A method for preparing an antibacterial self-crimping regenerated polyester fiber

Abstract

The application discloses a preparation method of antibacterial self-crimping regenerated polyester fiber and belongs to the technical field of regenerated polyester spinning. The preparation method comprises the following steps: (1) calcining mixed boric acid, melamine and soluble zinc salt in an inert atmosphere to obtain zinc-containing hexagonal boron nitride; (2) mixing and impregnating the zinc-containing hexagonal boron nitride and quaternary ammonium salt ionic liquid to obtain modified zinc-containing hexagonal boron nitride; (3) mixing the modified zinc-containing hexagonal boron nitride, polyester bottle pieces and ethylene glycol, and performing alcoholysis reaction to obtain a mixture A; (4) drying and melting the polyester bottle pieces and the mixture A respectively and sequentially, and then performing parallel composite spinning to obtain primary fibers; and (5) performing drafting, crimping, cutting and relaxation heat setting on the primary fibers to obtain the regenerated polyester fiber. The single regenerated polyester is used as a raw material, alcoholysis catalysis is performed on the modified zinc-containing hexagonal boron nitride, viscosity difference of the system is realized, and the regenerated polyester fiber with excellent self-crimping effect and antibacterial performance is prepared.

Description

Technical Field

[0001] This invention relates to the field of recycled polyester spinning technology, and in particular to a method for preparing antibacterial self-crimping recycled polyester fiber. Background Technology

[0002] Polyester fiber, a commonly used filling material in the textile industry, has a wide range of applications. Among them, three-dimensional hollow polyester staple fiber, with its excellent warmth retention and resilience, is highly favored in products such as clothing, toys, pillows, and bedding. With the diversification of product categories, the application scenarios of polyester staple fiber are gradually extending to the home furnishing sector, and it is widely used in the production of mattresses, cushions, sofas, and other home furnishing products. This expansion of applications places higher demands on the fiber's performance to ensure the suitability of home furnishing products.

[0003] In existing technologies, the modification of recycled polyester fibers mostly focuses on achieving a single function, such as simple self-crimping modification or simple antibacterial modification. However, the preparation technology of recycled polyester staple fibers that effectively combine antibacterial function and self-crimping performance is still imperfect. Some attempts at composite functional modification generally suffer from the following problems: First, it is difficult to balance crimp morphology and antibacterial performance, often resulting in a decrease in crimp due to increased antibacterial agent addition, or sacrificing antibacterial effect to ensure crimp performance; second, the overall performance of the fibers is poor, such as low mechanical strength, insufficient wash resistance, and unstable crimp recovery rate; third, the preparation process is complex, requiring excessively high-end equipment, making industrial-scale mass production difficult.

[0004] Patent CN116607244A discloses a parallel composite self-crimping recycled polyester staple fiber, its preparation method, and its applications. This process uses recycled PET bottle flakes as a high-viscosity component and polyester industrial foam as a low-viscosity component. A viscosity control strategy of "intelligent coarse blending + online fine blending" is used to regulate the melt viscosity ratio of the two components. A parallel composite spinning process is employed, and after stretching and heat treatment, the difference in thermal shrinkage rates between the two components forms a three-dimensional helical crimp structure. The resulting fiber possesses excellent bulkiness and elastic recovery, making it suitable for applications such as wool-like fabrics and high-end home textile fillings. However, this technology only focuses on optimizing self-crimping performance and efficiently utilizing recycled polyester raw materials, without endowing the fiber with antibacterial functions. This makes it difficult to meet the antibacterial and antimicrobial performance requirements of medical protective equipment and intimate apparel textiles. Furthermore, the single recycled polyester composite system lacks functional modification design, and the fiber's weather resistance and anti-aging properties need improvement, making it unsuitable for complex application environments such as humid and high-bacterial environments.

[0005] Patent CN116676683B discloses a method for preparing antibacterial recycled polyester staple fiber. This method uses recycled PET bottle flakes as raw material, which are washed, dried, and melt-extruded to obtain recycled polyester melt. A nano-zinc oxide antibacterial agent is mixed with a polyester carrier to prepare an antibacterial masterbatch. The antibacterial masterbatch is then blended with the recycled polyester melt, and antibacterial recycled polyester staple fiber is obtained through melt spinning, drawing, and cutting processes. The resulting fiber has a certain inhibitory effect on Escherichia coli and Staphylococcus aureus, and is suitable for home textiles, nonwoven fabrics, and other fields. However, nano-zinc oxide is prone to agglomeration in the recycled polyester matrix, resulting in poor dispersion uniformity of the antibacterial agent and insufficient stability of antibacterial performance. Simultaneously, the antibacterial spectrum of a single nano-zinc oxide antibacterial agent is narrow, making it difficult to effectively inhibit the growth of fungi, molds, and other microorganisms. Furthermore, the antibacterial performance of the fiber significantly decreases after repeated washing, failing to meet the long-term antibacterial requirements of high-end applications such as medical protective clothing and intimate apparel.

[0006] Therefore, there is an urgent need for a novel method for preparing antibacterial self-curling recycled polyester fiber to overcome the above-mentioned shortcomings and promote the development and application of antibacterial self-curling recycled polyester fiber. Summary of the Invention

[0007] In view of this, the technical problem to be solved by the present invention is to provide a method for preparing antibacterial self-crimping recycled polyester fiber. The recycled polyester fiber prepared by the method has excellent crimping properties and antibacterial properties.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] This invention provides a method for preparing antibacterial self-crimping recycled polyester fiber, comprising the following steps:

[0010] (1) The mixture of boric acid, melamine and soluble zinc salt was calcined under an inert atmosphere to obtain zinc-containing hexagonal boron nitride;

[0011] (2) The zinc-containing hexagonal boron nitride and the quaternary ammonium salt ionic liquid are mixed and impregnated to obtain modified zinc-containing hexagonal boron nitride;

[0012] (3) The modified zinc-containing hexagonal boron nitride, polyester bottle flakes, and ethylene glycol are mixed and subjected to alcoholysis to obtain mixture A;

[0013] (4) The mixture A and the polyester bottle flakes are dried and melted in sequence, and then the nascent fibers are obtained by parallel composite spinning;

[0014] (5) The nascent fibers are sequentially stretched, crimped, cut and relaxed for heat setting to obtain antibacterial self-crimping regenerated polyester fibers;

[0015] In step (4), the viscosity of mixture A is 0.05-0.12 dL / g lower than that of the polyester flakes;

[0016] In step (5), the cutting and relaxation heat setting can be performed in an interchangeable order.

[0017] The above preparation method involves modifying zinc-containing hexagonal boron nitride with a quaternary ammonium salt ionic liquid to obtain modified zinc-containing hexagonal boron nitride. This modified zinc-containing hexagonal boron nitride can achieve highly efficient catalysis of alcoholysis reactions.

[0018] Furthermore, the modified zinc-containing hexagonal boron nitride can significantly reduce the high viscosity of polyester bottle flakes, enabling the recycled polyester fibers prepared by parallel composite spinning of the modified boron nitride and the original high-viscosity component polyester bottle flakes to have excellent crimping and antibacterial properties.

[0019] This invention uses a single recycled polyester (polyester bottle flakes) as raw material and achieves viscosity differentiation of the system through alcoholysis to prepare dual viscosity components with matched performance (mixture A is the low viscosity component and polyester bottle flakes is the high viscosity component). Based on this, recycled polyester fibers with excellent self-curling effect, strong curling stability and excellent antibacterial properties are obtained.

[0020] Preferably, the viscosity of mixture A in step (4) of this invention is 0.51-0.75 dL / g;

[0021] Preferably, the viscosity of the polyester bottle flakes in step (4) is 0.63-0.80 dL / g.

[0022] Preferably, in step (1), the zinc-containing hexagonal boron nitride has a rod-like microstructure. Preferably, the mass ratio of boric acid to soluble zinc salt is 1:(0.01-1); more preferably 1:(0.04-0.6). In some specific embodiments of the present invention, the ratios are preferably 1:0.04, 1:0.08, 1:0.2, 1:0.5, 1:0.4, or 1:0.6.

[0023] Preferably, the mass ratio of melamine to soluble zinc salt is 1:(0.01-1); more preferably 1:(0.04-0.6).

[0024] The soluble zinc salts include, but are not limited to, ZnSO4, ZnCl2, Zn(NO3)2, Zn3(PO4)2, or Zn(OAc)2.

[0025] In step (1), boric acid, melamine, and soluble zinc salt are mixed in water, and the water is removed before calcination. The method of water removal is not particularly limited and can be any means well-known to those skilled in the art.

[0026] In some specific embodiments of the present invention, evaporation is preferred for water removal, and the evaporation temperature is 50℃-100℃.

[0027] The mixture of boric acid, melamine, and soluble zinc salt is the precursor of zinc-containing hexagonal boron nitride.

[0028] The inert atmosphere includes, but is not limited to, argon, nitrogen, etc.

[0029] The present invention does not impose any special limitation on the calcination equipment; any equipment known to those skilled in the art is acceptable.

[0030] In some specific embodiments of the present invention, a tubular furnace is preferred.

[0031] Preferably, the quaternary ammonium salt ionic liquid in step (2) of this invention is selected from benzyl(ethyl)dimethylammonium bis(trifluoromethanesulfonyl)imide or trioctylmethyltetrafluoroborate ammonium.

[0032] Preferably, in step (1) of this invention, the calcination temperature is 800℃-1200℃;

[0033] Preferably, the calcination time in step (1) is 2-5 h;

[0034] Preferably, the immersion temperature in step (2) is 40℃-120℃;

[0035] Preferably, the soaking time in step (2) is 8-24 h.

[0036] In the above preparation method, after the impregnation in step (2) is completed, post-treatment such as filtration, washing and drying are also included.

[0037] The present invention does not impose any particular limitation on the solvent used for washing and the method used for drying; any solvent or method known to those skilled in the art may be used.

[0038] In some specific embodiments of the present invention, the washing solvent is selected from deionized water.

[0039] In some specific embodiments of the present invention, the drying method is selected from vacuum drying.

[0040] The preferred temperature for vacuum drying is 50℃-70℃.

[0041] Preferably, in step (3), the mass ratio of polyester flakes to ethylene glycol is (5-60):(17-140); more preferably, it is (5-35):(17-70); in some specific embodiments of the present invention, it is preferably 5:17 or 10:21 or 15:31 or 21:41 or 23:70 or 21:53 or 23:41 or 17:41 or 34:78.

[0042] Preferably, in step (3), the mass ratio of polyester flakes to modified zinc-containing hexagonal boron nitride is (5-60):(1-15); more preferably, it is (5-25):(17-20). In some specific embodiments of the present invention, the ratio is preferably 5:1 or 10:2 or 15:5 or 21:11 or 23:13 or 21:10 or 23:11 or 17:8 or 34:20.

[0043] Preferably, the alcoholysis reaction in step (3) is carried out at a temperature of 260°C-290°C.

[0044] The present invention does not impose any particular limitation on the equipment for the alcoholysis reaction; any suitable equipment known to those skilled in the art is acceptable.

[0045] In some specific embodiments of the present invention, a screw extruder is preferably used to carry out the alcoholysis reaction.

[0046] This invention achieves viscosity reduction through the alcoholysis reaction, and then conditions and adjusts the viscosity of the reduced product.

[0047] The present invention does not impose any special limitations on the equipment used for conditioning and viscosity adjustment; any applicable equipment known to those skilled in the art is acceptable.

[0048] In some specific embodiments of the present invention, a dual-horizontal disc film-forming, devolatilization, and thickening reactor is preferably used for conditioning and thickening.

[0049] After the above viscosity reduction and conditioning, the present invention uses polyester bottle flakes as the high viscosity component raw material and alcoholysis reaction product mixture A as the low viscosity component raw material, and performs drying and melting treatment on both respectively.

[0050] The drying process is preferably continuous drying;

[0051] The preferred conditions for continuous drying are:

[0052] The pre-crystallization temperature is 130℃-160℃;

[0053] The pre-crystallization air volume is 400-600 m³. 3 / h;

[0054] The drying temperature is 70℃-120℃;

[0055] Drying air volume is 400-600 m³ 3 / h;

[0056] Dry air dew point ≤ -50℃;

[0057] After drying, the moisture content of mixture A and the polyester flakes is ≤70 ppm, respectively.

[0058] After the above drying process is completed, the dried mixture A and the polyester bottle flakes are respectively subjected to melt treatment.

[0059] In this invention, the melting process is preferably performed using screw melting.

[0060] After melting, mixture A and the polyester flakes are then filtered separately.

[0061] The filtration process includes primary filtration and secondary filtration, the purpose of which is to remove impurities and improve the spinning quality.

[0062] Then, the mixture A melt obtained from filtration and the polyester bottle chip melt are spun in parallel to prepare nascent fibers.

[0063] Preferably, in the parallel composite spinning process described in step (4), the content of mixture A is 30wt%-70wt%, and the remainder is polyester bottle flakes.

[0064] The present invention does not specifically limit the equipment used for the parallel composite spinning; any equipment well-known to those skilled in the art is acceptable. Preferably, the draw ratio in step (5) is 1.5-2.1.

[0065] Preferably, the relaxation heat setting temperature is 110℃-140℃; more preferably, it is 110℃-135℃.

[0066] The present invention also provides an antibacterial self-crimping recycled polyester fiber, which is prepared by the above-described preparation method;

[0067] Preferably, the crimp rate of the antibacterial self-crimping recycled polyester fiber is ≥19.3;

[0068] Preferably, the antibacterial self-crimping recycled polyester fiber has an antibacterial rate of ≥98.1%;

[0069] Preferably, the bacterial strains used in the antibacterial rate are selected from Escherichia coli, Staphylococcus aureus, or Candida albicans.

[0070] The antibacterial self-crimping recycled polyester staple fiber preferably has an antibacterial rate of 98.2%-99.4% against Escherichia coli.

[0071] The antibacterial self-crimping recycled polyester staple fiber preferably has an antibacterial rate of 98.1%-99.7% against Staphylococcus aureus;

[0072] The antibacterial self-curling recycled polyester staple fiber preferably has an antibacterial rate of 98.1%-99.2% against Candida albicans.

[0073] Compared with the prior art, the method for preparing antibacterial self-crimping recycled polyester fiber provided by the present invention...

[0074] This invention discloses a method for preparing antibacterial self-curling recycled polyester fiber, comprising the following steps: (1) calcining a mixture of boric acid, melamine and soluble zinc salt under an inert atmosphere to obtain zinc-containing hexagonal boron nitride; (2) mixing the zinc-containing hexagonal boron nitride with a quaternary ammonium salt ionic liquid and impregnating it to obtain modified zinc-containing hexagonal boron nitride; (3) mixing the modified zinc-containing hexagonal boron nitride with polyester flakes and ethylene glycol, and obtaining mixture A through alcoholysis reaction; (4) drying and melting mixture A and polyester flakes respectively, and then obtaining nascent fibers through parallel composite spinning; (5) stretching, curling, cutting and relaxing heat setting of the nascent fibers to prepare antibacterial self-curling recycled polyester fiber; wherein, in step (4), the viscosity of mixture A is 0.05-0.12 dL / g lower than that of polyester flakes; and in step (5), the cutting and relaxing heat setting can be interchanged. This invention uses a single recycled polyester as raw material and modifies the alcoholysis catalysis and antibacterial / bacteriostatic functions of zinc hexagonal boron nitride with quaternary ammonium salt ionic liquid to achieve system viscosity differentiation, thereby producing recycled polyester fibers with excellent self-crimping effect and strong antibacterial properties, solving the problems of poor antibacterial performance and low crimp rate of existing products. Attached Figure Description

[0075] Figure 1 SEM image of zinc-containing hexagonal boron nitride prepared in Example 1. Detailed Implementation

[0076] To further illustrate the present invention, the preparation method of antibacterial self-curling recycled polyester fiber provided by the present invention will be described in detail below with reference to embodiments.

[0077] The reagents described below are all commercially available products.

[0078] The recycled parallel composite polyester staple fibers or antibacterial staple fibers in Examples 1-10 below are all antibacterial self-crimping recycled polyester fibers described in this invention.

[0079] Example 1

[0080] (1) Dissolve 1.26 g H3BO3 and 1.23 g C3H6N6 with 0.05 g Zn(OAc)2 in 100 mL of deionized water and evaporate to dryness to obtain a precursor. Place the precursor in a tube furnace and calcine it under a nitrogen atmosphere. The calcination conditions are: 800 ℃, holding time 2h, to obtain zinc-containing hexagonal boron nitride.

[0081] (2) The zinc-containing hexagonal boron nitride prepared in (1) was placed in 20 mL of benzyl(ethyl)dimethylammonium bis(trifluoromethanesulfonyl)imide (a quaternary ammonium salt ionic liquid), heated and stirred at a constant temperature. The impregnation conditions were: heating temperature 40 ℃ and stirring time 8 h. After impregnation, the filtered product was washed several times with deionized water, and finally vacuum dried at 60 ℃ for 3 h to obtain the quaternary ammonium salt ionic liquid modified zinc-containing hexagonal boron nitride.

[0082] (3) The polyester bottle flakes, ethylene glycol, and the modified zinc-containing hexagonal boron nitride obtained in step (2) are fed into a screw extruder at a mass ratio of 5:17:1, heated to 260 °C, and reacted for 10 min; then they are fed into a twin-horizontal disc film-forming devolve-thickening and thickening reactor for conditioning and thickening, and the micro-alcoholic de-thickening product is the mixture A.

[0083] (4) Using polyester bottle flakes as the high viscosity component raw material and the micro-alcoholic viscosity-reducing product in (3) as the low viscosity component raw material (controlling the viscosity of mixture A to be 0.05-0.12 dL / g lower than that of polyester bottle flakes), the raw materials are respectively sent to a continuous drying system to dry them.

[0084] (5) The dried polyester bottle flakes and the micro-alcoholic viscosity-reducing product in step (3) are fed into the screw melt and primary filter in a ratio of 7:3, and then pumped into the secondary filter through the melt gear pump. The filtered melt enters the spinning box. The high and low viscosity melts are fed into the parallel composite spinneret through the respective component metering pumps to perform parallel composite spinning to obtain nascent fibers.

[0085] (6) The nascent fibers are then stretched, crimped, cut / relaxed and heat-set, and relaxed heat-set / cut to prepare recycled parallel composite polyester staple fibers, wherein the stretching ratio is 1.5 and the heat-setting temperature is 110 ℃.

[0086] Figure 1 The image shows a SEM image of zinc-containing hexagonal boron nitride, illustrating the rod-shaped microstructure of the zinc-containing hexagonal boron nitride of this invention.

[0087] The prepared antibacterial short fibers were tested for antibacterial properties and crimp rate, with a crimp rate of 20.1%. Tests were conducted against some common bacterial species: Escherichia coli, Staphylococcus aureus, and Candida albicans. The antibacterial rate against Escherichia coli was 98.5%, against Staphylococcus aureus was 99.4%, and against Candida albicans was 98.3%.

[0088] Example 2

[0089] (1) Dissolve 1.26 g H3BO3 and 1.23 g C3H6N6 and 0.1 g Zn(OAc)2 in 100 mL of deionized water and evaporate to dryness to obtain a precursor. Place the precursor in a tube furnace and calcine it under a nitrogen atmosphere. The calcination conditions are: 850 °C and 2 h holding time to obtain zinc-containing hexagonal boron nitride.

[0090] (2) The zinc-containing hexagonal boron nitride prepared in (1) was placed in 20 mL of benzyl(ethyl)dimethylammonium bis(trifluoromethanesulfonyl)imide, heated and stirred at a constant temperature. The impregnation conditions were: heating temperature 50 ℃ and stirring time 8 h. After impregnation, the filtered product was washed several times with deionized water, and finally vacuum dried at 60 ℃ for 3 h to obtain quaternary ammonium salt ionic liquid modified zinc-containing hexagonal boron nitride;

[0091] (3) The polyester bottle flakes, ethylene glycol, and the modified zinc-containing hexagonal boron nitride obtained in step (2) are fed into a screw extruder at a mass ratio of 10:21:2, heated to 260 ℃, and reacted for 12 min; then it is fed into a twin-horizontal disc film-forming devolve viscosity-increasing reactor for conditioning and viscosity adjustment, and the micro-alcoholic viscosity-reducing product is the mixture A.

[0092] (4) Using polyester bottle flakes as the high viscosity component raw material and the micro-alcoholic viscosity-reducing product in (3) as the low viscosity component raw material (controlling the viscosity of mixture A to be 0.05-0.12 dL / g lower than that of polyester bottle flakes), the raw materials are respectively sent to a continuous drying system to dry them.

[0093] (5) The dried polyester bottle flakes and the micro-alcoholic viscosity-reducing product in step (3) are fed into the screw melt and primary filter in a ratio of 7:4, and then pumped into the secondary filter through the melt gear pump. The filtered melt enters the spinning box. The high and low viscosity melts are fed into the parallel composite spinneret through the respective component metering pumps to perform parallel composite spinning to obtain nascent fibers.

[0094] (6) The nascent fibers are then stretched, crimped, cut / relaxed and heat-set, and relaxed heat-set / cut to prepare recycled parallel composite polyester staple fibers, wherein the stretching ratio is 1.5 and the heat-setting temperature is 115 ℃.

[0095] Morphology and structure of zinc-containing hexagonal boron nitride Figure 1 Similarly, the prepared antibacterial short fibers were tested for antibacterial properties and crimp rate, with a crimp rate of 20.4%. Tests were conducted against some common bacterial species: *Escherichia coli*, *Staphylococcus aureus*, and *Candida albicans*. The antibacterial rate against *Escherichia coli* was 98.5%, against *Staphylococcus aureus* was 98.1%, and against *Candida albicans* was 99.3%.

[0096] Example 3

[0097] (1) Dissolve 1.26 g H3BO3 and 1.23 g C3H6N6 and 0.25 g ZnCl2 in 100 mL of deionized water and evaporate to dryness to obtain a precursor. Place the precursor in a tube furnace and calcine it under a nitrogen atmosphere. The calcination conditions are: 900 ℃, holding time 3h, to obtain zinc-containing hexagonal boron nitride.

[0098] (2) The zinc-containing hexagonal boron nitride prepared in (1) was placed in 30 mL of benzyl(ethyl)dimethylammonium bis(trifluoromethanesulfonyl)imide, heated and stirred at a constant temperature. The impregnation conditions were: heating temperature 60 ℃ and stirring time 9 h. After impregnation, the filtered product was washed several times with deionized water, and finally vacuum dried at 60 ℃ for 3 h to obtain quaternary ammonium salt ionic liquid modified zinc-containing hexagonal boron nitride;

[0099] (3) The polyester bottle flakes, ethylene glycol, and the modified zinc-containing hexagonal boron nitride obtained in step (2) are fed into a screw extruder at a mass ratio of 15:31:5, heated to 260 °C, and reacted for 14 min; then it is fed into a twin-horizontal disc film-forming de-volatilization and viscosity-increasing reactor for conditioning and viscosity adjustment, and the micro-alcoholic viscosity-reducing product is the mixture A.

[0100] (4) Using polyester bottle flakes as the high viscosity component raw material and the micro-alcoholic viscosity-reducing product in (3) as the low viscosity component raw material (controlling the viscosity of mixture A to be 0.05-0.12 dL / g lower than that of polyester bottle flakes), the raw materials are respectively sent to a continuous drying system to dry them.

[0101] (5) The dried polyester bottle flakes and the micro-alcoholic viscosity-reducing product in step (3) are fed into the screw melt and primary filter in a ratio of 7:5, and then pumped into the secondary filter through the melt gear pump. The filtered melt enters the spinning box. The high and low viscosity melts are fed into the parallel composite spinneret through the respective component metering pumps to perform parallel composite spinning to obtain nascent fibers.

[0102] (6) The nascent fibers are then stretched, crimped, cut / relaxed and heat-set, and relaxed heat-set / cut to prepare recycled parallel composite polyester staple fibers, wherein the stretching ratio is 1.6 and the heat-setting temperature is 120 ℃.

[0103] Morphology and structure of zinc-containing hexagonal boron nitride Figure 1 Similarly, the prepared antibacterial short fibers were tested for antibacterial properties and crimp rate, with a crimp rate of 21.4%. Tests were conducted against some common bacterial species: Escherichia coli, Staphylococcus aureus, and Candida albicans. The antibacterial rate against Escherichia coli was 98.6%, against Staphylococcus aureus was 99.4%, and against Candida albicans was 98.3%.

[0104] Example 4

[0105] (1) Dissolve 1.56 g H3BO3 and 1.53 g C3H6N6 and 0.35 g ZnCl2 in 100 mL of deionized water and evaporate to dryness to obtain a precursor. Place the precursor in a tube furnace and calcine it under a nitrogen atmosphere. The calcination conditions are: 1000 ℃, holding time 3h, to obtain zinc-containing hexagonal boron nitride.

[0106] (2) The zinc-containing hexagonal boron nitride prepared in (1) was placed in 30 mL of benzyl(ethyl)dimethylammonium bis(trifluoromethanesulfonyl)imide, heated and stirred at a constant temperature. The impregnation conditions were: heating temperature 60 ℃ and stirring time 9 h. After impregnation, the filtered product was washed several times with deionized water, and finally vacuum dried at 60 ℃ for 3 h to obtain quaternary ammonium salt ionic liquid modified zinc-containing hexagonal boron nitride;

[0107] (3) The polyester bottle flakes, ethylene glycol, and the modified zinc-containing hexagonal boron nitride obtained in step (2) are fed into a screw extruder at a mass ratio of 21:41:11, heated to 270 °C, and reacted for 10 min; then it is fed into a twin-horizontal disc film-forming devolve-thickening and thickening reactor for conditioning and thickening, and the micro-alcoholic viscosity-reducing product is the mixture A.

[0108] (4) Using polyester bottle flakes as the high viscosity component raw material and the micro-alcoholic viscosity-reducing product in (3) as the low viscosity component raw material (controlling the viscosity of mixture A to be 0.05-0.12 dL / g lower than that of polyester bottle flakes), the raw materials are respectively sent to a continuous drying system to dry them.

[0109] (5) The dried polyester bottle flakes and the micro-alcoholic viscosity-reducing product in step (3) are fed into the screw melt and primary filter in a ratio of 7:6, and then pumped into the secondary filter through the melt gear pump. The filtered melt enters the spinning box. The high and low viscosity melts are fed into the parallel composite spinneret through the respective component metering pumps to perform parallel composite spinning to obtain nascent fibers.

[0110] (6) The nascent fibers are then stretched, crimped, cut / relaxed and heat-set, and relaxed heat-set / cut to prepare recycled parallel composite polyester staple fibers, wherein the stretch ratio is 1.6 and the heat-setting temperature is 125 ℃.

[0111] Morphology and structure of zinc-containing hexagonal boron nitride Figure 1 Similarly, the prepared antibacterial short fibers were tested for antibacterial properties and crimp rate, with a crimp rate of 19.3%. Tests were conducted against some common bacterial species: Escherichia coli, Staphylococcus aureus, and Candida albicans. The antibacterial rate against Escherichia coli was 98.2%, against Staphylococcus aureus was 99.3%, and against Candida albicans was 98.4%.

[0112] Example 5

[0113] (1) Dissolve 1.26 g H3BO3 and 1.23 g C3H6N6 and 0.6 g Zn(NO3)2 in 100 mL of deionized water and evaporate to dryness to obtain a precursor. Place the precursor in a tube furnace and calcine it under a nitrogen atmosphere. The calcination conditions are: 1000 ℃, holding time 5 h, to obtain zinc-containing hexagonal boron nitride.

[0114] (2) The zinc-containing hexagonal boron nitride prepared in (1) was placed in 50 mL of benzyl(ethyl)dimethylammonium bis(trifluoromethanesulfonyl)imide, heated and stirred at a constant temperature. The impregnation conditions were: heating temperature 90 ℃ and stirring time 10 h. After impregnation, the filtered product was washed several times with deionized water, and finally vacuum dried at 60 ℃ for 3 h to obtain quaternary ammonium salt ionic liquid modified zinc-containing hexagonal boron nitride;

[0115] (3) The polyester bottle flakes, ethylene glycol, and the modified zinc-containing hexagonal boron nitride obtained in step (2) are fed into a screw extruder at a mass ratio of 23:70:13, heated to 270 °C, and reacted for 8 min; then it is fed into a twin-horizontal disc film-forming devolve viscous reactor for conditioning and viscosity adjustment, and the micro-alcoholic viscous reduction product is the mixture A.

[0116] (4) Using polyester bottle flakes as the high viscosity component raw material and the micro-alcoholic viscosity-reducing product in (3) as the low viscosity component raw material (controlling the viscosity of mixture A to be 0.05-0.12 dL / g lower than that of polyester bottle flakes), the raw materials are respectively sent to a continuous drying system to dry them.

[0117] (5) The dried polyester bottle flakes and the micro-alcoholic viscosity-reducing product in step (3) are fed into the screw melt and primary filter in a ratio of 7:7, and then pumped into the secondary filter through the melt gear pump. The filtered melt enters the spinning box. The high and low viscosity melts are fed into the parallel composite spinneret through the respective component metering pumps to perform parallel composite spinning to obtain nascent fibers.

[0118] (6) The nascent fibers are then stretched, crimped, cut / relaxed and heat-set, and relaxed heat-set / cut to prepare recycled parallel composite polyester staple fibers, wherein the stretching ratio is 1.6 and the heat-setting temperature is 130 ℃.

[0119] Morphology and structure of zinc-containing hexagonal boron nitride Figure 1 Similarly, the prepared antibacterial short fibers were tested for antibacterial properties and crimp rate, with a crimp rate of 20.2%. Tests were conducted against some common bacterial species: Escherichia coli, Staphylococcus aureus, and Candida albicans. The antibacterial rate against Escherichia coli was 99.4%, against Staphylococcus aureus was 98.9%, and against Candida albicans was 98.7%.

[0120] Example 6

[0121] (1) Dissolve 1.26 g H3BO3 and 1.23 g C3H6N6 and 0.45 g Zn(NO3)2 in 100 mL of deionized water and evaporate to dryness to obtain a precursor. Place the precursor in a tube furnace and calcine it under a nitrogen atmosphere. The calcination conditions are: 1100 ℃, holding time 3 h, to obtain zinc-containing hexagonal boron nitride.

[0122] (2) The zinc-containing hexagonal boron nitride prepared in (1) was placed in 30 mL of trioctylmethyltetrafluoroborate ammonium, heated and stirred at a constant temperature. The impregnation conditions were: heating temperature 60 ℃ and stirring time 9 h. After impregnation, the filtered product was washed several times with deionized water, and finally vacuum dried at 60 ℃ for 3 h to obtain quaternary ammonium salt ionic liquid modified zinc-containing hexagonal boron nitride;

[0123] (3) The polyester bottle flakes, ethylene glycol, and the modified zinc-containing hexagonal boron nitride obtained in step (2) are fed into a screw extruder at a mass ratio of 15:31:5, heated to 275 °C, and reacted for 12 min; then it is fed into a twin-horizontal disc film-forming devolve-thickening and thickening reactor for conditioning and thickening, and the micro-alcoholic de-thickening product is the mixture A.

[0124] (4) Using polyester bottle flakes as the high viscosity component raw material and the micro-alcoholic viscosity-reducing product in (3) as the low viscosity component raw material (controlling the viscosity of mixture A to be 0.05-0.12 dL / g lower than that of polyester bottle flakes), the raw materials are respectively sent to a continuous drying system to dry them.

[0125] (5) The dried polyester bottle flakes and the micro-alcoholic viscosity-reducing product in step (3) are fed into the screw melt and primary filter in a ratio of 3:7, and then pumped into the secondary filter through the melt gear pump. The filtered melt enters the spinning box. The high and low viscosity melts are fed into the parallel composite spinneret through the respective component metering pumps to perform parallel composite spinning to obtain nascent fibers.

[0126] (6) The nascent fibers are then stretched, crimped, cut / relaxed and heat-set, and relaxed heat-set / cut to prepare recycled parallel composite polyester staple fibers, wherein the stretch ratio is 1.7 and the heat-setting temperature is 125 ℃.

[0127] Morphology and structure of zinc-containing hexagonal boron nitride Figure 1 Similarly, the prepared antibacterial short fibers were tested for antibacterial properties and crimp rate, with a crimp rate of 19.7%. Tests were conducted against some common bacterial species: Escherichia coli, Staphylococcus aureus, and Candida albicans. The antibacterial rate against Escherichia coli was 98.7%, against Staphylococcus aureus was 99.5%, and against Candida albicans was 98.1%.

[0128] Example 7

[0129] (1) Dissolve 1.26 g H3BO3 and 1.23 g C3H6N6 and 0.6 g Zn3(PO4)2 in 100 mL of deionized water and evaporate to dryness to obtain a precursor. Place the precursor in a tube furnace and calcine it under a nitrogen atmosphere. The calcination conditions are: 1100 ℃, holding time 5 h, to obtain zinc-containing hexagonal boron nitride.

[0130] (2) The zinc-containing hexagonal boron nitride prepared in (1) was placed in 40 mL of trioctylmethyltetrafluoroborate ammonium, heated and stirred at a constant temperature. The impregnation conditions were: heating temperature 70 ℃ and stirring time 12 h. After impregnation, the filtered product was washed several times with deionized water, and finally vacuum dried at 60 ℃ for 3 h to obtain quaternary ammonium salt ionic liquid modified zinc-containing hexagonal boron nitride;

[0131] (3) The polyester bottle flakes, ethylene glycol, and the modified zinc-containing hexagonal boron nitride obtained in step (2) are fed into a screw extruder at a mass ratio of 21:53:10, heated to 280 ℃, and reacted for 10 min; then it is fed into a twin-horizontal disc film-forming devolve viscosity-increasing reactor for conditioning and viscosity adjustment, and the micro-alcoholic viscosity-reducing product is the mixture A.

[0132] (4) Using polyester bottle flakes as the high viscosity component raw material and the micro-alcoholic viscosity-reducing product in (3) as the low viscosity component raw material (controlling the viscosity of mixture A to be 0.05-0.12 dL / g lower than that of polyester bottle flakes), the raw materials are respectively sent to a continuous drying system to dry them.

[0133] (5) The dried polyester bottle flakes and the micro-alcoholic viscosity-reducing product in step (3) are fed into the screw melt and primary filter in a ratio of 4:7, and then pumped into the secondary filter through the melt gear pump. The filtered melt enters the spinning box. The high and low viscosity melts are fed into the parallel composite spinneret through the respective component metering pumps to perform parallel composite spinning to obtain nascent fibers.

[0134] (6) The nascent fibers are then stretched, crimped, cut / relaxed and heat-set, and relaxed heat-set / cut to prepare recycled parallel composite polyester staple fibers, wherein the stretching ratio is 1.7 and the heat-setting temperature is 130 ℃.

[0135] Morphology and structure of zinc-containing hexagonal boron nitride Figure 1 Similarly, the prepared antibacterial short fibers were tested for antibacterial properties and crimp rate, with a crimp rate of 21.7%. Tests were conducted against some common bacterial species: Escherichia coli, Staphylococcus aureus, and Candida albicans. The antibacterial rate against Escherichia coli was 98.7%, against Staphylococcus aureus was 98.5%, and against Candida albicans was 99.1%.

[0136] Example 8

[0137] (1) Dissolve 1.26 g H3BO3 and 1.23 g C3H6N6 and 0.75 g Zn3(PO4)2 in 100 mL of deionized water and evaporate to dryness to obtain a precursor. Place the precursor in a tube furnace and calcine it under a nitrogen atmosphere. The calcine conditions are: 1200 ℃, holding time 3 h, to obtain zinc-containing hexagonal boron nitride.

[0138] (2) The zinc-containing hexagonal boron nitride prepared in (1) was placed in 50 mL of trioctylmethyltetrafluoroborate ammonium, heated and stirred at a constant temperature. The impregnation conditions were: heating temperature 90 ℃ and stirring time 10 h. After impregnation, the filtered product was washed several times with deionized water, and finally dried under vacuum at 60 ℃ for 3 h to obtain quaternary ammonium salt ionic liquid modified zinc-containing hexagonal boron nitride;

[0139] (3) The polyester bottle flakes, ethylene glycol, and the modified zinc-containing hexagonal boron nitride obtained in step (2) are fed into a screw extruder at a mass ratio of 23:41:11, heated to 280 °C, and reacted for 12 min; then it is fed into a twin-horizontal disc film-forming devolve viscosity-increasing reactor for conditioning and viscosity adjustment, and the micro-alcoholic viscosity-reducing product is the mixture A.

[0140] (4) Using polyester bottle flakes as the high viscosity component raw material and the micro-alcoholic viscosity-reducing product in (3) as the low viscosity component raw material (controlling the viscosity of mixture A to be 0.05-0.12 dL / g lower than that of polyester bottle flakes), the raw materials are respectively sent to a continuous drying system to dry them.

[0141] (5) The dried polyester bottle flakes and the micro-alcoholic viscosity-reducing product in step (3) are fed into the screw melt and primary filter in a ratio of 5:7, and then pumped into the secondary filter through the melt gear pump. The filtered melt enters the spinning box. The high and low viscosity melts are fed into the parallel composite spinneret through the respective component metering pumps to perform parallel composite spinning to obtain nascent fibers.

[0142] (6) The nascent fibers are then stretched, crimped, cut / relaxed and heat-set, and relaxed heat-set / cut to prepare recycled parallel composite polyester staple fibers, wherein the stretching ratio is 1.8 and the heat-setting temperature is 130 ℃.

[0143] Morphology and structure of zinc-containing hexagonal boron nitride Figure 1 Similarly, the prepared antibacterial short fibers were tested for antibacterial properties and crimp rate, with a crimp rate of 20.7%. Tests were conducted against some common bacterial species: Escherichia coli, Staphylococcus aureus, and Candida albicans. The antibacterial rate against Escherichia coli was 98.3%, against Staphylococcus aureus was 98.5%, against Candida albicans was 99.2%, and the crimp rate was 20.7%.

[0144] Example 9

[0145] (1) Dissolve 1.56 g H3BO3 and 1.53 g C3H6N6 and 0.7 g ZnSO4 in 100 mL of deionized water and evaporate to dryness to obtain a precursor. Place the precursor in a tube furnace and calcine it under a nitrogen atmosphere. The calcination conditions are: 1200 ℃, holding time 4 h, to obtain zinc-containing hexagonal boron nitride.

[0146] (2) The zinc-containing hexagonal boron nitride prepared in (1) was placed in 30 mL of trioctylmethyltetrafluoroborate ammonium, heated and stirred at a constant temperature. The impregnation conditions were: heating temperature 110 ℃ and stirring time 9 h. After impregnation, the filtered product was washed several times with deionized water, and finally dried under vacuum at 60 ℃ for 3 h to obtain quaternary ammonium salt ionic liquid modified zinc-containing hexagonal boron nitride;

[0147] (3) The polyester bottle flakes, ethylene glycol, and the modified zinc-containing hexagonal boron nitride obtained in step (2) are fed into a screw extruder at a mass ratio of 17:41:8, heated to 290 °C, and reacted for 8 min; then the mixture is fed into a twin-horizontal disc film-forming de-volatilization and viscosity-increasing reactor for conditioning and viscosity adjustment, and the micro-alcoholic viscosity-reducing product is the mixture A.

[0148] (4) Using polyester bottle flakes as the high viscosity component raw material and the micro-alcoholic viscosity-reducing product in (3) as the low viscosity component raw material (controlling the viscosity of mixture A to be 0.05-0.12 dL / g lower than that of polyester bottle flakes), the raw materials are respectively sent to a continuous drying system to dry them.

[0149] (5) The dried polyester bottle flakes and the micro-alcoholic viscosity-reducing product in step (3) are fed into the screw melt and primary filter in a ratio of 6:7, and then pumped into the secondary filter through the melt gear pump. The filtered melt enters the spinning box. The high and low viscosity melts are fed into the parallel composite spinneret through the respective component metering pumps to perform parallel composite spinning to obtain nascent fibers.

[0150] (6) The nascent fibers are then stretched, crimped, cut / relaxed and heat-set, and relaxed heat-set / cut to prepare recycled parallel composite polyester staple fibers, wherein the stretching ratio is 1.9 and the heat-setting temperature is 135 ℃.

[0151] Morphology and structure of zinc-containing hexagonal boron nitride Figure 1 Similarly, the prepared antibacterial short fibers were tested for antibacterial properties and crimp rate, with a crimp rate of 19.8%. Tests were conducted against some common bacterial species: Escherichia coli, Staphylococcus aureus, and Candida albicans. The antibacterial rate against Escherichia coli was 98.7%, against Staphylococcus aureus was 99.7%, and against Candida albicans was 98.2%.

[0152] Example 10

[0153] (1) 1.26 g H3BO3 and 1.23 g C3H6N6 and 0.45 g ZnSO4 were dissolved in 100 mL deionized water and evaporated to dryness to obtain a precursor. The precursor was placed in a tube furnace and calcined under a nitrogen atmosphere at 1200 °C for 5 h to obtain zinc-containing hexagonal boron nitride. The SEM image of the zinc-containing hexagonal boron nitride in this example is similar to that in Example 1;

[0154] (2) The zinc-containing hexagonal boron nitride prepared in (1) was placed in 60 mL of trioctylmethyltetrafluoroborate ammonium, heated and stirred at a constant temperature. The impregnation conditions were: heating temperature 120 ℃ and stirring time 12 h. After impregnation, the filtered product was washed several times with deionized water, and finally vacuum dried at 60 ℃ for 3 h to obtain quaternary ammonium salt ionic liquid modified zinc-containing hexagonal boron nitride;

[0155] (3) The polyester bottle flakes, ethylene glycol, and the modified zinc-containing hexagonal boron nitride obtained in step (2) are fed into a screw extruder at a mass ratio of 34:78:20, heated to 290 °C, and reacted for 10 min; then it is fed into a twin-horizontal disc film-forming de-volatilization and viscosity-increasing reactor for conditioning and viscosity adjustment, and the micro-alcoholic viscosity-reducing product is the mixture A.

[0156] (4) Using polyester bottle flakes as the high viscosity component raw material and the micro-alcoholic viscosity-reducing product in (3) as the low viscosity component raw material (controlling the viscosity of mixture A to be 0.05-0.12 dL / g lower than that of polyester bottle flakes), the raw materials are respectively sent to a continuous drying system to dry them.

[0157] (5) The dried polyester bottle flakes and the micro-alcoholic viscosity-reducing product in step (3) are fed into the screw melt and primary filter in a ratio of 6:7, and then pumped into the secondary filter through the melt gear pump. The filtered melt enters the spinning box. The high and low viscosity melts are fed into the parallel composite spinneret through the respective component metering pumps to perform parallel composite spinning to obtain nascent fibers.

[0158] (6) The nascent fibers are then stretched, crimped, cut / relaxed and heat-set, and relaxed heat-set / cut to obtain recycled parallel composite polyester staple fibers, wherein the stretch ratio is 2.0 and the heat-setting temperature is 140 ℃.

[0159] Morphology and structure of zinc-containing hexagonal boron nitride Figure 1 Similarly, the prepared antibacterial short fibers were tested for antibacterial properties and crimp rate, with a crimp rate of 20.6%. Tests were conducted against some common bacterial species: Escherichia coli, Staphylococcus aureus, and Candida albicans. The antibacterial rate against Escherichia coli was 98.8%, against Staphylococcus aureus was 99.5%, and against Candida albicans was 98.6%.

[0160] Comparative Example 1

[0161] (1) Dissolve 1.26 g H3BO3 and 1.23 g C3H6N6 and 0.45 g ZnSO4 in 100 mL of deionized water and evaporate to dryness to obtain a precursor. Place the precursor in a tube furnace and calcine it under a nitrogen atmosphere. The calcination conditions are: 800 ℃ and 3 h holding time to obtain zinc-containing hexagonal boron nitride.

[0162] (2) Polyester bottle flakes, ethylene glycol, and zinc-containing hexagonal boron nitride were fed into a screw extruder at a mass ratio of 15:21:1, heated to 260 °C, and subjected to a micro-alcohololysis reaction for 10 min; then the mixture was fed into a twin-horizontal disc film-forming devolve-thickening and thickening reactor for conditioning and viscosity adjustment to obtain a micro-alcohololysis viscosity-reducing product.

[0163] (3) Using polyester bottle flakes as the high viscosity component raw material and the micro-alcoholization viscosity-reducing product in (3) as the low viscosity component raw material (controlling the viscosity of the micro-alcoholization viscosity-reducing product to be 0.05-0.12 dL / g lower than that of polyester bottle flakes), the raw materials are respectively sent to a continuous drying system to dry them.

[0164] (4) The dried polyester bottle flakes and the micro-alcoholic viscosity-reducing product in step (2) are fed into the screw melt and primary filter in a ratio of 7:3, and then pumped into the secondary filter through the melt gear pump. The filtered melt enters the spinning box. The high and low viscosity melts are fed into the parallel composite spinneret through the respective component metering pumps to perform parallel composite spinning to obtain nascent fibers.

[0165] (5) The nascent fibers are then stretched, crimped, cut / relaxed and heat-set, and relaxed heat-set / cut to prepare recycled parallel composite polyester staple fibers, wherein the stretching ratio is 1.6 and the heat-setting temperature is 125 ℃.

[0166] The SEM image of the zinc-containing hexagonal boron nitride prepared in this comparative example is similar to that of Example 1. The prepared recycled side-by-side composite polyester staple fibers were tested for antibacterial properties and crimp rate. The crimp rate of the antibacterial staple fibers was 21.6%. Tests were conducted against some common bacterial species: Escherichia coli, Staphylococcus aureus, and Candida albicans. The antibacterial rate against Escherichia coli was 50.4%, against Staphylococcus aureus was 46.5%, and against Candida albicans was 57.5%. The crimp rate was [not specified in the original text].

[0167] Comparative Example 2

[0168] (1) Dissolve 1.26 g H3BO3 and 1.23 g C3H6N6 in 100 mL of deionized water and evaporate to dryness to obtain a precursor. Place the precursor in a tube furnace and calcine it under a nitrogen atmosphere. The calcination conditions are: 1200 ℃, holding time 2 h, to obtain hexagonal boron nitride.

[0169] (2) The hexagonal boron nitride prepared in (1) was placed in 60 mL of trioctylmethyltetrafluoroborate ammonium, heated and stirred at a constant temperature. The impregnation conditions were: heating temperature 120 ℃ and stirring time 12 h. After impregnation, the filtered product was washed several times with deionized water, and finally vacuum dried at 60 ℃ for 3 h to obtain quaternary ammonium salt ionic liquid modified boron nitride;

[0170] (3) The polyester bottle flakes, ethylene glycol, and the modified hexagonal boron nitride obtained in step (2) are fed into a screw extruder at a mass ratio of 15:21:1, heated to 260 °C, and subjected to a micro-alcohololysis reaction for 10 min; then the mixture is fed into a twin-horizontal disc film-forming devolve-thickening and viscosity-increasing reactor for conditioning and viscosity adjustment to obtain a micro-alcohololysis viscosity-reducing product.

[0171] (4) Using polyester bottle flakes as the high viscosity component raw material and the micro-alcoholic viscosity-reducing product in (3) as the low viscosity component raw material (due to the absence of zinc, the viscosity cannot be effectively controlled), the raw materials are respectively sent to a continuous drying system to dry them;

[0172] (5) The dried polyester bottle flakes and the micro-alcoholic viscosity-reducing product in step (3) are fed into the screw melt and primary filter in a ratio of 7:6, and then pumped into the secondary filter through the melt gear pump. The filtered melt enters the spinning box. The high and low viscosity melts are fed into the parallel composite spinneret through the respective component metering pumps to perform parallel composite spinning to obtain nascent fibers.

[0173] (6) The nascent fibers are then stretched, crimped, cut / relaxed and heat-set, and relaxed heat-set / cut to prepare recycled parallel composite polyester staple fibers, wherein the stretching ratio is 1.7 and the heat-setting temperature is 135 ℃.

[0174] The SEM image of the boron nitride prepared in this comparative example is similar to that of Example 1, showing no zinc-containing species on the surface. The prepared recycled side-by-side composite polyester staple fibers were tested for antibacterial properties and crimp rate. The crimp rate of the antibacterial staple fibers was 17.5%. Tests were conducted against some common bacterial species: Escherichia coli, Staphylococcus aureus, and Candida albicans. The antibacterial rate against Escherichia coli was 90.7%, against Staphylococcus aureus was 89.6%, and against Candida albicans was 91.5%.

[0175] Performance testing

[0176] (1) Antibacterial properties

[0177] The test was conducted in accordance with the GB / T 20944.3-2008 standard.

[0178] (2) Curlability

[0179] The test was conducted in accordance with the GB / T 14338-2022 standard.

[0180] The test results for the antibacterial and curl properties are shown in Tables 1 and 2.

[0181] Table 1. Test results of antibacterial and crimp properties of the recycled polyester fibers prepared in Examples 1-8

[0182]

[0183] Table 2. Test results of antibacterial and crimp properties of the recycled polyester fibers prepared in Comparative Examples 1 and 2.

[0184]

[0185] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing antibacterial self-crimping recycled polyester fiber, characterized in that, Includes the following steps: (1) The mixture of boric acid, melamine and soluble zinc salt was calcined under an inert atmosphere to obtain zinc-containing hexagonal boron nitride; (2) The zinc-containing hexagonal boron nitride and the quaternary ammonium salt ionic liquid are mixed and impregnated to obtain modified zinc-containing hexagonal boron nitride; (3) The modified zinc-containing hexagonal boron nitride, polyester bottle flakes, and ethylene glycol are mixed and subjected to alcoholysis to obtain mixture A; (4) The mixture A and the polyester bottle flakes are dried and melted in sequence, and then the nascent fibers are obtained by parallel composite spinning; (5) The nascent fibers are sequentially stretched, crimped, cut and relaxed for heat setting to obtain antibacterial self-crimping regenerated polyester fibers; In step (4), the viscosity of mixture A is 0.05-0.12 dL / g lower than that of the polyester flakes; In step (5), the cutting and relaxation heat setting can be performed in an interchangeable order.

2. The preparation method according to claim 1, characterized in that, The viscosity of mixture A in step (4) is 0.51-0.75 dL / g; The viscosity of the polyester bottle flakes in step (4) is 0.63-0.80 dL / g.

3. The preparation method according to claim 1 or 2, characterized in that, The zinc-containing hexagonal boron nitride in step (1) has a rod-shaped microstructure.

4. The preparation method according to claim 1, characterized in that, The mass ratio of boric acid to soluble zinc salt is 1:(0.01-1). The mass ratio of melamine to soluble zinc salt is 1:(0.01-1).

5. The preparation method according to claim 1, characterized in that, The quaternary ammonium salt ionic liquid in step (2) is selected from benzyl(ethyl)dimethylammonium bis(trifluoromethanesulfonyl)imide or trioctylmethyltetrafluoroborate ammonium.

6. The preparation method according to claim 1, characterized in that, The calcination temperature in step (1) is 800℃-1200℃; The calcination time in step (1) is 2-5 h; The immersion temperature in step (2) is 40℃-120℃; The soaking time in step (2) is 8-24 hours.

7. The preparation method according to claim 1, characterized in that, In step (3), the mass ratio of polyester flakes to ethylene glycol is (5-60):(17-140). In step (3), the mass ratio of polyester bottle flakes to modified zinc-containing hexagonal boron nitride is (5-60):(1-15). The alcoholysis reaction in step (3) is carried out at a temperature of 260℃-290℃.

8. The preparation method according to claim 1, characterized in that, In the parallel composite spinning described in step (4), the content of mixture A is 30wt%-70wt%, and the remainder is polyester bottle flakes.

9. The preparation method according to claim 1, characterized in that, The draw ratio in step (5) is 1.5-2.1; The relaxation heat setting temperature is 110℃-140℃.

10. An antibacterial self-curling recycled polyester fiber, characterized in that, Prepared by the preparation method according to any one of claims 1-9; The crimp rate of the antibacterial self-crimping recycled polyester fiber is ≥19.

3. The antibacterial self-crimping recycled polyester fiber has an antibacterial rate of ≥98.1%; The bacterial strains used in the antibacterial rate are selected from Escherichia coli, Staphylococcus aureus, or Candida albicans.

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