Superabsorbent wet polyester fiber and method of making same

Abstract

The present application relates to the technical field of synthetic fiber manufacturing, and is a kind of superconducting wet polyester fiber and its preparation method, low melting point polyethylene terephthalate resin and sulfonated polyphenylene sulfide are melt blended, extruded and granulated, and then the blended chip is melted and mixed with low melting point polyethylene terephthalate chip or melt, melt spinning, cooling, bundling, drawing and post-processing are carried out, and the obtained blended staple fiber is treated with sodium hydroxide solution, then washed, neutralized and dried to obtain superconducting wet polyester fiber. The present application adopts an integrated process of "pre-dispersion blending-online addition spinning-synergistic alkali treatment", so that the fiber has internal moisture transport channels and surface hydrophilic properties at the same time, thereby obtaining superconducting wet polyester fiber. The combination of microporous structure and surface hydrophilic modification significantly improves the capillary effect and moisture conduction efficiency. The process flow of the method is controllable and easy to industrialize, and the obtained fiber has wide application prospects in the field of sports wear and other fields.

Description

Technical Field

[0001] This invention relates to the field of synthetic fiber manufacturing technology, specifically to a superconducting wet polyester fiber and its preparation method. Background Technology

[0002] With the increasing market demand for healthy, comfortable, and functional textiles, superconducting polyester fibers, possessing excellent moisture-wicking and quick-drying properties, are gaining popularity. The preparation of superconducting polyester fibers typically involves: 1) altering the shape of the spinneret to create moisture-wicking grooves in the fiber; and 2) microporousizing the fiber body to significantly enhance its capillary effect and water absorption capacity. Currently, the mainstream technical route for preparing microporous polyester fibers is the "soluble polymer blending-dissolution method." Its principle involves melt-blending and spinning a pore-forming agent (usually a water-soluble polymer) that can be selectively removed in subsequent processing with a polyester (such as PET) matrix.

[0003] The pore structure of fibers can be controlled to some extent through formulation and process, and is considered to have good industrialization prospects. However, this technology still faces several technical bottlenecks that urgently need to be overcome in industrial applications: On the one hand, there are issues with the thermal stability and processing compatibility of pore-forming agents. An ideal pore-forming agent needs to have sufficient thermal stability under the high-temperature conditions of polyester melt spinning (usually 270℃ to 300℃) and not undergo significant decomposition; at the same time, it needs to have suitable compatibility with the polyester matrix and similar melting points to ensure that a uniformly sized and distributed dispersed phase can be formed during melt blending. Some commonly used water-soluble polymers, such as polyvinyl alcohol (PVA), although water-soluble, have limited thermal stability and are prone to thermal degradation or drastic changes in melt viscosity when close to the polyester spinning temperature, leading to instability in the spinning process and an increased fiber breakage rate. On the other hand, there is the issue of the dispersibility of pore-forming agents. In addition to PVA, some studies have also attempted to use inorganic salts as pore-forming agents. For example, water-soluble inorganic salts such as sodium carbonate and calcium carbonate have excellent thermal stability, but their large particle size makes them easy to clog the spinneret orifice, and they are extremely difficult to blend and disperse with polymer melts, resulting in a narrow process window and poor reproducibility.

[0004] Patent document CN117403361B discloses a superconducting, quick-drying, and moisture-wicking yarn, its preparation method, and applications. It describes a method for blending high-shrinkage polyester and cotton fibers to obtain the yarn. The preparation of the high-shrinkage polyester fiber includes two parts: raw material synthesis and fiber forming. Terephthalic acid and ethylene glycol are used as raw materials. After esterification, polyethylene glycol and aromatic dicarboxylic acid sulfonate are added, resulting in high-shrinkage polyester chips. These chips are then used as raw materials for spinning to obtain high-shrinkage polyester fibers. The yarn's two-component design creates a micro-circulation diffusion system with superconducting moisture absorption, effectively improving the hygroscopicity of the polyester fiber. Even after multiple washes, it retains excellent superconducting and quick-drying properties. While this patent improves hygroscopicity by adding aromatic dicarboxylic acid sulfonate, it does not deeply chemically modify the polyester (PET) molecular chain, and its moisture wicking primarily relies on inter-fiber gaps, limiting its wicking speed and capacity. In contrast, this invention introduces permanent hydrophilic groups (such as carboxyl and hydroxyl groups) into the surface of hydrolyzed PET by alkali treatment, thereby improving the instantaneous wetting performance from a chemical perspective, and then relies on the porous structure of the fiber body to exert capillary water absorption and conduction.

[0005] Another patent document, CN120756161B, discloses a moisture-wicking functional fabric and its preparation method. This involves preparing a blended yarn by mixing an inner layer of polyester and nylon profiled fibers with an outer layer of modified polypropylene and hollow polyester fibers. The modified polypropylene fibers are obtained by melt spinning and stretching a mixture of polypropylene chips and modified jade powder. While the resulting fabric possesses lightweight properties and rapid moisture wicking capabilities, the preparation process is complex, involving the preparation of composite fibers and blended yarns. Furthermore, the fibers and yarns themselves do not possess super-moisture-wicking capabilities; only the combined fabric possesses these capabilities. The fabric composition and structure are fixed, limiting its scalability. In contrast, this invention only requires composite spinning to obtain super-moisture-wicking fibers, without affecting the subsequent design and development of yarns and fabrics, thus broadening the product range.

[0006] Therefore, there is an urgent need in the industry to develop a new method for preparing microporous polyester fibers that can operate stably on conventional melt spinning equipment and achieve precise control over the microporous structure inside the fiber, thereby obtaining excellent superconducting moisture properties while ensuring the fiber's excellent mechanical properties and processability. Summary of the Invention

[0007] This invention provides a superconducting moisture-wicking polyester fiber and its preparation method, which overcomes the shortcomings of the prior art. It can effectively solve the problem that the thermal stability, compatibility and removability of the pore-forming agent are difficult to coordinate in the existing "blending-dissolution method", thereby solving the problem of poor hydrophilicity and insufficient moisture absorption and perspiration performance of polyester fiber.

[0008] One of the technical solutions of the present invention is achieved through the following measures: a method for preparing a superconducting wet polyester fiber, comprising the following steps: S1, dry-mix the required amount of polyethylene terephthalate chips and soluble pore-forming agent, and then melt-blend and extrude granulate the resulting dry mixture to obtain polyethylene terephthalate / sulfonated polyphenylene sulfide blend chips (i.e., pore-forming functional masterbatch). S2, melt the pore-forming functional masterbatch to obtain the secondary component melt, use the same polyethylene terephthalate chips or melt as the main component melt, then inject the secondary component melt into the main component melt online, and after mixing, the resulting mixed melt is melt-spun, cooled, bundled, drawn and post-treated to obtain blended short fibers; S3, the blended short fibers are treated in a sodium hydroxide solution, and the treated fibers are then washed, neutralized and dried to obtain superconducting wet polyester fibers.

[0009] The following are further optimizations and / or improvements to one of the above-mentioned technical solutions: In step S1 above, the mass ratio of polyethylene terephthalate chips to soluble pore-forming agent is 60 to 80: 20 to 40, the polyethylene terephthalate chips are low-melting-point polyethylene terephthalate, and the soluble pore-forming agent is sulfonated polyphenylene sulfide.

[0010] The melting point of the aforementioned low-melting-point polyethylene terephthalate resin is 200°C to 240°C, the molecular weight of the sulfonated polyphenylene sulfide is 20,000 to 50,000, and the degree of sulfonation of the sulfonated polyphenylene sulfide is 40% to 65%.

[0011] In step S1 above, melt blending is carried out in a twin-screw extruder. The feed zone temperature of the twin-screw extruder is 200°C to 230°C, the melt blending zone temperature is 260°C to 280°C, and the die temperature is 265°C to 275°C.

[0012] In step S2 above, when the secondary component melt is injected online into the primary component melt, the secondary component melt accounts for 10% to 30% of the total mass of the mixed melt. The spinning temperature of the melt spinning is 250°C to 280°C, and the drawing is a multi-stage hot drawing carried out in a hot water bath at 80°C to 95°C, with a total drawing ratio of 3.5 to 4.8 times.

[0013] In step S3 above, the temperature of the sodium hydroxide solution is 90°C to 98°C, the mass concentration of the sodium hydroxide solution is 5 g / L to 15 g / L, and a nonionic surfactant with a mass concentration of 1 g / L to 5 g / L is added to the sodium hydroxide solution during treatment. The treatment time is 30 min to 60 min.

[0014] The aforementioned nonionic surfactant is one or more of fatty alcohol polyoxyethylene ether, isooctyl alcohol polyoxyethylene ether, and isooctyl alcohol polyoxyethylene ether phosphate.

[0015] In step S3 above, the specific steps of water washing, neutralization and drying include: after the fiber treated with sodium hydroxide solution is rolled to remove excess alkali, it is immersed in an acidic aqueous solution with a pH of 5.0 to 7.0 and a temperature of 30°C to 45°C for treatment, and then rolled and dried.

[0016] The treatment time in the above acidic aqueous solution is 5 to 10 seconds, the drying temperature is 100°C to 120°C, and the time is 5 to 20 minutes.

[0017] The second technical solution of the present invention is achieved through the following measures: a method for preparing superconducting wet polyester fiber to obtain superconducting wet polyester fiber.

[0018] This invention employs an integrated process of "pre-dispersion blending - online addition spinning - synergistic alkali treatment" to enable fibers to simultaneously possess internal rapid moisture transport channels and surface hydrophilic properties, thereby obtaining superconducting wet polyester fibers. The combination of its microporous structure and surface hydrophilic modification significantly improves capillary effect and moisture conduction efficiency. This method has a controllable process flow, is easy to industrialize, and the resulting fibers have broad application prospects in fields such as sportswear. Attached Figure Description

[0019] Appendix Figure 1 This is an electron microscope image of the superconducting wet polyester fiber obtained in Example 12 of the present invention; Appendix Figure 2 The application is shown in the figure of water droplet wetting of the superconducting wet polyester fiber obtained in Example 12 of the present invention within 1 minute after water is dripped; Appendix Figure 3 This is a diagram showing the wetting of water droplets on conventional polyester fibers within 1 minute after being dripped. Detailed Implementation

[0020] This invention is not limited to the following embodiments, and specific implementation methods can be determined according to the technical solutions and actual conditions of this invention. Unless otherwise specified, all chemical reagents and chemicals mentioned in this invention are well-known and commonly used chemical reagents and chemicals in the prior art; unless otherwise specified, all percentages in this invention are mass percentages; unless otherwise specified, all solutions in this invention are aqueous solutions with water as the solvent, for example, hydrochloric acid solution is an aqueous solution of hydrochloric acid; room temperature in this invention generally refers to a temperature between 15°C and 25°C, generally defined as 25°C.

[0021] In this invention, the low-melting-point polyethylene terephthalate (PET) resin is produced by our company (or can be purchased from the market); sulfonated polyphenylene sulfide (sPPS) is purchased from Hangzhou Mike Chemical Instrument Co., Ltd.; and the nonionic surfactants fatty alcohol polyoxyethylene ether (JFC), isooctyl alcohol polyoxyethylene ether (JFC-6), and isooctyl alcohol polyoxyethylene ether phosphate (OEP-70) are produced by Yixing Kexin Chemical Co., Ltd.

[0022] The present invention will be further described below with reference to embodiments: Example 1: The preparation method of this superconducting wet polyester fiber is carried out according to the following steps: S1, Pre-dispersion of soluble pore-forming agent: The required amount of low-melting-point polyethylene terephthalate chips and soluble pore-forming agent are dry-mixed. The resulting dry mixture is then melt-blended and extruded and granulated using a twin-screw extruder at a certain temperature to obtain a pore-forming functional masterbatch. This step achieves uniform pre-dispersion of sulfonated polyphenylene sulfide in the polyethylene terephthalate chip matrix. S2, Online addition of secondary component melt and spinning: The pore-forming functional masterbatch is melted through a separate screw extruder to obtain a secondary component melt. Low-melting-point polyethylene terephthalate chips or melt are used as the primary component melt, and pre-spinning injection molding equipment is used. The secondary component melt is then injected online into the primary component melt. The two melts are thoroughly mixed by a static mixer, and the resulting mixed melt is transported to the spinning box. At the required spinning temperature, the mixed melt is extruded by a metering pump and a spinneret. The nascent fibers are cooled by a ring blower, oiled and bundled, and then subjected to multi-stage hot stretching in a hot water bath at the required temperature. Subsequently, conventional processes such as heat setting, crimping, relaxation setting, and cutting are performed to obtain blended short fibers. S3, synergistic treatment of fiber pore formation and surface hydrophilication: The blended short fibers are placed in a sodium hydroxide solution with added nonionic surfactant for treatment. After treatment, excess alkali solution is squeezed out with rollers until the liquid content is below 60%. After immersion in water for washing, the fibers are rolled until the liquid content is below 60% and then dried to obtain superconducting wet polyester fibers.

[0023] The method for preparing superconducting wet polyester fiber in this invention first involves melt-blending sulfonated polyphenylene sulfide (a pore-forming agent) with PET resin and granulating the resulting blended chips. Then, the melt of these blended chips is injected online into a main PET melt channel at a specific ratio. After mixing, spinning, and drawing, the blended fiber is obtained. Finally, the fiber undergoes further alkali treatment to synergistically achieve the dissolution of the pore-forming agent (forming three-dimensional interconnected micropores inside and on the fiber surface) and the hydrolysis of the PET on the fiber surface (introducing permanent hydrophilic groups). This method endows the fiber with both rapid internal moisture transport channels and surface hydrophilic properties, thus obtaining superconducting wet polyester fiber. The process is controllable, easily industrialized, and the resulting fiber has broad application prospects in fields such as sportswear.

[0024] Example 2: As an optimization of the above example, in step S1, the mass ratio (dry weight ratio) of polyethylene terephthalate chips and soluble pore-forming agent is 60 to 80: 20 to 40, the polyethylene terephthalate chips are low-melting-point polyethylene terephthalate resin, and the soluble pore-forming agent is sulfonated polyphenylene sulfide.

[0025] Example 3: As an optimization of the above example, the melting point of the low melting point polyethylene terephthalate resin is 200°C to 240°C, the molecular weight of the sulfonated polyphenylene sulfide is 20,000 to 50,000, and the degree of sulfonation of the sulfonated polyphenylene sulfide is 40% to 65%.

[0026] Example 4: As an optimization of the above example, in step S1, melt blending is carried out in a twin-screw extruder. The feed zone temperature of the twin-screw extruder is 200°C to 230°C, the melt blending zone temperature is 260°C to 280°C, and the die temperature is 265°C to 275°C.

[0027] Example 5: As an optimization of the above example, in step S2, when the secondary component melt is injected online into the primary component melt, the secondary component melt accounts for 10% to 30% of the total mass of the mixed melt, the spinning temperature of melt spinning is 250°C to 280°C, and the drawing is multi-stage hot drawing carried out in a hot water bath at 80°C to 95°C, with a total drawing ratio of 3.5 to 4.8 times.

[0028] Example 6: As an optimization of the above example, in step S3, the temperature of the sodium hydroxide solution is 90°C to 98°C, the mass concentration of the sodium hydroxide solution is 5 g / L to 15 g / L, and a nonionic surfactant with a mass concentration of 1 g / L to 5 g / L is added to the sodium hydroxide solution during treatment, and the treatment time is 30 min to 60 min.

[0029] Example 7: As an optimization of the above examples, the nonionic surfactant is one or more of fatty alcohol polyoxyethylene ether, isooctanol polyoxyethylene ether, and isooctanol polyoxyethylene ether phosphate.

[0030] Example 8: As an optimization of the above example, the specific steps of washing, neutralizing and drying in step S3 include: after the fiber treated with sodium hydroxide solution is rolled to remove excess alkali, it is immersed in an acidic aqueous solution with a pH of 5.0 to 7.0 and a temperature of 30°C to 45°C for treatment, and then rolled and dried.

[0031] Example 9: As an optimization of the above example, the treatment time in the acidic aqueous solution is 5s to 10s, the drying temperature is 100℃ to 120℃, and the time is 5min to 20min.

[0032] Example 10: Superconducting wet polyester fiber obtained by the preparation method of the superconducting wet polyester fiber.

[0033] Example 11: The preparation method of this superconducting wet polyester fiber is carried out according to the following steps: S1, Pre-dispersion of soluble pore-forming agent: Using low-melting-point PET resin with a melting point of 220℃ as the matrix material and sPPS with a molecular weight of 35,000 and a sulfonation degree of 45% as a soluble pore-forming agent, the low-melting-point PET resin and sPPS were blended at a mass ratio of 70:30. Then, the mixture was vacuum dried at 155℃ for 4 hours. The resulting dry mixture was melt-blended and extruded into granules using a twin-screw extruder at specific temperatures (feed zone 215℃, melt blending zone 270℃, die temperature 268℃) to obtain polyethylene terephthalate / sulfonated polyphenylene sulfide blend chips (this step achieved uniform pre-dispersion of sPPS in the PET matrix). S2, Online addition of secondary component melt and spinning: Polyethylene terephthalate / sulfonated polyphenylene sulfide blend chips were melted in a separate screw extruder to obtain a secondary component melt. Conventional PET chips or melts with similar melting points were used as the primary component melt. The secondary component melt (20% by mass) was then injected online into the primary component melt. The two melts were thoroughly mixed in a static mixer, and the resulting mixed melt was conveyed to the spinning box. At a spinning temperature of 258°C, the mixed melt was extruded through a metering pump and spinneret. The nascent fibers were cooled by ring blowing, oiled, and bundled, then subjected to multi-stage hot drawing in a 90°C hot water bath, with the total draw ratio controlled at 4 times. Subsequently, conventional processes such as heat setting, crimping, relaxation setting, and cutting were performed to obtain blended short fibers. S3, synergistic treatment of fiber pore formation and surface hydrophilication: The blended short fibers were placed in a sodium hydroxide solution (3.5 g / L nonionic surfactant JFC) at a temperature of 95℃ and a mass concentration of 6 g / L for 45 min. Then, the excess alkali solution was squeezed out with rollers until the liquid content was below 60%. The fibers were then immersed in an aqueous solution at a pH of 5.2 and a temperature of 35℃ for 5 s. After being rolled to a liquid content of 60%, the fibers were dried at 110℃ for 10 min to obtain superconducting wet polyester fibers.

[0034] Example 12: The preparation method of this superconducting wet polyester fiber is carried out according to the following steps: S1, Pre-dispersion of soluble pore-forming agent: Using low-melting-point PET resin with a melting point of 220℃ as the matrix material and sPPS with a molecular weight of 45,000 and a sulfonation degree of 62% as a soluble pore-forming agent, the low-melting-point PET resin and sPPS were blended at a mass ratio of 60:40. Then, the mixture was vacuum dried at 155℃ for 4 hours. The resulting dry mixture was melt-blended and extruded into granules using a twin-screw extruder at specific temperatures (feed zone 210℃, melt blending zone 270℃, die temperature 268℃) to obtain a pore-forming functional masterbatch (this step achieved uniform pre-dispersion of sPPS in the PET matrix). S2, Online addition of secondary component melt and spinning: The pore-forming masterbatch is melted in a separate screw extruder to obtain a secondary component melt. Conventional PET chips or melts with similar or identical melting points are used as the primary component melt. The secondary component melt (30% by mass) is then injected online into the primary component melt. The two melts are thoroughly mixed in a static mixer, and the resulting mixed melt is conveyed to the spinning box. At a spinning temperature of 258°C, the mixed melt is extruded through a metering pump and spinneret. The nascent fibers are cooled by ring blowing, oiled, and bundled, then subjected to multi-stage hot drawing in a 90°C hot water bath, with the total draw ratio controlled at 4.5 times. Subsequently, conventional processes such as heat setting, crimping, relaxation setting, and cutting are performed to obtain blended short fibers. S3, synergistic treatment of fiber pore formation and surface hydrophilication: The blended short fibers were placed in a sodium hydroxide solution (1.5 g / L nonionic surfactant JFC) at a temperature of 95℃ and a mass concentration of 12 g / L for 45 min. Then, the excess alkali solution was squeezed out with rollers until the liquid content was below 60%. The fibers were then immersed in an aqueous solution at a pH of 5.2 and a temperature of 40℃ for 10 s. After being rolled to a liquid content of 60%, the fibers were dried at 105℃ for 20 min to obtain superconducting wet polyester fibers.

[0035] Example 13: The preparation method of this superconducting wet polyester fiber is carried out according to the following steps: S1, Pre-dispersion of soluble pore-forming agent: Using low-melting-point PET resin with a melting point of 235℃ as the matrix material and sPPS with a molecular weight of 35,000 and a sulfonation degree of 45% as a soluble pore-forming agent, the low-melting-point PET resin and sPPS were blended at a mass ratio of 70:30. Then, the mixture was vacuum dried at 155℃ for 4 hours. The resulting dry mixture was melt-blended and extruded into granules using a twin-screw extruder at specific temperatures (feed zone 220℃, melt blending zone 275℃, die temperature 272℃) to obtain polyethylene terephthalate / sulfonated polyphenylene sulfide blend chips (this step achieved uniform pre-dispersion of sPPS in the PET matrix). S2, Online addition of secondary component melt and spinning: Polyethylene terephthalate / sulfonated polyphenylene sulfide blend chips were melted in a separate screw extruder to obtain a secondary component melt. Conventional PET chips or melts with similar melting points were used as the primary component melt. The secondary component melt (30% by mass) was then injected online into the primary component melt. The two melts were thoroughly mixed in a static mixer, and the resulting mixed melt was conveyed to the spinning box. At a spinning temperature of 270°C, the mixed melt was extruded through a metering pump and spinneret. The nascent fibers were cooled by ring blowing, oiled, and bundled, then subjected to multi-stage hot drawing in an 85°C hot water bath, with the total draw ratio controlled at 4 times. Subsequently, conventional processes such as heat setting, crimping, relaxation setting, and cutting were performed to obtain blended short fibers. S3, synergistic treatment of fiber pore formation and surface hydrophilication: The blended short fibers were placed in a sodium hydroxide solution (4.0 g / L nonionic surfactant JFC-6) at a temperature of 95℃ and a mass concentration of 10 g / L for 35 min. Then, the excess alkali solution was squeezed out with rollers until the liquid content was below 60%. The fibers were then immersed in an aqueous solution at a pH of 6.5 and a temperature of 42℃ for 10 s. After being rolled to a liquid content of 60%, the fibers were dried at 115℃ for 7 min to obtain superconducting wet polyester fibers.

[0036] Example 14: The preparation method of this superconducting wet polyester fiber is carried out according to the following steps: S1, Pre-dispersion of soluble pore-forming agent: Using low-melting-point PET resin with a melting point of 235℃ as the matrix material and sPPS with a molecular weight of 45,000 and a sulfonation degree of 62% as a soluble pore-forming agent, the low-melting-point PET resin and sPPS were blended at a mass ratio of 60:40. Then, the mixture was vacuum dried at 155℃ for 4 hours. The resulting dry mixture was melt-blended and extruded into granules using a twin-screw extruder at specific temperatures (feed zone 215℃, melt blending zone 275℃, die temperature 270℃) to obtain polyethylene terephthalate / sulfonated polyphenylene sulfide blend chips (this step achieved uniform pre-dispersion of sPPS in the PET matrix). S2, Online addition of secondary component melt and spinning: Polyethylene terephthalate / sulfonated polyphenylene sulfide blend chips were melted in a separate screw extruder to obtain a secondary component melt. Conventional PET chips or melts with similar melting points were used as the primary component melt. The secondary component melt (15% by mass) was then injected online into the primary component melt. The two melts were thoroughly mixed in a static mixer, and the resulting mixed melt was conveyed to the spinning box. At a spinning temperature of 270°C, the mixed melt was extruded through a metering pump and spinneret. The nascent fibers were cooled by ring blowing, oiled, and bundled, then subjected to multi-stage hot drawing in an 85°C hot water bath, with the total draw ratio controlled at 4.5 times. Subsequently, conventional processes such as heat setting, crimping, relaxation setting, and cutting were performed to obtain blended short fibers. S3, synergistic treatment of fiber pore formation and surface hydrophilication: The blended short fibers were placed in a sodium hydroxide solution (4.0 g / L nonionic surfactant OEP-70) at a temperature of 95℃ and a mass concentration of 12 g / L for 55 min. Then, the excess alkali solution was squeezed out with rollers until the liquid content was below 60%. The fibers were then immersed in an aqueous solution at a pH of 6.5 and a temperature of 42℃ for 10 s. After being rolled to a liquid content of 60%, the fibers were dried at 115℃ for 15 min to obtain superconducting wet polyester fibers.

[0037] Experimental example: The superconducting wet polyester fibers obtained in Examples 11 to 14 were tested using the following methods: (1) Test of water wetting time: The fibers are combed neatly and fixed at both ends. 100 μL of clean water and an aqueous solution containing 2 g / L Acid Green 25 are dropped onto the surface of the fiber bundle. The time it takes for the water droplet to be completely absorbed by the fiber is calculated and the results are recorded.

[0038] (2) Water absorption test: Take three dry fiber samples of the superconducting wet polyester fibers obtained in Examples 11 to 14, each weighing approximately 5 to 10 grams. After weighing the dry weight G0, immerse the samples in a beaker containing distilled water at 20±1℃ for 30 minutes. Remove the samples, squeeze out excess liquid, and then place them in a special PET mesh bag of a centrifugal dehydrator. Centrifuge at 500 rpm for 5 minutes, remove the wet fibers, and quickly weigh the wet weight G1. The water absorption rate of the fiber is M = (G1 - G0) / G0, and the average water absorption rate of the three parallel samples is taken as the final result.

[0039] Fiber strength test: The fiber breaking strength and elongation at break are tested in accordance with GB / T14337-2022 "Test Method for Tensile Properties of Chemical Fibers (Short Fibers)".

[0040] Results Analysis: The properties of the superconducting wet polyester fibers obtained in Examples 11 to 14 are shown in Table 1. Conventional polyester fibers (i.e., control samples, conventional polyester staple fibers previously produced by the applicant's company, i.e., without the addition of sulfonated polyphenylene sulfide and without processing step S3) have a hydrophobic surface (water wetting time > 10 s), very low water absorption (only 22.4%), and very poor water diffusion properties (as shown in the attached table). Figure 2 (As shown). The superconducting moisture-conducting polyester fibers obtained by this invention all exhibit hydrophilicity, with a water wetting time ≤2s and a water absorption rate higher than 50%; their breaking strength is also higher than 2.1cN / dtex, which can meet the requirements of subsequent processing and use. In particular, the superconducting moisture-conducting polyester fiber obtained in Example 12 has a water wetting time of 1s to 2s and a water absorption rate of 57.2%, exhibiting excellent moisture-conducting and water-absorbing properties.

[0041] The superconducting wet polyester fiber obtained in Example 12 of this invention was observed under an electron microscope, and the results are as follows: Figure 1 As shown; the wetting of water droplets on the superconducting wet polyester fiber obtained in Example 12 of the invention within 1 minute after water is applied is as follows. Figure 2 As shown; the wetting behavior of water droplets on conventional polyester fibers within 1 minute after being dripped is as follows. Figure 3 As shown.

[0042] Comparative Example 1: The difference from Example 12 is that in step S1, the degree of sulfonation of sulfonated polyphenylene sulfide is replaced with "30%" instead of "45%", while the rest of the process is the same as in Example 12.

[0043] The performance test results of the fiber obtained in Comparative Example 1 are shown in Table 2. Table 2 shows that its water absorption rate is only 33.5%, which is significantly lower than the water absorption rate of the superconducting wet polyester fiber obtained in Example 12. This is because the sulfonated polyphenylene sulfide has a low degree of sulfonation, resulting in poor water solubility. During the alkaline solution treatment in step S3, the sulfonated polyphenylene sulfide is difficult to completely dissolve, leading to incomplete pore formation and poor water absorption.

[0044] Comparative Example 2: The difference from Example 12 is that in step S1, the molecular weight of sulfonated polyphenylene sulfide is replaced with "60000" instead of "45000". The rest of the process is the same as in Example 12.

[0045] The performance test results of the fiber obtained in Comparative Example 2 are shown in Table 2. Table 2 shows that its water absorption rate is only 37.2%, a significant decrease compared to the water absorption rate of the superconducting wet polyester fiber obtained in Example 12. This is because the higher the molecular weight of the polymer, the worse its solubility. During the alkaline solution treatment in step S3, the high molecular weight sulfonated polyphenylene sulfide is difficult to completely dissolve, resulting in poor pore formation.

[0046] Comparative Example 3: The difference from Example 12 is that in step S1, the molecular weight of sulfonated polyphenylene sulfide is replaced with "10000" instead of "45000". The rest of the process is the same as in Example 12.

[0047] The performance test results of the fiber obtained in Comparative Example 3 are shown in Table 2. Table 2 shows that the fiber has good water absorption, but its breaking strength and elongation at break are significantly reduced, with a strength of only 1.69 cN / dtex, which is insufficient to meet the requirements of downstream production units. This is because the molecular weight of sulfonated polyphenylene sulfide is too low, resulting in poor melt rheological properties. This adversely affects the crystallization and nucleation of the fiber-forming polymer melt during the solidification and fiber formation process, leading to poor fiber mechanical properties.

[0048] Comparative Example 4: The difference from Example 12 is that in step S1, the mass ratio of low melting point PET resin to sPPS "60:40" is replaced with "85:15", and the rest of the process is the same as in Example 12.

[0049] The performance test results of the fiber obtained in Comparative Example 4 are shown in Table 2. Table 2 shows that its water absorption rate is only 42.2%, a significant decrease compared to the water absorption rate of the superconducting wet polyester fiber obtained in Example 12. This is because the proportion of sulfonated polyphenylene sulfide pore-forming agent is too low, resulting in fewer pores in the fiber and poor water absorption performance.

[0050] Comparative Example 5: The difference from Example 12 is that in step S1, the mass ratio of low melting point PET resin to sPPS "60:40" is replaced with "50:50", and the rest of the process is the same as in Example 12.

[0051] The performance test results of the fiber obtained in Comparative Example 5 are shown in Table 2. Table 2 shows that the water absorption rate of this fiber is significantly improved compared to the fiber obtained in Example 2, but the fiber strength and elongation at break are drastically reduced to only 1.22 cN / dtex, making it difficult to utilize in textile processing. This is because the proportion of the pore-forming agent is too high, resulting in excessive pores in the fiber and causing excessive damage to the fiber itself.

[0052] Comparative Example 6: The difference from Example 12 is that in step S2, the mass percentage of the minor component melt "30%" is replaced with "7%", and the rest of the process is the same as in Example 12.

[0053] The performance test results of the fiber obtained in Comparative Example 6 are shown in Table 2. Table 2 shows that its water absorption rate is only 24.6%, a significant decrease compared to the water absorption rate of the superconducting wet polyester fiber obtained in Example 12. This is because the melt proportion of the minor component is too low; the sulfonated polyphenylene sulfide pore-forming agent actually accounts for only 2.8% of the fiber's weight (i.e., 7% * 40%), resulting in a very small number of pores in the fiber and poor water absorption performance.

[0054] Comparative Example 7: The difference from Example 12 is that in step S3, the mass concentration of sodium hydroxide is replaced by "2 g / L" instead of "10 g / L". The rest of the process is the same as in Example 12.

[0055] The performance test results of the fiber obtained in Comparative Example 7 are shown in Table 2. Table 2 shows that the surface water wetting time of the fiber was 6 to 7 seconds, and the water absorption rate was only 32.5%, both significantly lower than the performance of the superconducting wet polyester fiber obtained in Example 12. This is because the alkali concentration was too low, resulting in limited hydroxyl and carboxyl groups generated by hydrolysis on the PET fiber surface, and limited dissolution of the sulfonated polyphenylene sulfide pore-forming agent, leading to a smaller number of pores in the fiber and poor hydrophilicity and water absorption properties.

[0056] Comparative Example 8: The difference from Example 12 is that in step S3, the mass concentration of sodium hydroxide is replaced by "20 g / L" instead of "10 g / L". The rest of the process is the same as in Example 12.

[0057] The performance test results of the fiber obtained in Comparative Example 8 are shown in Table 2. Table 2 shows that the fiber surface wettability and water absorption properties are both good, but the fiber strength decreases significantly. This is because excessively high alkali concentration leads to increased fiber hydrolysis and excessive damage to mechanical properties.

[0058] Comparative Example 9: The difference from Example 12 is that in step S3, the concentration of the nonionic surfactant (JFC-6) is replaced with "0.5 g / L" instead of "4 g / L". The rest of the process is the same as in Example 12.

[0059] The performance test results of the fiber obtained in Comparative Example 9 are shown in Table 2. Table 2 shows that the water absorption rate of this fiber is only 38.7%, indicating poor water absorption. This is because the low concentration of the penetrant makes it difficult for the alkaline solution to quickly and effectively penetrate the hydrophobic PET fiber, and the sulfonated polyphenylene sulfide pore-forming agent is difficult to dissolve effectively, resulting in a small number of pores in the fiber and poor water absorption performance.

[0060] Comparative Example 10: The difference from Example 12 is that in step S3, the temperature of the alkaline solution treatment is changed from "95°C" to "83°C", and the rest of the process is the same as in Example 12.

[0061] The performance test results of the fiber obtained in Comparative Example 10 are shown in Table 2. Table 2 shows that the fiber surface wetting time is 4 to 5 seconds, and the water absorption rate is only 40.2%, indicating that its moisture-wicking and water-absorbing properties are generally poor. This is because the alkaline solution treatment temperature is low, the degree of hydrolysis on the PET fiber surface is limited, and the sulfonated polyphenylene sulfide pore-forming agent is difficult to dissolve quickly, resulting in a limited number of hydrophilic groups on the fiber surface and pores inside the fiber, leading to poor moisture-wicking and water-absorbing properties.

[0062] Comparative Example 11: The difference from Example 12 is that in step S3, the nonionic surfactant "(JFC-6)" is replaced with "anionic T" (scientific name: sodium diisooctyl maleate sulfonate), and the rest of the process is the same as in Example 12.

[0063] The performance test results of the fiber obtained in Comparative Example 11 are shown in Table 2. Table 2 shows that the water absorption rate of the fiber is only 34.7%. The fiber's water absorption performance is poor. This is because the penetrant T is an anionic surfactant, which has intermolecular repulsion (like charges repel) with sulfonated polyphenylene sulfide, which is also anionic. This makes it difficult to enhance the penetration of sulfonated polyphenylene sulfide, resulting in poor dissolution of the pore-forming agent and difficulty in forming a large number of pores inside the fiber, thus leading to poor water absorption performance.

[0064] Comparative Example 12: The difference from Example 12 is that in step S3, the treatment time in the alkaline solution is changed from "45 min" to "20 min", and the rest of the process is the same as in Example 12.

[0065] The performance test results of the fiber obtained in Comparative Example 12 are shown in Table 2. Table 2 shows that the water absorption rate of the fiber is only 38.5%, indicating poor water absorption. This is because the alkali treatment time was too short, resulting in insufficient dissolution of the sulfonated polyphenylene sulfide and a low number of internal pores in the fiber, thus leading to poor water absorption.

[0066] As can be seen from Tables 1 and 2, the superconducting moisture-wicking polyester fiber of the present invention has good moisture-wicking, water-absorbing and mechanical properties.

[0067] In summary, this invention employs an integrated process of "pre-dispersion blending - online addition spinning - synergistic alkali treatment," enabling the fiber to simultaneously possess internal rapid moisture transport channels and surface hydrophilic properties, thereby obtaining superconducting wet polyester fiber. The combination of its microporous structure and surface hydrophilic modification significantly enhances capillary effect and moisture conduction efficiency. This method has a controllable process flow, is easy to industrialize, and the resulting fiber has broad application prospects in fields such as sportswear.

[0068] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

Claims

1. A method for preparing superconducting wet polyester fiber, characterized in that... Follow these steps: S1, dry mix the required amount of polyethylene terephthalate chips and soluble pore-forming agent, and after melt blending and extrusion granulation of the resulting dry mixture, polyethylene terephthalate / sulfonated polyphenylene sulfide blend chips are obtained, which is the pore-forming functional masterbatch. S2, melt the pore-forming functional masterbatch to obtain the secondary component melt, use the same polyethylene terephthalate chips or melt as the main component melt, then inject the secondary component melt into the main component melt online, and after mixing, the resulting mixed melt is melt-spun, cooled, bundled, drawn and post-treated to obtain blended short fibers; S3, the blended short fibers are treated in a sodium hydroxide solution, and the treated fibers are then washed, neutralized and dried to obtain superconducting wet polyester fibers.

2. The method for preparing superconducting wet polyester fiber according to claim 1, characterized in that... In step S1, the mass ratio of polyethylene terephthalate chips to soluble pore-forming agent is 60 to 80: 20 to 40, the polyethylene terephthalate chips are low-melting-point polyethylene terephthalate, and the soluble pore-forming agent is sulfonated polyphenylene sulfide.

3. The method for preparing superconducting wet polyester fiber according to claim 2, characterized in that... The melting point of the low-melting-point polyethylene terephthalate resin is 200°C to 240°C, the molecular weight of the sulfonated polyphenylene sulfide is 20,000 to 50,000, and the degree of sulfonation of the sulfonated polyphenylene sulfide is 40% to 65%.

4. The method for preparing superconducting wet polyester fiber according to claim 1, 2, or 3, characterized in that... In step S1, melt blending is carried out in a twin-screw extruder. The feed zone temperature of the twin-screw extruder is 200°C to 230°C, the melt blending zone temperature is 260°C to 280°C, and the die temperature is 265°C to 275°C.

5. The method for preparing superconducting wet polyester fiber according to claim 4, characterized in that... In step S2, when the secondary component melt is injected online into the primary component melt, the secondary component melt accounts for 10% to 30% of the total mass of the mixed melt. The spinning temperature of the melt spinning is 250°C to 280°C, and the drawing is a multi-stage hot drawing carried out in a hot water bath at 80°C to 95°C, with a total drawing ratio of 3.5 to 4.8 times.

6. The method for preparing superconducting wet polyester fiber according to claim 1, 2, 3, or 5, characterized in that... In step S3, the temperature of the sodium hydroxide solution is 90°C to 98°C, the mass concentration of the sodium hydroxide solution is 5 g / L to 15 g / L, and a nonionic surfactant with a mass concentration of 1 g / L to 5 g / L is added to the sodium hydroxide solution during treatment. The treatment time is 30 min to 60 min.

7. The method for preparing superconducting wet polyester fiber according to claim 6, characterized in that... The nonionic surfactant is one or more of fatty alcohol polyoxyethylene ether, isooctyl alcohol polyoxyethylene ether, and isooctyl alcohol polyoxyethylene ether phosphate.

8. The method for preparing superconducting wet polyester fiber according to claim 1, 2, 3, 5, or 7, characterized in that... In step S3, the specific steps of water washing, neutralization and drying include: after the fibers treated with sodium hydroxide solution are rolled to remove excess alkali, they are immersed in an acidic aqueous solution with a pH of 5.0 to 7.0 and a temperature of 30°C to 45°C for treatment, and then rolled and dried.

9. The method for preparing superconducting wet polyester fiber according to claim 8, characterized in that... The treatment time in the acidic aqueous solution is 5 to 10 seconds, and the drying temperature is 100°C to 120°C for 5 to 20 minutes.

10. A superconducting wet polyester fiber obtained by the preparation method of the superconducting wet polyester fiber according to any one of claims 1 to 9.

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