the mass of the PET bottle chips; polycondensation is carried out at 280 °C to distill off ethylene glycol and trimethylolpropane.

5. The method for preparing moisture-absorbing and antistatic polyester filament from recycled polyester fiber according to claim 1, characterized in that, in step S2, melt extrusion is carried out using a twin-screw extruder, the melting temperature is 285 °C, the screw speed is 120 rpm, and the filtration is carried out using a filter screen with a mesh size of 20 μm.

6. The method for preparing moisture-absorbing and antistatic polyester filament from recycled polyester fiber according to claim 1, characterized in that, the temperature during spinning is 270 - 285 °C, the linear density of the recycled polyester fiber filament is 200 dtex, and the draw ratio is 3.

5.

7. The method for preparing moisture-absorbing and antistatic polyester filament from recycled polyester fiber according to claim 1, characterized in that, the drying and shaping temperature in step S4 is 85 - 95 °C, and the time is 30 - 40 min; the drying and shaping temperature in step S5 is 80 - 90 °C, and the time is 20 - 30 min.

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