A kind of heat-insulating antibacterial polyester fiber and its preparation process

Abstract

The present invention relates to the technical field of textiles, specifically to a heat-insulating antibacterial polyester fiber and a preparation process thereof. The present invention discloses a heat-insulating antibacterial polyester fiber and a preparation process thereof; a modified PET is prepared by adding a bishydroxypyridinium quaternary ammonium salt having antibacterial properties and a polycaprolactam prepolymer ester having hydrophilic properties during the polycondensation of dimethyl terephthalate; wherein the bishydroxypyridinium quaternary ammonium salt is obtained by reacting 2,6-pyridine dicarbonyl chloride with ethanolamine and then grafting with bromobutylene; the polycaprolactam prepolymer ester is obtained by polycondensing caprolactam, using terephthalic acid as a capping agent, and then reacting with ethylene glycol for esterification. The modified PET and PBT are melted, spun, and then composited to obtain polyester fiber precursor, and then the polyester fiber precursor is stretched and shaped to obtain a heat-insulating antibacterial polyester fiber with good performance.

Description

Technical Field

[0001] The invention relates to the technical field of textiles, in particular to a heat-insulating antibacterial polyester fiber and a preparation process thereof. Background Art

[0002] Polyester fiber is a common synthetic fiber made from organic dibasic acid and diol by chemical polycondensation, and is a kind of polymer compound. Polyester fiber has excellent wrinkle resistance and shape retention, and its elastic recovery ability is strong, so the clothes made of it are not easy to wrinkle and can maintain their original shape for a long time; secondly, polyester fiber has high strength, strong wear resistance and long service life.

[0003] Fabrics made of polyester fiber have better thermal insulation properties than most other fabrics. However, due to the properties of the polyester fiber material itself, the moisture absorption rate of polyester fiber fabric is low, so it is easy to generate static electricity, resulting in a poor experience when wearing clothing made of polyester fiber fabric, especially in the cold and dry winter. It is not only easy to absorb dust and hair, but also causes static electricity damage to the human body. In addition, as a chemically synthesized fiber, polyester fiber itself does not have antibacterial ability. As people's living standards continue to improve, the use of fiber fabrics with antibacterial properties can, on the one hand, prevent the fabric from getting moldy and being corroded by bacteria, and on the other hand, protect the human body from damage by microorganisms such as viruses, bacteria, spores and fungi, and protect human health. Summary of the invention

[0004] The object of the present invention is to provide a heat-insulating antibacterial polyester fiber and a preparation process thereof, so as to solve the problems raised in the above background technology.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: a heat-insulating antibacterial polyester fiber and a preparation process thereof, comprising the following steps:

[0006] Step 1:

[0007] Disperse ethanolamine in N,N-dimethylformamide, maintain the system temperature at 20-25°C, use triethylamine as an acid binding agent, stir and mix for 20-30 minutes, add 2,6-pyridinedicarbonyl chloride dispersed in N,N-dimethylformamide, maintain the temperature for reaction for 12-15 hours, heat to 70-80°C and continue to keep the temperature for reaction for 20-24 hours; after the reaction is completed, cool naturally, wash with deionized water, filter, dry, disperse in chloroform, add bromobutyl, heat to 65-75°C, react for 10-12 hours, add methanol to quench the reaction, wash, filter, and dry to obtain a bishydroxypyridine quaternary ammonium salt;

[0008] Step 2:

[0009] At 80-85° C., caprolactam and terephthalic acid are mixed, added into deionized water, stirred for 10-15 minutes, and heated to 210-230° C. in a nitrogen environment to obtain a polycaprolactam prepolymer; ethylene glycol is added into the polycaprolactam prepolymer to carry out an esterification reaction for 2-3 hours to obtain a polycaprolactam prepolymer esterification product;

[0010] Step 3:

[0011] Dimethyl terephthalate and ethylene glycol are mixed, ethylene glycol antimony is used as a catalyst, and the mixture is reacted at 160-220° C. for 2-3 hours, and the remaining ethylene glycol is removed to obtain an intermediate; polycaprolactam prepolymer esterification product and dihydroxypyridinium quaternary ammonium salt are added to the intermediate, the mixture is heated to 270-280° C. under vacuum, the mixture is reacted for 1.5-2.5 hours, and the mixture is discharged and pelletized to obtain modified PET chips;

[0012] Step 4:

[0013] The modified PET slices and PBT slices are respectively melted by screws, placed in a spinning box, and spun and compounded in parallel to prepare polyester fiber precursors. The polyester fiber precursors are wound and oiled, and then stretched and shaped to obtain warm-keeping antibacterial polyester fibers.

[0014] Furthermore, in step 1, the molar ratio of ethanolamine, 2,6-pyridinedicarbonyl chloride and bromobutane is 2:1:1.

[0015] Furthermore, in step 2, caprolactam and terephthalic acid are mixed in a molar ratio of (2 to 2.5):1.

[0016] Furthermore, in step 2, ethylene glycol is added to the polycaprolactam prepolymer at a molar ratio of the terminal carboxyl group of the polycaprolactam prepolymer to ethylene glycol of 1:(1.2-1.4).

[0017] Furthermore, in step 3, dimethyl terephthalate and ethylene glycol are mixed in a molar ratio of 1:(2-2.4) to react to obtain an intermediate.

[0018] Furthermore, in step 3, the intermediate, the polycaprolactam prepolymer ester, and the dihydroxypyridinium quaternary ammonium salt are mixed and reacted in a weight ratio of (8-10):(1-1.5):(0.5-0.8).

[0019] Furthermore, in step 4, the stretching temperature is 150-160° C. and the stretching ratio is 4-5 times.

[0020] Furthermore, in step 4, the contents of the components in the heat-insulating antibacterial polyester fiber are, by weight percentage, 55-90% of modified PET and 10-45% of PBT.

[0021] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: the present invention prepares a heat-insulating antibacterial polyester fiber, and the modification of PET is achieved by adding a bishydroxypyridinium quaternary ammonium salt with antibacterial properties and a polycaprolactam prepolymer ester with hydrophilic properties during the polycondensation of dimethyl terephthalate. The bishydroxypyridinium quaternary ammonium salt is obtained by reacting 2,6-pyridine dicarbonyl chloride with ethanolamine in a molar ratio of 1:2, and then grafting with butyl bromide; the polycaprolactam prepolymer ester is obtained by polycondensing caprolactam, capping with terephthalic acid as a capping agent, and then esterifying the end carboxyl group of the capped product with ethylene glycol; since the polycaprolactam prepolymer ester and dimethyl terephthalate have similar molecular structures, the two have good compatibility. In the process of PET modification, when in the initial stage of the reaction, dimethyl terephthalate and ethylene glycol undergo ester exchange reaction to generate intermediates, and the intermediates undergo ester exchange reaction again with dihydroxypyridinium quaternary ammonium salt and polycaprolactam prepolymer esterification to generate oligomers, and finally modified PET chips are obtained through condensation reaction, discharging and pelletizing.

[0022] It should be noted that the polycaprolactam prepolymer ester itself is a polymer, and its molecular weight has a significant effect on the performance of the modified PET. When the molecular weight of the polycaprolactam prepolymer ester is large, its reaction activity in the polycondensation reaction of the modified PET decreases. At the same time, the large molecular weight has a greater steric effect. Under the combined influence of the two, the growth of the modified polyester molecular chain is hindered, resulting in poor performance of the modified polyester. The molecular weight of the polycaprolactam prepolymer ester can be obtained by controlling the ratio of the raw material caprolactam and the end-capping agent terephthalic acid; when the terephthalic acid content is higher, the esterification reaction is easier to occur, and the molecular weight of the polycaprolactam prepolymer ester is relatively lower. Therefore, by controlling the molar ratio of caprolactam and terephthalic acid (2 to 2.5): 1, the obtained polycaprolactam prepolymer ester has a good modification effect on PET.

[0023] The modified PET slices and PBT slices are melted, spun and composited to obtain polyester fiber precursor, and then the polyester fiber precursor is stretched and shaped to obtain thermal insulation antibacterial polyester fiber with good performance. After modification, the polyester fiber has good antibacterial properties; although the presence of amide groups will lead to a decrease in tensile strength, the tensile elongation is also improved. At the same time, due to the hydrophilicity of the amide group, the moisture absorption rate of the polyester fiber is higher than before modification. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Materials used in the present invention and their sources: Ethylene glycol antimony comes from Eryuan Chemical Co., Ltd., Tonggu County, Jiangxi Province; PBT slices come from Polyplastics Co., Ltd., Japan 300FP PBT.

[0026] Embodiment 1: A heat-insulating antibacterial polyester fiber and a preparation process thereof, comprising the following steps:

[0027] Step 1:

[0028] Disperse ethanolamine in N,N-dimethylformamide, maintain the system temperature at 20°C, use triethylamine as an acid binding agent, stir and mix for 20 minutes, add 2,6-pyridinedicarbonyl chloride dispersed in N,N-dimethylformamide, maintain the temperature for reaction for 12 hours, heat to 70°C and continue to heat for reaction for 20 hours; after the reaction is completed, cool naturally, wash with deionized water, filter, dry, disperse in chloroform, add butyl bromide, heat to 65°C, react for 10 hours, add methanol to quench the reaction, wash, filter, and dry to obtain dihydroxypyridine quaternary ammonium salt; wherein the molar ratio of ethanolamine, 2,6-pyridinedicarbonyl chloride, and butyl bromide is 2:1:1;

[0029] Step 2:

[0030] At 80°C, caprolactam and terephthalic acid were mixed in a molar ratio of 2.5:1, added into deionized water, stirred for 10 minutes, and heated to 210°C in a nitrogen environment to obtain a polycaprolactam prepolymer; ethylene glycol was added in a molar ratio of 1:1.3 between the terminal carboxyl group of the polycaprolactam prepolymer and ethylene glycol, and the esterification reaction was carried out for 2 hours to obtain a polycaprolactam prepolymer ester;

[0031] Step 3:

[0032] Dimethyl terephthalate and ethylene glycol are mixed in a molar ratio of 1:2.4, ethylene glycol antimony is used as a catalyst, and the mixture is reacted at 160° C. for 2 hours, and the remaining ethylene glycol is removed to obtain an intermediate; polycaprolactam prepolymer ester and dihydroxypyridinium quaternary ammonium salt are added to the intermediate, the mixture is heated to 270° C. under vacuum, the mixture is reacted for 1.5 hours, and the modified PET slices are obtained by discharging and pelletizing; wherein the weight ratio of the intermediate, the polycaprolactam prepolymer ester and the dihydroxypyridinium quaternary ammonium salt is 10:1:0.5;

[0033] Step 4:

[0034] The modified PET slices are screw melted, and the temperature of the screw melting zone 1 is 285°C, the temperature of the screw melting zone 2 is 284°C, the temperature of the screw melting zone 3 is 283°C, the temperature of the screw melting zone 4 is 283°C, the temperature of the screw melting zone 5 is 282°C, and the temperature of the screw melting zone 6 is 270°C; the PBT slices are screw melted, and the temperature of the screw melting zone 1 is 259°C, the temperature of the screw melting zone 2 is 265.5°C, the temperature of the screw melting zone 3 is 269.3°C, the temperature of the screw melting zone 4 is 270.3°C, and the temperature of the screw melting zone 5 is 271.3°C; the above melted materials are placed in a spinning box, and the spinning and parallel compounding are carried out to prepare polyester fiber precursor; the polyester fiber precursor is wound and oiled, and then stretched 4.5 times at 150°C and shaped to obtain a thermal insulation antibacterial polyester fiber; wherein, the thermal insulation antibacterial polyester fiber contains 90% modified PET and 10% PBT by weight.

[0035] Embodiment 2: A heat-insulating antibacterial polyester fiber and a preparation process thereof, comprising the following steps:

[0036] Step 1:

[0037] Disperse ethanolamine in N,N-dimethylformamide, maintain the system temperature at 25°C, use triethylamine as an acid binding agent, stir and mix for 25 minutes, add 2,6-pyridinedicarbonyl chloride dispersed in N,N-dimethylformamide, maintain the temperature for reaction for 14 hours, heat to 75°C and continue to keep warm for reaction for 22 hours; after the reaction is completed, cool naturally, wash with deionized water, filter, dry, disperse in chloroform, add butyl bromide, heat to 70°C, react for 11 hours, add methanol to quench the reaction, wash, filter, and dry to obtain dihydroxypyridine quaternary ammonium salt; wherein the molar ratio of ethanolamine, 2,6-pyridinedicarbonyl chloride, and butyl bromide is 2:1:1;

[0038] Step 2:

[0039] At 85°C, caprolactam and terephthalic acid were mixed in a molar ratio of 2.5:1, added into deionized water, stirred for 13 minutes, and heated to 220°C in a nitrogen environment to obtain a polycaprolactam prepolymer; ethylene glycol was added in a molar ratio of 1:1.3 between the terminal carboxyl group of the polycaprolactam prepolymer and ethylene glycol, and the esterification reaction was carried out for 2.5 hours to obtain a polycaprolactam prepolymer ester;

[0040] Step 3:

[0041] Dimethyl terephthalate and ethylene glycol are mixed in a molar ratio of 1:2.4, ethylene glycol antimony is used as a catalyst, and the mixture is reacted at 180°C for 2.5 hours, and the remaining ethylene glycol is removed to obtain an intermediate; polycaprolactam prepolymer ester and dihydroxypyridinium quaternary ammonium salt are added to the intermediate, and the mixture is heated to 275°C under vacuum, and the mixture is reacted for 2 hours, and the modified PET slices are obtained by discharging and pelletizing; wherein the weight ratio of the intermediate, the polycaprolactam prepolymer ester and the dihydroxypyridinium quaternary ammonium salt is 10:1:0.5;

[0042] Step 4:

[0043] The modified PET slices are screw melted, and the temperature of the screw melting zone 1 is 285°C, the temperature of the screw melting zone 2 is 284°C, the temperature of the screw melting zone 3 is 283°C, the temperature of the screw melting zone 4 is 283°C, the temperature of the screw melting zone 5 is 282°C, and the temperature of the screw melting zone 6 is 270°C; the PBT slices are screw melted, and the temperature of the screw melting zone 1 is 259°C, the temperature of the screw melting zone 2 is 265.5°C, the temperature of the screw melting zone 3 is 269.3°C, the temperature of the screw melting zone 4 is 270.3°C, and the temperature of the screw melting zone 5 is 271.3°C; the above melted materials are placed in a spinning manifold, and the spinning and parallel compounding are carried out to prepare polyester fiber precursor; the polyester fiber precursor is wound and oiled, and then stretched 4.5 times at 155°C, and shaped to obtain a thermal insulation antibacterial polyester fiber; wherein, the thermal insulation antibacterial polyester fiber contains 90% modified PET and 10% PBT by weight.

[0044] Embodiment 3: A heat-insulating antibacterial polyester fiber and a preparation process thereof, comprising the following steps:

[0045] Step 1:

[0046] Disperse ethanolamine in N,N-dimethylformamide, maintain the system temperature at 25°C, use triethylamine as an acid binding agent, stir and mix for 30 minutes, add 2,6-pyridinedicarbonyl chloride dispersed in N,N-dimethylformamide, maintain the temperature for reaction for 15 hours, heat to 80°C and continue to heat for reaction for 24 hours; after the reaction is completed, cool naturally, wash with deionized water, filter, dry, disperse in chloroform, add butyl bromide, heat to 75°C, react for 12 hours, add methanol to quench the reaction, wash, filter, and dry to obtain dihydroxypyridine quaternary ammonium salt; wherein the molar ratio of ethanolamine, 2,6-pyridinedicarbonyl chloride, and butyl bromide is 2:1:1;

[0047] Step 2:

[0048] At 85°C, caprolactam and terephthalic acid were mixed in a molar ratio of 2.5:1, added into deionized water, stirred for 15 minutes, and heated to 230°C in a nitrogen environment to obtain a polycaprolactam prepolymer; ethylene glycol was added in a molar ratio of 1:1.3 between the terminal carboxyl group of the polycaprolactam prepolymer and ethylene glycol, and the esterification reaction was carried out for 3 hours to obtain a polycaprolactam prepolymer ester;

[0049] Step 3:

[0050] Dimethyl terephthalate and ethylene glycol are mixed in a molar ratio of 1:2.4, ethylene glycol antimony is used as a catalyst, and the mixture is reacted at 220° C. for 3 hours, and the remaining ethylene glycol is removed to obtain an intermediate; polycaprolactam prepolymer ester and dihydroxypyridinium quaternary ammonium salt are added to the intermediate, and the mixture is heated to 280° C. under vacuum, and the mixture is reacted for 2.5 hours, and the modified PET slices are obtained by discharging and pelletizing; wherein the weight ratio of the intermediate, the polycaprolactam prepolymer ester and the dihydroxypyridinium quaternary ammonium salt is 10:1:0.5;

[0051] Step 4:

[0052] The modified PET slices are screw-melted, and the temperatures of screw melting zone 1 are 285°C, zone 2 is 284°C, zone 3 is 283°C, zone 4 is 283°C, zone 5 is 282°C, and zone 6 is 270°C; the PBT slices are screw-melted, and the temperatures of screw melting zone 1 are 259°C, zone 2 is 265.5°C, zone 3 is 269.3°C, zone 4 is 270.3°C, and zone 5 is 271.3°C; the above-mentioned melted materials are placed in a spinning manifold, and after spinning and parallel compounding, polyester fiber precursor is prepared; the polyester fiber precursor is wound and oiled, and then stretched 4.5 times at 160°C and shaped to obtain a thermal insulation antibacterial polyester fiber; wherein, the thermal insulation antibacterial polyester fiber contains 90% modified PET and 10% PBT by weight.

[0053] Embodiment 4: A heat-insulating antibacterial polyester fiber and a preparation process thereof, comprising the following steps:

[0054] Step 1:

[0055] Disperse ethanolamine in N,N-dimethylformamide, maintain the system temperature at 20°C, use triethylamine as an acid binding agent, stir and mix for 20 minutes, add 2,6-pyridinedicarbonyl chloride dispersed in N,N-dimethylformamide, maintain the temperature for reaction for 12 hours, heat to 80°C and continue to heat for reaction for 20 hours; after the reaction is completed, cool naturally, wash with deionized water, filter, dry, disperse in chloroform, add butyl bromide, heat to 75°C, react for 10 hours, add methanol to quench the reaction, wash, filter, and dry to obtain dihydroxypyridine quaternary ammonium salt; wherein the molar ratio of ethanolamine, 2,6-pyridinedicarbonyl chloride, and butyl bromide is 2:1:1;

[0056] Step 2:

[0057] At 80°C, caprolactam and terephthalic acid were mixed in a molar ratio of 2.5:1, added into deionized water, stirred for 15 minutes, and heated to 230°C in a nitrogen environment to obtain a polycaprolactam prepolymer; ethylene glycol was added in a molar ratio of 1:1.3 between the terminal carboxyl group of the polycaprolactam prepolymer and ethylene glycol, and the esterification reaction was carried out for 3 hours to obtain a polycaprolactam prepolymer ester;

[0058] Step 3:

[0059] Dimethyl terephthalate and ethylene glycol are mixed in a molar ratio of 1:2.4, ethylene glycol antimony is used as a catalyst, reacted at 220°C for 3 hours, and the remaining ethylene glycol is removed to obtain an intermediate; polycaprolactam prepolymer ester and dihydroxypyridinium quaternary ammonium salt are added to the intermediate, the temperature is raised to 275°C under vacuum, the reaction is performed for 2 hours, and the modified PET slices are obtained by discharging and pelletizing; wherein the weight ratio of the intermediate, the polycaprolactam prepolymer ester and the dihydroxypyridinium quaternary ammonium salt is 10:1:0.6;

[0060] Step 4:

[0061] The modified PET slices are screw melted, and the temperature of the screw melting zone 1 is 285°C, the temperature of the screw melting zone 2 is 284°C, the temperature of the screw melting zone 3 is 283°C, the temperature of the screw melting zone 4 is 283°C, the temperature of the screw melting zone 5 is 282°C, and the temperature of the screw melting zone 6 is 270°C; the PBT slices are screw melted, and the temperature of the screw melting zone 1 is 259°C, the temperature of the screw melting zone 2 is 265.5°C, the temperature of the screw melting zone 3 is 269.3°C, the temperature of the screw melting zone 4 is 270.3°C, and the temperature of the screw melting zone 5 is 271.3°C; the above melted materials are placed in a spinning box, and the spinning and parallel compounding are carried out to prepare polyester fiber precursor; the polyester fiber precursor is wound and oiled, and then stretched 4.5 times at 150°C and shaped to obtain a thermal insulation antibacterial polyester fiber; wherein, the thermal insulation antibacterial polyester fiber contains 90% modified PET and 10% PBT by weight.

[0062] Embodiment 5: A heat-insulating antibacterial polyester fiber and a preparation process thereof, comprising the following steps:

[0063] Step 1:

[0064] Disperse ethanolamine in N,N-dimethylformamide, maintain the system temperature at 25°C, use triethylamine as an acid binding agent, stir and mix for 25 minutes, add 2,6-pyridinedicarbonyl chloride dispersed in N,N-dimethylformamide, maintain the temperature for reaction for 13 hours, heat to 75°C and continue to heat for reaction for 22 hours; after the reaction is completed, cool naturally, wash with deionized water, filter, dry, disperse in chloroform, add butyl bromide, heat to 65°C, react for 12 hours, add methanol to quench the reaction, wash, filter, and dry to obtain a dihydroxypyridine quaternary ammonium salt; wherein the molar ratio of ethanolamine, 2,6-pyridinedicarbonyl chloride, and butyl bromide is 2:1:1;

[0065] Step 2:

[0066] At 85°C, caprolactam and terephthalic acid were mixed in a molar ratio of 2.5:1, added into deionized water, stirred for 15 minutes, and heated to 230°C in a nitrogen environment to obtain a polycaprolactam prepolymer; ethylene glycol was added in a molar ratio of 1:1.3 between the terminal carboxyl group of the polycaprolactam prepolymer and ethylene glycol, and the esterification reaction was carried out for 2.5 hours to obtain a polycaprolactam prepolymer ester;

[0067] Step 3:

[0068] Dimethyl terephthalate and ethylene glycol are mixed in a molar ratio of 1:2.4, ethylene glycol antimony is used as a catalyst, and the mixture is reacted at 215°C for 2.5 hours, and the remaining ethylene glycol is removed to obtain an intermediate; polycaprolactam prepolymer ester and dihydroxypyridinium quaternary ammonium salt are added to the intermediate, and the mixture is heated to 275°C under vacuum, and the mixture is reacted for 2 hours, and the modified PET slices are obtained by discharging and pelletizing; wherein the weight ratio of the intermediate, the polycaprolactam prepolymer ester and the dihydroxypyridinium quaternary ammonium salt is 10:1:0.7;

[0069] Step 4:

[0070] The modified PET slices are screw melted, and the temperature of the screw melting zone 1 is 285°C, the temperature of the screw melting zone 2 is 284°C, the temperature of the screw melting zone 3 is 283°C, the temperature of the screw melting zone 4 is 283°C, the temperature of the screw melting zone 5 is 282°C, and the temperature of the screw melting zone 6 is 270°C; the PBT slices are screw melted, and the temperature of the screw melting zone 1 is 259°C, the temperature of the screw melting zone 2 is 265.5°C, the temperature of the screw melting zone 3 is 269.3°C, the temperature of the screw melting zone 4 is 270.3°C, and the temperature of the screw melting zone 5 is 271.3°C; the above melted materials are placed in a spinning manifold, and the spinning and parallel compounding are carried out to prepare polyester fiber precursor; the polyester fiber precursor is wound and oiled, and then stretched 4.5 times at 155°C, and shaped to obtain a thermal insulation antibacterial polyester fiber; wherein, the thermal insulation antibacterial polyester fiber contains 90% modified PET and 10% PBT by weight.

[0071] Embodiment 6: A heat-insulating antibacterial polyester fiber and a preparation process thereof, comprising the following steps:

[0072] Step 1:

[0073] Disperse ethanolamine in N,N-dimethylformamide, maintain the system temperature at 25°C, use triethylamine as an acid binding agent, stir and mix for 25 minutes, add 2,6-pyridinedicarbonyl chloride dispersed in N,N-dimethylformamide, maintain the temperature for reaction for 14 hours, heat to 75°C and continue to keep warm for reaction for 22 hours; after the reaction is completed, cool naturally, wash with deionized water, filter, dry, disperse in chloroform, add butyl bromide, heat to 70°C, react for 11 hours, add methanol to quench the reaction, wash, filter, and dry to obtain dihydroxypyridine quaternary ammonium salt; wherein the molar ratio of ethanolamine, 2,6-pyridinedicarbonyl chloride, and butyl bromide is 2:1:1;

[0074] Step 2:

[0075] At 85°C, caprolactam and terephthalic acid were mixed in a molar ratio of 2.5:1, added into deionized water, stirred for 13 minutes, and heated to 225°C in a nitrogen environment to obtain a polycaprolactam prepolymer; ethylene glycol was added in a molar ratio of 1:1.3 between the terminal carboxyl group of the polycaprolactam prepolymer and ethylene glycol, and the esterification reaction was carried out for 2.5 hours to obtain a polycaprolactam prepolymer ester;

[0076] Step 3:

[0077] Dimethyl terephthalate and ethylene glycol are mixed in a molar ratio of 1:2.4, ethylene glycol antimony is used as a catalyst, and the mixture is reacted at 185°C for 2.5 hours, and the remaining ethylene glycol is removed to obtain an intermediate; polycaprolactam prepolymer ester and dihydroxypyridinium quaternary ammonium salt are added to the intermediate, and the mixture is heated to 275°C under vacuum, and the mixture is reacted for 2 hours, and the modified PET slices are obtained by discharging and pelletizing; wherein the weight ratio of the intermediate, the polycaprolactam prepolymer ester and the dihydroxypyridinium quaternary ammonium salt is 10:1:0.8;

[0078] Step 4:

[0079] The modified PET slices are screw-melted, and the temperatures of screw melting zone 1 are 285°C, zone 2 is 284°C, zone 3 is 283°C, zone 4 is 283°C, zone 5 is 282°C, and zone 6 is 270°C; the PBT slices are screw-melted, and the temperatures of screw melting zone 1 are 259°C, zone 2 is 265.5°C, zone 3 is 269.3°C, zone 4 is 270.3°C, and zone 5 is 271.3°C; the above-mentioned melted materials are placed in a spinning manifold, and after spinning and parallel compounding, polyester fiber precursor is prepared; the polyester fiber precursor is wound and oiled, and then stretched 4.5 times at 160°C and shaped to obtain a thermal insulation antibacterial polyester fiber; wherein, the thermal insulation antibacterial polyester fiber contains 90% modified PET and 10% PBT by weight.

[0080] Comparative Example 1: No dihydroxypyridinium quaternary ammonium salt was added, and the other parameters were the same as those in Example 1.

[0081] Step 1:

[0082] At 80°C, caprolactam and terephthalic acid were mixed in a molar ratio of 2.5:1, added into deionized water, stirred for 10 minutes, and heated to 210°C in a nitrogen environment to obtain a polycaprolactam prepolymer; ethylene glycol was added in a molar ratio of 1:1.3 between the terminal carboxyl group of the polycaprolactam prepolymer and ethylene glycol, and the esterification reaction was carried out for 2 hours to obtain a polycaprolactam prepolymer ester;

[0083] Step 2:

[0084] Dimethyl terephthalate and ethylene glycol are mixed in a molar ratio of 1:2.4, ethylene glycol antimony is used as a catalyst, reacted at 160°C for 2 hours, and the remaining ethylene glycol is removed to obtain an intermediate; polycaprolactam prepolymer ester and dihydroxypyridinium quaternary ammonium salt are added to the intermediate, the temperature is raised to 270°C under vacuum, the reaction is carried out for 1.5 hours, and the modified PET chips are obtained by discharging and pelletizing; wherein the weight ratio of the intermediate to the polycaprolactam prepolymer ester is 10:1;

[0085] Step 3:

[0086] The modified PET slices are screw melted, and the temperature of the screw melting zone 1 is 285°C, the temperature of the screw melting zone 2 is 284°C, the temperature of the screw melting zone 3 is 283°C, the temperature of the screw melting zone 4 is 283°C, the temperature of the screw melting zone 5 is 282°C, and the temperature of the screw melting zone 6 is 270°C; the PBT slices are screw melted, and the temperature of the screw melting zone 1 is 259°C, the temperature of the screw melting zone 2 is 265.5°C, the temperature of the screw melting zone 3 is 269.3°C, the temperature of the screw melting zone 4 is 270.3°C, and the temperature of the screw melting zone 5 is 271.3°C; the above melted materials are placed in a spinning box, and the spinning and parallel compounding are carried out to prepare polyester fiber precursor; the polyester fiber precursor is wound and oiled, and then stretched 4.5 times at 150°C and shaped to obtain a thermal insulation antibacterial polyester fiber; wherein, the thermal insulation antibacterial polyester fiber contains 90% modified PET and 10% PBT by weight.

[0087] Comparative Example 2: No polycaprolactam prepolymer ester was added, and the other parameters were the same as those in Example 2.

[0088] Step 1:

[0089] Disperse ethanolamine in N,N-dimethylformamide, maintain the system temperature at 25°C, use triethylamine as an acid binding agent, stir and mix for 25 minutes, add 2,6-pyridinedicarbonyl chloride dispersed in N,N-dimethylformamide, maintain the temperature for reaction for 14 hours, heat to 75°C and continue to keep warm for reaction for 22 hours; after the reaction is completed, cool naturally, wash with deionized water, filter, dry, disperse in chloroform, add butyl bromide, heat to 70°C, react for 11 hours, add methanol to quench the reaction, wash, filter, and dry to obtain dihydroxypyridine quaternary ammonium salt; wherein the molar ratio of ethanolamine, 2,6-pyridinedicarbonyl chloride, and butyl bromide is 2:1:1;

[0090] Step 2:

[0091] Dimethyl terephthalate and ethylene glycol are mixed in a molar ratio of 1:2.4, ethylene glycol antimony is used as a catalyst, reacted at 180°C for 2.5 hours, and the remaining ethylene glycol is removed to obtain an intermediate; dihydroxypyridinium quaternary ammonium salt is added to the intermediate, the temperature is raised to 275°C under vacuum, the reaction is performed for 2 hours, the material is discharged, and the pellets are cut to obtain modified PET chips; wherein the weight ratio of the intermediate to the dihydroxypyridinium quaternary ammonium salt is 10:0.5;

[0092] Step 3:

[0093] The modified PET slices are screw melted, and the temperature of the screw melting zone 1 is 285°C, the temperature of the screw melting zone 2 is 284°C, the temperature of the screw melting zone 3 is 283°C, the temperature of the screw melting zone 4 is 283°C, the temperature of the screw melting zone 5 is 282°C, and the temperature of the screw melting zone 6 is 270°C; the PBT slices are screw melted, and the temperature of the screw melting zone 1 is 259°C, the temperature of the screw melting zone 2 is 265.5°C, the temperature of the screw melting zone 3 is 269.3°C, the temperature of the screw melting zone 4 is 270.3°C, and the temperature of the screw melting zone 5 is 271.3°C; the above melted materials are placed in a spinning manifold, and the spinning and parallel compounding are carried out to prepare polyester fiber precursor; the polyester fiber precursor is wound and oiled, and then stretched 4.5 times at 155°C, and shaped to obtain a thermal insulation antibacterial polyester fiber; wherein, the thermal insulation antibacterial polyester fiber contains 90% modified PET and 10% PBT by weight.

[0094] Comparative Example 3: The molar ratio of caprolactam and terephthalic acid was increased, and the other parameters were the same as those in Example 3.

[0095] Step 1:

[0096] Disperse ethanolamine in N,N-dimethylformamide, maintain the system temperature at 25°C, use triethylamine as an acid binding agent, stir and mix for 30 minutes, add 2,6-pyridinedicarbonyl chloride dispersed in N,N-dimethylformamide, maintain the temperature for reaction for 15 hours, heat to 80°C and continue to heat for reaction for 24 hours; after the reaction is completed, cool naturally, wash with deionized water, filter, dry, disperse in chloroform, add butyl bromide, heat to 75°C, react for 12 hours, add methanol to quench the reaction, wash, filter, and dry to obtain dihydroxypyridine quaternary ammonium salt; wherein the molar ratio of ethanolamine, 2,6-pyridinedicarbonyl chloride, and butyl bromide is 2:1:1;

[0097] Step 2:

[0098] At 85°C, caprolactam and terephthalic acid were mixed in a molar ratio of 3.5:1, added into deionized water, stirred for 15 minutes, and heated to 230°C in a nitrogen environment to obtain a polycaprolactam prepolymer; ethylene glycol was added in a molar ratio of 1:1.3 between the terminal carboxyl group of the polycaprolactam prepolymer and ethylene glycol, and the esterification reaction was carried out for 3 hours to obtain a polycaprolactam prepolymer ester;

[0099] Step 3:

[0100] Dimethyl terephthalate and ethylene glycol are mixed in a molar ratio of 1:2.4, ethylene glycol antimony is used as a catalyst, and the mixture is reacted at 220° C. for 3 hours, and the remaining ethylene glycol is removed to obtain an intermediate; polycaprolactam prepolymer ester and dihydroxypyridinium quaternary ammonium salt are added to the intermediate, and the mixture is heated to 280° C. under vacuum, and the mixture is reacted for 2.5 hours, and the modified PET slices are obtained by discharging and pelletizing; wherein the weight ratio of the intermediate, the polycaprolactam prepolymer ester and the dihydroxypyridinium quaternary ammonium salt is 10:1:0.5;

[0101] Step 4:

[0102] The modified PET slices are screw-melted, and the temperatures of screw melting zone 1 are 285°C, zone 2 is 284°C, zone 3 is 283°C, zone 4 is 283°C, zone 5 is 282°C, and zone 6 is 270°C; the PBT slices are screw-melted, and the temperatures of screw melting zone 1 are 259°C, zone 2 is 265.5°C, zone 3 is 269.3°C, zone 4 is 270.3°C, and zone 5 is 271.3°C; the above-mentioned melted materials are placed in a spinning manifold, and after spinning and parallel compounding, polyester fiber precursor is prepared; the polyester fiber precursor is wound and oiled, and then stretched 4.5 times at 160°C and shaped to obtain a thermal insulation antibacterial polyester fiber; wherein, the thermal insulation antibacterial polyester fiber contains 90% modified PET and 10% PBT by weight.

[0103] Experiment: The performance of the polyester fibers prepared in Examples 1 to 6 and Comparative Examples 1 to 3 was tested, and the experimental results are shown in the following table.

[0104] Antibacterial performance test: According to GB / T 20944.3-2008 "Evaluation of antibacterial properties of textiles Part 3: Oscillation method", the fiber was tested for antibacterial performance and the antibacterial rate was calculated. The bacteria used were Escherichia coli.

[0105] Tensile strength: The mechanical properties of polyester fiber were tested according to GB / T 14344-2008 “Test method for tensile properties of chemical filaments”. During the test, the pre-tension was 5 cN, the tensile speed was 400 mm / min, and the clamping distance was 200 mm.

[0106] Moisture regain: in accordance with GB / T 6503-2017 "Test method for moisture regain of chemical fibers".

[0107] project Antibacterial rate (%) Breaking strength (cN / dtex) Elongation at break (%) Moisture regain (%) Example 1 98.2 3.49 33.7 0.65 Example 2 98.3 3.48 33.5 0.66 Example 3 98.2 3.51 33.9 0.65 Example 4 98.7 3.47 33.6 0.64 Example 5 98.9 3.47 33.8 0.63 Example 6 99.1 3.46 33.7 0.63 Comparative Example 1 74.9 3.50 33.9 0.66 Comparative Example 2 98.1 3.82 16.8 0.41 Comparative Example 3 93.4 3.37 22.4 0.51

[0108] Conclusion: The data of Examples 1 to 6 show that the polyester fiber prepared by the present invention has good performance. The data of Example 1 and Comparative Example 1 show that after adding dihydroxypyridinium quaternary ammonium salt, the antibacterial property of polyester fiber is improved; the data of Example 2 and Comparative Example 2 show that after adding polycaprolactam prepolymer ester, although the breaking strength of polyester fiber decreases, the elongation at break and the moisture regain increase; the data of Example 3 and Comparative Example 3 show that when the molar ratio of caprolactam and terephthalic acid is too high, the molecular weight of the obtained polycaprolactam prepolymer ester is too large, which has an adverse effect on the polycondensation reaction, so the performance of polyester fiber is poor.

[0109] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A preparation process of heat-insulating antibacterial polyester fiber, characterized in that: The following steps are involved: Step 1: Disperse ethanolamine in N,N-dimethylformamide, maintain the system temperature at 20-25°C, use triethylamine as an acid binding agent, stir and mix for 20-30 minutes, add 2,6-pyridinedicarbonyl chloride dispersed in N,N-dimethylformamide, maintain the temperature for reaction for 12-15 hours, heat to 70-80°C and continue to keep warm for reaction for 20-24 hours; after the reaction is completed, cool naturally, wash with deionized water, filter, dry, disperse in chloroform, add butyl bromide, heat to 65-75°C, react for 10-12 hours, add methanol to quench the reaction, wash, filter, and dry to obtain dihydroxypyridine quaternary ammonium salt; Step 2: At 80-85°C, caprolactam and terephthalic acid are mixed, added into deionized water, stirred for 10-15 minutes, and heated to 210-230°C in a nitrogen environment to obtain a polycaprolactam prepolymer; ethylene glycol is added into the polycaprolactam prepolymer to perform an esterification reaction for 2-3 hours to obtain a polycaprolactam prepolymer ester; wherein caprolactam and terephthalic acid are mixed in a molar ratio of (2-2.5):1; Step 3: Dimethyl terephthalate and ethylene glycol are mixed, ethylene glycol antimony is used as a catalyst, and the mixture is reacted at 160-220° C. for 2-3 hours, and the remaining ethylene glycol is removed to obtain an intermediate; polycaprolactam prepolymer esterification product and dihydroxypyridinium quaternary ammonium salt are added to the intermediate, the mixture is heated to 270-280° C. under vacuum, the mixture is reacted for 1.5-2.5 hours, and the mixture is discharged and pelletized to obtain modified PET chips; Step 4: The modified PET slices and PBT slices are respectively melted by screws, placed in a spinning box, and spun and compounded in parallel to prepare polyester fiber precursors; the polyester fiber precursors are wound and oiled, and then stretched and shaped to obtain thermal insulation antibacterial polyester fibers; wherein, the thermal insulation antibacterial polyester fibers have a content of each component, by weight percentage, of 55-90% modified PET and 10-45% PBT.

2. The process for preparing a heat-insulating antibacterial polyester fiber according to claim 1, characterized in that: In step 1, the molar ratio of ethanolamine, 2,6-pyridinedicarbonyl chloride and bromobutane is 2:1:

1.

3. The preparation process of the heat-insulating antibacterial polyester fiber according to claim 1, characterized in that: In step 2, ethylene glycol is added to the polycaprolactam prepolymer at a molar ratio of the terminal carboxyl group of the polycaprolactam prepolymer to ethylene glycol of 1:(1.2-1.4).

4. The process for preparing a heat-insulating antibacterial polyester fiber according to claim 1, characterized in that: In step 3, dimethyl terephthalate and ethylene glycol are mixed in a molar ratio of 1:(2-2.4) to react to obtain an intermediate.

5. The preparation process of the heat-insulating antibacterial polyester fiber according to claim 1, characterized in that: In step 3, the intermediate, the polycaprolactam prepolymer ester, and the dihydroxypyridinium quaternary ammonium salt are mixed and reacted in a weight ratio of (8-10): (1-1.5): (0.5-0.8).

6. The preparation process of the heat-insulating antibacterial polyester fiber according to claim 1, characterized in that: In step 4, the stretching temperature is 150-160°C.

7. The process for preparing the heat-insulating antibacterial polyester fiber according to claim 1, characterized in that: In step 4, the stretching ratio is 4 to 5 times.

8. The heat-insulating antibacterial polyester fiber prepared by the preparation process according to any one of claims 1 to 7.