Split-type composite fiber

Abstract

The present invention provides a split-type composite fiber that has a low initial fiber opening rate, can be effectively opened by physical treatment such as hot water without the use of chemicals, and is bulky and flexible after opening. [Solution] The present invention relates to a segmented composite fiber comprising polymer A and polymer B, wherein in the fiber cross-section, polymer A is continuously distributed, polymer B is divided into large segments and small segments, and all segments are exposed on the fiber surface, and in the cross-section of a single fiber there are 1 to 3 maximum segments of the same area and 2 or more small segments smaller than the maximum segments, the area of ​​one maximum segment accounts for 7.5 to 70.0% of the area of ​​the fiber cross-section, and the area of ​​one maximum segment is more than twice the area of ​​one small segment.

Description

[Technical Field]

[0001] The present invention relates to a segmented composite fiber, and more specifically, to a segmented composite fiber comprising polymer A and polymer B, wherein polymer B is divided into large segments and small segments, resulting in a low initial fiber opening rate and a high fiber opening rate after boiling water treatment. [Background technology]

[0002] Synthetic fibers, such as polyester and polyamide, possess excellent flexibility, elastic recovery, abrasion resistance, and alkali resistance, making them important in various fields such as clothing, home furnishings, vehicle interiors, and industrial materials. In recent years, differentiated fibers with different functions have been introduced to the market. Amidst this trend, the development of synthetic split fibers and raw cotton suitable for cotton and industrial applications is progressing.

[0003] Currently, techniques are being widely investigated for obtaining bulky and flexible fibers by physically or chemically opening split-type composite fibers, which consist of two types of polymers and have cross-sections such as parallel, radial, and hollow annular. Patent Document 1 discloses split-type composite long fibers and nonwoven fabrics made of split-type composite long fibers. Split-type composite long fibers, which use a propylene-based polymer with a melt flow rate (MFR) of 40 g / 10 min or more at a load of 2160 g and 230 °C and high-pressure low-density polyethylene, and in which the propylene-based polymer portion and the high-pressure low-density polyethylene portion are in contact with each other, can be opened by high-pressure water flow to improve their splitting properties. However, the condition of high-pressure water flow is relatively harsh, and the cost of opening the fibers increases. Patent Document 2 discloses split-type composite fibers consisting of a polyamide composition and a fiber-forming polymer that has no affinity for the polyamide composition, which exhibit good splitting performance when treated with low-concentration benzyl alcohol or a non-swelling treatment agent. However, because it utilizes the high shrinkage properties of polyamides whose main constituent units are aliphatic dicarboxylic acids and aromatic diamines, it has high requirements for polymer performance and cannot be applied to the splitting process of split fibers made of ordinary polymers. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Taiwan patent TW200825225A [Patent Document 2] China patent CN101646813A [Overview of the project] [Problems that the invention aims to solve]

[0005] The object of the present invention is to provide a split-type composite fiber that has a low initial fiber opening rate, can be effectively opened after physical treatment such as hot water without the use of chemicals, and is bulky and flexible after opening. [Means for solving the problem]

[0006] The technical solution of the present invention is as follows.

[0007] The segmented composite fiber of the present invention comprises polymer A and polymer B, wherein in the fiber cross-section, polymer A is continuously distributed, polymer B is divided into large segments and small segments, and all segments are exposed on the fiber surface. In the cross-section of a single fiber, there are 1 to 3 maximum segments of the same area and 2 or more small segments smaller than the maximum segments, the area of ​​one maximum segment accounts for 7.5 to 70.0% of the area of ​​the fiber cross-section, and the area of ​​one maximum segment is at least twice the area of ​​one small segment.

[0008] The circumference of one largest segment is L1, the contact length between the largest segment and polymer A is L2, and it is preferable that L2 / L1 is 45-80%.

[0009] It is preferable that the angle formed by the tectonic line at the intersection of the largest segment and the outer circumference of the fiber cross-section is 90° or more.

[0010] After treating the composite fibers with boiling water, it is preferable that the shrinkage rate of polymer A is greater than that of polymer B, and that the difference is 5% or more.

[0011] The difference in solubility parameters between polymer A and polymer B is 1.0 to 10.8 J. 1 / 2 / cm 3 / 2 It is preferable that this be the case.

[0012] It is preferable that polymer A and polymer B are polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polypropylene, polyamide-4, polyamide-6, polyamide-56, polyamide-66, polyamide-510, or polyamide-610, respectively.

[0013] It is preferable that the area ratio of polymer A to polymer B in the cross-section of the composite fiber is 70:30 to 30:70.

[0014] Preferably, the composite fiber has an initial fiber opening rate of 5% or less, and a fiber opening rate of 90% or more after boiling water treatment.

[0015] The composite fiber is preferably a short fiber with an initial fiber opening rate of 5% or less.

[0016] It is preferable that the water absorption rate of polymer A is 1.5% or less. [Effects of the Invention]

[0017] This invention improves fiber opening performance by preferentially opening the largest segment through the cross-sectional design of the segmented composite fiber, creating a movable space that is advantageous for opening smaller segments. At the same time, as a preferred technical solution, controlling the ratio of contact length to circumference and the contact angle within the fiber of the largest segment avoids the appearance of an "anchor effect" in the largest segment, further favoring fiber opening. Furthermore, by controlling the difference in polymer solubility parameters and the water absorption rate of polymer A, it is possible to achieve an initial fiber opening rate of 5% or less and a fiber opening rate of 90% or more after boiling water treatment, whether it is segmented composite long fiber or short fiber. [Brief explanation of the drawing]

[0018] [Figure 1] Figure 1 is a cross-sectional view of the segmented composite fiber of the present invention. [Figure 2] Figure 2 is a cross-sectional view of the segmented composite fiber of the present invention. [Figure 3] Figure 3 is a cross-sectional view of the segmented composite fiber of the present invention. [Figure 4] Figure 4 shows cross-sectional views of the segmented composite fibers of Examples 01-06, 14 and 18 of the present invention. [Figure 5] Figure 5 is a cross-sectional view of the segmented composite fiber according to Example 07 of the present invention. [Figure 6] Figure 6 is a cross-sectional view of a segmented composite fiber according to Example 08 of the present invention. [Figure 7] Figure 7 is a cross-sectional view of a segmented composite fiber according to Example 09 of the present invention. [Figure 8] Figure 8 is a cross-sectional view of a segmented composite fiber according to Example 10 of the present invention. [Figure 9] Figure 9 is a cross-sectional view of a segmented composite fiber according to Embodiment 11 of the present invention. [Figure 10] Figure 10 is a cross-sectional view of a segmented composite fiber according to Example 12 of the present invention. [Figure 11] Figure 11 is a cross-sectional view of a segmented composite fiber according to Embodiment 13 of the present invention. [Figure 12] Figure 12 is a cross-sectional view of a segmented composite fiber according to Example 15 of the present invention. [Figure 13] Figure 13 is a cross-sectional view of a segmented composite fiber according to Example 16 of the present invention. [Figure 14] Figure 14 is a cross-sectional view of the segmented composite fiber of Embodiment 17 of the present invention. [Figure 15] Figure 15 is a cross-sectional view of a segmented composite fiber according to Example 19 of the present invention. [Figure 16] Figure 16 is a cross-sectional view of a segmented composite fiber according to Example 20 of the present invention. [Figure 17] Figure 17 is a cross-sectional view of the segmented composite fiber of Comparative Example 01 of the present invention. [Figure 18] Figure 18 is a cross-sectional view of the segmented composite fiber of Comparative Example 02 of the present invention. [Figure 19] Figure 19 is a cross-sectional view of the segmented composite fiber of Comparative Example 03 of the present invention. [Figure 20] Figure 20 is a cross-sectional view of the segmented composite fiber of Comparative Example 04 of the present invention.

[0019] In Figures 1 to 3, S represents the area of ​​the fiber cross-section, S1 represents the area of ​​the largest segment in the fiber cross-section, S2 represents the area of ​​a small segment in the fiber cross-section, L1 represents the circumference of the largest segment, and L2 represents the contact length between the largest segment and polymer A. [Modes for carrying out the invention]

[0020] The segmented composite fiber of the present invention has two types of polymers in its cross-section, polymer A and polymer B, with polymer A being continuously distributed and polymer B being divided into large and small segments, all of which are exposed on the fiber surface.

[0021] In the melt spinning process of split-type composite fibers, segments made of polymer B are positioned on the outside of the fiber, preferentially cooled after being spun from the spinneret, and polymer B is more likely to orient under constant spinning speed stretching. This results in a high boiling water shrinkage rate, making it difficult to create a shrinkage difference with polymer A, which is unfavorable for opening the split-type composite fiber. Therefore, in this invention, polymer B is divided into 1 to 3 largest segments of equal area and 2 or more segments smaller than the largest segments. This makes it more difficult for the largest segments to orient than the smaller segments during the melt spinning process, creating a shrinkage difference between the largest segments and polymer A, and facilitating separation. When the split-type composite fiber is treated with boiling water, the largest segments act as the starting point for separation and peel off quickly, creating a large movable space for polymer A, and making it easier for the smaller segments to detach.

[0022] In the cross-section of the divided composite fiber, there are 1 to 3 maximum segments of equal area, and the area of ​​one maximum segment accounts for 7.5 to 70.0% of the fiber's cross-sectional area. If there are more than 3 maximum segments, the proportion of the fiber's cross-sectional area is too large, resulting in high fineness of the fibers made up of the maximum segments after fiber opening, which is detrimental to providing a bulky and flexible texture. Although fiber opening is promoted, the initial fiber opening rate is too high, affecting the passability of the fiber in post-processing. If the area of ​​one maximum segment is less than 7.5% of the fiber's cross-sectional area, it is detrimental to fiber opening. If the area of ​​one maximum segment exceeds 70.0% of the fiber's cross-sectional area, the single-fiber fineness of the fibers made up of the maximum segments after fiber opening is too high, which is detrimental to providing a bulky and flexible texture. To obtain excellent fiber opening performance and bulkiness after boiling water treatment, it is preferable that the area of ​​one maximum segment accounts for 10.0 to 30.0% of the fiber's cross-sectional area.

[0023] In addition to 1 to 3 maximum segments with equal area, the cross-section of the segmented composite fiber contains 2 or more sub-segments smaller than the maximum segments. That is, all segments with an area smaller than the maximum segments are called sub-segments. These sub-segments may be the same size or may be of different sizes.

[0024] In this invention, in order to further clarify the distinction between the largest and smallest segments, create a clear visual recognition of the size between each segment, and ensure a high shrinkage difference between the largest segment and polymer A, thereby providing a bulky and flexible texture, it is preferable that the area of ​​one largest segment is at least twice the area of ​​one smallest segment. The area of ​​the smallest segment is not particularly limited in satisfying this area ratio. The area of ​​one smallest segment may be less than 7.5% or 7.5% or more of the total area of ​​the composite fiber cross-section.

[0025] As is well known, the frictional force between two components and the force applied to the contact surface show a positive correlation, while the frictional force between two components and the contact area show a negative correlation. The smaller the ratio of the contact length L2 between the largest segment and polymer A to the circumference L1 of the largest segment, the smaller the contact area between the largest segment and polymer A becomes, which is advantageous for opening the split-type composite fiber. However, if the L2 / L1 ratio is too small, i.e., the contact area between the largest segment and polymer A is small, the opening of the split-type composite fiber by boiling water treatment is promoted, but the initial opening rate of the composite fiber becomes large, affecting the passability in the manufacturing and processing of textile products. For this reason, the L2 / L1 ratio is preferably 45% to 80%, and more preferably 45% to 70%.

[0026] Furthermore, it is desirable that the angle between the largest segment and the fiber cross-section, that is, the angle formed by the cleavage line at the intersection of the largest segment and the outer circumference of the fiber cross-section, not be too small. Otherwise, during division, the "anchor effect" makes it difficult for the largest segment to detach from the space created by the shrinkage of polymer A, resulting in poor fiber opening of the divided composite fiber. In the present invention, it is preferable that the angle formed by the cleavage line at the intersection of the largest segment and the outer circumference of the fiber cross-section is 90° or more.

[0027] To facilitate the separation of the largest segment from polymer A, it is preferable that the shrinkage rate of polymer A after boiling water treatment is greater than that of polymer B. Based on the principle that polymer A shrinks in the axial direction of the composite fiber due to shrinkage stress after boiling water treatment, and that its mass and volume do not change, polymer A in the cross-section of the composite fiber expands and becomes larger, the opening that accommodates the largest segment enlarges, and a movable space is created in the largest segment, making it easier to open the fibers. In this invention, it is preferable that the shrinkage rate of polymer A after boiling water treatment is greater than that of polymer B, and that the difference is 5% or more, and more preferably 10% or more.

[0028] The fiber-opening effect of the split-type composite fiber is influenced not only by the difference in shrinkage between polymer A and polymer B, but also by the affinity between polymer A and polymer B. If the affinity between polymer A and polymer B is good, fiber-opening of the split-type composite fiber becomes difficult, and the expected fiber-opening effect cannot be achieved. If the affinity is too poor, fluffing is likely to occur during the melt-spinning stage, worsening process passability and making production unfavorable. In this invention, the affinity is expressed using the absolute value of the difference in solubility parameters (SP values) between polymer A and polymer B (hereinafter referred to as the difference in SP values), and the smaller the difference in SP values, the better the affinity. In order to achieve both a good fiber-opening effect and spinning performance in the split-type composite fiber, the difference in SP values ​​between polymer A and polymer B is 1.0 to 10.8 J. 1 / 2 / cm 3 / 2 Preferably, it is 3.0 to 7.0 J 1 / 2 / cm 3 / 2 It is preferable that it be so.

[0029] Polymers A and B are not particularly limited and may be ordinary polymers used in melt spinning, such as polyethylene terephthalate (PET), polypropylene terephthalate (PPT), polybutylene terephthalate (PBT), polypropylene (PP), polyamide-4, polyamide-6, polyamide-56, polyamide-66, polyamide-510, or polyamide-610, or polymers that have been functionally modified from the above polymers, such as by adding particles or modifying their shrinkage performance.

[0030] Assuming all other conditions are met, if the area occupied by polymer B in the cross-section of the split composite fiber is too small, it is disadvantageous for fiber opening, and if the area occupied by polymer B is too large, it is disadvantageous for providing a bulky and flexible texture. For this reason, it is preferable that the area ratio of polymer A to polymer B is 70:30 to 30:70.

[0031] Unless otherwise specified, the split composite fiber may be a long fiber or a short fiber. When it is a long fiber, it is suitably used for flexible clothing and wiping cloths. When it is a short fiber, it is suitably used for nonwoven fabrics, such as face masks with good liquid retention and skin adhesion. Short fibers are preferable from the viewpoint that the initial fiber opening rate is small, ensuring passability through subsequent processing steps, and that the fibers can be sufficiently opened even in boiling water.

[0032] In the case of long fibers, if the specified conditions for the distribution number and area of ​​the largest and smallest segments are met, characteristics such as an initial fiber opening rate of 5% or less can be achieved. However, in the case of short fibers, during the process of turning the filaments into raw cotton, i.e., cutting them into short fibers, the initial fiber opening rate is negatively affected by moisture absorption swelling during stretching in a hot water bath, resulting in a higher initial fiber opening rate than that of long fibers of the same composition and structure. The inventors investigated the cause of the high initial fiber opening rate of short fibers, which is due to the creation of a movable space by the water absorption swelling of polymer A during the cutting process, making it easier for the largest segment to separate from the main structure. They then achieved their objective of lowering the initial fiber opening rate of short fibers by using polymer A with a low water absorption rate to avoid water absorption swelling of polymer A during the cutting process. From the viewpoint of obtaining a segmented composite short fiber with a low initial fiber opening rate, it is preferable that the water absorption rate of polymer A is 1.5% or less.

[0033] Using polymer A having a water absorption rate within a preferred range, the desired fiber opening rate can be obtained later by a physical or chemical fiber opening treatment method, and in particular, the fiber opening rate after boiling water treatment can reach 90% or more. The segmented composite fiber of the present invention utilizes a combination of maximum and minimum segments through precise cross-sectional design, limits the size relationship between the maximum and minimum segments, has an initial fiber opening rate of 5% or less, is easily segmented after boiling water treatment, has a fiber opening rate of 90% or more, and is suitable for use in various bulky and flexible fiber structures. [Examples]

[0034] The measurement method according to the present invention will be described below.

[0035] (1) Area of ​​the fiber cross-section (S), area of ​​the largest segment (S1), area of ​​the smallest segment (S2) After wrapping the segmented composite fiber in black or white combed cotton strips, it is passed through small holes in a copper plate, and the fiber is cut using a blade to obtain a fiber cross-section. The fiber cross-section is observed and photographed using a "Keyence VHX-6000" ultra-high-depth 3D microscope, and the area of ​​the fiber cross-section (S), the area of ​​the largest segment (S1), and the area of ​​the smallest segment (S2) are measured using a microscope measurement tool. This is repeated 10 times, and the average value is taken as the final result.

[0036] (2) Circumference L1 and contact length L2 of the largest segment After wrapping the segmented composite fiber with black or white combed cotton strips, it is passed through small holes in a copper plate, and the fiber is cut using a blade to obtain a fiber cross-section. The fiber cross-section is observed and photographed using a "Keyence VHX-6000" ultra-high-depth 3D microscope, and the circumference L1 of the largest segment and the contact length L2 between the largest segment and polymer A are measured using a microscope measurement tool. This is repeated 10 times, and the average value is taken as the final result.

[0037] (3) An angle formed by the cleavage line at the intersection of the largest segment and the outer periphery of the fiber cross-section. After wrapping the segmented composite fiber in black or white combed cotton strips, it is passed through small holes in a copper plate, and the fiber is cut using a blade to obtain a fiber cross-section. The fiber cross-section is observed and photographed using a "Keyence VHX-6000" ultra-deep-field 3D microscope, and the angle formed by the tectonic line at the intersection of the largest segment and the outer circumference of the fiber cross-section is measured using a microscope measurement tool. This is repeated 10 times, and the average value is taken as the final result.

[0038] (4) Difference in shrinkage rate after boiling water treatment A 20cm (L0) section of split composite fiber is cut and scouring is performed at 40°C (2g / L scouring agent + 0.6% NaOH aqueous solution) to remove oils and slurries from the fiber surface. Next, the fiber is opened in a 98°C water bath for 20 minutes, then removed and air-dried at 20°C × 65% RH for 4 hours. After that, polymer B and polymer A are separated with tweezers, and the lengths L3 of polymer B and L4 of polymer A are measured. The difference in shrinkage rates between polymer A and polymer B after boiling water treatment is calculated as [(L3-L4) / L0] × 100%. This is done for 10 fibers, and the average value is taken as the final result.

[0039] (5) Solubility parameter (SP value) The SP value δp of a polymer is measured by turbidity titration. The specific procedure is as follows:

[0040] A. After the split composite fibers are opened, polymer A and polymer B are separated using tweezers.

[0041] B. Dissolve 0.5 g of polymer A in 100 ml of solvent (see the table below) to prepare a polymer A solution.

[0042] C. Transfer 10 ml of polymer A solution to a test tube using a pipette, and titrate with n-pentane until a precipitate appears in the solution. Shake the test tube to dissolve the precipitate. Continue titrating with n-pentane until the precipitate does not dissolve even after shaking; this is considered the endpoint. Let V1 be the volume of n-pentane used.

[0043] D. Titrate the polymer A solution obtained in step C with methanol. As the titration progresses, the original precipitate gradually disappears and a new precipitate appears. Shake the test tube to dissolve the precipitate. Continue titrating with methanol until the precipitate does not dissolve even with shaking. Let V2 be the volume of methanol used.

[0044] E. The solubility parameter of polymer A is calculated using the following formula.

[0045] Lower limit of polymer A solubility parameter δml = [V1 / (V1+V2)] × 14.3 The upper limit of the polymer A solubility parameter is δmh = [V1 / (V1+V2)] × 30.2 Solubility parameter of polymer A: δp = δmh + δml In steps C and D above, the amount of titration from the titration tube should be 0.5 ml per drop.

[0046] Steps B to E are repeated using 0.5g of polymer B to determine the solubility parameter of polymer B.

[0047] Ten samples each of polymer A and polymer B were taken and measured, and the average value was used as the final result.

[0048] [Table 1]

[0049] (6) Initial fiber opening rate and fiber opening rate after boiling water treatment The split composite fibers are cut using a blade to obtain fiber cross-sections, which are then bonded to a conductive adhesive and subjected to metal plating. The fiber cross-sections are observed using a Hitachi TM3030plus scanning electron microscope (SEM), and the initial fiber opening rate is calculated using the following formula. Twenty samples are measured for each, and the average value is taken as the initial fiber opening rate.

[0050] The split composite fibers are scouring-treated at 40°C (2g / L scouring agent + 0.6% NaOH aqueous solution) to remove oils, slurries, etc. from the fiber surface. Next, they are boiled in a 98°C water bath for 20 minutes to open the fibers, then removed and air-dried at 20°C × 65% RH for 4 hours. The dried fibers are cut using a blade to obtain fiber cross-sections, which are then attached to a conductive adhesive and subjected to metal plating. The fiber cross-sections are observed using a Hitachi TM3030plus scanning electron microscope (SEM), and the fiber opening rate is calculated using the following formula. Twenty samples are measured for each, and the average value is taken as the fiber opening rate. Fiber opening rate (%) = (Number of observed segments / Total theoretical number of segments) × 100% In the above equation, the observed number of segments represents the number of segments that have been completely detached from polymer A, while the theoretical total number of segments represents the total number of segments.

[0051] (7) Water absorption rate After opening the split composite fibers using the method described above, 0.5 g of polymer A is removed with tweezers, dried in a vacuum oven at 105°C for 8 hours, and then conditioned at 20°C × 65% RH for 24 hours. Next, the saturated water content of the polymer is measured using a differential pressure moisture meter, and this saturated water content is defined as the water absorption rate. Ten samples are measured, and the average value is taken as the final result.

[0052] (8) Bulky Using a split composite fiber, circular knitting is performed, and the resulting circular knit is scouring-treated at 40°C (2g / L scouring agent + 0.6% NaOH aqueous solution) to remove surface oils and slurries. Next, the fibers are opened by boiling in a 98°C water bath for 20 minutes, then removed and air-dried at 20°C × 65% RH for 4 hours. The bulkiness of the circular knit is then evaluated using the KES FB3 method. A higher compression energy (WC) value indicates greater compressibility and improved bulkiness of the circular knit.

[0053] The advantages of the present invention will be explained in detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0054] Example 01 Polymer A (PBT, intrinsic viscosity 1.10 dL / g, water absorption rate 0.4%, SP value 20.5 J 1 / 2 / cm 3 / 2 ) and Polymer B (hydrophobically modified PET (2% blend of polypropylene), SP value 19.7 J 1 / 2 / cm 3 / 2 ) were extruded from the nozzles of a composite spinneret having a split cross-section of 1 large segment and 16 small segments by the melt spinning method, and FDY long fibers were produced by the FDY process. Parameters in the FDY process: spinning temperature 278 °C, temperature of the spinning block corresponding to PET 278 °C, temperature of the spinning block corresponding to PBT 260 °C, cooling temperature 20 °C, cooling air velocity 0.8 m / s, speed of the first roller 1200 m / min, temperature of the first roller 80 °C, speed of the second roller 2250 m / min, temperature of the second roller 160 °C.

[0055] The obtained split-type composite long fibers (56T - 18 - FDY) had, in the cross-section, S1 / S of 11%, S1 / S2 of 9.1, L2 / L1 of 62%, the angle formed by the tangent at the intersection of the largest segment and the outer periphery of the fiber cross-section was 90°, the initial fiber opening rate of the long fibers was 1%, after heat treatment in a 98 °C water bath for 20 min and natural drying at 20 °C × 65% RH for 4 h, the fiber opening rate was 76%, the difference in boiling water shrinkage rate between Polymer A and Polymer B was 11%, and the compression energy of the circular knitted fabric after fiber opening was 0.383 gf·cm / cm 2 (0.383×0.98×10 -2 N·cm / cm 2 ). The initial fiber opening rate of the short fibers obtained from the split-type composite long fibers was 2%.

[0056] Example 02 Polymer A (PBT, intrinsic viscosity 1.10 dL / g, water absorption rate 0.4%, SP value 20.5 J 1 / 2 / cm 3 / 2 ) and Polymer B (hydrophobically modified PET (5% blend of polypropylene), SP value 19.5 J 1 / 2 / cm 3 / 2FDY long fibers were produced by melt spinning using a composite die nozzle having a divided cross-section of one large segment and 16 small segments, and extruding the material from the die through a melt spinning process. Parameters in the FDY process: spinning temperature 278°C, spinning block temperature for PET 278°C, spinning block temperature for PBT 260°C, cooling temperature 20°C, cooling air velocity 0.8 m / s, first roller speed 1200 m / min, first roller temperature 80°C, second roller speed 2250 m / min, second roller temperature 160°C.

[0057] The obtained segmented composite filament (56T-18-FDY) had the following characteristics in its cross-section: S1 / S ratio of 11%, S1 / S2 ratio of 9.1%, L2 / L1 ratio of 62%, an angle of 90° between the cleavage line at the intersection of the largest segment and the outer circumference of the fiber cross-section, an initial fiber opening rate of 1%, a fiber opening rate of 90% after heat treatment in a 98°C water bath for 20 mins and natural drying at 20°C × 65%RH for 4 hours, a difference of 11% in boiling water shrinkage rates between polymer A and polymer B, and a compressive energy of 0.433 gf·cm / cm² for the circular knitted fabric after fiber opening. 2 (0.433 × 0.98 × 10 -2 N·cm / cm 2 The initial fiber opening rate of the short fibers obtained from the aforementioned split-type composite long fibers was 2%.

[0058] Example 03 Polymer A (PBT) with a volume ratio of 70:30, intrinsic viscosity 1.10 dL / g, water absorption rate 0.4%, SP value 20.5 J 1 / 2 / cm 3 / 2 ) and polymer B (PP, MFR=60g / 10min, SP value 16.8J) 1 / 2 / cm 3 / 2 FDY long fibers were produced by melt spinning using a composite die nozzle having a divided cross-section of one large segment and 16 small segments, and extruding the material from the die through a FDY process. Parameters in the FDY process: spinning temperature 260°C, spinning block temperature for PP 250°C, spinning block temperature for PBT 260°C, cooling temperature 20°C, cooling air velocity 0.8 m / s, first roller speed 1200 m / min, first roller temperature 70°C, second roller speed 2250 m / min, second roller temperature 160°C.

[0059] The obtained segmented composite filament (56T-18-FDY) had the following characteristics in its cross-section: S1 / S ratio of 11%, S1 / S2 ratio of 9.1%, L2 / L1 ratio of 62%, an angle of 90° between the cleavage line at the intersection of the largest segment and the outer circumference of the fiber cross-section, an initial fiber opening rate of 3%, a fiber opening rate of 93% after heat treatment in a 98°C water bath for 20 minutes and natural drying at 20°C × 65%RH for 4 hours, a difference of 12% in boiling water shrinkage rates between polymer A and polymer B, and a compression energy of 0.485 gf·cm / cm² for the circular knitted fabric after fiber opening. 2 (0.485 × 0.98 × 10 -2 N·cm / cm 2 The initial fiber opening rate of the short fibers obtained from the aforementioned split-type composite long fibers was 4%.

[0060] Example 04 Polymer A(N6) with a volume ratio of 70:30, relative viscosity ηr=2.9, water absorption rate 3.3%, SP value 27.6J 1 / 2 / cm 3 / 2 ) and polymer B (PET, intrinsic viscosity 0.61 dL / g, SP value 21.0 J) 1 / 2 / cm 3 / 2 FDY long fibers were produced by melt spinning using a composite die nozzle having a divided cross-section of one large segment and 16 small segments, and then the FDY process was performed. Parameters in the FDY process: spinning temperature 278°C, spinning block temperature corresponding to N6 275°C, spinning block temperature corresponding to PET 278°C, cooling temperature 20°C, cooling air velocity 0.8 m / s, first roller speed 1200 m / min, first roller temperature 80°C, second roller speed 2450 m / min, second roller temperature 160°C.

[0061] The obtained segmented composite filament (56T-18-FDY) had the following characteristics in its cross-section: S1 / S ratio of 11%, S1 / S2 ratio of 9.1%, L2 / L1 ratio of 62%, an angle of 90° between the largest segment and the tectonic line at the intersection of the outer circumference of the fiber cross-section, an initial fiber opening rate of 3%, a fiber opening rate of 92% after heat treatment in a 98°C water bath for 20 mins and natural drying at 20°C × 65%RH for 4 hours, an 8% difference in boiling water shrinkage rates between polymer A and polymer B, and a compression energy of 0.526 gf·cm / cm² for the circular knitted fabric after fiber opening.2 (0.526 × 0.98 × 10 -2 N·cm / cm 2 The initial fiber opening rate of the short fibers obtained from the aforementioned split-type composite long fibers was 12%.

[0062] Example 05 Polymer A(N6) with a volume ratio of 70:30, relative viscosity ηr=2.9, water absorption rate 3.3%, SP value 27.6J 1 / 2 / cm 3 / 2 ) and polymer B (PP, MFR=60g / 10min, SP value 16.8J) 1 / 2 / cm 3 / 2 FDY long fibers were produced by melt spinning using a composite die nozzle having a divided cross-section of one large segment and 16 small segments, and then the FDY process was performed. Parameters in the FDY process: spinning temperature 275°C, spinning block temperature for PP 250°C, spinning block temperature for N6 275°C, cooling temperature 20°C, cooling air velocity 0.8 m / s, first roller speed 1200 m / min, first roller temperature 70°C, second roller speed 2450 m / min, second roller temperature 160°C.

[0063] The obtained segmented composite filament (56T-18-FDY) had the following characteristics in its cross-section: S1 / S ratio of 11%, S1 / S2 ratio of 9.1%, L2 / L1 ratio of 62%, an angle of 90° between the cleavage line at the intersection of the largest segment and the outer circumference of the fiber cross-section, an initial fiber opening rate of 5%, a fiber opening rate of 98% after heat treatment in a 98°C water bath for 20 mins and natural drying at 20°C × 65%RH for 4 hours, a difference of 11% in boiling water shrinkage rates between polymer A and polymer B, and a compression energy of 0.539 gf·cm / cm² for the circular knitted fabric after fiber opening. 2 (0.539 × 0.98 × 10 -2 N·cm / cm 2 The initial fiber opening rate of the short fibers obtained from the aforementioned split-type composite long fibers was 16%.

[0064] Example 06 Polymer A (N610) with a volume ratio of 70:30, relative viscosity ηr = 2.7, water absorption rate 1.0%, SP value 27.8 J 1 / 2 / cm 3 / 2) and polymer B (PP, MFR=60g / 10min, SP value 16.8J) 1 / 2 / cm 3 / 2 FDY long fibers were produced by melt spinning using a composite die nozzle having a divided cross-section of one large segment and 16 small segments, and then the FDY process was performed. Parameters in the FDY process: spinning temperature 275°C, spinning block temperature for PP 250°C, spinning block temperature for N610 275°C, cooling temperature 20°C, cooling air velocity 0.8 m / s, first roller speed 1200 m / min, first roller temperature 70°C, second roller speed 2450 m / min, second roller temperature 160°C.

[0065] The obtained segmented composite long fiber (56T-18-FDY) had the following characteristics in its cross-section: S1 / S ratio of 11%, S1 / S2 ratio of 9.1%, L2 / L1 ratio of 62%, an angle of 90° between the cleavage line at the intersection of the largest segment and the outer circumference of the fiber cross-section, an initial fiber opening rate of 7%, a fiber opening rate of 98% after heat treatment in a 98°C water bath for 20 mins and natural drying at 20°C × 65%RH for 4 hours, a difference of 11% in boiling water shrinkage rates between polymer A and polymer B, and a compressive energy of 0.527 gf·cm / cm² for the circular knitted fabric after fiber opening. 2 (0.527 × 0.98 × 10 -2 N·cm / cm 2 The initial fiber opening rate of the short fibers obtained from the aforementioned split-type composite long fibers was 11%.

[0066] Example 07 Polymer A(N6) with a volume ratio of 70:30, relative viscosity ηr=2.9, water absorption rate 3.3%, SP value 27.6J 1 / 2 / cm 3 / 2 ) and polymer B (PET, intrinsic viscosity 0.61 dL / g, SP value 21.0 J) 1 / 2 / cm 3 / 2FDY long fibers were produced by melt spinning using a composite die nozzle having a divided cross-section of one large segment and four small segments, and extruding the material from the die through the FDY process. Parameters in the FDY process: spinning temperature 278°C, spinning block temperature corresponding to PET 278°C, spinning block temperature corresponding to N6 275°C, cooling temperature 20°C, cooling air velocity 0.8 m / s, first roller speed 1200 m / min, first roller temperature 80°C, second roller speed 2450 m / min, second roller temperature 160°C.

[0067] The obtained segmented composite long fiber (56T-18-FDY) had the following characteristics in its cross-section: S1 / S ratio of 10%, S1 / S2 ratio of 2.0%, L2 / L1 ratio of 58%, an angle of 105° between the largest segment and the outer circumference of the fiber cross-section, an initial fiber opening rate of 3%, a fiber opening rate of 95% after heat treatment in a 98°C water bath for 20 mins and natural drying at 20°C × 65%RH for 4 hours, a difference of 10% in boiling water shrinkage rates between polymer A and polymer B, and a compressive energy of 0.467 gf·cm / cm² for the circular knitted fabric after fiber opening. 2 (0.467 × 0.98 × 10 -2 N·cm / cm 2 The initial fiber opening rate of the short fibers obtained from the aforementioned split-type composite long fibers was 16%.

[0068] Example 08 Polymer A(N6) with a volume ratio of 70:30, relative viscosity ηr=2.9, water absorption rate 3.3%, SP value 27.6J 1 / 2 / cm 3 / 2 ) and polymer B (PET, intrinsic viscosity 0.61 dL / g, SP value 21.0 J) 1 / 2 / cm 3 / 2 FDY long fibers were produced by melt spinning using a composite die nozzle having a divided cross-section of 2 large segments and 12 small segments, and then extruding the material through the FDY process. Parameters in the FDY process: spinning temperature 278°C, spinning block temperature corresponding to PET 278°C, spinning block temperature corresponding to N6 275°C, cooling temperature 20°C, cooling air velocity 0.8 m / s, first roller speed 1200 m / min, first roller temperature 80°C, second roller speed 2450 m / min, second roller temperature 160°C.

[0069] The obtained segmented composite long fiber (56T-18-FDY) had the following characteristics in its cross-section: S1 / S ratio of 9%, S1 / S2 ratio of 9.0%, L2 / L1 ratio of 61%, an angle of 91° between the largest segment and the tectonic line at the intersection of the outer circumference of the fiber cross-section, an initial fiber opening rate of 3%, a fiber opening rate of 95% after heat treatment in a 98°C water bath for 20 mins and natural drying at 20°C × 65%RH for 4 hours, an 8% difference in boiling water shrinkage rates between polymer A and polymer B, and a compression energy of 0.488 gf·cm / cm² for the circular knitted fabric after fiber opening. 2 (0.488 × 0.98 × 10 -2 N·cm / cm 2 The initial fiber opening rate of the short fibers obtained from the aforementioned split-type composite long fibers was 12%.

[0070] Example 09 Polymer A(N6) with a volume ratio of 70:30, relative viscosity ηr=2.9, water absorption rate 3.3%, SP value 27.6J 1 / 2 / cm 3 / 2 ) and polymer B (PET, intrinsic viscosity 0.61 dL / g, SP value 21.0 J) 1 / 2 / cm 3 / 2 FDY long fibers were produced by melt spinning using a composite die nozzle having a divided cross-section of 3 large segments and 6 small segments, and extruding the material from the die through the FDY process. Parameters in the FDY process: spinning temperature 278°C, spinning block temperature corresponding to PET 278°C, spinning block temperature corresponding to N6 275°C, cooling temperature 20°C, cooling air velocity 0.8 m / s, first roller speed 1200 m / min, first roller temperature 80°C, second roller speed 2450 m / min, second roller temperature 160°C.

[0071] The obtained segmented composite filament (56T-18-FDY) had the following characteristics in its cross-section: S1 / S ratio of 7.5%, S1 / S2 ratio of 6.0%, L2 / L1 ratio of 61%, an angle of 91° between the largest segment and the tectonic line at the intersection of the outer circumference of the fiber cross-section, an initial fiber opening rate of 5%, a fiber opening rate of 95% after heat treatment in a 98°C water bath for 20 mins and natural drying at 20°C × 65%RH for 4 hours, an 8% difference in boiling water shrinkage rates between polymer A and polymer B, and a compression energy of 0.463 gf·cm / cm² for the circular knitted fabric after fiber opening. 2(0.463 × 0.98 × 10 -2 N·cm / cm 2 The initial fiber opening rate of the short fibers obtained from the aforementioned split-type composite long fibers was 15%.

[0072] Comparative Example 01 Polymer A(N6) with a volume ratio of 70:30, relative viscosity ηr=2.9, water absorption rate 3.3%, SP value 27.6J 1 / 2 / cm 3 / 2 ) and polymer B (PET, intrinsic viscosity 0.61 dL / g, SP value 21.0 J) 1 / 2 / cm 3 / 2 FDY long fibers were produced by melt spinning using a composite die nozzle having 18 small segmented cross-sections, and extruding the material from the die through a FDY process. Parameters in the FDY process: spinning temperature 278°C, spinning block temperature corresponding to PET 278°C, spinning block temperature corresponding to N6 275°C, cooling temperature 20°C, cooling air velocity 0.8 m / s, first roller speed 1200 m / min, first roller temperature 80°C, second roller speed 2450 m / min, second roller temperature 160°C.

[0073] The obtained segmented composite filament (56T-18-FDY) had the following characteristics in its cross-section: the area of ​​one segment accounted for 1% of the fiber's cross-sectional area; the contact length between one segment and polymer A accounted for 68% of the segment's circumference; the angle formed by the tectonic line at the intersection of the segment and the outer circumference of the fiber's cross-section was 90°; the initial fiber opening rate of the filament was 2%; after heat treatment in a 98°C water bath for 20 minutes and natural drying at 20°C × 65%RH for 4 hours, the fiber opening rate was 56%; the difference in boiling water shrinkage rates between polymer A and polymer B was 6%; and the compression energy of the circular knitted fabric after fiber opening was 0.319 gf·cm / cm². 2 (0.319 × 0.98 × 10 -2 N·cm / cm 2 The initial fiber opening rate of the short fibers obtained from the aforementioned split-type composite long fibers was 8%.

[0074] Because large segments were absent, the fiber opening rate after boiling water treatment was reduced.

[0075] Comparative Example 02 Polymer A(N6) with a volume ratio of 50:50, relative viscosity ηr=2.9, water absorption rate 3.3%, SP value 27.6J 1 / 2 / cm 3 / 2 ) and polymer B (PET, intrinsic viscosity 0.61 dL / g, SP value 21.0 J) 1 / 2 / cm 3 / 2 FDY long fibers were produced by melt spinning using a composite die nozzle having a divided cross-section of 4 large segments and 8 small segments, and extruding the material from the die through a FDY process. Parameters in the FDY process: spinning temperature 278°C, spinning block temperature corresponding to PET 278°C, spinning block temperature corresponding to N6 275°C, cooling temperature 20°C, cooling air velocity 0.8 m / s, first roller speed 1200 m / min, first roller temperature 80°C, second roller speed 2450 m / min, second roller temperature 160°C.

[0076] The obtained segmented composite filament (56T-18-FDY) had the following characteristics in its cross-section: S1 / S ratio of 8.0%, S1 / S2 ratio of 3.6%, L2 / L1 ratio of 58%, an angle of 101° between the largest segment and the tectonic line at the intersection of the outer circumference of the fiber cross-section, an initial fiber opening rate of 13%, a fiber opening rate of 95% after heat treatment in a 98°C water bath for 20 mins and natural drying at 20°C × 65%RH for 4 hours, an 8% difference in boiling water shrinkage rates between polymer A and polymer B, and a compression energy of 0.312 gf·cm / cm² for the circular knitted fabric after fiber opening. 2 (0.312 × 0.98 × 10 -2 N·cm / cm 2 The initial fiber opening rate of the short fibers obtained from the aforementioned split-type composite long fibers was 15%.

[0077] Due to the excessively large number of maximum segments, the initial fiber opening rate of both long and short fibers increased.

[0078] Comparative Example 03 Polymer A(N6) with a volume ratio of 70:30, relative viscosity ηr=2.9, water absorption rate 3.3%, SP value 27.6J 1 / 2 / cm 3 / 2 ) and polymer B (PET, intrinsic viscosity 0.61 dL / g, SP value 21.0 J) 1 / 2 / cm 3 / 2) was extruded from the nozzle of a composite spinneret having a split cross-section of one large segment and 23 small segments by the melt spinning method, and FDY long fibers were produced by the FDY process. Parameters in the FDY process: spinning temperature 278 °C, temperature of the spinning block corresponding to PET 278 °C, temperature of the spinning block corresponding to N6 275 °C, cooling temperature 20 °C, cooling air velocity 0.8 m / s, speed of the first roller 1200 m / min, temperature of the first roller 80 °C, speed of the second roller 2450 m / min, temperature of the second roller 160 °C.

[0079] The obtained split-type composite long fiber (56T-18-FDY) had, in the cross-section, S1 / S of 4.0%, S1 / S2 of 3.5, L2 / L1 of 63%, the angle formed by the tangent at the intersection of the largest segment and the outer periphery of the fiber cross-section being 91°, the initial fiber opening rate of the long fiber being 1%, the fiber opening rate after heat treatment in a 98 °C water bath for 20 min and natural drying at 20 °C × 65% RH for 4 h being 63%, the difference in the boiling water shrinkage rate between polymer A and polymer B being 7%, and the compression energy of the circular knitted fabric after fiber opening being 0.331 gf·cm / cm 2 (0.331×0.98×10 -2 N·cm / cm 2 ). The initial fiber opening rate of the short fibers obtained from the split-type composite long fiber was 9%.

[0080] Since the ratio of the area of the largest segment to the fiber cross-sectional area was too small, it was disadvantageous for fiber opening, and the fiber opening rate after boiling water treatment became small.

[0081] Comparative Example 04 Polymer A (N6, relative viscosity ηr = 2.9, water absorption rate 3.3%, SP value 27.6 J 1 / 2 / cm 3 / 2 ) and polymer B (PET, intrinsic viscosity 0.61 dL / g, SP value 21.0 J 1 / 2 / cm 3 / 2) was extruded from the nozzle of a composite spinneret having a split cross-section of one large segment and three small segments by the melt spinning method, and FDY long fibers were produced by the FDY process. Parameters in the FDY process: spinning temperature 278 °C, temperature of the spinning block corresponding to PET 278 °C, temperature of the spinning block corresponding to N6 275 °C, cooling temperature 20 °C, cooling air velocity 0.8 m / s, speed of the first roller 1200 m / min, temperature of the first roller 80 °C, speed of the second roller 2450 m / min, temperature of the second roller 160 °C.

[0082] In the obtained segmented composite long fiber (56T - 18 - FDY), in the cross-section, S1 / S is 72.0%, S1 / S2 is 72.0, L2 / L1 is 63%, the angle formed by the tangent at the intersection of the maximum segment and the outer periphery of the fiber cross-section is 101°, the initial fiber opening rate of the long fiber is 2%, after heat treatment in a 98 °C water bath for 20 min and natural drying at 20 °C × 65% RH for 4 h, the fiber opening rate is 88%, the difference in boiling water shrinkage rate between polymer A and polymer B is 8%, and the compression energy of the circular knitted fabric after fiber opening is 0.246 gf·cm / cm 2 (0.246×0.98×10 -2 N·cm / cm 2 ). The initial fiber opening rate of the short fibers obtained from the segmented composite long fiber was 9%.

[0083] Since the ratio of the area of the maximum segment to the fiber cross-sectional area was too large, the bulkiness of the circular knitted fabric after fiber opening decreased, and the touch became poor.

[0084] Example ********** 10 Polymer A (N6, relative viscosity ηr = 2.9, water absorption rate 3.3%, SP value 27.6 J 1 / 2 / cm 3 / 2 ) and polymer B (PET, intrinsic viscosity 0.61 dL / g, SP value 21.0 J 1 / 2 / cm 3 / 2FDY long fibers were produced by melt spinning using a composite die nozzle having a divided cross-section of one large segment and four small segments, and extruding the material from the die through the FDY process. Parameters in the FDY process: spinning temperature 278°C, spinning block temperature corresponding to PET 278°C, spinning block temperature corresponding to N6 275°C, cooling temperature 20°C, cooling air velocity 0.8 m / s, first roller speed 1200 m / min, first roller temperature 80°C, second roller speed 2450 m / min, second roller temperature 160°C.

[0085] The obtained segmented composite filament (56T-18-FDY) had the following characteristics in its cross-section: S1 / S ratio of 17.0%, S1 / S2 ratio of 2.1%, L2 / L1 ratio of 58%, an angle of 106° between the largest segment and the tectonic line at the intersection of the outer circumference of the fiber cross-section, an initial fiber opening rate of 3%, a fiber opening rate of 95% after heat treatment in a 98°C water bath for 20 mins and natural drying at 20°C × 65%RH for 4 hours, an 8% difference in boiling water shrinkage rates between polymer A and polymer B, and a compression energy of 0.451 gf·cm / cm² for the circular knitted fabric after fiber opening. 2 (0.451 × 0.98 × 10 -2 N·cm / cm 2 The initial fiber opening rate of the short fibers obtained from the aforementioned split-type composite long fibers was 16%.

[0086] Example 11 Polymer A(N6) with a volume ratio of 30:70, relative viscosity ηr=2.9, water absorption rate 3.3%, SP value 27.6J 1 / 2 / cm 3 / 2 ) and polymer B (PET, intrinsic viscosity 0.61 dL / g, SP value 21.0 J) 1 / 2 / cm 3 / 2 FDY long fibers were produced by melt spinning using a composite die nozzle having a divided cross-section of one large segment and four small segments, and extruding the material from the die through the FDY process. Parameters in the FDY process: spinning temperature 278°C, spinning block temperature corresponding to PET 278°C, spinning block temperature corresponding to N6 275°C, cooling temperature 20°C, cooling air velocity 0.8 m / s, first roller speed 1200 m / min, first roller temperature 80°C, second roller speed 2450 m / min, second roller temperature 160°C.

[0087] The obtained segmented composite filament (56T-18-FDY) had the following characteristics in its cross-section: S1 / S ratio of 24.0%, S1 / S2 ratio of 2.1%, L2 / L1 ratio of 68%, an angle of 101° between the largest segment and the outer circumference of the fiber cross-section, an initial fiber opening rate of 2%, a fiber opening rate of 92% after heat treatment in a 98°C water bath for 20 mins and natural drying at 20°C × 65%RH for 4 hours, a difference of 7% in boiling water shrinkage rates between polymer A and polymer B, and a compression energy of 0.443 gf·cm / cm² for the circular knitted fabric after fiber opening. 2 (0.443 × 0.98 × 10 -2 N·cm / cm 2 The initial fiber opening rate of the short fibers obtained from the aforementioned split-type composite long fibers was 17%.

[0088] Example 12 Polymer A(N6) with a volume ratio of 70:30, relative viscosity ηr=2.9, water absorption rate 3.3%, SP value 27.6J 1 / 2 / cm 3 / 2 ) and polymer B (PET, intrinsic viscosity 0.61 dL / g, SP value 21.0 J) 1 / 2 / cm 3 / 2 FDY long fibers were produced by melt spinning using a composite die nozzle having a divided cross-section of one large segment and four small segments, and extruding the material from the die through the FDY process. Parameters in the FDY process: spinning temperature 278°C, spinning block temperature corresponding to PET 278°C, spinning block temperature corresponding to N6 275°C, cooling temperature 20°C, cooling air velocity 0.8 m / s, first roller speed 1200 m / min, first roller temperature 80°C, second roller speed 2450 m / min, second roller temperature 160°C.

[0089] The obtained segmented composite filament (56T-18-FDY) had the following characteristics in its cross-section: S1 / S ratio of 9.0%, S1 / S2 ratio of 8.1%, L2 / L1 ratio of 80%, an angle of 101° between the largest segment and the tectonic line at the intersection of the outer circumference of the fiber cross-section, an initial fiber opening rate of 1%, a fiber opening rate of 75% after heat treatment in a 98°C water bath for 20 mins and natural drying at 20°C × 65%RH for 4 hours, an 8% difference in boiling water shrinkage rates between polymer A and polymer B, and a compression energy of 0.482 gf·cm / cm² for the circular knitted fabric after fiber opening. 2(0.482 × 0.98 × 10 -2 N·cm / cm 2 The initial fiber opening rate of the short fibers obtained from the aforementioned split-type composite long fibers was 8%.

[0090] Example 13 Polymer A(N6) with a volume ratio of 50:50, relative viscosity ηr=2.9, water absorption rate 3.3%, SP value 27.6J 1 / 2 / cm 3 / 2 ) and polymer B (PET, intrinsic viscosity 0.61 dL / g, SP value 21.0 J) 1 / 2 / cm 3 / 2 FDY long fibers were produced by melt spinning using a composite die nozzle having a divided cross-section of one large segment and four small segments, and extruding the material from the die through the FDY process. Parameters in the FDY process: spinning temperature 278°C, spinning block temperature corresponding to PET 278°C, spinning block temperature corresponding to N6 275°C, cooling temperature 20°C, cooling air velocity 0.8 m / s, first roller speed 1200 m / min, first roller temperature 80°C, second roller speed 2450 m / min, second roller temperature 160°C.

[0091] The obtained segmented composite long fiber (56T-18-FDY) had the following characteristics in its cross-section: S1 / S ratio of 18.0%, S1 / S2 ratio of 2.3%, L2 / L1 ratio of 74%, an angle of 73° between the cleavage line at the intersection of the largest segment and the outer circumference of the fiber cross-section, an initial fiber opening rate of 1%, a fiber opening rate of 58% after heat treatment in a 98°C water bath for 20 mins and natural drying at 20°C × 65%RH for 4 hours, an 8% difference in boiling water shrinkage rates between polymer A and polymer B, and a compressive energy of 0.379 gf·cm / cm² for the circular knitted fabric after fiber opening. 2 (0.379 × 0.98 × 10 -2 N·cm / cm 2 The initial fiber opening rate of the short fibers obtained from the aforementioned split-type composite long fibers was 6%.

[0092] Example 14 Polymer A(N6) with a volume ratio of 70:30, relative viscosity ηr=3.2, water absorption rate 3.4%, SP value 27.6J 1 / 2 / cm 3 / 2) and polymer B (PET, intrinsic viscosity 0.61 dL / g, SP value 21.0 J) 1 / 2 / cm 3 / 2 FDY long fibers were produced by melt spinning using a composite die nozzle having a divided cross-section of one large segment and 16 small segments, and then the FDY process was performed. Parameters in the FDY process: spinning temperature 278°C, spinning block temperature corresponding to PET 278°C, spinning block temperature corresponding to N6 275°C, cooling temperature 20°C, cooling air velocity 0.8 m / s, first roller speed 1200 m / min, first roller temperature 80°C, second roller speed 2450 m / min, second roller temperature 160°C.

[0093] The obtained segmented composite filament (56T-18-FDY) had the following characteristics in its cross-section: S1 / S ratio of 11.0%, S1 / S2 ratio of 9.1%, L2 / L1 ratio of 63%, an angle of 90° between the cleavage line at the intersection of the largest segment and the outer circumference of the fiber cross-section, an initial fiber opening rate of 2%, a fiber opening rate of 98% after heat treatment in a 98°C water bath for 20 mins and natural drying at 20°C × 65%RH for 4 hours, a difference of 15% in boiling water shrinkage rates between polymer A and polymer B, and a compression energy of 0.532 gf·cm / cm² for the circular knitted fabric after fiber opening. 2 (0.532 × 0.98 × 10 -2 N·cm / cm 2 The initial fiber opening rate of the short fibers obtained from the aforementioned split-type composite long fibers was 12%.

[0094] Example 15 Polymer A (N610, relative viscosity ηr=2.7, water absorption rate 1.5%, SP value 27.8J) with a volume ratio of 50:50 1 / 2 / cm 3 / 2 ) and polymer B (PET, intrinsic viscosity 0.61 dL / g, SP value 21.0 J) 1 / 2 / cm 3 / 2FDY long fibers were produced by melt spinning using a composite die nozzle having a divided cross-section of one large segment and four small segments, and extruding the material from the die through the FDY process. Parameters in the FDY process: spinning temperature 278°C, spinning block temperature for PET 278°C, spinning block temperature for N610 275°C, cooling temperature 20°C, cooling air velocity 0.8 m / s, first roller speed 1200 m / min, first roller temperature 80°C, second roller speed 2450 m / min, second roller temperature 160°C.

[0095] The obtained segmented composite filament (56T-18-FDY) had the following characteristics in its cross-section: S1 / S ratio of 17.0%, S1 / S2 ratio of 2.1%, L2 / L1 ratio of 58%, an angle of 106° between the largest segment and the outer circumference of the fiber cross-section, an initial fiber opening rate of 0%, a fiber opening rate of 95% after heat treatment in a 98°C water bath for 20 mins and natural drying at 20°C × 65%RH for 4 hours, an 8% difference in boiling water shrinkage rates between polymer A and polymer B, and a compression energy of 0.487 gf·cm / cm² for the circular knitted fabric after fiber opening. 2 (0.487 × 0.98 × 10 -2 N·cm / cm 2 The initial fiber opening rate of the short fibers obtained from the aforementioned split-type composite long fibers was 5%.

[0096] Example 16 Polymer A(N6) with a volume ratio of 50:50, relative viscosity ηr=2.9, water absorption rate 3.3%, SP value 27.6J 1 / 2 / cm 3 / 2 ) and polymer B (PET, intrinsic viscosity 0.61 dL / g, SP value 21.0 J) 1 / 2 / cm 3 / 2 FDY long fibers were produced by melt spinning using a composite die nozzle having a divided cross-section of one large segment and four small segments, and extruding the material from the die through the FDY process. Parameters in the FDY process: spinning temperature 278°C, spinning block temperature corresponding to PET 278°C, spinning block temperature corresponding to N6 275°C, cooling temperature 20°C, cooling air velocity 0.8 m / s, first roller speed 1200 m / min, first roller temperature 80°C, second roller speed 2450 m / min, second roller temperature 160°C.

[0097] The obtained segmented composite filament (56T-18-FDY) had the following characteristics in its cross-section: S1 / S ratio of 18.0%, S1 / S2 ratio of 2.3%, L2 / L1 ratio of 45%, an angle of 126° between the largest segment and the outer circumference of the fiber cross-section, an initial fiber opening rate of 5%, a fiber opening rate of 97% after heat treatment in a 98°C water bath for 20 mins and natural drying at 20°C × 65%RH for 4 hours, an 8% difference in boiling water shrinkage rates between polymer A and polymer B, and a compression energy of 0.489 gf·cm / cm² for the circular knitted fabric after fiber opening. 2 (0.489 × 0.98 × 10 -2 N·cm / cm 2 The initial fiber opening rate of the short fibers obtained from the aforementioned split-type composite long fibers was 12%.

[0098] Example 17 Polymer A(N6) with a volume ratio of 50:50, relative viscosity ηr=2.9, water absorption rate 3.3%, SP value 27.6J 1 / 2 / cm 3 / 2 ) and polymer B (PET, intrinsic viscosity 0.61 dL / g, SP value 21.0 J) 1 / 2 / cm 3 / 2 FDY long fibers were produced by melt spinning using a composite die nozzle having a divided cross-section of one large segment and four small segments, and extruding the material from the die through the FDY process. Parameters in the FDY process: spinning temperature 278°C, spinning block temperature corresponding to PET 278°C, spinning block temperature corresponding to N6 275°C, cooling temperature 20°C, cooling air velocity 0.8 m / s, first roller speed 1200 m / min, first roller temperature 80°C, second roller speed 2450 m / min, second roller temperature 160°C.

[0099] The obtained segmented composite long fiber (56T-18-FDY) had the following characteristics in its cross-section: S1 / S ratio of 18.0%, S1 / S2 ratio of 2.3%, L2 / L1 ratio of 40%, an angle of 135° between the largest segment and the tectonic line at the intersection of the outer circumference of the fiber cross-section, an initial fiber opening rate of 7%, a fiber opening rate of 97% after heat treatment in a 98°C water bath for 20 mins and natural drying at 20°C × 65%RH for 4 hours, an 8% difference in boiling water shrinkage rates between polymer A and polymer B, and a compression energy of 0.474 gf·cm / cm² for the circular knitted fabric after fiber opening.2 (0.474 × 0.98 × 10 -2 N·cm / cm 2 The initial fiber opening rate of the short fibers obtained from the aforementioned split-type composite long fibers was 16%.

[0100] Example 18 Polymer A(N6) with a volume ratio of 70:30, relative viscosity ηr=2.4, water absorption rate 3.4%, SP value 27.6J 1 / 2 / cm 3 / 2 ) and polymer B (PET, intrinsic viscosity 0.61 dL / g, SP value 21.0 J) 1 / 2 / cm 3 / 2 FDY long fibers were produced by melt spinning using a composite die nozzle having a divided cross-section of one large segment and 16 small segments, and then the FDY process was performed. Parameters in the FDY process: spinning temperature 278°C, spinning block temperature corresponding to PET 278°C, spinning block temperature corresponding to N6 275°C, cooling temperature 20°C, cooling air velocity 0.8 m / s, first roller speed 1200 m / min, first roller temperature 80°C, second roller speed 2450 m / min, second roller temperature 160°C.

[0101] The obtained segmented composite long fiber (56T-18-FDY) had the following characteristics in its cross-section: S1 / S ratio of 11.0%, S1 / S2 ratio of 9.1%, L2 / L1 ratio of 63%, an angle of 90° between the cleavage line at the intersection of the largest segment and the outer circumference of the fiber cross-section, an initial fiber opening rate of 2%, a fiber opening rate of 81% after heat treatment in a 98°C water bath for 20 mins and natural drying at 20°C × 65%RH for 4 hours, a difference of 4% in boiling water shrinkage rates between polymer A and polymer B, and a compressive energy of 0.485 gf·cm / cm² for the circular knitted fabric after fiber opening. 2 (0.485 × 0.98 × 10 -2 N·cm / cm 2 The initial fiber opening rate of the short fibers obtained from the aforementioned split-type composite long fibers was 8%.

[0102] Example 19 Polymer A(N6) with a volume ratio of 25:75, relative viscosity ηr=2.9, water absorption rate 3.3%, and SP value 27.6J 1 / 2 / cm 3 / 2) and polymer B (PET, intrinsic viscosity 0.61 dL / g, SP value 21.0 J) 1 / 2 / cm 3 / 2 FDY long fibers were produced by melt spinning using a composite die nozzle having a divided cross-section of one large segment and three small segments, and extruding the material from the die through the FDY process. Parameters in the FDY process: spinning temperature 278°C, spinning block temperature corresponding to PET 278°C, spinning block temperature corresponding to N6 275°C, cooling temperature 20°C, cooling air velocity 0.8 m / s, first roller speed 1200 m / min, first roller temperature 80°C, second roller speed 2450 m / min, second roller temperature 160°C.

[0103] The obtained segmented composite long fiber (56T-18-FDY) had the following characteristics in its cross-section: S1 / S ratio of 70.0%, S1 / S2 ratio of 42.0%, L2 / L1 ratio of 73%, an angle of 101° between the largest segment and the outer circumference of the fiber cross-section, an initial fiber opening rate of 2%, a fiber opening rate of 90% after heat treatment in a 98°C water bath for 20 mins and natural drying at 20°C × 65%RH for 4 hours, an 8% difference in boiling water shrinkage rates between polymer A and polymer B, and a compression energy of 0.253 gf·cm / cm² for the circular knitted fabric after fiber opening. 2 (0.253 × 0.98 × 10 -2 N·cm / cm 2 The initial fiber opening rate of the short fibers obtained from the aforementioned split-type composite long fibers was 9%.

[0104] Example 20 Polymer A(N6) with a volume ratio of 80:20, relative viscosity ηr=2.9, water absorption rate 3.3%, SP value 27.6J 1 / 2 / cm 3 / 2 ) and polymer B (PET, intrinsic viscosity 0.61 dL / g, SP value 21.0 J) 1 / 2 / cm 3 / 2FDY long fibers were produced by melt spinning using a composite die nozzle having a divided cross-section of one large segment and four small segments, and extruding the material from the die through the FDY process. Parameters in the FDY process: spinning temperature 278°C, spinning block temperature corresponding to PET 278°C, spinning block temperature corresponding to N6 275°C, cooling temperature 20°C, cooling air velocity 0.8 m / s, first roller speed 1200 m / min, first roller temperature 80°C, second roller speed 2450 m / min, second roller temperature 160°C.

[0105] The obtained segmented composite filament (56T-18-FDY) had the following characteristics in its cross-section: S1 / S ratio of 8.0%, S1 / S2 ratio of 2.6%, L2 / L1 ratio of 56%, an angle of 102° between the largest segment and the outer circumference of the fiber cross-section, an initial fiber opening rate of 3%, a fiber opening rate of 90% after heat treatment in a 98°C water bath for 20 mins and natural drying at 20°C × 65%RH for 4 hours, a difference of 7% in boiling water shrinkage rates between polymer A and polymer B, and a compression energy of 0.448 gf·cm / cm² for the circular knitted fabric after fiber opening. 2 (0.448 × 0.98 × 10 -2 N·cm / cm 2 The initial fiber opening rate of the short fibers obtained from the aforementioned split-type composite long fibers was 16%.

[0106] [Table 2]

[0107] [Table 3]

[0108] [Table 4]

[0109] [Table 5] [Explanation of symbols]

[0110] S: Area of ​​the cross-section of the fiber S1: Area of ​​the largest segment in the cross-section of the fiber. S2: Area of ​​a small segment in the cross-section of a fiber L1: Circumference of the largest segment L2: Contact length between the largest segment and polymer A

Claims

1. A segmented composite fiber comprising polymer A and polymer B, wherein polymer A is continuously distributed in the fiber cross-section, polymer B is divided into large segments and small segments, and all segments are exposed on the fiber surface, characterized in that in the cross-section of a single fiber there are 1 to 3 maximum segments of the same area and 2 or more small segments smaller than the maximum segments, the area of ​​one maximum segment accounts for 7.5 to 70.0% of the area of ​​the fiber cross-section, and the area of ​​one maximum segment is more than twice the area of ​​one small segment.

2. The segmented composite fiber according to claim 1, characterized in that L1 is the circumference of one largest segment, L2 is the contact length between the largest segment and polymer A, and L2 / L1 is 45-80%.

3. The segmented composite fiber according to claim 1 or 2, characterized in that the angle formed by the tectonic line at the intersection of the largest segment and the outer circumference of the fiber cross-section is 90° or more.

4. The segmented composite fiber according to claim 1 or 2, characterized in that, after treating the composite fiber with boiling water, the shrinkage rate of polymer A is greater than that of polymer B, and the difference is 5% or more.

5. The difference in solubility parameters between polymer A and polymer B is 1.0 to 10.8 J. 1 / 2 / cm 3 / 2 The segmented composite fiber according to claim 1 or 2, characterized in that it is such.

6. The split-type composite fiber according to claim 1 or 2, characterized in that polymer A and polymer B are, respectively, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polypropylene, polyamide-4, polyamide-6, polyamide-56, polyamide-66, polyamide-510, or polyamide-610.

7. The segmented composite fiber according to claim 1 or 2, characterized in that the area ratio of polymer A to polymer B in the cross-section of the composite fiber is 70:30 to 30:

70.

8. The split-type composite fiber according to claim 1 or 2, characterized in that the initial fiber opening rate of the composite fiber is 5% or less, and the fiber opening rate after boiling water treatment is 90% or more.

9. The segmented composite fiber according to claim 1 or 2, characterized in that the composite fiber is a short fiber and the initial fiber opening rate is 5% or less.

10. The segmented composite fiber according to claim 9, characterized in that the water absorption rate of polymer A is 1.5% or less.

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