A melt direct spinning antimony-free polyester fiber and a method for preparing the same

Abstract

The present application relates to the field of polyester fiber, disclose a kind of melt direct spinning antimony-free polyester fiber and its preparation method, the polyester fiber is made by following method: with terephthalic acid and ethylene glycol as reaction raw material, add antibacterial agent, antistatic modifier and titanium catalyst, after esterification reaction and pre-polycondensation process, further through final polycondensation reaction and spinning process obtain;Antibacterial agent is synthesized antibacterial intermediate using 2-pyridine methanol and decyl bromide, then isophorone diisocyanate is used as connecting agent, antibacterial intermediate is grafted with chitosan, and further grafted with p-hydroxybenzoic acid;Antistatic modifier is obtained by grafting double bond graphene oxide, methacryloyloxyethyl trimethylammonium chloride and methoxy polyethylene glycol acrylate copolymerization, the present application is added by antibacterial agent and antistatic modifier, endows polyester fiber with excellent fracture toughness, hygroscopicity and antistatic performance is good, simultaneously has excellent antibacterial property.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of polyester fibers, and particularly relates to a melt direct spinning antimony-free polyester fiber and a preparation method thereof. BACKGROUND

[0002] Polyester fiber is a synthetic fiber obtained by spinning polyester obtained by polycondensation of organic dibasic acid and dibasic alcohol, which is referred to as PET fiber. The polyester fiber has become one of the most widely used and largest consumed chemical fiber varieties due to its excellent modulus, strength, elasticity, shape retention and heat resistance, and accounts for more than 50% of the total amount of textile fibers, and is commonly used in the fields of home, clothing, industrial textiles and the like.

[0003] At present, the production method of polyester fiber includes chip spinning and melt direct spinning. The chip spinning process mainly melts and extrudes polyester chips through drying, screw heating and then extruding to a spinning box for fiber production. The early polyester fiber production mainly adopts this method. However, the chip spinning technology has the disadvantages of high energy consumption, long process and unstable product quality. In recent years, chip spinning has been gradually replaced by melt direct spinning. The melt direct spinning process has the advantages of scale efficiency and low cost and has become the main process route for polyester fiber production.

[0004] The polyester fiber prepared by the prior art does not have antibacterial function. Its loose and porous surface is easy to be attached by external bacteria and microorganisms, and the bacteria can rapidly grow and reproduce under the nutrition condition of human sweat. In addition, the macromolecules of the polyester fiber are connected to each other by covalent bonds, cannot be ionized, and cannot transfer electrons and ions. In addition, the molecular group polarity is small, and the hydrophilicity is poor, resulting in insufficient moisture absorption capacity and easy generation of static electricity. The static electricity not only causes difficulties in the production process of the polyester fiber, makes the fabrics entangled with each other and absorb dust, but also makes the fiber fabrics entangle with the human body and produce discomfort. SUMMARY

[0005] In order to solve the problems mentioned in the background, the present application aims to provide a melt direct spinning antimony-free polyester fiber and a preparation method thereof. By adding the antibacterial agent and the antistatic modifier, the polyester fiber is endowed with excellent breaking toughness, moisture absorption and antistatic performance, and excellent antibacterial performance.

[0006] The object of the present application can be achieved by the following technical solutions:

[0007] A method for preparing melt direct spinning antimony-free polyester fiber, comprising the following steps: taking terephthalic acid and ethylene glycol as raw materials in a molar ratio of 1:1.3-1.6, adding an antibacterial agent, an antistatic modifier and a titanium catalyst, and then performing esterification reaction and pre-polycondensation, followed by final polycondensation reaction and spinning process to obtain the melt direct spinning antimony-free polyester fiber; the mass of the antibacterial agent is 1-4% of the mass of terephthalic acid, and the mass of the antistatic modifier is 0.5-2% of the mass of terephthalic acid.

[0008] The antibacterial agent is prepared by synthesizing an antibacterial intermediate from 2-pyridine methanol and decyl bromide, then grafting the antibacterial intermediate with chitosan by using isophorone diisocyanate as a connecting agent, and further grafting p-hydroxybenzoic acid; and the antistatic modifier is prepared by modifying graphene oxide with gamma-methacryloyloxypropyl trimethoxysilane, and then copolymerizing with methacryloyloxyethyl trimethyl ammonium chloride and methoxy polyethylene glycol acrylate.

[0009] Preferably, the titanium catalyst is one or a combination of ethylene glycol titanium, titanate and nano titanium dioxide.

[0010] Preferably, the preparation method of the antibacterial agent comprises the following steps:

[0011] A. 2-pyridine methanol and decyl bromide are taken in a reactor, 1,4-dioxane solvent is added, and stirring is performed at 95-110 DEG C for 42-48 hours; after the reaction is completed, rotary evaporation, washing, suction filtration and drying are performed to obtain an antibacterial intermediate;

[0012] B. isophorone diisocyanate is taken in a reactor, anhydrous butyl acetate solvent and dibutyl tin dilaurate catalyst are added, the temperature is raised to 35-45 DEG C, the antibacterial intermediate is added, and stirring is performed for 5-6 hours to obtain an isocyanate-antibacterial intermediate;

[0013] C. chitosan is dispersed in a methanol-water solution to obtain a chitosan solution, benzaldehyde is dissolved in methanol and then added to the chitosan solution, the pH value of the system is adjusted to 4.5-5, the temperature is raised to 45-55 DEG C, and reaction is performed for 3-5 hours; after the reaction is completed, suction filtration, washing and drying are performed to obtain N-benzylidene chitosan;

[0014] D. N-benzylidene chitosan is dissolved in acetone, the temperature is raised to 50-70 DEG C, dibutyl tin dilaurate catalyst is added, the isocyanate-antibacterial intermediate is mixed with acetone and then added to the reaction system, and reaction is performed for 8-11 hours; the obtained product is dissolved in a mixed solution of hydrochloric acid and ethanol, and reaction is performed for 20-24 hours; after the reaction is completed, suction filtration, washing and drying are performed to obtain modified chitosan;

[0015] E, the modified chitosan is dissolved in deionized water to obtain a mixed solution, p-hydroxybenzoic acid is dissolved in methanol, 1-ethyl-(3-dimethylaminopropyl) carbonyl diimidazole hydrochloride and N-hydroxy succinimide are added, and the mixture is stirred and then added to the mixed solution, and the mixture is reacted at 30-40℃ for 20-24h. After the reaction is completed, the antibacterial agent is prepared by dialysis and drying.

[0016] Preferably, the mass ratio of the 2-pyridine methanol, decyl bromide and isophorone diisocyanate is 1:3.8-4.4:1.4-1.8.

[0017] Preferably, the preparation method of the antistatic modifier comprises the following steps:

[0018] (1) The graphene oxide is dispersed in anhydrous ethanol by water bath ultrasonic dispersion, γ-methacryloyloxypropyl trimethoxysilane is added, and the mixture is refluxed at 105-120℃ under nitrogen atmosphere for 10-12h. After the reaction is completed, the modified graphene oxide is prepared by filtration, washing and drying.

[0019] (2) The modified graphene oxide is ultrasonically dispersed in anhydrous ethanol, and methacryloyloxyethyl trimethyl ammonium chloride and methoxy polyethylene glycol acrylate are added under nitrogen atmosphere. The mixture is stirred and mixed uniformly at room temperature, and then azobisisobutyronitrile is added. The mixture is heated to 70-80℃ and reacted for 6-7h. After the reaction is completed, the mixture is cooled to room temperature, and the antistatic modifier is prepared by dialysis and drying.

[0020] Preferably, the mass ratio of the methacryloyloxyethyl trimethyl ammonium chloride, the modified graphene oxide and the methoxy polyethylene glycol acrylate in step (2) is 7.5-9.2:0.5-1:4-5.

[0021] Preferably, the method specifically comprises the following steps:

[0022] S1, uniformly mix 70-75% of the total amount of ethylene glycol and terephthalic acid to obtain a mixed slurry;

[0023] S2, uniformly mix 15-20% of the total amount of ethylene glycol and titanium catalyst to obtain a catalyst solution;

[0024] S3, uniformly mix the antibacterial agent, the antistatic modifier and the remaining ethylene glycol to obtain an additive suspension;

[0025] S4, mix the mixed slurry and the catalyst solution to perform a first esterification reaction at a temperature of 230-250℃ for 1-3h. When the esterification rate of antimony-free polyester reaches 85-90%, the additive suspension is added to perform a second esterification reaction at a temperature of 230-250℃ for 0.5-1h to obtain an esterification product.

[0026] S5, the esterification product is pressed into a pre-polycondensation kettle, low vacuum is extracted to discharge excess ethylene glycol, and pre-polycondensation is carried out to obtain a pre-polycondensation product;

[0027] S6, the pre-polycondensation product is pressed into a final polycondensation kettle, and further high vacuum polycondensation is carried out to obtain a melt;

[0028] S7, the melt is prepared into a melt direct spinning antimony-free polyester fiber through a spinning process.

[0029] Preferably, the pre-polycondensation vacuum degree is 1-100 KPa, the temperature is 250-265 DEG C, and the reaction time is 0.5-1 h; the vacuum degree of the final polycondensation kettle is 30-80 Pa, the final polycondensation temperature is 260-280 DEG C, and the reaction time is 0.8-3 h.

[0030] Preferably, the parameters of the spinning process are set as follows: the spinning temperature is 270-295 DEG C, the side air cooling temperature is 25-30 DEG C, the side air cooling speed is 0.2-0.4 m / s, the spinning speed is 2800-3500 m / min, and the draft ratio is 3.0-4.0.

[0031] A melt direct spinning antimony-free polyester fiber is prepared by the preparation method.

[0032] The beneficial effects of the present application are as follows:

[0033] The present application utilizes 2-pyridine methanol and decyl bromide to synthesize an antibacterial intermediate, then the hydroxyl group on the surface of the antibacterial intermediate and the isocyanate group directly connected to the cyclohexane in the isophorone diisocyanate molecule are reacted first to synthesize an isocyanate antibacterial intermediate, then N-benzylidene chitosan Schiff base is formed by chitosan and benzaldehyde to protect the amino group on the chitosan molecule, and then the isocyanate antibacterial intermediate is further reacted to make the isocyanate group react with the hydroxyl group on the surface of N-benzylidene chitosan, so that the antibacterial intermediate containing a quaternary ammonium salt structure is grafted on the surface of chitosan to prepare modified chitosan, and then the amino group in the structure of the modified chitosan and the carboxyl group in the structure of p-hydroxybenzoic acid are subjected to amidation reaction to prepare an antibacterial agent. The quaternary ammonium salt group and the phenolic structure in the antibacterial agent molecule and chitosan synergistically antibacterial, and excellent antibacterial effect is given to the polyester fiber, and meanwhile, multiple amide groups and carbamate groups generated in the reaction are polar and hydrophilic, so that the moisture absorption capacity of the polyester fiber is enhanced.

[0034] The application utilizes gamma-methacryloxypropyl trimethoxysilane to modify graphene oxide, so that the graphene oxide is grafted with double bond structure, and then copolymerized with methacryloxyethyl trimethyl ammonium chloride and methoxy polyethylene glycol acrylate to prepare the antistatic modifier. The graphene oxide has excellent mechanical properties, the methacryloxyethyl trimethyl ammonium chloride serves as the main body of the antistatic agent, the methoxy polyethylene glycol acrylate is introduced into the molecular chain of the copolymer as the hydrophilic component to enhance the moisture absorption performance of the copolymer, and the addition of the antistatic modifier can endow the polyester fiber with excellent breaking strength, breaking elongation, moisture absorption and antistatic performance. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0036] The preparation method of the antibacterial agent in the embodiment 1 comprises the following steps:

[0037] A. 2.74g of 2-pyridinemethanol and 11.06g of decyl bromide are taken into a reactor, 50mL of 1,4-dioxane solvent is added, and stirring reaction is carried out at 105℃ for 42h. After the reaction is completed, rotary evaporation, washing, suction filtration and drying are carried out to prepare an antibacterial intermediate;

[0038] B. 3.85g of isophorone diisocyanate is taken into a reactor, 40mL of anhydrous butyl acetate solvent and 0.02g of dibutyltin dilaurate catalyst are added, the temperature is raised to 40℃, and the antibacterial intermediate is added for stirring reaction for 6h to prepare an isocyanate-antibacterial intermediate;

[0039] C. 2g of chitosan is dispersed in a 50% methanol-water solution to obtain a chitosan solution, 7.9g of benzaldehyde is dissolved in 20mL of methanol and then added to the chitosan solution, the pH value of the system is adjusted to 4.5, the temperature is raised to 50℃, and reaction is carried out for 4h. After the reaction is completed, suction filtration, washing and drying are carried out to prepare N-benzylidene chitosan;

[0040] D. 2g of N-benzylidene chitosan is dissolved in 100mL of acetone, the temperature is raised to 65℃, 0.02g of dibutyltin dilaurate catalyst is added, 5g of the isocyanate-antibacterial intermediate is uniformly mixed with 20mL of acetone and then added to the reaction system for reaction for 10h. The obtained product is dissolved in a 0.5mol / L hydrochloric acid / ethanol solution, reaction is carried out for 24h, and after the reaction is completed, suction filtration, washing and drying are carried out to prepare modified chitosan;

[0041] E. Take 2 g of modified chitosan and dissolve it in 60 mL of deionized water to obtain a mixed solution. Take 0.9 g of p-hydroxybenzoic acid and dissolve it in 50 mL of methanol. Add 1.2 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.7 g of N-hydroxysuccinimide. After stirring and mixing, add them to the mixed solution and place it at 30°C to react for 24 hours. After the reaction is completed, dialyze and dry to prepare an antibacterial agent.

[0042] Example 2 A method for preparing an antistatic modifier comprises the following steps:

[0043] (1) 0.2 g of graphene oxide was dissolved in 20 mL of anhydrous ethanol and dispersed by ultrasonication in a water bath. 3 g of γ-methacryloxypropyltrimethoxysilane was added and refluxed at 110 ° C for 12 h in a nitrogen atmosphere. After the reaction was completed, the modified graphene oxide was filtered, washed, and dried to obtain the modified graphene oxide.

[0044] (2) Take 0.8 g of modified graphene oxide and ultrasonically disperse it in 150 mL of anhydrous ethanol. In a nitrogen atmosphere, add 8.2 g of methacryloyloxyethyl trimethylammonium chloride and 4.7 g of methoxy polyethylene glycol acrylate, stir and mix evenly at room temperature, then add azobisisobutyronitrile, raise the temperature to 70-80 ° C and react for 6-7 hours. After the reaction is completed, cool to room temperature, precipitate and dry to prepare an antistatic modifier.

[0045] Example 3 A method for preparing melt-spun antimony-free polyester fiber comprises the following steps:

[0046] S1. Ethylene glycol (75% of the total amount of ethylene glycol) and terephthalic acid are uniformly mixed to obtain a mixed slurry, wherein the molar ratio of the total amount of ethylene glycol to terephthalic acid is 1.5:1;

[0047] S2. Ethylene glycol (15% of the total amount of ethylene glycol) and nano-titanium dioxide are mixed uniformly to obtain a catalyst solution, wherein the amount of nano-titanium dioxide used is 250ppm based on the total mass of terephthalic acid;

[0048] S3, taking 1% by weight of terephthalic acid prepared in Example 1, the antimicrobial agent prepared in Example 2 with 0.5% by weight of terephthalic acid, and the remaining ethylene glycol, and mixing them uniformly to obtain an additive suspension;

[0049] S4, mixing the mixed slurry and the catalyst liquid and performing a first esterification reaction at a temperature of 230° C. for a reaction time of 1.5 h. When the antimony-free polyester polymerization esterification rate reaches 85%, adding the additive suspension and performing a second esterification reaction at a temperature of 240° C. for a reaction time of 1 h to obtain an esterified product;

[0050] S5, the esterification product is pressed into a pre-polycondensation kettle, low vacuum is extracted to discharge excess ethylene glycol, the temperature is 250 DEG C, the reaction time is 1h, and pre-polycondensation is carried out to obtain a pre-polycondensation product;

[0051] S6, the pre-polycondensation product is pressed into a final polycondensation kettle, the temperature is 270 DEG C, the reaction time is 1.5h, and high vacuum is further extracted to obtain a melt;

[0052] S7, the melt is prepared into melt direct spinning antimony-free polyester fiber through a spinning process, the spinning temperature is 290 DEG C, the side-blowing air cooling temperature is 25 DEG C, the side-blowing air speed is 0.3m / s, the spinning speed is 3000m / min, and the draft ratio is 3.5.

[0053] Example 4, a preparation method of melt direct spinning antimony-free polyester fiber, comprising the following steps:

[0054] S1, ethylene glycol and terephthalic acid are uniformly mixed to obtain a mixed slurry, and the molar ratio of the total amount of ethylene glycol to terephthalic acid is 1.5:1;

[0055] S2, ethylene glycol and nano titanium dioxide are uniformly mixed to obtain a catalyst liquid, and the amount of nano titanium dioxide is 250ppm of the total mass of terephthalic acid;

[0056] S3, 2% of the antibacterial agent prepared in example 1 by mass of terephthalic acid, 1% of the antistatic modifier prepared in example 2 by mass of terephthalic acid and the remaining ethylene glycol are uniformly mixed to obtain an additive suspension;

[0057] S4, the mixed slurry and the catalyst liquid are mixed to carry out first esterification reaction, the temperature is 230 DEG C, the reaction time is 1.5h, when the esterification rate of antimony-free polyester reaches 85%, the additive suspension is added to carry out second esterification reaction, the temperature is 240 DEG C, the reaction time is 1h, and the esterification product is obtained;

[0058] S5, the esterification product is pressed into a pre-polycondensation kettle, low vacuum is extracted to discharge excess ethylene glycol, the temperature is 250 DEG C, the reaction time is 1h, and pre-polycondensation is carried out to obtain a pre-polycondensation product;

[0059] S6, the pre-polycondensation product is pressed into a final polycondensation kettle, the temperature is 270 DEG C, the reaction time is 1.5h, and high vacuum is further extracted to obtain a melt;

[0060] S7, the melt is prepared into melt direct spinning antimony-free polyester fiber through a spinning process, the spinning temperature is 290 DEG C, the side-blowing air cooling temperature is 25 DEG C, the side-blowing air speed is 0.3m / s, the spinning speed is 3000m / min, and the draft ratio is 3.5.

[0061] Example 5, a preparation method of melt direct spinning antimony-free polyester fiber, comprising the following steps:

[0062] S1, 75% of the total amount of ethylene glycol and terephthalic acid were mixed uniformly to obtain a mixed slurry, and the molar ratio of the total amount of ethylene glycol to terephthalic acid was 1.5:1;

[0063] S2, 15% of the total amount of ethylene glycol and nano titanium dioxide were mixed uniformly to obtain a catalyst liquid, and the amount of nano titanium dioxide was 250ppm of the total mass of terephthalic acid;

[0064] S3, 4% of the terephthalic acid prepared in example 1 was mixed with 2% of the antistatic modifier prepared in example 2 and the remaining ethylene glycol to obtain an additive suspension;

[0065] S4, after mixing the mixed slurry and the catalyst liquid, the first esterification reaction was carried out at a temperature of 230℃ for 1.5h, and when the esterification rate of antimony-free polyester polymerization reached 85%, the additive suspension was added, and the second esterification reaction was carried out at a temperature of 240℃ for 1h to obtain an esterification product;

[0066] S5, the esterification product was pressed into a pre-polycondensation kettle, excess ethylene glycol was removed by low vacuum, the temperature was 250℃, and the reaction time was 1h to carry out pre-polycondensation to obtain a pre-polycondensation product;

[0067] S6, the pre-polycondensation product was pressed into a final polycondensation kettle, the temperature was 270℃, and the reaction time was 1.5h to further polycondense by high vacuum to obtain a melt;

[0068] S7, the melt was prepared into a melt direct spinning antimony-free polyester fiber by a spinning process, the spinning temperature was 290℃, the side air cooling temperature was 25℃, the side air cooling speed was 0.3m / s, the spinning speed was 3000m / min, and the draft ratio was 3.5.

[0069] The preparation method of the antibacterial agent of comparative example 1 comprises the following steps:

[0070] A, 2-pyridine methanol and decyl bromide were taken in a reactor, 1,4-dioxane solvent was added, and stirring was carried out at 95-110℃ for 42-48h, after the reaction was completed, rotary evaporation, washing, suction filtration and drying were carried out to prepare an antibacterial intermediate;

[0071] B, isophorone diisocyanate was taken in a reactor, anhydrous butyl acetate solvent and dibutyl tin dilaurate catalyst were added, the temperature was raised to 35-45℃, the antibacterial intermediate was added, and stirring was carried out for 5-6h to prepare an isocyanate antibacterial intermediate;

[0072] C. The chitosan is dispersed in a methanol-water solution to obtain a chitosan solution, benzaldehyde is dissolved in methanol and then added to the chitosan solution, the pH value of the system is adjusted to 4.5-5, the temperature is raised to 45-55°C, and the reaction is carried out for 3-5 hours. After the reaction is completed, the product is obtained by filtration, washing and drying to prepare N-benzal chitosan;

[0073] D. The N-benzal chitosan is dissolved in acetone, the temperature is raised to 50-70°C, and dibutyltin dilaurate is added as a catalyst. An isocyanate-antibacterial intermediate is uniformly mixed with acetone and then added to the reaction system to react for 8-11 hours. The obtained product is dissolved in a mixture of hydrochloric acid and ethanol, and the reaction is carried out for 20-24 hours. After the reaction is completed, the product is obtained by filtration, washing and drying to prepare an antibacterial agent.

[0074] A preparation method of a melt direct spinning antimony-free polyester fiber, comprising the following steps:

[0075] S1. A mixture of 75% of the total amount of ethylene glycol and terephthalic acid is uniformly mixed to obtain a mixed slurry, and the molar ratio of the total amount of ethylene glycol to terephthalic acid is 1.5:1.

[0076] S2. A mixture of 15% of the total amount of ethylene glycol and nano-titanium dioxide is uniformly mixed to obtain a catalyst solution, and the amount of nano-titanium dioxide is 250 ppm of the total mass of terephthalic acid.

[0077] S3. A mixture of 4% of the antibacterial agent prepared in Comparative Example 1, 2% of the antistatic modifier prepared in Example 2, and the remaining ethylene glycol is uniformly mixed to obtain an additive suspension.

[0078] S4. The mixed slurry and the catalyst solution are mixed to carry out a first esterification reaction at a temperature of 230°C for 1.5 hours. When the esterification rate of the antimony-free polyester reaches 85%, the additive suspension is added to carry out a second esterification reaction at a temperature of 240°C for 1 hour to obtain an esterification product.

[0079] S5. The esterification product is pressed into a pre-polycondensation kettle, and excess ethylene glycol is discharged under low vacuum at a temperature of 250°C for 1 hour to carry out pre-polycondensation to obtain a pre-polycondensation product.

[0080] S6. The pre-polycondensation product is pressed into a final polycondensation kettle, and further high vacuum polycondensation is carried out at a temperature of 270°C for 1.5 hours to obtain a melt.

[0081] S7. The melt is prepared into a melt direct spinning antimony-free polyester fiber by a spinning process at a spinning temperature of 290°C, a side air cooling temperature of 25°C, a side air cooling speed of 0.3 m / s, a spinning speed of 3000 m / min, and a draft ratio of 3.5.

[0082] Preparation method of a melt direct spinning antimony-free polyester fiber, comprising the following steps:

[0083] S1, uniformly mix ethylene glycol with a total amount of 75% and terephthalic acid to obtain a mixed slurry, the molar ratio of the total amount of ethylene glycol to terephthalic acid being 1.5:1;

[0084] S2, uniformly mix ethylene glycol with a total amount of 15% and nano-titanium dioxide to obtain a catalyst liquid, the amount of nano-titanium dioxide being 250ppm of the total mass of terephthalic acid;

[0085] S3, uniformly mix chitosan with a mass of 4% of terephthalic acid, the antistatic modifier prepared in example 2 with a mass of 2% of terephthalic acid, and the remaining ethylene glycol to obtain an additive suspension;

[0086] S4, after mixing the mixed slurry and the catalyst liquid, perform a first esterification reaction at a temperature of 230℃ for 1.5h, then add the additive suspension when the esterification rate of the antimony-free polyester reaches 85%, perform a second esterification reaction at a temperature of 240℃ for 1h to obtain an esterification product;

[0087] S5, press the esterification product into a pre-polycondensation kettle, extract low vacuum to discharge excess ethylene glycol, the temperature being 250℃, and the reaction time being 1h to perform pre-polycondensation to obtain a pre-polycondensation product;

[0088] S6, press the pre-polycondensation product into a final polycondensation kettle, the temperature being 270℃, and the reaction time being 1.5h to further extract high vacuum for polycondensation to obtain a melt;

[0089] S7, prepare a melt direct spinning antimony-free polyester fiber through a spinning process, the spinning temperature being 290℃, the side-blowing cooling temperature being 25℃, the side-blowing wind speed being 0.3m / s, the spinning speed being 3000m / min, and the draft ratio being 3.5.

[0090] Preparation method of a melt direct spinning antimony-free polyester fiber, comprising the following steps:

[0091] S1, uniformly mix ethylene glycol with a total amount of 75% and terephthalic acid to obtain a mixed slurry, the molar ratio of the total amount of ethylene glycol to terephthalic acid being 1.5:1;

[0092] S2, uniformly mix ethylene glycol with a total amount of 15% and nano-titanium dioxide to obtain a catalyst liquid, the amount of nano-titanium dioxide being 250ppm of the total mass of terephthalic acid;

[0093] S3, uniformly mix the antibacterial agent prepared in example 1 with a mass of 4% of terephthalic acid and the remaining ethylene glycol to obtain an additive suspension;

[0094] S4, after mixing the mixed slurry and catalyst liquid, a first esterification reaction is carried out at a temperature of 230 DEG C for 1.5 h, when the esterification rate of antimony-free polyester polymerization reaches 85%, an additive suspension is added, a second esterification reaction is carried out at a temperature of 240 DEG C for 1 h, and an esterification product is obtained;

[0095] S5, the esterification product is pressed into a pre-polycondensation kettle, low vacuum is extracted to discharge excess ethylene glycol, the temperature is 250 DEG C, the reaction time is 1 h, pre-polycondensation is carried out to obtain a pre-polycondensation product;

[0096] S6, the pre-polycondensation product is pressed into a final polycondensation kettle, the temperature is 270 DEG C, the reaction time is 1.5 h, further high vacuum polycondensation is carried out to obtain a melt;

[0097] S7, the melt is prepared into a melt direct spinning antimony-free polyester fiber by a spinning process, the spinning temperature is 290 DEG C, the side air cooling temperature is 25 DEG C, the side air cooling speed is 0.3 m / s, the spinning speed is 3000 m / min, and the draft ratio is 3.5.

[0098] Performance detection

[0099] The polyester fibers prepared in Examples 3-5 and Comparative Examples 2-4 are subjected to performance detection: the mechanical properties of the fibers are tested according to GB / T 14337-2022; the antibacterial performance is detected according to GB / T 20944.3-2008; 50 g of polyester fiber is rinsed with ethanol for 2 times and then placed in an oven for drying to constant weight, the mass M0 is recorded, then immersed in a beaker containing deionized water, and after standing for 48 h, taken out and placed on a 100-mesh standard sieve for 30 min until no liquid drops drop, then weighed, the mass M1 is recorded, and the water absorption rate is tested, the water absorption rate is calculated according to the following formula: water absorption rate = (M1-M0) / M0 x 100%, and the data results are shown in Table 1.

[0100] Table 1 Performance detection results of samples

[0101]

[0102] As can be seen from the data in Table 1, the polyester fibers prepared in Examples 3-5 of the present application are not prone to breaking, have good moisture absorption and antistatic properties, and also have excellent antibacterial properties. The antibacterial agent added in Comparative Example 2 does not contain a phenolic group structure, and only chitosan is added as an antibacterial agent in Comparative Example 3. The measured antibacterial properties of Comparative Examples 2-3 are significantly lower than those of Examples 3-5, indicating that both the phenolic group structure and the quaternary ammonium salt group can have a synergistic antibacterial effect with chitosan. The measured moisture absorption and antistatic properties of Comparative Examples 2-3 are slightly worse than those of Examples 3-5, because the isocyanate-derivatized antibacterial intermediate reacts with N-benzylidene chitosan to form a urethane group, and the modified chitosan reacts with p-hydroxybenzoic acid to form an amide group. The amide group and the urethane group are both polar and hydrophilic, which enhances the moisture absorption and antistatic properties of the polyester fibers. In Comparative Example 4, no antistatic modifier is added, and the measured breaking strength, elongation at break, and water absorption are lower than those of Examples 3-5, and the volume specific resistance is higher than that of Examples 3-5, indicating that the addition of an antistatic modifier can improve the mechanical properties, moisture absorption, and antistatic properties of the polyester fibers.

[0103] In the description of the present specification, the description of the terms "one embodiment", "an example", "a specific example", and the like means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0104] The basic principles, main features, and advantages of the present application have been shown and described above. It should be understood by those skilled in the art that the present application is not limited by the above embodiments, and the above embodiments and descriptions in the specification are only illustrative of the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application.

Claims

1. A method for preparing melt-spun antimony-free polyester fiber, characterized in that: The invention is prepared by the following method: terephthalic acid and ethylene glycol in a molar ratio of 1:1.3-1.6 are used as reaction raw materials, an antimicrobial agent, an antistatic modifier and a titanium catalyst are added, and the fibers are subjected to an esterification reaction and a pre-polycondensation process, and then a final polycondensation reaction and a spinning process to prepare a melt-spun antimony-free polyester fiber; the mass of the antimicrobial agent is 1-4% of the mass of the terephthalic acid, and the mass of the antistatic modifier is 0.5-2% of the mass of the terephthalic acid; The antibacterial agent is prepared by synthesizing an antibacterial intermediate using 2-pyridinemethanol and decyl bromide, then grafting the antibacterial intermediate with chitosan using isophorone diisocyanate as a linker, and further grafting p-hydroxybenzoic acid to obtain the antibacterial agent; the antistatic modifier is prepared by modifying graphene oxide using γ-methacryloyloxypropyltrimethoxysilane, and then copolymerizing it with methacryloyloxyethyltrimethylammonium chloride and methoxy polyethylene glycol acrylate to obtain the antistatic modifier.

2. The method for preparing melt-spun antimony-free polyester fiber according to claim 1, characterized in that: The titanium catalyst is one or more combinations of titanium glycol, titanate, and nano titanium dioxide.

3. The method for preparing melt-spun antimony-free polyester fiber according to claim 1, characterized in that: The preparation method of the antibacterial agent comprises the following steps: A. Take 2-pyridinemethanol and decyl bromide in a reactor, add 1,4-dioxane solvent, place it at 95-110°C and stir to react for 42-48 hours. After the reaction is completed, the product is rotary evaporated, washed, filtered, and dried to obtain an antibacterial intermediate; B. Take isophorone diisocyanate in a reactor, add anhydrous butyl acetate solvent and dibutyltin dilaurate catalyst, raise the temperature to 35-45° C., add the antibacterial intermediate and stir the reaction for 5-6 hours to prepare an isocyanate antibacterial intermediate; C. Dispersing chitosan in a methanol-water solution to obtain a chitosan solution, dissolving benzaldehyde in methanol and adding it to the chitosan solution, adjusting the pH value of the system to 4.5-5, heating to 45-55°C and reacting for 3-5 hours, and filtering after completion of the reaction, washing, and drying to prepare N-benzylidene chitosan; D. Dissolve N-benzylidene chitosan in acetone, raise the temperature to 50-70°C, add dibutyltin dilaurate catalyst, mix the isocyanate antibacterial intermediate with acetone, and then add it to the reaction system to react for 8-11 hours. Dissolve the obtained product in a mixture of hydrochloric acid and ethanol and react for 20-24 hours. After the reaction is completed, filter, wash, and dry to prepare modified chitosan; E. Take modified chitosan and dissolve it in deionized water to obtain a mixed solution, take p-hydroxybenzoic acid and dissolve it in methanol, add 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide, stir and mix, then add them to the mixed solution, place it at 30-40°C to react for 20-24 hours, dialyze and dry after the reaction to prepare an antibacterial agent.

4. The method for preparing melt-spun antimony-free polyester fiber according to claim 3, characterized in that: The mass ratio of the 2-pyridinemethanol, decyl bromide and isophorone diisocyanate is 1:3.8-4.4:1.4-1.

8.

5. The method for preparing melt-spun antimony-free polyester fiber according to claim 1, characterized in that: The preparation method of the antistatic modifier comprises the following steps: (1) Graphene oxide is dissolved in anhydrous ethanol, ultrasonically dispersed in a water bath, γ-methacryloxypropyltrimethoxysilane is added, and the mixture is refluxed at 105-120° C. in a nitrogen atmosphere for 10-12 hours. After the reaction is completed, the mixture is filtered, washed, and dried to prepare modified graphene oxide; (2) Modified graphene oxide was ultrasonically dispersed in anhydrous ethanol, and methacryloyloxyethyl trimethylammonium chloride and methoxy polyethylene glycol acrylate were added in a nitrogen atmosphere, and stirred and mixed evenly at room temperature. Then, azobisisobutyronitrile was added, and the temperature was raised to 70-80°C for 6-7h. After the reaction was completed, the temperature was lowered to room temperature, and the antistatic modifier was prepared by precipitation and drying.

6. The method for preparing melt-spun antimony-free polyester fiber according to claim 5, characterized in that: In the step (2), the mass ratio of methacryloyloxyethyltrimethylammonium chloride, modified graphene oxide and methoxy polyethylene glycol acrylate is 7.5-9.2:0.5-1:4-5.

7. The method for preparing melt-spun antimony-free polyester fiber according to claim 1, characterized in that: The method specifically comprises the following steps: S1. Evenly mix ethylene glycol (70-75% of the total amount of ethylene glycol) and terephthalic acid to obtain a mixed slurry; S2. Evenly mix 15-20% of the total amount of ethylene glycol and a titanium-based catalyst to obtain a catalyst liquid; S3, taking the antibacterial agent, antistatic modifier and remaining ethylene glycol and mixing them evenly to obtain an additive suspension; S4, mixing the mixed slurry and the catalyst liquid and performing a first esterification reaction at a temperature of 230-250° C. for a reaction time of 1-3 hours. When the esterification rate of the antimony-free polyester polymerization reaches 85-90%, adding the additive suspension and performing a second esterification reaction at a temperature of 230-250° C. for a reaction time of 0.5-1 hour to obtain an esterified product; S5, pressing the esterification product into a pre-condensation reactor, applying low vacuum to discharge excess ethylene glycol, and performing pre-condensation to obtain a pre-condensation product; S6, pressing the pre-polycondensation product into a final polycondensation kettle, and further evacuating the polycondensation vessel to obtain a melt; S7. The melt is subjected to a spinning process to prepare melt-spun antimony-free polyester fibers.

8. The method for preparing melt-spun antimony-free polyester fiber according to claim 7, characterized in that: The vacuum degree of the pre-polycondensation is 1-100KPa, the temperature is 250-265°C, and the reaction time is 0.5-1h; the vacuum degree of the final polycondensation kettle is 30-80Pa, the final polycondensation temperature is 260-280°C, and the reaction time is 0.8-3h.

9. The method for preparing melt-spun antimony-free polyester fiber according to claim 7, characterized in that: The parameters of the spinning process are set as follows: spinning temperature 270-295° C., side blowing cooling temperature 25-30° C., side blowing wind speed 0.2-0.4 m / s, spinning speed 2800-3500 m / min, and draft ratio 3.0-4.

0.

10. A melt-spun antimony-free polyester fiber, characterized in that: Prepared by the preparation method according to any one of claims 1 to 9.

Images