A spinning method for colored nylon ultrafine fibers

Abstract

The present invention relates to a spinning method for colored nylon superfine fibers. After the island component and the sea component are subjected to composite spinning to obtain spun fibers, the spun fibers are sequentially subjected to heat treatment, heat drawing and fiber opening to obtain colored nylon superfine fibers. The island component includes PA6 and toner, and the content of the toner in the island component does not exceed 5wt%. The sea component contains a coupling agent, and the coupling agent simultaneously contains a group X that is pro-toner and a group Y that is pro-PA6. The type of group X, the type of group Y and the process parameters meet the following conditions: before fiber opening, group X couples with the toner, and group Y reacts with the end group of PA6. The heat treatment temperature is 40-50°C for not less than 30min. The heat drawing temperature is 60-80°C, and the multiple is 1.5-4.5 times. The method of the present invention is simple and can enable the fiber to obtain good color rendering under the condition of a small amount of toner added.

Description

Technical Field

[0001] The invention belongs to the field of ultrafine fibers and relates to a spinning method of colored nylon ultrafine fibers. Background Art

[0002] Commonly used methods for spinning colored fibers include post-processing dyeing and co-blended spinning dyeing. Among them, post-processing dyeing refers to dyeing the microfiber bundles after fiber opening. Dyeing is difficult, polluting, and energy-intensive. In addition, the post-processing process is difficult to evenly treat the surface of each fiber in the microfiber bundle, resulting in uneven dyeing. The colored fibers produced by co-blended spinning dyeing have high color fastness and do not fade. Therefore, co-blended spinning dyeing is more suitable for dyeing microfiber bundles prepared from sea island fibers. Among them, co-blended spinning dyeing refers to uniformly mixing the color powder or masterbatch (dispersing high-concentration color powder in a polymer carrier of the same material as the island) with the island components, and then spinning them through melt extrusion.

[0003] CN102650081A discloses a colored fixed island composite staple fiber and a production method thereof, comprising the following steps: (1) adding the island component nylon 6, a mixture of nylon-based coloring masterbatch and a compatibilizer, and the sea component low-density polyethylene into respective storage bins, and then respectively entering respective screw extruders; in one screw extruder, heating, extruding, and melting the sea component into a spinnable melt A; in another screw extruder, heating, extruding, and melting the island component mixture into a spinnable melt B; after filtering, the spinnable melt A and the spinnable melt B are metered through respective spinning boxes and then enter the same spinning assembly; The molten metal is instantly converged at the spinneret, and a thin stream of melt is ejected from the spinneret hole; (2) the thin stream of melt ejected from the spinneret hole is cooled and formed to obtain a fiber, which is then oiled, bundled, and dropped into a barrel in sequence, and placed for 24 to 72 hours to eliminate its internal stress; (3) the fiber bundle obtained in step (2) is bundled by a bundler, and the bundled fiber bundle enters the first drawing machine, and then enters the second drawing machine through an oil bath; (4) the fiber bundle after drawing enters the crimping machine through a stacking machine, is crimped, and then sent to a relaxation heat setting machine for setting; (5) the fiber bundle after relaxation heat setting is cut by a cutting machine to obtain the colored fixed island composite short fiber.

[0004] However, the color powder is a heterogeneous material (inorganic particles) relative to the island phase (PA6 or PET), which will reduce the physical properties of the fiber. As the color powder content increases, its physical properties will be greatly reduced. Therefore, for fibers with high color rendering properties, the tensile properties are often poor. Summary of the Invention

[0005] The purpose of the present invention is to solve the problems existing in the prior art and provide a method for spinning colored nylon ultrafine fibers.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A method for spinning colored nylon ultrafine fibers comprises the steps of: performing composite spinning of island components and sea components to obtain spun fibers, and then sequentially subjecting the spun fibers to heat treatment, heat drawing, and fiber opening to obtain colored nylon ultrafine fibers;

[0008] The island component includes PA6 and color powder, and the content of the color powder in the island component does not exceed 5wt%;

[0009] The sea component contains a coupling agent, which contains a group X that is affinity for color powder and a group Y that is affinity for PA6; the group X is a siloxane group, and the group Y is an epoxy group or an amino group;

[0010] The temperature of heat treatment is 40-50°C, and the time is not less than 30 minutes; the temperature of hot stretching is 60-80°C, and the multiple is 1.5-4.5 times.

[0011] Usually, in order to obtain highly saturated colors, it is necessary to improve the color rendering by adding a large amount of color powder. However, color powder is usually incompatible with the PA6 matrix. The more it is added, the easier it is for the fiber to break. When the addition amount is controlled within 5%, good mechanical properties can be maintained, but the color rendering is not ideal at this time.

[0012] Prior art uses of toner typically require the use of a coupling agent to modify the toner's surface, enabling the modified toner to be stably dispersed in an organic matrix. It is well known that coupling agents can achieve good interfacial bonding between inorganic fillers and organic polymers, despite their vastly different surface properties, improving the compatibility between the two phases. Coupling agents typically contain two types of groups in their chemical structure: one group, X, that is affinity for the inorganic filler, and one group, X, that is affinity for the organic polymer. Group X interacts with the monolayer of bound water or protons (H+) of hydroxyl groups on the surface of the inorganic filler.

[0013] In order to obtain good color development even with a small amount of toner added, the present invention adds a coupling agent to the sea phase;

[0014] Coupling agents are small molecules with low melting points. They are liquid at room temperature and have the strongest diffusion ability. Toners also have diffusion ability, but due to their high melting point, they are usually solid during the entire processing process. Toners are surrounded by PA6, and their diffusion ability is easily limited by the mobility of PA6. When PA6 is completely frozen (ambient temperature is below the glass transition temperature), diffusion is extremely slow. When PA6 is in a highly elastic state or viscous flow state, diffusion is accelerated.

[0015] The present invention controls the temperature and time of the heat treatment so that the coupling agent can diffuse into the shallow layer of the island phase before the toner diffuses into the sea phase and fully react with the PA6 in the shallow layer of the island phase. On the one hand, the coupling agent remains in the shallow layer of the island phase and no longer diffuses into the interior of the island phase. On the other hand, the coupling agent plays a role in the heat drawing process, coupling with the toner in the shallow layer of the island phase, preventing the toner from significantly diffusing into the sea phase.

[0016] Specifically, the present invention controls the heat treatment temperature to be 40-50°C and the duration to be no less than 30 minutes. The heat treatment temperature of the present invention is lower than the glass transition temperature of PA6. Therefore, during the heat treatment process, the coupling agent has a stronger diffusion ability, while the colorant has a weaker diffusion ability. Before the colorant diffuses into the sea phase, the coupling agent can diffuse into the shallow surface layer of the island phase. If the heat treatment temperature significantly exceeds the glass transition temperature of PA6 and reaches a highly elastic state, although it can accelerate the continuous diffusion of the coupling agent in the sea phase to the shallow surface layer of the island phase, it will also cause the colorant to overflow to the interface prematurely, causing the colorant to diffuse into the sea phase. Therefore, it is necessary to control the heat treatment temperature to be 40-50°C. The heat treatment duration of the present invention is no less than 30 minutes to ensure that the coupling agent fully reacts with the PA6 in the shallow surface layer of the island phase.

[0017] The present invention controls the temperature and multiple of heat drawing so that after the coupling agent diffuses to the shallow surface layer of the island phase and fully reacts with the PA6 in the shallow surface layer of the island phase, the color powder can diffuse to the shallow surface layer of the island phase;

[0018] Specifically, the present invention controls the temperature of hot stretching to be 60-80°C and the stretching multiple to be 1.5-4.5 times; at the hot stretching temperature, the PA6 molecular chains and the color powder dispersed in the molecular chains begin to move violently. Since the color powder is incompatible with the internal PA6, the color powder is likely to accelerate outward diffusion at this stage; the movement ability of the PA6 molecular chains and the color powder in this process depends on the temperature conditions (stretching temperature) and the stretching force conditions (stretching multiple) given by the outside world; if the temperature is too low, the movement ability of the PA6 molecular chains and the color powder is hindered, the color powder diffuses slowly, and the color rendering of the obtained fiber is poor; if the temperature is too high, it is easy to stick to the roller and cannot be processed; the stretching multiple is adjusted, that is, a speed difference is created between the front and rear rollers, thereby forming a stretching force, causing the fiber to undergo a large deformation along the stretching direction. During the large deformation process, slippage occurs between the molecular chains, and the fiber becomes thinner. At this time, the color powder originally "frozen" between the molecular chains is accelerated to diffuse outward;

[0019] When the toner diffuses to the shallow layer of the island phase, the PA6 and toner in the shallow layer of the island phase can be better compatible under the action of the coupling agent because the shallow layer of the island phase contains a coupling agent. However, there is no coupling agent inside the island phase, and the PA6 and toner inside the island phase are incompatible. The toner will gradually diffuse and gather from the inside of the island phase to the shallow layer of the island phase. In this way, a large amount of toner can be concentrated in the shallow layer of the island phase, and excellent color rendering can be achieved even if the amount of toner added is small.

[0020] As the preferred technical solution:

[0021] The spinning method of the colored nylon microfiber as described above, wherein the island component is composed of 100 parts of PA6 and 0.1-5.0 parts of color powder, by weight; the sea component is composed of 100 parts of LDPE and 0.2-0.5 parts of coupling agent, by weight; the mass ratio of the island component to the sea component is 40:60-80:20.

[0022] In the spinning method of the colored nylon ultrafine fiber as described above, the relative viscosity of PA6 is 2.4-3.2, and the MI of LDPE is 26-60 g / 10 min.

[0023] Color powders have poor compatibility with PA6. The present invention uses PA6 with a lower relative viscosity. This not only facilitates better initial dispersion of the poorly compatible color powder in the screw, preventing severe agglomeration, but also facilitates surface diffusion of the color powder under specific conditions (hot drawing). Stable island-in-the-sea fiber spinning requires matching flow properties between the sea and island phases in known composite systems. The present invention controls the MI of the sea component base material, LDPE, to 26-60 g / 10 min to match the relative viscosity of the island component base material, PA6, which has a relative viscosity of 2.4-3.2, thus achieving stable island-in-the-sea fiber spinning performance.

[0024] As described above, in the spinning method of colored nylon ultrafine fibers, during composite spinning, the island component spinning melt temperature is 180-250°C, the sea component spinning melt temperature is 240-285°C, and the spinning speed is 200-1200m / min.

[0025] In the above-mentioned method for spinning colored nylon ultrafine fibers, the heat treatment is carried out by water bath heating.

[0026] In the spinning method of the colored nylon ultrafine fiber as described above, the speed of the hot drawing is 5-50 m / min.

[0027] In the spinning method of the colored nylon ultrafine fiber as described above, hot toluene is used to dissolve the LDPE in the fiber during fiber opening.

[0028] As described above, the spinning method of colored nylon ultrafine fibers has a fineness of 0.05-0.3 dtex, a breaking strength of 2.5-10.1 cN / dtex, an elongation at break of 10-45%, and a color saturation of 0.8%-8.2%. Under the condition of the same amount of color powder added, the color saturation of the fibers of the present invention is significantly higher than that of conventional fibers.

[0029] Beneficial effects:

[0030] The present invention utilizes the difference in the temperature dependence of the mobility of the coupling agent and the color powder in PA6, and controls the heat treatment temperature close to the glass transition temperature of PA6. This is conducive to the sufficient diffusion of the coupling agent in the sea phase to the shallow surface layer of the island phase and sufficient reaction with the active end groups thereon. The temperature of the heat stretching is then controlled above the glass transition temperature. At this time, the color powder will accelerate its outward diffusion as the molecular chain thaws, and couple with the coupling agent in the shallow surface layer of the island phase, so that the finally obtained colored nylon microfiber has better color rendering. Under the condition of having the same color rendering, the amount of color powder added is less and the mechanical properties are better. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a schematic diagram of a cross section of a primary fiber of the present invention;

[0032] Among them, 1-marine phase, 2-island phase. DETAILED DESCRIPTION

[0033] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0034] The following is the test method for the performance in each embodiment:

[0035] Relative viscosity test: measured by capillary method in GB / T 10247-2008;

[0036] MI test: Determined by the MFR method in GB / T 3682.1-2008;

[0037] Color saturation: GB / T 17644 "Test method for whiteness and chromaticity of textile fibers" was used to characterize fiber color. A fiber bundle made of 100 microfibers was used as a sample to test its color saturation.

[0038] Fineness, elongation at break, and breaking strength: GB / T 14337-2008 "Standard method for testing tensile properties of chemical staple fibers" was used to test the breaking strength and elongation of the fiber. GB / T 14335-2008 "Test method for linear density of chemical staple fibers" was used to test the fineness of the fiber. Fiber breaking strength (cN / dtex) = breaking strength (cN) / fineness (dtex).

[0039] Example 1

[0040] A method for spinning colored nylon ultrafine fibers comprises the following steps:

[0041] (1) Preparation of raw materials:

[0042] PA6: Manufacturer: Guangdong Xinhui Meida Nylon Co., Ltd., brand: M32800, relative viscosity: 2.8;

[0043] LDPE: The manufacturer is Beijing Yanshan Branch of Sinopec, brand 1I50, and the measured MI of LDPE is 51g / 10min;

[0044] Toner: Manufacturer: Hunan Kelai New Materials Co., Ltd., brand: PBK26;

[0045] Coupling agent: The manufacturer is Hangzhou Jessica Chemical Co., Ltd., the brand is KH-550 aminosilane;

[0046] (2) Configure island components and sea components;

[0047] By weight, the island component consists of 100 parts PA6 and 2.2 parts toner;

[0048] In parts by weight, the sea component consists of 100 parts of LDPE and 0.3 parts of coupling agent;

[0049] (3) The island component and the sea component with a mass ratio of 50:50 are composite-spun to obtain spun fibers, such as Figure 1 As shown, the island phase 2 is distributed in the sea phase 1, and the coupling agent is distributed in the sea phase 1; wherein, the melting temperature of the island component spinning is 240°C, the melting temperature of the sea component spinning is 270°C, and the spinning speed is 700 m / min;

[0050] (4) treating the as-spun fiber at 45°C for 40 min in a water bath, and then performing hot stretching at a temperature of 70°C, a speed of 30 m / min, and a stretching multiple of 3;

[0051] (5) Splitting the spun fibers after heat drawing to obtain colored nylon ultrafine fibers; during the fiber spreading process, hot toluene is used to dissolve the LDPE in the fibers.

[0052] The final colored nylon ultrafine fiber has a fineness of 0.09 dtex, a breaking strength of 8 cN / dtex, an elongation at break of 18%, and a color saturation of 4.2%.

[0053] Comparative Example 1

[0054] A method for spinning colored nylon ultrafine fibers is basically the same as that of Example 1, except that the number of toners in the island component of step (2) is 8 parts.

[0055] Too much color powder added will cause the spun fibers to be very brittle and unable to undergo subsequent hot drawing.

[0056] By comparing Example 1 with Comparative Example 1, it can be seen that when too much color powder is added in Comparative Example 1, the nascent fibers prepared during the spinning process will be very brittle and unable to undergo subsequent hot drawing, which is not conducive to fiber spinning. This is because the color powder is usually incompatible with the PA6 matrix. If too much color powder is added, the prepared fibers will be easily broken.

[0057] Comparative Example 2

[0058] A method for spinning colored nylon ultrafine fibers is basically the same as that in Example 1, except that in step (2), no coupling agent is added to the sea phase, but an equal amount of coupling agent is added to the island phase.

[0059] The final colored nylon ultrafine fiber has a fineness of 0.09 dtex, a breaking strength of 8.2 cN / dtex, an elongation at break of 19%, and a color saturation of 2.0%.

[0060] Comparing Example 1 and Comparative Example 2, it can be seen that in Comparative Example 2, no coupling agent is added to the sea phase, which leads to a significant decrease in the color saturation of the fiber. This is because the toner has a weak diffusion ability and is incompatible with the PA6 matrix. The coupling agent can achieve good interfacial bonding between the inorganic filler and the organic polymer with significantly different surface properties, thereby improving the affinity between the two phases. If the coupling agent is not added, the color saturation of the produced fiber is greatly reduced.

[0061] Example 2

[0062] A method for spinning colored nylon ultrafine fibers comprises the following steps:

[0063] (1) Preparation of raw materials:

[0064] PA6: Manufacturer: Jiangsu Huafeng Microfiber Material Co., Ltd., brand: HF1024, relative viscosity: 2.4;

[0065] LDPE: The manufacturer is Asia Polymers Co., Ltd., the brand is M2100, and the MI of LDPE is 26g / 10min;

[0066] Toner: Manufacturer: Hunan Kelai New Materials Co., Ltd., brand: PBK26;

[0067] Coupling agent: The manufacturer is Hangzhou Jessica Chemical Co., Ltd., the brand is KH-550 aminosilane;

[0068] (2) Configure island components and sea components;

[0069] By weight, the island component consists of 100 parts of PA6 and 0.1 parts of toner;

[0070] In parts by weight, the sea component consists of 100 parts of LDPE and 0.2 parts of coupling agent;

[0071] (3) The island component and the sea component are composite-spun at a mass ratio of 40:60 to obtain spun fibers; wherein the melt temperature of the island component spinning is 180°C, the melt temperature of the sea component spinning is 240°C, and the spinning speed is 200 m / min;

[0072] (4) treating the as-spun fiber at 40°C for 30 min in a water bath, and then performing hot stretching at a temperature of 60°C, a speed of 5 m / min, and a stretching ratio of 4.5 times;

[0073] (5) Splitting the spun fibers after heat drawing to obtain colored nylon ultrafine fibers; during the fiber spreading process, hot toluene is used to dissolve the LDPE in the fibers.

[0074] The final colored nylon ultrafine fiber has a fineness of 0.05 dtex, a breaking strength of 10.1 cN / dtex, an elongation at break of 10%, and a color saturation of 0.8%.

[0075] Comparative Example 3

[0076] A method for spinning colored nylon ultrafine fibers is basically the same as that in Example 2, except that the treatment temperature of the spun fibers in step (4) is 30° C. by water bath heating.

[0077] The final colored nylon ultrafine fiber has a fineness of 0.05 dtex, a breaking strength of 12.2 cN / dtex, an elongation at break of 14%, and a color saturation of 0.4%.

[0078] By comparing Example 2 and Comparative Example 3, it can be seen that the heat treatment temperature in Comparative Example 3 is too low, which will lead to insufficient reaction between the coupling agent and the island component nylon at the boundary, and in the subsequent hot stretching process, the color powder diffuses into the sea phase in large quantities. When the fibers are opened, the color powder is extracted by the solvent together with the sea phase polymer, so that the color saturation of the final ultrafine fiber is significantly worse than that of Example 2.

[0079] Comparative Example 4

[0080] A method for spinning colored nylon ultrafine fibers is basically the same as that of Example 2, except that the treatment temperature of the spun fibers in step (4) is 60° C. by water bath heating.

[0081] The final colored nylon ultrafine fiber has a fineness of 0.05 dtex, a breaking strength of 11.7 cN / dtex, an elongation at break of 13%, and a color saturation of 0.5%.

[0082] Comparing Example 1 and Comparative Example 4, it can be seen that the heat treatment temperature in Comparative Example 4 is too high, resulting in a decrease in color saturation. This is because if the heat treatment temperature significantly exceeds the glass transition temperature of PA6 and reaches a high elastic state, although it can accelerate the continuous diffusion of the coupling agent in the sea phase to the shallow surface layer of the island phase, it will also cause the color powder to overflow to the interface prematurely, causing the color powder to diffuse into the sea phase, resulting in a smaller color powder content in the island phase and a significant decrease in color saturation.

[0083] Comparative Example 5

[0084] A method for spinning colored nylon ultrafine fibers is basically the same as that in Example 2, except that the spun fibers are treated with water bath heating for 20 minutes in step (4).

[0085] The final colored nylon ultrafine fiber has a fineness of 0.05 dtex, a breaking strength of 11.8 cN / dtex, an elongation at break of 13%, and a color saturation of 0.4%.

[0086] Comparing Example 2 and Comparative Example 5, it can be seen that the heat treatment time in Comparative Example 5 is too short, resulting in a decrease in color saturation. This is because the heat treatment temperature is low, and it takes a long time for the coupling agent to fully react with the PA6 in the shallow surface layer of the island phase. If the reaction time is insufficient, it is easy to cause significant diffusion of color powder into the sea phase during the subsequent hot stretching process, resulting in a smaller color powder content in the island phase and a significant decrease in color saturation.

[0087] Comparative Example 6

[0088] A method for spinning colored nylon ultrafine fibers is basically the same as that in Example 2, except that the temperature during the heat drawing of the spun fibers in step (4) is 55°C.

[0089] The final colored nylon ultrafine fiber has a fineness of 0.05 dtex, a breaking strength of 10.5 cN / dtex, an elongation at break of 12%, and a color saturation of 0.6%.

[0090] By comparing Example 2 and Comparative Example 6, it can be seen that the temperature during the hot drawing of the spun fiber in Comparative Example 6 is too low, which will lead to a decrease in color saturation. This is because if the temperature is too low, the mobility of the PA6 molecular chain and the color powder will be hindered. If the color powder diffuses slowly, the color powder will not be able to fully adjust its distribution during the hot drawing stage and will be frozen again after the hot drawing, resulting in poor color rendering of the obtained ultrafine fiber.

[0091] Comparative Example 7

[0092] A spinning method for colored nylon ultrafine fibers is basically the same as that in Example 2, except that the temperature during hot stretching of the spun fibers in step (4) is 90° C., which is too high to allow subsequent processing.

[0093] Comparing Example 2 with Comparative Example 7, it can be seen that the temperature during hot stretching of the spun fibers in Comparative Example 7 is too high, which makes it impossible to process. This is because the sea phase of the spun fibers easily sticks to the roller at this temperature, making subsequent processing impossible.

[0094] Comparative Example 8

[0095] A spinning method for colored nylon ultrafine fibers is basically the same as that in Example 2, except that the thermal stretching ratio of the spun fibers in step (4) is 1.

[0096] The colored nylon microfibers finally obtained were not fully drawn and crystallized, and the strength of a single microfiber was too low to measure the fineness, breaking strength and breaking elongation data. The color saturation was 0.6%.

[0097] By comparing Example 2 and Comparative Example 8, it can be seen that the thermal stretching multiple of the spun fibers in Comparative Example 8 is too low, which will lead to too low strength of the colored nylon microfibers and decreased color saturation. This is because the displacement of the fiber molecular chains during thermal stretching is too small, which is not conducive to the diffusion movement of the color powder particles between the molecular chains, resulting in insufficient diffusion of the color powder to the surface and poor color saturation.

[0098] Comparative Example 9

[0099] A spinning method for colored nylon ultrafine fibers is basically the same as that in Example 2, except that the thermal stretching ratio of the spun fibers in step (4) is 5 times.

[0100] If the drafting ratio of the spun fiber during hot drawing is too large, the spun fiber will be too thin and have many broken fibers, and the colored nylon ultrafine fiber cannot be finally produced.

[0101] Example 3

[0102] A method for spinning colored nylon ultrafine fibers comprises the following steps:

[0103] (1) Preparation of raw materials:

[0104] PA6: Manufacturer: Guangdong Xinhui Meida Nylon Co., Ltd., brand: M32800, relative viscosity: 2.8;

[0105] LDPE: The manufacturer is Beijing Yanshan Branch of Sinopec, brand 1I50, and the measured MI of LDPE is 51g / 10min;

[0106] Toner: Manufacturer: Hunan Kelai New Materials Co., Ltd., brand: PBK26;

[0107] Coupling agent: The manufacturer is Hangzhou Jessica Chemical Co., Ltd., the brand is KH-550 aminosilane;

[0108] (2) Configure island components and sea components;

[0109] By weight, the island component consists of 100 parts PA6 and 2.5 parts toner;

[0110] In parts by weight, the sea component consists of 100 parts of LDPE and 0.4 parts of coupling agent;

[0111] (3) The island component and the sea component with a mass ratio of 60:40 were composite-spun to obtain spun fibers; wherein the island component spinning melt temperature was 240°C, the sea component spinning melt temperature was 270°C, and the spinning speed was 700 m / min;

[0112] (4) treating the as-spun fiber at 45°C for 50 min in a water bath, and then performing hot stretching at a temperature of 70°C, a speed of 30 m / min, and a stretching multiple of 3;

[0113] (5) Splitting the spun fibers after heat drawing to obtain colored nylon ultrafine fibers; during the fiber spreading process, hot toluene is used to dissolve the LDPE in the fibers.

[0114] The final colored nylon ultrafine fiber has a fineness of 0.11 dtex, a breaking strength of 7.5 cN / dtex, a breaking elongation of 20%, and a color saturation of 6.1%.

[0115] Example 4

[0116] A method for spinning colored nylon ultrafine fibers comprises the following steps:

[0117] (1) Preparation of raw materials:

[0118] PA6: Manufacturer: Guangdong Xinhui Meida Nylon Co., Ltd., brand: M32800, relative viscosity: 2.8;

[0119] LDPE: The manufacturer is Beijing Yanshan Branch of Sinopec, brand 1I50, and the measured MI of LDPE is 51g / 10min;

[0120] Toner: Manufacturer: Shanghai Jingyan Chemical Co., Ltd., brand: S501;

[0121] Coupling agent: The manufacturer is Hangzhou Jessica Chemical Co., Ltd., the brand is KH-560 epoxy silane;

[0122] (2) Configure island components and sea components;

[0123] By weight, the island component consists of 100 parts PA6 and 2.5 parts toner;

[0124] In parts by weight, the sea component consists of 100 parts of LDPE and 0.4 parts of coupling agent;

[0125] (3) The island component and the sea component are composite-spun in a mass ratio of 70:30 to obtain spun fibers; wherein the island component spinning melt temperature is 240°C, the sea component spinning melt temperature is 270°C, and the spinning speed is 700 m / min;

[0126] (4) treating the as-spun fiber at 45°C for 60 min in a water bath, and then performing hot stretching at a temperature of 70°C, a speed of 30 m / min, and a stretching multiple of 2;

[0127] (5) Splitting the spun fibers after heat drawing to obtain colored nylon ultrafine fibers; during the fiber spreading process, hot toluene is used to dissolve the LDPE in the fibers.

[0128] The final colored nylon ultrafine fiber has a fineness of 0.2 dtex, a breaking strength of 5.2 cN / dtex, a breaking elongation of 25%, and a color saturation of 6.8%.

[0129] Example 5

[0130] A method for spinning colored nylon ultrafine fibers comprises the following steps:

[0131] (1) Preparation of raw materials:

[0132] PA6: Manufacturer: Guangdong Xinhui Meida Nylon Co., Ltd., brand: M3400, relative viscosity: 3.2;

[0133] LDPE: The manufacturer is Beijing Yanshan Branch of Sinopec, brand 1I60, and the measured MI of LDPE is 60g / 10min;

[0134] Toner: Manufacturer: Shanghai Jingyan Chemical Co., Ltd., brand number 75363;

[0135] Coupling agent: The manufacturer is Hangzhou Jessica Chemical Co., Ltd., the brand is KH-560 epoxy silane;

[0136] (2) Configure island components and sea components;

[0137] By weight, the island component consists of 100 parts PA6 and 5 parts toner;

[0138] In parts by weight, the sea component consists of 100 parts of LDPE and 0.5 parts of coupling agent;

[0139] (3) The island component and the sea component with a mass ratio of 80:20 were composite-spun to obtain spun fibers; wherein the melt temperature of the island component spinning was 250°C, the melt temperature of the sea component spinning was 285°C, and the spinning speed was 1200 m / min;

[0140] (4) treating the as-spun fiber at 50°C for 70 min in a water bath, and then performing hot stretching at a temperature of 80°C, a speed of 50 m / min, and a stretching ratio of 1.5 times;

[0141] (5) Splitting the spun fibers after heat drawing to obtain colored nylon ultrafine fibers; during the fiber spreading process, hot toluene is used to dissolve the LDPE in the fibers.

[0142] The final colored nylon ultrafine fiber has a fineness of 0.3 dtex, a breaking strength of 2.5 cN / dtex, a breaking elongation of 45%, and a color saturation of 8.2%.

Claims

1. A method for spinning colored nylon ultrafine fibers, characterized in that: After the island component and the sea component are composite-spun to obtain spun fibers, the spun fibers are sequentially heat-treated, heat-drawn and opened to obtain colored nylon microfibers. By weight, the island component consists of 100 parts of PA6 and 0.1-5.0 parts of color powder; The sea component is composed of 100 parts of LDPE and 0.2-0.5 parts of a coupling agent by weight; the coupling agent contains both a group X that is affinity for the color powder and a group Y that is affinity for PA6; the group X is a siloxane group, and the group Y is an epoxy group or an amino group; The mass ratio of island component to sea component is 40:60-80:20; The temperature of heat treatment is 40-50°C, and the time is not less than 30 minutes; the temperature of hot stretching is 60-80°C, and the multiple is 1.5-4.5 times.

2. The method for spinning colored nylon ultrafine fibers according to claim 1, characterized in that: The relative viscosity of PA6 is 2.4-3.2, and the MI of LDPE is 26-60g / 10min.

3. The method for spinning colored nylon ultrafine fibers according to claim 1, characterized in that: During composite spinning, the melting temperature of the island component is 180-250°C, the melting temperature of the sea component is 240-285°C, and the spinning speed is 200-1200 m / min.

4. The method for spinning colored nylon ultrafine fibers according to claim 1, characterized in that: The heat treatment is carried out by water bath heating.

5. The method for spinning colored nylon ultrafine fibers according to claim 1, characterized in that: The speed of hot drawing is 5-50m / min.

6. The method for spinning colored nylon ultrafine fibers according to claim 1, characterized in that: When opening the fibers, hot toluene is used to dissolve the LDPE in the fibers.

7. A method for spinning colored nylon ultrafine fibers according to any one of claims 1 to 6, characterized in that: The colored nylon microfiber has a fineness of 0.05-0.3 dtex, a breaking strength of 2.5-10.1 cN / dtex, an elongation at break of 10-45%, and a color saturation of 0.8%-8.2%.

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