JP2014210990A - Fine-denier porous hollow staple fiber, spun yarn using the same, woven or knitted fabric, and production method for fine-denier porous hollow fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a woven or knitted fabric made from synthetic fiber that combines all of water absorption property, water permeation resistance and heat insulation property, to provide a spun yarn that achieves the same, and to provide a raw material staple fiber for the spun yarn.SOLUTION: The problem is solved by a hollow fiber that has, in a profile of a fiber cross-section in a direction orthogonal to the fiber axis direction, at least three hollow holes in continuous communication in the fiber axis direction, and has a hollowness of 10 to 35%, and a single fiber fineness of 0.1 to 3.5 decitexes.

Description

  The present invention relates to a spun yarn that provides a woven or knitted fabric having water absorption, permeation resistance, and heat retention, a short fiber constituting the spun yarn, and a method for producing the same.

  Conventionally, a woven or knitted fabric using a natural fiber such as cotton or a synthetic fiber having a water absorption comparable to that of a semi-synthetic fiber such as rayon has been studied. In addition, a lightweight woven or knitted fabric with high heat retention has been demanded for winter clothing. Therefore, even if the basis weight of the woven or knitted fabric is lowered, it is a potential need to have excellent permeability.

  For example, an atypical polyester short fiber having a fineness of 1.3 dtex or more and having three or more protrusions as a cross-sectional shape and an atypality of 1.8 or more, or 2.2 dtex or more and 10 to 45% A spun yarn and a woven or knitted fabric containing hollow polyester short fibers having a hollow ratio of 2 are proposed (for example, see Patent Document 1). However, the woven or knitted fabric made of the fibers described in Patent Document 1 has a problem that the fineness is large, so that the gap formed between the single yarns is large and sufficient water absorption performance cannot be obtained.

  On the other hand, in order to make up for the drawbacks, the atypical polyester short fiber having a single fiber fineness of 2 dtex or less, a cross-sectional shape of 4 or more convex portions, and a variant degree of 1.7 to 4.0 and a round cross section A spun yarn and a woven or knitted fabric having polyester short fibers as main constituent fibers and excellent in water absorption, permeability, and softness have been proposed (for example, see Patent Document 2). However, in the woven or knitted fabric of Patent Document 2, since short fibers having a round cross section are blended, water absorption sufficient to make full use of the capillary phenomenon cannot be obtained, and voids between the fibers are still high. Therefore, the heat retaining property was not excellent.

  Also disclosed is a spun yarn and a woven or knitted fabric using a high-hollow polyester fiber characterized by a single fiber fineness of 0.5 to 6.0 dtex and a fiber cross-sectional hollowness of 50 to 85% ( For example, see Patent Document 3.) However, since the hollow ratio is too high, when a spun yarn is used, the twisted portion is crushed and flattened by any means, and the heat retention and permeation resistance, which are the characteristics of the high hollow, cannot be fully utilized. As described above, there has never been a woven or knitted fabric having water absorption, permeation resistance, and heat retention, and a spun yarn constituting the knitted fabric and short fibers serving as raw material fibers thereof.

JP 2008-133854 A JP 2012-107372 A Japanese Patent No. 4065592

  An object of the present invention is to provide a woven or knitted fabric made of a synthetic fiber having all of water absorption, permeation resistance and heat retention, a spun yarn and a spun yarn raw fiber for realizing the same.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventor has found that the number of cross-sectional hollow holes continuous in the fiber axis direction is 3 or more, the fineness is 0.1 to 3.5 dtex, and the hollow ratio is 10 The present inventors have found that a woven or knitted fabric made of spun yarn containing hollow fibers of ˜35% can have all of water absorbency, permeation resistance, and heat retention, and have reached the present invention.

  The fine-fine porous hollow short fibers of the present invention have excellent water absorption performance due to the appearance of a large number of pores at the fiber ends in spun yarns and woven or knitted fabrics comprising them, and irregular reflection consisting of porous thin hollows in the fiber axis direction. Therefore, it is possible to provide heat-proofing by heat and heat retention by dead air in the hollow portion. Furthermore, a soft texture can be given to the woven or knitted fabric depending on the fineness.

It is a schematic diagram of the spinneret used in Examples 1 to 3 and Example 5. It is the schematic diagram of the fiber cross section obtained in Examples 1-3 and Example 5. FIG. 6 is a schematic diagram of a spinneret used in Example 4. FIG. 6 is a schematic diagram of a fiber cross section obtained in Example 4. FIG. 3 is a schematic diagram of a fiber cross section obtained in Comparative Example 1. FIG. 5 is a schematic diagram of a fiber cross section obtained in Comparative Example 2. FIG.

  First, it is essential for the hollow short fiber of this invention to have the hollow part of 3 or more holes connected in the fiber axial direction in the cross-sectional shape of the fiber at right angles to the fiber axial direction. Because, in the hollow portion of one hole, the hollow portion is crushed by an external force such as a spinning twisting process, and the effect of permeation prevention and heat retention is reduced. It is possible to prevent hollow crushing due to twisting. The two-hole hollow is desirably a porous hollow fiber having three or more holes because the hollow formation is unstable and the hollow ratio is difficult to increase. The hollow of 3 holes or more can be obtained by using a known synthetic fiber (for melt spinning) die, but a porous fiber obtained by eluting an island portion of a sea-island composite fiber may be used. The number of hollow holes that can be stably produced as melt spinning is 3 to 9 holes.

  Moreover, in the hollow fiber of the present invention, the shape of the cross section of the hollow fiber is not limited to a round cross section, and has a hollow hole of three or more holes as described above, a triangle to a hexagon, or It may be a polygonal shape having more sides. Further, in such a polygonal shape, a part or all of the side is curved in an internal direction toward the center of the polygon or an outward direction away from the center, and a part or all of the side of the polygon is concave or convex. It includes shapes that are deformed into Further, the hollow fiber of the present invention may have a cross-sectional shape having a remarkable degree of bending and having six or more convex portions (projections) continuous in the fiber axis direction. There is an effect that the convex portion of one fiber and the concave portion formed between the convex portions of other fibers are engaged with each other over a certain length between the fibers, and the gap between the fibers becomes dense. This is the same as the hollow hole of the fiber, in which the air flow in the case of the woven or knitted fabric is blocked and the dead air part, that is, the outside is almost closed from the outside. Creates a space that does not exist and plays a role in improving heat retention. When the number of convex portions is less than 6, voids between fibers become large, and effective heat insulation cannot be exhibited when the basis weight of the woven or knitted fabric is lowered. The preferable range of the number of convex portions is about 8 to 16, and even if there are many convex portions, the heat insulating effect due to the meshing is hardly exhibited. The greater the degree of atypicality of the fiber cross-sectional shape, the greater the effect of biting the above-mentioned convex part and concave part.

  Another important factor of the short fiber of the present invention is 0.1 to 3.5 decitex, preferably 0.1 It is a porous hollow fiber having a fineness of 1.5 dtex. By making this level of fineness, the diameter of the hollow part is also extremely small, liquid absorption due to capillary phenomenon, permeation resistance due to light irregular reflection effect, gaps between single yarns and spun yarns in woven and knitted fabrics It becomes remarkably narrow, the air flow is cut off, and the heat retention due to the hollow portion effect that is not easily crushed can be remarkably improved.

The range of the hollow ratio is 10 to 35%, and the preferred range is 15 to 30%. If the hollow ratio is less than 10%, sufficient water absorption and heat retention cannot be obtained, and if the hollow ratio exceeds 35%, the hollow tends to be crushed, and the water absorption, heat retention, and permeability are reduced. There is a tendency. In addition, a hollow rate is represented with the following numerical formula.
Hollow ratio = (area of hollow portion of fiber cross section [plane perpendicular to fiber axis]) / (total area within closed curve surrounded by outer contour of fiber cross section) × 100
Moreover, it is preferable to use the fiber of this invention as a short fiber, The range of the single yarn fiber is preferable in the range of 5-1000 mm, and the range of 10-800 mm is more preferable.

  The kind of the polymer that forms the short fiber of the present invention is not particularly limited as long as the fiber form of the present invention can be realized. Polyester such as polyester, nylon 6 or nylon 66, polyolefin such as polyethylene, polypropylene, or polystyrene, etc. Examples of the fiber-forming polymer include polyesters such as polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polytrimethylene naphthalate, polybutylene naphthalate, and short fibers. It is preferably composed of polyalkylene terephthalate, and more preferably 60 mol% or more of the constituent components constituting the porous hollow fiber are ethylene terephthalate units. The reason for this is that, as will be described later, it is possible to obtain a fine-fine porous hollow fiber without breaking the cross-sectional shape of the porous hollow fiber by flow-drawing the undrawn yarn. This is because it is easy. In the polymer, a cationic dye dyeing agent, a coloring inhibitor, a heat stabilizer, a fluorescent whitening agent, a matting agent, a coloring agent, a moisture absorbing agent may be contained in the polymer as long as the purpose of the present invention is not impaired. One type or two or more types of agents and inorganic fine particles may be contained.

  Although it was extremely difficult to produce fine hollow porous fibers of the level of the present invention by the usual melt spinning method and composite fiber spinning method, unstretched porous hollow cross section from polyalkylene terephthalate mainly composed of ethylene terephthalate A yarn is obtained by melt spinning and flow-stretched by 5 times or more, preferably 10 to 50 times in warm water or a heating medium bath at 70 to 100 ° C., so that the fineness is 3.5 dtex or less, preferably 1.5. A hollow porous fiber having a decitex or lower can be obtained. A die for obtaining a porous hollow fiber is exemplified in FIGS. 1 and 3, and a known porous hollow die for melt spinning can be used. As a spun yarn application, in order to obtain the strength to pass through the spinning process and the necessary spun yarn strength, after the flow stretching, neck stretching is performed at a temperature between room temperature and the glass transition temperature, and heat treatment (constant Long state or relaxed state). During flow drawing, the polymer is in a semi-molten state above the glass transition temperature, but the shape of the cross-sectional shape is maintained as it is, and the hollow ratio is larger than that of the undrawn yarn. It is. The fibers of the present invention can be crimped by a known method using a crimper or the like. The number of crimps is preferably 5 to 20 peaks / 25.4 mm. Moreover, after fixing crimp, the fiber of this invention can be cut in said range, and a short fiber can be obtained. Furthermore, in order to suitably use the hollow fiber of the present invention as the above-mentioned short fiber having water absorption, permeation resistance and heat retention or as a spun yarn, the fiber length is preferably in the range of 20 to 1000 mm. A more preferable fiber length is in the range of 30 to 500 mm, and a more preferable fiber length is in the range of 35 to 200 mm.

  After the short fiber is formed, a spun yarn can be produced through a kneading yarn, roving and fine spinning step through a blending step with only the fiber of the present invention or with other short fibers by a conventionally known method. As the spun yarn of the present invention, a known ring spinning machine, air spinning machine, mule spinning machine, open-end spinning machine, flyer spinning machine, cap spinning machine, pot spinning machine, or the like can be used. Moreover, the count of the spun yarn is not particularly limited. The spun yarn and woven or knitted fabric of the present invention may be blended with cellulosic fibers such as cotton and rayon, or other polyester, nylon, acrylic fiber, etc., in addition to the fine fine porous hollow short fibers of the present invention. The fine-fine porous hollow short fiber of the invention needs to be contained in the spun yarn at 30% by mass or more. If it is less than 30% by mass, the effects of water absorption, permeability, and heat retaining properties of the fiber of the present invention are not exhibited. A preferred range is 40% by weight or more, and a more preferred range is 50% by weight or more.

  In addition, the woven or knitted fabric of the present invention can be produced within the range where the target performance can be achieved even if the spun yarn, filament, etc. of the spun yarn of the present invention are woven or knitted. Further, the density of the woven fabric is preferably 150 / 2.54 cm or more for the background (more preferably 180 to 250 for the background). When the density of the woven fabric is smaller than the above range, low air permeability may not be obtained. In the woven fabric of the present invention, the woven fabric structure is not particularly limited, but it is a three-fold texture such as plain weave, twill weave, satin weave, etc. Is exemplified. The number of layers may be a single layer or a multilayer of two or more layers. In the knitted fabric, the structure of the woven or knitted fabric is not particularly limited in the woven / knitted structure and the number of layers. For example, knitting structures such as tengu, smooth, milling, kanoko, denby, and tricot are preferably exemplified, but are not limited thereto. The number of layers is preferably a single layer, but may be two or more.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to these at all. In addition, the measurement of each characteristic value in an Example followed the following method.

(1) Intrinsic viscosity Measured at 35 ° C. using orthochlorophenol as a solvent.
(2) Single yarn fineness It measured by the method as described in JIS L 1015: 1999 8.5.1 (Method A).
(3) Hollow ratio From the enlarged image of the optical micrograph of the fiber cross-sectional shape orthogonal to the fiber axis, the total area Sa of the cross-section of the single fiber (all within the closed curve surrounded by the outer contour of the fiber cross-section including the hollow portion) Area) and the hollow portion area Sb of the single fiber cross section were determined as Sb / Sa × 100 (%).
(4) High elongation measured by the method described in JIS L 1015: 1999 8.7.1.
(5) Number of crimps It was measured by the method described in JIS L 1015: 1999 8.12.1.
(6) Fiber length Measured by the method described in JIS L 1015: 1999 8.4.1 (C).
(7) Fabric basis weight Measured by the method described in JIS L 1096: 1999 8.4.2.
(8) Fabric thickness Measured by the method described in JIS L 1096: 1999 8.5.1.
(9) Fabric water absorption rate Measured by the method described in JIS L 1907: 2004 7.1.1 (Drip Method).
(10) Fabric water absorption Measured by the method described in JIS L 1907: 2004 7.1.2 (Bilec method).
(11) Fabric water absorption Measured by the method described in JIS L 1907: 2004 7.2 (water absorption method).
(12) Permeability of fabric Using a spectrophotometer (Konica Minolta CM-3600d), each L value (reflectance) is measured using a standard white board and a standard blackboard as the background of the sample fabric, and the permeation rate (%) is as follows. Obtained by the formula.
Permeability (%) = 100− (Lfw−Lfb) / (Lw−Lb) × 100
Lw: L value of the standard white board without the sample fabric Lb: L value of the standard blackboard without the sample fabric Lfw: L value when the sample fabric is placed on the standard white board Lfb: Sample fabric of the standard blackboard L value when placed on top (13) Fabric heat retention The heat release was measured by ASTM D-1518-57T, and the heat retention (%) was calculated by the following formula.
Thermal insulation (%) = (1-((Heat release amount [W] when a test piece is attached to a heating element) / (Heat release amount [W] of a blank test of a heating element)) × 100

[Example 1]
Polyethylene terephthalate having an intrinsic viscosity of 0.64 dL / g, a melting point of 256 ° C., and 0.30% by mass of anatase-type titanium oxide particles having an average particle size of 0.3 μm was melted at 280 ° C., and the spinning shown in FIG. It was discharged at 0.63 g / min per hole using a die, and the undrawn yarn was taken up while cooling with air at a spinning speed of 500 m / min. This was 9.6 times in 95 ° C. warm water (flow stretching), 2.2 times in neck warm water at 73 ° C. (neck stretching), then applied with spinning oil and crimped, then 140 ° C. Relaxed in hot air and cut to 38 mm. Table 1 shows the properties of the raw cotton, the specifications of the spun yarn made of 100% of the porous hollow raw cotton, and the fabric evaluation results of the woven fabric made of the spun yarn 100%. The cross-sectional shape of the fiber is as shown in FIG.

[Examples 2-3]
The same procedure as in Example 1 was performed except that the single-hole discharge rate was changed from 0.63 g / min to 0.99 g / min and 1.26 g / min, respectively. The results are shown in Table 1.

[Example 4]
The same procedure as in Example 3 was performed except that the spinneret was changed from that shown in FIG. 1 to that shown in FIG. The results are shown in Table 1. The cross-sectional shape of the fiber is as shown in FIG.

[Comparative Examples 1-2]
A test fabric (woven fabric) was prepared using a commercially available solid round cross section and W-shaped atypical cross section (both single yarn fineness: 1.4 dtex, fiber length: 38 mm length) as spun yarn. The results are shown in Table 1. The cross-sectional shape of the hollow fiber is as shown in FIGS. 5 and 6, respectively.

[Example 5]
A woven fabric made of 100% spun yarn obtained by blending 30% by mass of the short fiber of Example 3 and 70% by mass of the short fiber of Comparative Example 1 was prepared. The results are shown in Table 1.

  The fine-fine porous hollow short fibers of the present invention have excellent water absorption performance due to the appearance of a large number of pores at the fiber ends in spun yarns and woven or knitted fabrics comprising them, and irregular reflection consisting of porous thin hollows in the fiber axis direction. Therefore, it is possible to provide heat-proofing by heat and heat retention by dead air in the hollow portion. Furthermore, a soft texture can be given to the woven or knitted fabric depending on the fineness.

Claims (7)

  The cross-sectional shape of the fiber perpendicular to the fiber axis direction has three or more hollow holes communicating in the fiber axis direction, the hollowness is 10 to 35%, and the single yarn fineness is 0.1 to 3.5 dtex. Some hollow fiber.   The hollow fiber according to claim 1, wherein the single yarn fineness is 0.12 to 1.5 dtex.   The hollow fiber according to any one of claims 1 to 2, wherein 60 mol% or more of the constituent components are composed of ethylene terephthalate units.   The method for producing a hollow fiber according to any one of claims 1 to 3, further comprising a step of subjecting the undrawn yarn to flow drawing.   A spun yarn comprising the hollow fiber according to any one of claims 1 to 3.   A spun yarn comprising 30% by mass or more of the hollow fiber according to any one of claims 1 to 3.   A woven or knitted fabric comprising the spun yarn according to any one of claims 5 to 6.

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