Preparation method of intrinsic ultrafast moisture-wicking and quick-drying nylon chips and their application in nylon.

Abstract

This invention relates to the field of nylon, providing a method for preparing intrinsically fast-drying and moisture-wicking nylon chips and their application in nylon. The method includes the following steps: adding a dicarboxyl monomer and a diamine to caprolactam monomer or PA66 nylon salt, and polymerizing to obtain fast-drying and moisture-wicking nylon chips; the polymerization reaction includes sequential prepolymerization below 160°C, prepolymerization under pressure at 220-260°C, and polycondensation at 240-280°C; the dicarboxyl monomer contains hydrophilic side groups, which do not chemically react with carboxyl or amino groups in this reaction. Introducing modified functional groups into the conventional nylon molecular structure through copolymerization endows nylon fabrics with excellent moisture-wicking and quick-drying properties. Through copolymerization modification, the material's inherent properties are altered, resulting in significant and long-lasting effects.

Description

Technical Field

[0001] This invention relates to the field of nylon, and in particular to the preparation method of intrinsically ultrafast moisture-wicking and quick-drying nylon chips and their application in nylon. Background Technology

[0002] Moisture-wicking and quick-drying fabrics are mainly obtained through two methods: using moisture-wicking and quick-drying fibers and performing moisture-wicking and quick-drying finishing processes.

[0003] Moisture-wicking and quick-drying fibers are mainly made by shaping polyester or nylon into irregular cross-sections, such as "+", "Y", and "H" shapes. They utilize the capillary effect of the groove structure on the fiber surface to quickly conduct sweat or moisture from the inner layer to the outer layer for evaporation. Some fibers are also made into porous or honeycomb structures, and their principle and effect are basically similar to those of irregular cross-sections. These irregularly shaped fibers have high requirements for spinnerets and spinning processes, but the improvement in moisture absorption is limited. Usually, other hydrophilic materials need to be blended in during the spinning process to further improve the effect, such as patents CN117568950A, CN118272951A, and CN118257027A. These treatment methods will have a significant impact on the mechanical properties of the fiber, and the fiber strength will decrease significantly.

[0004] The finishing process involves using moisture-wicking finishing agents (such as TF-620) on polyester knitted fabrics or moisture-wicking and quick-drying finishing agents (such as Hydroperm NPU liq) on nylon-spandex knitted fabrics. This can also achieve the requirements of moisture wicking and quick-drying. The disadvantage is that the moisture wicking and quick-drying effect gradually decreases with the increase of washing times, so the durability and stability of its quick-drying function are poor.

[0005] Therefore, an ideal solution is needed. Summary of the Invention

[0006] This invention provides a method for preparing intrinsic ultrafast moisture-wicking and quick-drying nylon chips and their application in nylon. By introducing modified functional groups into the conventional nylon molecular structure, copolymerization imparts excellent moisture-wicking and quick-drying properties to nylon fabrics. Through copolymerization modification, the properties of the material itself are changed, resulting in significant and long-lasting effects.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] The method for preparing intrinsic ultrafast moisture-wicking and quick-drying nylon chips includes the following steps: adding a dicarboxylic acid monomer and a diamine to caprolactam monomer or PA66 nylon salt, and performing a polymerization reaction to obtain moisture-wicking and quick-drying nylon chips; the polymerization reaction includes prepolymerization below 160°C, prepolymerization under pressure at 220-260°C, and polycondensation at 240-280°C in sequence; the dicarboxylic acid monomer contains a hydrophilic side group, which does not chemically react with the carboxyl or amino groups in this reaction.

[0009] Preferably, the hydrophilic side group is a hydroxyl group or a sulfonate; the carbon chain length of the dicarboxylic monomer does not exceed C10.

[0010] Preferably, the dicarboxylic acid monomer is selected from one or more of hydroxysuccinic acid, dihydroxysuccinic acid, 3-hydroxyglutaric acid, 3-hydroxyadipic acid, 3-hydroxypimelic acid, sodium succinate sulfonate, sodium isophthalic acid sulfonate, and sodium 1,4-naphthalenedicarboxylic acid-6-sulfonate.

[0011] Preferably, the amount of the dicarboxylated monomer added is 0.5-30% of the mass of caprolactam monomer or PA66 nylon salt, and more preferably 1-10%.

[0012] Preferably, the diamine is selected from one or more of butanediamine, pentanediamine, and hexanediamine, and the molar amount is consistent with the molar amount of the dicarboxyl monomer.

[0013] Preferably, the polymerization reaction is carried out under the action of a catalyst, which is selected from one or more of phosphoric acid, boric acid, phosphorous acid, sodium hypophosphite and zinc hypophosphite, and the mass of the catalyst is 0.1-0.5% of the mass of caprolactam monomer or PA66 nylon salt.

[0014] Preferably, the prepolymerization conditions are a reaction at 60-160℃ for 0.5-2 hours.

[0015] As a preferred method, the prepolymerization conditions are 220-260℃ and 0.3-2MPa for 0.5-2h.

[0016] As a preferred method, polycondensation is carried out after prepolymerization and depressurization. The polycondensation conditions are 240-280℃ and vacuumed to a relative pressure of 0 to -0.1MPa for 0.5-2 hours.

[0017] Application of intrinsically ultrafast moisture-wicking and quick-drying nylon chips obtained by the above method in nylon. Intrinsically ultrafast moisture-wicking and quick-drying nylon can be prepared using conventional nylon spinning equipment.

[0018] Therefore, the beneficial effects of this invention are as follows: Although conventional nylon fabrics have a certain degree of moisture absorption, their effect cannot meet the requirements for quick-drying. The fundamental reason is that their hydrophilicity is insufficient, making it impossible to quickly absorb and wick away moisture. This invention introduces a certain amount of dicarboxyl monomers containing hydrophilic side groups into the nylon structural unit. Under certain conditions, these hydrophilic side groups will not chemically react with the end groups (carboxyl / amino) in the nylon, ensuring the full exposure of hydrophilic functional groups. This significantly improves the moisture absorption performance of the fabric, quickly wicking away sweat during wear and resulting in better wearing comfort. Detailed Implementation

[0019] The technical solution of the present invention will be further described below through specific embodiments.

[0020] In this invention, unless otherwise specified, the raw materials and equipment used are commercially available or commonly used in the art. The methods in the embodiments, unless otherwise specified, are conventional methods in the art. Unless otherwise specified, all parts are parts by weight, temperatures are expressed in °C or at ambient temperature, and pressures are at or near atmospheric pressure. Various variations and combinations of reaction conditions (e.g., component concentrations, required solvents, solvent mixtures, temperature, pressure, and other reaction ranges) and conditions that can be used to optimize the purity and yield of the product obtained by the method exist, and only reasonable routine experiments are needed to optimize such method conditions.

[0021] Example

[0022] The preparation method of intrinsic ultrafast moisture-absorbing and quick-drying nylon chips includes the following steps: adding a dicarboxylic acid monomer and a diamine to caprolactam monomer or PA66 nylon salt, and performing a polymerization reaction to obtain moisture-absorbing and quick-drying nylon chips.

[0023] The dicarboxylic monomer contains a hydrophilic side group, which does not chemically react with the carboxyl or amino group in this reaction. The hydrophilic side group is preferably a hydroxyl or sulfonate group. The carbon chain length of the dicarboxylic monomer does not exceed C10. The dicarboxylic monomer is preferably one or more of hydroxysuccinic acid, dihydroxysuccinic acid, 3-hydroxyglutaric acid, 3-hydroxyadipic acid, 3-hydroxypimelic acid, sodium succinate sulfonate, sodium isophthalate sulfonate, and sodium 1,4-naphthalenedicarboxylic acid-6-sulfonate. The amount of the dicarboxylic monomer added is 0.5-30% of the mass of the caprolactam monomer or PA66 nylon salt, more preferably 1-10%.

[0024] The diamine is selected from one or more of butanediamine, pentanediamine, and hexanediamine, and its molar amount is consistent with that of the dicarboxylic acid monomer.

[0025] The polymerization reaction is carried out under the action of a catalyst, which is selected from one or more of phosphoric acid, boric acid, phosphorous acid, sodium hypophosphite (also known as sodium hypophosphite), and zinc hypophosphite. The amount of catalyst added is 0.1-0.5% of the mass of caprolactam monomer or PA66 nylon salt.

[0026] The polymerization reaction includes prepolymerization below 160°C, prepolymerization under pressure at 220-260°C, and polycondensation at 240-280°C, performed sequentially. Specifically, the prepolymerization conditions are: reaction at 60-160°C for 0.5-2 hours; the prepolymerization conditions are: reaction at 220-260°C and 0.3-2 MPa for 0.5-2 hours; after depressurization and drainage of the prepolymer, polycondensation is carried out at 240-280°C under vacuum to a relative pressure of 0 to -0.1 MPa for 0.5-2 hours.

[0027] Application of intrinsically ultrafast moisture-wicking and quick-drying nylon chips obtained by the above method in nylon. Intrinsically ultrafast moisture-wicking and quick-drying nylon can be prepared using conventional nylon spinning equipment. There are no special requirements for the fiber shape; it can be ordinary round fibers or irregularly shaped fibers such as star-shaped or H-shaped fibers.

[0028] Conventional nylon fabrics lack sufficient hydrophilicity to quickly absorb and wick away moisture. This invention introduces dicarboxylated monomers with hydrophilic side groups into the nylon structural unit. Under certain conditions, these hydrophilic side groups do not chemically react with the end groups (carboxyl / amino) in the nylon, ensuring full exposure of the hydrophilic functional groups. This significantly improves the fabric's moisture absorption performance, allowing for rapid wicking away of sweat and providing a remarkable and long-lasting quick-drying effect.

[0029] Example 1

[0030] A method for preparing intrinsically ultrafast moisture-absorbing and quick-drying nylon chips includes the following steps: 50g of dihydroxysuccinic acid, 33g of butanediamine, 800g of caprolactam, 100g of deionized water, and 1g of sodium hypophosphite are added to a polymerization reactor. The mixture is heated to 80℃ for salt formation reaction for 1 hour, then heated to 240℃ / 1.5MPa for ring-opening prepolymerization for 1.5 hours. The pressure is then released to atmospheric pressure, water is drained, and the mixture is polycondensed at 250℃ for 2 hours to obtain hydrophilic modified nylon chips.

[0031] The hydrophilic modified nylon chips obtained by the above preparation method were used to prepare 70D / 24F FDY by a nylon spinning machine. The cross-sectional shape of the fiber was circular.

[0032] Example 2

[0033] The difference from Example 1 is that the dicarboxylic acid monomer is hydroxyadipic acid, as detailed below:

[0034] A method for preparing intrinsically ultrafast moisture-absorbing and quick-drying nylon chips includes the following steps: 50g of hydroxyadipic acid, 27.2g of butanediamine, 800g of caprolactam, 100g of deionized water, and 1g of sodium hypophosphite are added to a polymerization reactor. The mixture is heated to 80℃ for salt formation reaction for 1 hour, then heated to 240℃ / 1.5MPa for ring-opening prepolymerization for 1.5 hours. The pressure is then released to atmospheric pressure, water is drained, and the mixture is polycondensed at 250℃ for 2 hours to obtain hydrophilic modified nylon chips.

[0035] The hydrophilic modified nylon chips obtained by the above preparation method were used to prepare 70D / 24F FDY by a nylon spinning machine. The cross-sectional shape of the fiber was circular.

[0036] Example 3

[0037] The difference from Example 1 is that the dicarboxylic acid monomer is sodium succinate sulfonate, as detailed below:

[0038] A method for preparing intrinsically ultrafast moisture-absorbing and quick-drying nylon chips includes the following steps: 50g sodium succinate sulfonate, 10.0g butanediamine, 800g caprolactam, 100g demineralized water, and 1g sodium hypophosphite are added to a polymerization reactor. The mixture is heated to 80℃ for salt formation reaction for 1 hour, then heated to 240℃ / 1.5MPa for ring-opening prepolymerization for 1.5 hours. The pressure is then released to atmospheric pressure, water is drained, and the mixture is polycondensed at 250℃ for 2 hours to obtain hydrophilic modified nylon chips.

[0039] The hydrophilic modified nylon chips obtained by the above preparation method were used to prepare 70D / 24F FDY by a nylon spinning machine. The cross-sectional shape of the fiber was circular.

[0040] Example 4

[0041] The difference from Example 1 is that the dicarboxylic acid monomer is sodium isophthalate sulfonate, as detailed below:

[0042] A method for preparing intrinsically ultrafast moisture-absorbing and quick-drying nylon chips includes the following steps: 50g sodium isophthalate sulfonate, 16.4g butanediamine, 800g caprolactam, 100g deionized water, and 1g sodium hypophosphite are added to a polymerization reactor. The mixture is heated to 80℃ for salt formation reaction for 1 hour, then heated to 240℃ / 1.5MPa for ring-opening prepolymerization for 1.5 hours. The pressure is then released to atmospheric pressure, water is drained, and the mixture is polycondensed at 250℃ for 2 hours to obtain hydrophilic modified nylon chips.

[0043] The hydrophilic modified nylon chips obtained by the above preparation method were used to prepare 70D / 24F FDY by a nylon spinning machine. The cross-sectional shape of the fiber was circular.

[0044] Example 5

[0045] The difference from Example 1 is that the hydrophilic modified nylon chips are spun into a cross-shaped fiber for subsequent testing. Specifically, a method for preparing intrinsically ultrafast moisture-wicking and quick-drying nylon chips is as follows: 50g of dihydroxysuccinic acid, 33g of butanediamine, 800g of caprolactam, 100g of deionized water, and 1g of sodium hypophosphite are added to a polymerization reactor. The mixture is heated to 80°C for a salt-forming reaction for 1 hour, then heated to 240°C / 1.5MPa for ring-opening prepolymerization for 1.5 hours. The pressure is then released to atmospheric pressure, water is drained, and the mixture is polycondensed at 250°C for 2 hours to obtain hydrophilic modified nylon chips.

[0046] The hydrophilic modified nylon chips obtained by the above preparation method were used to prepare 70D / 24F FDY by a nylon spinning machine. The cross-sectional shape of the fiber was circular.

[0047] Example 6

[0048] The difference from Example 2 is that the hydrophilic modified nylon chips are spun into a cross-shaped fiber for subsequent testing. Specifically, a method for preparing intrinsically ultra-fast moisture-wicking and quick-drying nylon chips is as follows: 50g of hydroxyadipic acid, 27.2g of butanediamine, 800g of caprolactam, 100g of deionized water, and 1g of sodium hypophosphite are added to a polymerization reactor. The mixture is heated to 80°C for a salt-forming reaction for 1 hour, then heated to 240°C / 1.5MPa for ring-opening prepolymerization for 1.5 hours. The pressure is then released to atmospheric pressure, water is drained, and the mixture is polycondensed at 250°C for 2 hours to obtain hydrophilic modified nylon chips.

[0049] The hydrophilic modified nylon chips obtained by the above preparation method were used to prepare 70D / 24F FDY by a nylon spinning machine. The cross-sectional shape of the fiber was circular.

[0050] Example 7

[0051] The difference from Example 3 is that the hydrophilic modified nylon chips are spun into a star-shaped fiber. Specifically:

[0052] A method for preparing intrinsically ultrafast moisture-absorbing and quick-drying nylon chips includes the following steps: 50g sodium succinate sulfonate, 10.0g butanediamine, 800g caprolactam, 100g demineralized water, and 1g sodium hypophosphite are added to a polymerization reactor. The mixture is heated to 80℃ for salt formation reaction for 1 hour, then heated to 240℃ / 1.5MPa for ring-opening prepolymerization for 1.5 hours. The pressure is then released to atmospheric pressure, water is drained, and the mixture is polycondensed at 250℃ for 2 hours to obtain hydrophilic modified nylon chips.

[0053] The hydrophilic modified nylon chips obtained by the above preparation method were used to prepare 70D / 24F FDY by a nylon spinning machine. The cross-sectional shape of the fiber was star-shaped.

[0054] Example 8

[0055] The difference from Example 4 is that the hydrophilic modified nylon chips are spun into a star-shaped fiber. Specifically:

[0056] A method for preparing intrinsically ultrafast moisture-absorbing and quick-drying nylon chips includes the following steps: 50g sodium isophthalate sulfonate, 16.4g butanediamine, 800g caprolactam, 100g deionized water, and 1g sodium hypophosphite are added to a polymerization reactor. The mixture is heated to 80℃ for salt formation reaction for 1 hour, then heated to 240℃ / 1.5MPa for ring-opening prepolymerization for 1.5 hours. The pressure is then released to atmospheric pressure, water is drained, and the mixture is polycondensed at 250℃ for 2 hours to obtain hydrophilic modified nylon chips.

[0057] The hydrophilic modified nylon chips obtained by the above preparation method were used to prepare 70D / 24F FDY by a nylon spinning machine. The cross-sectional shape of the fiber was star-shaped.

[0058] Example 9

[0059] A method for preparing intrinsically ultrafast moisture-absorbing and quick-drying nylon chips includes the following steps: 8g of dihydroxysuccinic acid, 6.9g of hexamethylenediamine, 800g of PA66 nylon salt, 100g of demineralized water, and 4g of zinc hypophosphite are added to a polymerization reactor. The mixture is heated to 60℃ for salt formation reaction for 2 hours, then heated to 240℃ / 2.0MPa for ring-opening prepolymerization for 2 hours. The pressure is then released to atmospheric pressure, water is drained, and the mixture is polycondensed at 280℃ / -0.1MPa for 2 hours to obtain hydrophilic modified nylon chips.

[0060] The hydrophilic modified nylon chips obtained by the above preparation method were used to prepare 70D / 24F FDY by a nylon spinning machine. The cross-sectional shape of the fiber was circular.

[0061] Example 10

[0062] A method for preparing intrinsically ultrafast moisture-absorbing and quick-drying nylon chips includes the following steps: 80g of dihydroxysuccinic acid, 61g of pentanediamine, 800g of caprolactam, 100g of deionized water, and 2g of boric acid are added to a polymerization reactor. The mixture is heated to 160℃ for salt formation reaction for 0.5 hours, then heated to 260℃ / 1.0MPa for ring-opening prepolymerization for 0.5 hours. The pressure is then released to atmospheric pressure, water is drained, and the mixture is polycondensed at 280℃ for 0.5 hours before being discharged to obtain hydrophilic modified nylon chips.

[0063] The hydrophilic modified nylon chips obtained by the above preparation method were used to prepare 70D / 24F FDY by a nylon spinning machine. The cross-sectional shape of the fiber was circular.

[0064] Comparative Example

[0065] Comparative Example 1

[0066] Subsequent tests were conducted using round fibers spun from conventional PA6 chips.

[0067] Comparative Example 2

[0068] Subsequent tests were conducted using conventional PA6 chips spun into a cross-shaped fiber.

[0069] Comparative Example 3

[0070] Subsequent tests were conducted using the ultra-fast moisture-wicking and quick-drying masterbatch described in patent CN117568950A and PA6 chips spun into circular fibers. Details are as follows:

[0071] 237g of CoCl2·6H2O was dissolved in ethanol, then 30.5g of ethanolamine was slowly added, followed by 200mL of water. The mixture was stirred for 180min, and the product was dried to obtain ethanolamine cobalt complex powder. The prepared ethanolamine cobalt complex, cellulose nanofibers, and virgin nylon chips were mixed at a mass ratio of 5:1:100 to prepare an ultrafast moisture-wicking masterbatch. The ultrafast moisture-wicking masterbatch and PA6 chips were then used to prepare 70D / 24F FDY using a nylon spinning machine. The cross-sectional shape of the fiber was circular.

[0072] Comparative Example 4

[0073] Subsequent tests were conducted using the ultra-fast moisture-wicking and quick-drying masterbatch described in patent CN117568950A and PA6 chips spun into H-shaped fibers. Details are as follows:

[0074] 237g of CoCl2·6H2O was dissolved in ethanol, then 30.5g of ethanolamine was slowly added, followed by 200mL of water. The mixture was stirred for 180min, and the product was dried to obtain ethanolamine cobalt complex powder. The prepared ethanolamine cobalt complex, cellulose nanofibers, and virgin nylon chips were mixed at a mass ratio of 5:1:100 to prepare an ultrafast moisture-wicking masterbatch. The ultrafast moisture-wicking masterbatch and PA6 chips were then used to prepare 70D / 24F FDY using a nylon spinning machine. The cross-sectional shape of the fiber was H-shaped.

[0075] Comparative Example 5

[0076] The difference from Example 1 is that the dicarboxylic acid monomer is glutamic acid, wherein the hydrophilic side group is an amino group. Specifically:

[0077] Add 50g of glutamic acid, 30g of butanediamine, 800g of caprolactam, 100g of deionized water, and 1g of sodium hypophosphite to a polymerization reactor. Heat to 80℃ for salt formation reaction for 1 hour, then heat to 240℃ / 1.5MPa for ring-opening prepolymerization for 1.5 hours. Depressurize to atmospheric pressure and drain water. Crosslinking reaction occurs during the polycondensation stage at 260℃, making it impossible to discharge the material.

[0078] Comparative Example 6

[0079] The difference from Example 1 is that the dicarboxylic monomer is 1,3,5-tricarboxypentane, wherein the hydrophilic side group is a carboxyl group. Specifically, 50g of 1,3,5-tricarboxypentane, 21.6g of butanediamine, 800g of caprolactam, 100g of demineralized water, and 1g of sodium hypophosphite were added to a polymerization reactor. The mixture was heated to 80°C for salt formation reaction for 1 hour, then heated to 240°C / 1.5MPa for ring-opening prepolymerization for 1.5 hours. The pressure was then released to atmospheric pressure, and water was drained. Crosslinking reaction occurred during the polycondensation stage at 260°C, and the material could not be discharged.

[0080] Comparative Example 7

[0081] The difference from Example 1 is that the dicarboxylic acid monomer is 3-hydroxydodecanoic acid, where the hydrophilic modification essentially involves an excessively long carbon chain length in the monomer. Specifically:

[0082] 50g of 3-hydroxydodecanoic acid, 33g of butanediamine, 800g of caprolactam, 100g of deionized water, and 1g of sodium hypophosphite were added to a polymerization reactor. The mixture was heated to 80℃ for salt formation reaction for 1 hour, then heated to 240℃ / 1.5MPa for ring-opening prepolymerization for 1.5 hours. The pressure was released to atmospheric pressure, water was drained, and the mixture was polycondensed at 250℃ / -40kPa for 2 hours to obtain modified nylon chips.

[0083] The hydrophilic modified nylon chips obtained by the above preparation method were used to prepare 70D / 24F FDY by a nylon spinning machine. The cross-sectional shape of the fiber was circular.

[0084] Performance testing

[0085] The fibers obtained in each embodiment and comparative example were subjected to performance tests. The test method was as follows: the above fibers were woven into nylon fabrics of the same specifications, and the tests were conducted according to GB / T 21655.1-2023 "Evaluation of the quick-drying properties of textiles - Part 1: Single-item combination test method". The process of moisture absorption, diffusion and drying in the fabric was simulated by measuring the water absorption rate, water droplet diffusion time, drying rate and wicking height of the fabric under specified conditions, so as to comprehensively characterize the moisture absorption and quick-drying properties of the fabric.

[0086] The moisture-wicking and quick-drying performance grades of products are assessed according to Table 1. Products should meet the corresponding technical requirements both before and after washing. The moisture-wicking and quick-drying performance grades are divided into Grade I, Grade II, and Grade III: Grade I indicates good moisture-wicking and quick-drying performance; Grade II indicates good moisture-wicking and quick-drying performance; and Grade III indicates excellent moisture-wicking and quick-drying performance.

[0087] Table 1. Evaluation Table of Moisture Absorption and Quick-Drying Performance

[0088] project Level III Level II Level I Water absorption rate / % ≥150 ≥100 ≥80 Water diffusion time / s ≤2 ≤4 ≤6 Cubic suction height / mm ≥110 ≥90 ≥80 Drying rate (g / h) ≥0.40 ≥0.30 ≥0.20

[0089] The results are shown in Table 2.

[0090] Table 2. Test Results of Fiber Moisture Absorption and Quick-Drying Properties

[0091] sample Water absorption rate / % Water diffusion time / s Cubic suction height / mm Drying rate (g / h) Rating Example 1 157 3.5 159 0.35 II Example 2 155 4.3 155 0.32 I Example 3 146 2.7 135 0.30 Ⅱ Example 4 153 1.5 147 0.33 Ⅱ Example 5 184 <1 189 0.30 II Example 6 176 <1 181 0.32 Ⅱ Example 7 172 <1 174 0.30 Ⅱ Example 8 178 <1 185 0.31 Ⅱ Example 9 151 4.2 129 0.39 I Example 10 168 <1 162 0.33 Ⅱ Comparative Example 1 157 16 125 0.37 No moisture-wicking and quick-drying function Comparative Example 2 175 2.9 135 0.22 I Comparative Example 3 132 15.3 105 0.14 No moisture-wicking and quick-drying function Comparative Example 4 165 5.9 145 0.23 I Comparative Example 7 143 9.2 102 0.30 No moisture-wicking and quick-drying function

[0092] As shown in Table 2, conventional nylon or nylon prepared using the disclosed related invention (moisture-wicking masterbatch method) does not have moisture-wicking and quick-drying properties when prepared into round fibers. It only exhibits some moisture-wicking and quick-drying properties when spun into profiled fibers with grooved structures. However, the intrinsically moisture-wicking and quick-drying nylon prepared using the method described in this invention exhibits good moisture-wicking and quick-drying performance even in its round fiber form, with some formulation levels exceeding the level of nylon prepared using existing technologies. When processed into profiled fibers (Examples 5-8), its water absorption rate, drip diffusion time, and wicking height are significantly improved, with the drip diffusion time being less than 1 second, demonstrating better and faster moisture absorption performance. This allows for rapid wicking away of sweat during wear, resulting in better wearing comfort. Therefore, the intrinsically ultrafast moisture-wicking and quick-drying nylon prepared by copolymer modification using the method described in this invention has significant advantages. Compared to Example 1, in Comparative Examples 5 and 6, the hydrophilic modified monomers containing amino and carboxyl groups underwent cross-linking reactions during the polycondensation stage due to the presence of three or more amidation reactive groups, resulting in the modified PA6 becoming a thermosetting material that could not be discharged from the reactor. In Comparative Example 7, the carbon chain of the modified monomer was too long, and the effect of the carbon chain outweighed the effect of the hydrophilic groups, resulting in nylon that lacked moisture-wicking and quick-drying properties.

[0093] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for preparing intrinsically fast-drying, moisture-wicking nylon chips, characterized in that, Includes the following steps: A dicarboxylic acid monomer and a diamine are added to caprolactam monomer or PA66 nylon salt, and a polymerization reaction is carried out to obtain moisture-wicking and quick-drying nylon chips. The polymerization reaction includes prepolymerization at a temperature below 160°C, prepolymerization under pressure at 220-260°C, and polycondensation at 240-280°C. The dicarboxylic acid monomer contains a hydrophilic side group, which does not chemically react with the carboxyl or amino group in this reaction. The hydrophilic side group is a hydroxyl group or a sulfonate. The carbon chain length of the dicarboxylic acid monomer does not exceed C10. The amount of the dicarboxylic acid monomer added is 0.5-30% of the mass of caprolactam monomer or PA66 nylon salt.

2. The method for preparing intrinsically fast-drying nylon chips according to claim 1, characterized in that, The dicarboxylic acid monomer is selected from one or more of hydroxysuccinic acid, dihydroxysuccinic acid, 3-hydroxyglutaric acid, 3-hydroxyadipic acid, 3-hydroxypimelic acid, sodium succinate sulfonate, sodium isophthalic acid sulfonate, and sodium 1,4-naphthalenedicarboxylic acid-6-sulfonate.

3. The method for preparing intrinsically fast-drying nylon chips according to claim 1, characterized in that, The diamine is selected from one or more of butanediamine, pentamethylenediamine, and hexamethylenediamine.

4. The method for preparing intrinsically ultrafast moisture-absorbing and quick-drying nylon chips according to claim 1 or 3, characterized in that, The polymerization reaction is carried out in the presence of a catalyst, which is selected from one or more of phosphoric acid, boric acid, phosphorous acid, sodium hypophosphite, and zinc hypophosphite.

5. The method for preparing intrinsically fast-drying nylon chips according to claim 4, characterized in that, The mass of the catalyst is 0.1-0.5% of the mass of caprolactam monomer or PA66 nylon salt.

6. The method for preparing intrinsically fast-drying nylon chips according to claim 1, characterized in that, The prepolymerization conditions are a reaction at 60-160℃ for 0.5-2 hours.

7. The method for preparing intrinsically fast-drying nylon chips according to claim 1, characterized in that, The prepolymerization conditions are 220-260℃ and 0.3-2MPa for 0.5-2h.

8. The method for preparing intrinsically ultrafast moisture-absorbing and quick-drying nylon chips according to claim 1, 6, or 7, characterized in that, After prepolymerization and depressurization, polycondensation is carried out under the following conditions: 240-280℃, vacuumed to a relative pressure of 0~-0.1MPa for 0.5-2h.

9. The application of intrinsically ultrafast moisture-wicking and quick-drying nylon chips obtained by any one of claims 1-8 in nylon.