A heat-generating heat storage hollow cotton-like fiber and a preparation method thereof

Abstract

This invention relates to the field of cotton-like fiber technology, specifically to a heat-generating and heat-retaining hollow cotton-like fiber and its preparation method. The heat-generating and heat-retaining hollow cotton-like fiber has ≥2 hollow cavities. By weight, the raw materials for preparing the heat-generating and heat-retaining hollow cotton-like fiber include at least: 80-90 parts polyester, 10-20 parts polyamide, and 1.5-8 parts modified heat-generating and heat-retaining powder. The surface of the modified heat-generating and heat-retaining powder contains amide groups, ester groups, and active double bonds.

Description

Technical Field

[0001] This invention relates to the field of cotton-like fiber technology, specifically to a heat-generating and heat-storing hollow cotton-like fiber and its preparation method. Background Technology

[0002] Current cotton-like polyester fibers only possess one or two of the excellent properties of cotton fibers in terms of moisture absorption, appearance, and dyeing performance. They have not yet achieved comprehensive imitation of cotton in multiple properties, and there is still room for further development of cotton-like polyester fibers.

[0003] The modification of polyester for cotton-like fibers is divided into chemical modification and physical modification. Physical modification uses physical methods, such as melt blending, to change the morphology and aggregate structure of the fibers, thereby improving fiber properties. Typically, the poor hygroscopicity of polyester can be compensated for by blending it with polyamide. However, due to the kinetic and thermodynamic incompatibility between polyamide and polyester, blend spinning easily leads to uneven mixing of the polymer melt, poor fiber-forming performance, and severe striping or spotting during dyeing. Chinese patent application (publication number CN 112663172 A) discloses a high-performance polyester-polyamide blend fiber, which improves the compatibility of polyester and polyamide by adding compatibilizers and end-capping agent decanediamine polyamide. The resulting blend fiber has good dyeing properties, but because polyester and polyamide are inherently insulators, the physically modified fiber remains insulator, limiting its application. Furthermore, the compatibilizer only improves interfacial compatibility and does not possess multi-functional composite properties. Summary of the Invention

[0004] To address the aforementioned issues, this invention introduces modified heat-generating and heat-storing powders into the fiber system, combined with fiber structure design, effectively solving the problem of poor compatibility between polyester and polyamide. It achieves comprehensive cotton-like properties from three perspectives: appearance, moisture absorption and wicking, and additional functions, thus better meeting practical application needs.

[0005] This invention provides a heat-generating and heat-storing hollow cotton-like fiber, wherein the heat-generating and heat-storing hollow cotton-like fiber has ≥2 hollow cavities; by weight, the raw materials for preparing the heat-generating and heat-storing hollow cotton-like fiber include at least: 80-90 parts of polyester, 10-20 parts of polyamide, and 1.5-8 parts of modified heat-generating and heat-storing powder; the surface of the modified heat-generating and heat-storing powder contains amide groups, ester groups, and active double bonds.

[0006] In one embodiment, the polyester is selected from at least one of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), or polypropylene terephthalate (PTT).

[0007] In one embodiment, the polyamide is selected from at least one of PA6 (polyamide 6), PA56 (polyamide 56), or PA66 (polyamide 66).

[0008] In one embodiment, the raw materials for preparing the modified heat-generating and heat-storing powder include at least heat-generating and heat-storing powder, N-(2-hydroxyethyl) itacamide acid, and an acid catalyst.

[0009] In one embodiment, the heat-generating and heat-storing powder is selected from rare earth elements or rare earth compounds, wherein the rare earth elements include at least one of lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, holmium, erbium, terbium, dysprosium, thulium, ytterbium, lutetium, scandium, or yttrium; and the rare earth compounds are selected from at least one of salts, oxides, or borides of lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, holmium, erbium, terbium, dysprosium, thulium, ytterbium, lutetium, scandium, or yttrium.

[0010] In one embodiment, the salt compound is selected from at least one of lanthanum hydroxide, lanthanum carbonate, cerium phosphate, neodymium carbonate, cerium hydroxide, samarium phosphate, yttrium phosphate, praseodymium carbonate, cerium carbonate, or lanthanum phosphate.

[0011] In one embodiment, the acid catalyst is selected from p-toluenesulfonic acid.

[0012] In one embodiment, the mass ratio of the heat-generating and heat-storing powder, N-(2-hydroxyethyl)itacamide acid, and acid catalyst is 20:(40-80):(0.32-0.96).

[0013] In one embodiment, the method for preparing the modified heat-generating and heat-storing powder includes the following steps: placing the heat-generating and heat-storing powder in a solvent to obtain a suspension; ultrasonically dispersing the suspension; adding N-(2-hydroxyethyl) itacamide acid and an acid catalyst to carry out a modification reaction; and preparing the modified heat-generating and heat-storing powder by vacuum distillation and vacuum drying.

[0014] In one embodiment, the D100 of the suspension is 1~2 μm.

[0015] In one embodiment, the solvent is N,N-dimethylacetamide.

[0016] In one embodiment, the mass ratio of the heat-generating and heat-storing powder to the solvent is 1:(1-2).

[0017] In one embodiment, the mass ratio of the heat-generating and heat-storing powder to the solvent is 1:(1.25-1.5).

[0018] In one embodiment, the modification reaction is carried out at a temperature of 115-130°C for 4-7 hours.

[0019] In one embodiment, the vacuum drying temperature is 70-75°C, and the drying time is 10-12 hours.

[0020] In one embodiment, the method for preparing N-(2-hydroxyethyl)itacinamide includes the following steps: dissolving 15-35 parts by weight of diethanolamine and 15-35 parts by weight of itaconic anhydride in 20-40 parts by weight of N,N-dimethylacetamide to obtain a diethanolamine solution and an itaconic anhydride solution, transferring the diethanolamine solution to a reactor in one step, slowly adding the itaconic anhydride solution, and stirring the reaction at 0-10°C for 3-5 hours to obtain N-(2-hydroxyethyl)itacinamide.

[0021] Traditional compatibilizers used in polyester-polyamide cotton-like fiber systems tend to reduce fiber strength, failing to meet practical application requirements. This invention introduces modified heat-generating and heat-storing powders containing amide groups, ester groups, and active double bonds on their surface, effectively improving the compatibility between polyester and polyamide in the system. Simultaneously, it endows the fibers with corresponding functionalities, resulting in fibers with not only excellent mechanical properties but also superior dyeing uniformity. The inventors believe the reason for this is that this invention uses N-(2-hydroxyethyl)itacamide acid to modify rare earth elements or rare earth compounds under acid catalysis. The surface of the rare earth elements or rare earth compounds is coated with hyperbranched polyamide esters containing active double bonds, ester groups, and amide bond structural units. This results in good compatibility with the polyester and polyamide in the system. Simultaneously, the active double bonds react with the terminal amino groups of the polyamide and the terminal hydroxyl groups of the polyester, allowing the rare earth elements or rare earth compounds to stably exist at the interface between the two phases. This acts as a compatibilizer, improving the interfacial compatibility between polyester and polyamide and ensuring the overall performance of the fiber.

[0022] In one embodiment, the morphology of the heat-generating and heat-storing hollow imitation cotton fiber includes one of short fibers, pre-oriented yarns, or fully drawn yarns.

[0023] Another aspect of the present invention provides a method for preparing heat-generating and heat-storing hollow cotton-like fibers, comprising at least the following steps: mixing polyester, polyamide, and modified heat-generating and heat-storing powder after vacuum drying to obtain a mixture, melting and blending the mixture in a spinning machine, and spinning it through a shaped spinneret to obtain heat-generating and heat-storing hollow cotton-like fibers.

[0024] In one embodiment, the micropores of the irregular spinneret are M-shaped pores that are centrally symmetrical, and the heat-generating and heat-storing hollow imitation cotton fiber has four hollow cavities.

[0025] In one embodiment, a single spinneret unit of the irregularly shaped spinneret contains two centrally symmetrical M-shaped melt channels. The bend in the middle of the M-shaped structure is arc-shaped. The left side of the M-shaped structure is higher than the right side, and the extension length of the left end is longer than that of the right end. The distance 'a' between the ends of the two M-shaped melt channels is 0.08-0.1 mm. On the inner side of the left side, a channel A extending towards the central region is provided. On the inner side of the bend in the middle of the M-shaped structure, a channel B extending towards the central region is provided. The distance 'b' between the ends of channels A and B and the center point is 0.04-0.6 mm. Channel A is straight or curved.

[0026] Currently, cotton-like fiber products mimic the soft, fluffy, and warm properties of cotton fibers by designing hollow structures. However, the grooves are shallow, and there is no supporting skeleton within the cavity. Under external force, the entire cross-section of the fiber will deform and collapse, thus affecting the warmth retention effect and failing to meet weaving requirements. This invention optimizes the microporous structure of the shaped spinneret to obtain four-hole hollow fibers. Two height-gradient protrusions and the internal skeleton provide double-layer protection for the fiber, improving its resistance to compression and deformation. The combination of the arc-shaped grooves on both sides and the hollow structure provides excellent warmth retention and moisture-wicking properties, while giving the fiber a fluffy feel and soft luster similar to cotton fibers.

[0027] In one embodiment, the screw melting temperature of the spinning machine is 230~298°C, and the spinning box temperature is 258~292°C.

[0028] In one embodiment, the heat-generating and heat-storing hollow imitation cotton fiber is in the form of short fibers, and the spinning conditions include: primary drafting temperature of 50~60℃, secondary drafting temperature of 120~150℃, total drafting ratio of 3.0~4.5 times, crimping temperature of 100~130℃, crimp number of 20~25, and the shaped fiber is cut into short fibers of 32~38mm on a cutting machine.

[0029] In one embodiment, the heat-generating and heat-storing hollow imitation cotton fiber is in the form of pre-oriented yarn (POY filament), and the spinning conditions include: annular air cooling temperature of 25±1℃, air speed of 0.2~0.4m / s, and winding speed of 2800~3500m / min.

[0030] In one embodiment, the heat-generating and heat-storing hollow imitation cotton fiber is in the form of fully drawn yarn (FDY filament), and the spinning conditions include: first hot roller temperature 55~82℃, second hot roller temperature 120~150℃, heat setting temperature 160~180℃, and winding speed 3800~4700m / min.

[0031] The heat-generating and heat-storing hollow cotton-like fiber provided by this invention achieves multiple cotton-like effects in terms of moisture absorption, dyeing performance, appearance performance and functionality. In particular, it has excellent heat-generating and heat-storing effects. When used as a fabric, it exhibits good heat-generating stability and antistatic properties.

[0032] Beneficial effects

[0033] 1. This invention effectively solves the problem of poor compatibility between polyester and polyamide by introducing modified heat-generating and heat-storing powder into the fiber system and combining it with fiber structure design. It achieves comprehensive cotton-like properties from three aspects: appearance, moisture absorption and wicking, and additional functions, thus better meeting the needs of practical applications.

[0034] 2. This invention introduces modified heat-generating and heat-storing powders containing amide groups, ester groups and active double bonds on the surface, which effectively improves the compatibility between polyester and polyamide in the system, while endowing the fiber with corresponding functionality. The prepared fiber not only has excellent mechanical properties, but also excellent dyeing uniformity.

[0035] 3. This invention obtains four-hole hollow fibers by optimizing the microporous structure of the irregular spinneret. The two height-gradient protrusions and the internal skeleton provide double-layer protection for the fiber, improving the fiber's resistance to compression and deformation. The combination of the arc-shaped grooves on both sides and the hollow structure provides good warmth retention and moisture wicking properties, while giving the fiber a fluffy feel and soft luster similar to cotton fibers.

[0036] 4. The heat-generating and heat-storing hollow cotton-like fiber provided by the present invention achieves multiple cotton-like effects in terms of moisture absorption, dyeing performance, appearance performance and functionality. In particular, it has excellent heat-generating and heat-storing effects. When used as a fabric, it exhibits good heat-generating stability and antistatic properties. Attached Figure Description

[0037] Figure 1 The diagram shows the irregular spinneret structure in Example 1. In the diagram, 1 is channel A, 2 is channel B, 3 is the center point, a is the distance between the ends of the two M-shaped melt channels, and b is the distance between the ends of channel A and channel B and the center point.

[0038] Figure 2 This is a schematic diagram of the irregular spinneret structure in Example 4. In the figure, 1 is flow channel A, 2 is flow channel B, 3 is the center point, a is the distance between the ends of the two M-shaped melt flow channels, and b is the distance between the ends of flow channel A and flow channel B and the center point. Detailed Implementation

[0039] The formulations of the heat-generating and heat-storing powders in each embodiment and comparative example are shown in Table 1 below.

[0040] Table 1

[0041]

[0042] Note: The above proportions are explained using Example 4 as an example: the mass ratio of salt compound, boride, and oxide is 1.6:1.6:6.8, and the mass ratio of cerium phosphate and neodymium carbonate in the salt compound is 1:1.

[0043] Example 1

[0044] In one aspect, Embodiment 1 of the present invention provides a heat-generating and heat-storing hollow cotton-like fiber, wherein the heat-generating and heat-storing hollow cotton-like fiber has four hollow cavities; by weight, the raw materials for preparing the heat-generating and heat-storing hollow cotton-like fiber include: 90 parts of polyester, 10 parts of polyamide, and 1.5 parts of modified heat-generating and heat-storing powder; the surface of the modified heat-generating and heat-storing powder contains amide groups, ester groups, and active double bonds.

[0045] The polyester is PET ("polyethylene terephthalate chips PET", Zhejiang Hengyi Petrochemical Co., Ltd., intrinsic viscosity is 0.65 dL / g).

[0046] The polyamide is PA6 ("polyamide 6 chips PA6", Guangdong Xinhui Meida Nylon Co., Ltd., with a relative viscosity of 2.48).

[0047] The raw materials for preparing the modified heat-generating and heat-storing powder include heat-generating and heat-storing powder, N-(2-hydroxyethyl) itacamide acid and acid catalyst, wherein the mass ratio of the heat-generating and heat-storing powder, N-(2-hydroxyethyl) itacamide acid and acid catalyst is 20:40:0.32.

[0048] The acid catalyst is p-toluenesulfonic acid.

[0049] The method for preparing the modified heat-generating and heat-storing powder includes the following steps: the heat-generating and heat-storing powder and solvent are loaded into a ball mill flask and placed on a horizontal ball mill for ball mill dispersion treatment to obtain a suspension; the suspension is ultrasonically dispersed for 30 min, N-(2-hydroxyethyl) itacamide acid and acid catalyst are added, nitrogen gas is purged for 20 min, and the mixture is stirred for 30 min and heated to carry out a modification reaction; the water generated in the reaction is removed by a water separator, and the modified heat-generating and heat-storing powder is prepared by vacuum distillation and vacuum drying at 70℃ for 12 h.

[0050] The D100 of the suspension is 1~2μm.

[0051] The solvent is N,N-dimethylacetamide.

[0052] The mass ratio of the heat-generating and heat-storing powder to the solvent is 1:1.25.

[0053] The modification reaction was carried out at a temperature of 130°C for 4 hours.

[0054] The vacuum drying temperature is 70℃, and the drying time is 12 hours.

[0055] The preparation method of N-(2-hydroxyethyl)itaconamic acid includes the following steps: dissolving 21.5 parts by weight of diethanolamine and 22.5 parts by weight of itaconic anhydride in 30 parts by weight of N,N-dimethylacetamide to obtain a diethanolamine solution and an itaconic anhydride solution, transferring the diethanolamine solution to a reactor in one step, slowly adding the itaconic anhydride solution, and stirring the reaction at 6°C for 4 hours to obtain N-(2-hydroxyethyl)itaconamic acid.

[0056] The heat-generating and heat-storing hollow cotton-like fiber is in the form of pre-oriented yarn (POY filament).

[0057] In another aspect, Embodiment 1 of the present invention provides a method for preparing heat-generating and heat-storing hollow cotton-like fibers, comprising the following steps: mixing polyester, polyamide, and modified heat-generating and heat-storing powder under vacuum drying for 2 hours to obtain a mixture, melting and blending the mixture in a spinning machine, and spinning it through a shaped spinneret to obtain heat-generating and heat-storing hollow cotton-like fibers.

[0058] The micropores of the irregular spinneret are M-shaped pores that are centrally symmetrical, and the heat-generating and heat-storing hollow imitation cotton fiber has 4 hollow cavities.

[0059] See Figure 1 Each spinneret unit of the irregularly shaped spinneret contains two centrally symmetrical M-shaped melt channels. The bend in the middle of the M-shaped structure is arc-shaped. The left side of the M-shaped structure is higher than the right side, and the extension length of the left end is longer than that of the right end. The distance a between the ends of the two M-shaped melt channels is 0.08 mm. On the inner side of the left side, there is a channel A1 extending towards the central region. On the inner side of the bend in the middle of the M-shaped structure, there is a channel B2 extending towards the central region. The distance b between the ends of channels A1 and B2 and the center point 3 is 0.05 mm. Channel A1 is straight.

[0060] The screw melting temperature of the spinning machine is 275℃ in zone one, 292℃ in zone two, and 292℃ in zone three; the spinning box temperature is 290℃.

[0061] The spinning conditions include: annular air cooling temperature of 25±1℃, air speed of 0.2~0.4m / s, and winding speed of 2800~3500m / min.

[0062] The heat-generating and heat-storing hollow imitation cotton fiber is in the form of fully drawn yarn (FDY filament), and the spinning conditions include: annular cooling temperature of 26℃, wind speed of 0.35m / s, and winding speed of 3400m / min.

[0063] Example 2

[0064] Example 2 of the present invention provides a heat-generating and heat-storing hollow cotton-like fiber and its preparation method. The specific implementation method is the same as in Example 1, except that, by weight, the raw materials for preparing the heat-generating and heat-storing hollow cotton-like fiber include: 80 parts polyester, 20 parts polyamide, and 3 parts modified heat-generating and heat-storing powder; the mass ratio of the heat-generating and heat-storing powder, N-(2-hydroxyethyl) itacamide acid, and acid catalyst is 20:60:0.6; the modification reaction temperature is 125℃, and the time is 5 hours. The heat-generating and heat-storing hollow cotton-like fiber is in the form of fully drawn filament (FDY filament); the screw melting temperature of the spinning machine is 278℃ in zone one, 292℃ in zone two, and 295℃ in zone three; the spinning box temperature is 292℃. The spinning conditions include: a primary hot roller temperature of 70℃, a primary hot roller speed of 2000 m / min, a secondary hot roller temperature of 130℃, a secondary hot roller speed of 4200 m / min, and a winding speed of 4100 m / min.

[0065] Example 3

[0066] Example 3 of the present invention provides a heat-generating and heat-storing hollow cotton-like fiber and its preparation method. The specific implementation method is the same as that of Example 1, except that, by weight, the raw materials for preparing the heat-generating and heat-storing hollow cotton-like fiber include: 82 parts of polyester, 18 parts of polyamide, and 45 parts of modified heat-generating and heat-storing powder; the mass ratio of the heat-generating and heat-storing powder, N-(2-hydroxyethyl) itacamide acid, and acid catalyst is 20:80:0.96; the temperature of the modification reaction is 115°C and the time is 7 hours; the morphology of the heat-generating and heat-storing hollow cotton-like fiber is short fiber; the spinning conditions include: a first-stage drawing temperature of 80°C, a second-stage drawing temperature of 110°C, a third-stage drawing temperature of 130°C, a draw ratio of 2.5, followed by mechanical crimping of the fiber, setting at 158°C for 15 minutes, and cutting it to 35 cm on a cutting machine.

[0067] Example 4

[0068] Example 4 of the present invention provides a heat-generating and heat-storing hollow cotton-like fiber and its preparation method. The specific implementation method is the same as in Example 3, except that, by weight, the raw materials for preparing the heat-generating and heat-storing hollow cotton-like fiber include: 85 parts polyester, 15 parts polyamide, and 6 parts modified heat-generating and heat-storing powder. The micropores of the shaped spinneret are M-shaped pores with overall central symmetry, and the heat-generating and heat-storing hollow cotton-like fiber has four hollow cavities.

[0069] See Figure 2The individual spinneret unit of the irregularly shaped spinneret contains two centrally symmetrical M-shaped melt channels. The bend in the middle of the M-shaped structure is arc-shaped. The left side of the M-shaped structure is higher than the right side, and the extension length of the left end is longer than that of the right end. The distance 'a' between the ends of the two M-shaped melt channels is 0.08 mm. On the inner side of the left side, a channel A1 extending towards the central region is provided. On the inner side of the bend in the middle of the M-shaped structure, a channel B2 extending towards the central region is provided. The distance 'b' between the ends of channels A1 and B2 and the center point is 0.05 mm. Channel A1 is curved. The spinning conditions include: a first-stage drafting temperature of 82℃, a second-stage drafting temperature of 115℃, a third-stage drafting temperature of 128℃, a draw ratio of 2.7, followed by mechanical crimping of the fibers, setting at 158℃ for 15 minutes, and cutting to 32 cm lengths on a cutting machine.

[0070] Example 5

[0071] Embodiment 5 of the present invention provides a heat-generating and heat-storing hollow imitation cotton fiber and its preparation method. The specific implementation method is the same as that of Embodiment 2, except that the micropores of the irregular spinneret are M-shaped pores with overall central symmetry, and the heat-generating and heat-storing hollow imitation cotton fiber has 4 hollow cavities.

[0072] See Figure 2 Each spinneret unit of the irregularly shaped spinneret contains two centrally symmetrical M-shaped melt channels. The bend in the middle of the M-shaped structure is arc-shaped. The left side of the M-shaped structure is higher than the right side, and the extension length of the left end is longer than that of the right end. The distance a between the ends of the two M-shaped melt channels is 0.08 mm. On the inner side of the left side, there is a channel A1 extending towards the central region. On the inner side of the bend in the middle of the M-shaped structure, there is a channel B2 extending towards the central region. The distance b between the ends of channels A1 and B2 and the center point is 0.05 mm. Channel A1 is curved.

[0073] Example 6

[0074] Example 6 of the present invention provides a heat-generating and heat-storing hollow cotton-like fiber and its preparation method. The specific implementation method is the same as in Example 2, except that, by weight, the raw materials for preparing the heat-generating and heat-storing hollow cotton-like fiber include 82 parts polyester, 18 parts polyamide, and 5 parts modified heat-generating and heat-storing powder; the polyester is PBT ("poly(terephthalic acid) chips PBT", Wuxi Xingsheng New Materials Co., Ltd., intrinsic viscosity: 1.18 dL / g). The screw melting temperature of the spinning machine is 250℃ in zone one, 258℃ in zone two, and 262℃ in zone three; the spinning box temperature is 260℃. The spinning conditions include: a primary hot roller temperature of 55℃, a primary hot roller speed of 1900 m / min, a secondary hot roller temperature of 130℃, a secondary hot roller speed of 4300 m / min, and a winding speed of 4250 m / min.

[0075] Example 7

[0076] Example 7 of the present invention provides a heat-generating and heat-storing hollow cotton-like fiber and its preparation method. The specific implementation method is the same as in Example 2, except that, by weight, the raw materials for preparing the heat-generating and heat-storing hollow cotton-like fiber include 82 parts polyester, 18 parts polyamide, and 5 parts modified heat-generating and heat-storing powder; the polyester is PBT ("poly(terephthalic acid) chips PBT", Wuxi Xingsheng New Materials Co., Ltd., intrinsic viscosity: 1.18 dL / g). The screw melting temperature of the spinning machine is 245℃ in zone one, 255℃ in zone two, and 260℃ in zone three; the spinning box temperature is 258℃. The spinning conditions include: a primary hot roller temperature of 60℃, a primary hot roller speed of 1700 m / min, a secondary hot roller temperature of 125℃, a secondary hot roller speed of 4250 m / min, and a winding speed of 4150 m / min.

[0077] Example 8

[0078] Example 8 of the present invention provides a heat-generating and heat-storing hollow cotton-like fiber and its preparation method. The specific implementation method is the same as in Example 2, except that, by weight, the raw materials for preparing the heat-generating and heat-storing hollow cotton-like fiber include 82 parts polyester, 18 parts polyamide, and 5 parts modified heat-generating and heat-storing powder; the polyamide is PA56 ("bio-based polyamide 56 chips PA56", Shanghai Kaisai Biotechnology Co., Ltd., with a relative viscosity of 2.65). The screw melting temperature of the spinning machine is 270℃ in zone one, 285℃ in zone two, and 285℃ in zone three; the spinning box temperature is 285℃. The spinning conditions include: a primary hot roller temperature of 80℃, a primary hot roller speed of 1600 m / min, a secondary hot roller temperature of 150℃, a secondary hot roller speed of 4800 m / min, and a winding speed of 4600 m / min.

[0079] Example 9

[0080] Example 9 of the present invention provides a heat-generating and heat-storing hollow cotton-like fiber and its preparation method. The specific implementation method is the same as in Example 2, except that, by weight, the raw materials for preparing the heat-generating and heat-storing hollow cotton-like fiber include 82 parts polyester, 18 parts polyamide, and 5 parts modified heat-generating and heat-storing powder; the polyamide is PA66 (PA66 chips, Huafeng Group Co., Ltd., relative viscosity 2.67). The screw melting temperature of the spinning machine is 250℃ in zone one, 258℃ in zone two, and 262℃ in zone three; the spinning box temperature is 265℃. The spinning conditions include: a primary hot roller temperature of 75℃, a primary hot roller speed of 2000 m / min, a secondary hot roller temperature of 130℃, a secondary hot roller speed of 4200 m / min, and a winding speed of 4100 m / min.

[0081] Example 10

[0082] Example 10 of the present invention provides a heat-generating and heat-storing hollow cotton-like fiber and its preparation method. The specific implementation method is the same as in Example 2, except that, by weight, the raw materials for preparing the heat-generating and heat-storing hollow cotton-like fiber include 82 parts polyester, 18 parts polyamide, and 8 parts modified heat-generating and heat-storing powder; the polyamide is PA66 (PA66 chips, Huafeng Group Co., Ltd., relative viscosity 2.67). The screw melting temperature of the spinning machine is 260℃ in zone one, 270℃ in zone two, and 275℃ in zone three; the spinning box temperature is 273℃. The spinning conditions include: a primary hot roller temperature of 75℃, a primary hot roller speed of 2000 m / min, a secondary hot roller temperature of 130℃, a secondary hot roller speed of 4200 m / min, and a winding speed of 4100 m / min.

[0083] Comparative Example 1

[0084] Comparative Example 1 of the present invention provides a cotton-like fiber and its preparation method, the specific implementation of which is the same as that of Example 2, except that the modified heat-generating and heat-retaining powder is replaced by 3 parts by weight of unmodified heat-generating and heat-retaining powder.

[0085] Comparative Example 2

[0086] Comparative Example 2 of the present invention provides a cotton-like fiber and its preparation method. The specific implementation method is the same as in Example 2, except that, by weight, the raw materials for preparing the cotton-like fiber include: 80 parts polyester, 20 parts polyamide, 3 parts unmodified heat-generating and heat-storing powder, and 3 parts polyamide ester copolymer. The preparation method of the polyamide copolymer includes the following steps: N-(2-hydroxyethyl)itaclamic acid and an acid catalyst (the mass ratio of N-(2-hydroxyethyl)itaclamic acid to the acid catalyst is 60:0.6), nitrogen gas is passed through for 20 min, stirring is performed for 30 min, and the temperature is raised to 125°C for 5 h. The water generated during the reaction is removed through a water separator, and the polyamide copolymer is prepared by vacuum distillation and vacuum drying at 70°C for 12 h.

[0087] Comparative Example 3

[0088] Comparative Example 3 of the present invention provides a cotton-like fiber and its preparation method. The specific implementation method is the same as that of Example 2, except that the irregular spinneret is replaced with a circular spinneret, the cotton-like fiber has no hollow cavity, and the cross-section of the cotton-like fiber is a solid circle.

[0089] Comparative Example 4

[0090] Comparative Example 4 of the present invention provides a cotton-like fiber and its preparation method. The specific implementation method is the same as that of Example 2, except that the irregular spinneret is replaced with a double "C"-shaped hollow spinneret, the cotton-like fiber has a hollow cavity, and the cross-section of the cotton-like fiber is circular and hollow.

[0091] Performance testing

[0092] The cotton-like fibers provided in the examples and comparative examples were tested as follows. The results of the appearance and performance tests are shown in Table 1, and the results of the functional performance tests are shown in Table 2.

[0093] Tensile strength (cN / dtex) and elongation at break (%): filaments were tested according to GB / T14344-2008, and staple fibers were tested according to GB / T14337-2008.

[0094] Hollowness: Tested according to FZ / T50002-2013 "Experimental Method for the Deformity of Chemical Fibers".

[0095] Core absorption height: The heat-generating and heat-storing hollow cotton-like fibers provided in the various embodiments and comparative examples are spun into textiles with a specification of 186g / m². 2 The test was conducted according to GB / T21655.1 and compared with pure cotton fabric.

[0096] Moisture regain (%): Filament was tested according to GB / T6503-2001, and staple fiber was tested according to GB / T14341-1993, and compared with pure cotton fabric.

[0097] Dyeing uniformity (grade): Tested according to GB / T6508-2015.

[0098] Softness: The heat-generating and heat-storing hollow cotton-like fibers provided in the various embodiments and comparative examples were spun into textiles with a specification of 186 g / m². 2 The PY-H613 microcomputer softener was used for testing. The lower the softness value, the softer the fabric, which is used to characterize the feel and is compared with pure cotton fabric.

[0099] Compression elasticity: Tested according to FZ / T50009.4-2019.

[0100] Heat generation and heat storage performance: The heat generation and heat storage hollow cotton-like fibers provided in the various embodiments and comparative examples were spun into textiles with a specification of 186 g / m². 2 The test was conducted in accordance with GB / T18319-2019, and the maximum temperature rise within 20 minutes was recorded.

[0101] Electrostatic properties: Filaments were tested according to FZ / T50035-2016, and short fibers were tested according to GB / T14342-2015.

[0102] Luster: Using sensory evaluation, the heat-generating and heat-storing hollow cotton-like fibers provided in the various embodiments and comparative examples were spun, and the specifications of the textiles were 186 g / m². 2 The textile samples were compared with pure cotton fabric. The textile samples and pure cotton were arranged in a D65 standard light source box, with the angle between the light source and the sample fixed at 45°. The samples were cut into uniform 18*18cm pieces. A visually competent evaluator subjectively evaluated the gloss of the samples, describing the gloss state as five categories: 1. Dull; 2. Neither dull nor soft; 3. Soft; 4. Bright; 5. Sparkling.

[0103] Table 1

[0104]

[0105] In Table 1, " / " indicates that the corresponding item was not measured.

[0106] Analysis of the test results in Table 1 shows that the fabrics woven from the products provided in Examples 1-10 are highly similar to pure cotton fabric in terms of softness, luster, and wicking performance. Meanwhile, the moisture regain is 2.3 to 4.2 times higher than that of polyester fiber (0.4%). Furthermore, the short fibers and filaments provided in Examples 1-10 exhibit superior mechanical properties and higher uniformity of dyeing compared to Comparative Examples 1 and 2, indicating that the fibers prepared by adding modified heat-retaining and heat-generating powder can better meet the requirements of subsequent weaving and dyeing processes. By comparing the wicking height and luster with Comparative Examples 3-4, it is evident that the fiber structure designed in this invention has superior moisture-wicking performance compared to traditional round fibers.

[0107] Table 2

[0108]

[0109] Analysis of the test results in Table 2 shows that the fabrics woven from the fibers prepared in Examples 1-10 of this invention have good heat retention performance, with a maximum temperature rise of 16℃, advancing the thermal insulation application of fibers to a new level. It is speculated that the modified heat-generating and heat-storing powder and the hollow structure jointly enhance the thermal insulation performance of the fibers through radiant and conductive heat. Compared with Comparative Example 1, Example 2, under the same additive dosage, showed a 2.8℃ increase in temperature change and a two-order-of-magnitude improvement in antistatic ability. It is speculated that after the stretching process, the nanoparticles enriched at the phase interface are distributed into linear shapes along with the change in the shape of the dispersed phase, forming a conductive network, thereby improving the antistatic ability. Compared with Comparative Example 4, the compression elasticity of the filament increased by up to 14%, exhibiting better resistance to compression. Comparative Example 4 had a lower compression elasticity, so its heat-generating and heat-storing performance and antistatic performance were not tested.

Claims

1. A heat-generating and heat-storing hollow cotton-like fiber, characterized in that, The heat-generating and heat-storing hollow imitation cotton fiber has ≥2 hollow cavities; The raw materials for preparing the heat-generating and heat-storing hollow cotton-like fiber, by weight, include: 80-90 parts polyester, 10-20 parts polyamide, and 1.5-8 parts modified heat-generating and heat-storing powder; the surface of the modified heat-generating and heat-storing powder contains amide groups, ester groups, and active double bonds; the raw materials for preparing the modified heat-generating and heat-storing powder include heat-generating and heat-storing powder, N-(2-hydroxyethyl) itacamide acid, and an acid catalyst, wherein the mass ratio of the heat-generating and heat-storing powder, N-(2-hydroxyethyl) itacamide acid, and the acid catalyst is 20:(40-80):(0.32-0.96); the preparation method of the modified heat-generating and heat-storing powder includes the following steps: the heat-generating and heat-storing powder is placed in a solvent to obtain a suspension; the suspension is ultrasonically dispersed, N-(2-hydroxyethyl) itacamide acid and the acid catalyst are added for modification reaction, and the modified heat-generating and heat-storing powder is prepared by vacuum distillation and vacuum drying; the temperature of the modification reaction is 115-130℃, and the time is 4-7h.

2. The heat-generating and heat-storing hollow cotton-like fiber according to claim 1, characterized in that, The polyester is selected from at least one of polyethylene terephthalate, polybutylene terephthalate, or polypropylene terephthalate.

3. The heat-generating and heat-storing hollow cotton-like fiber according to claim 1, characterized in that, The polyamide is selected from at least one of PA6, PA56, or PA66.

4. The heat-generating and heat-storing hollow cotton-like fiber according to claim 1, characterized in that, The heat-generating and heat-storing powder is selected from rare earth elements or rare earth compounds. The rare earth elements include one of lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, holmium, erbium, terbium, dysprosium, thulium, ytterbium, lutetium, scandium, or yttrium. The rare earth compounds are selected from at least one of the following: salts, oxides, or borides of lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, holmium, erbium, terbium, dysprosium, thulium, ytterbium, lutetium, scandium, or yttrium.

5. A method for preparing a heat-generating and heat-storing hollow cotton-like fiber according to any one of claims 1-4, characterized in that, Includes the following steps: Polyester, polyamide, and modified heat-generating and heat-storing powder are vacuum dried and then mixed to obtain a mixture. The mixture is then melt-blended in a spinning machine and spun through a shaped spinneret to obtain heat-generating and heat-storing hollow cotton-like fiber.

6. The method for preparing heat-generating and heat-storing hollow cotton-like fiber according to claim 5, characterized in that, The micropores of the irregular spinneret are M-shaped pores that are centrally symmetrical, and the heat-generating and heat-storing hollow imitation cotton fiber has 4 hollow cavities.

7. The method for preparing heat-generating and heat-storing hollow cotton-like fiber according to claim 5, characterized in that, The heat-generating and heat-storing hollow imitation cotton fiber includes one of the following forms: short fiber, pre-oriented yarn, or fully drawn yarn.

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