Multifilament, woven / knit fabric, and fiber product

Abstract

Provided is a multifilament in which: modified cross-section fibers having different cross-sectional shapes are dispersed and mixed; the fibers have 3 to 20 recesses continuous in a fiber axis direction; and the ratio of the maximum depth of the recesses between the fibers is 1.1 to 5.0. The multifilament is configured so that: composite fibers having different composite cross-sections are dispersed and mixed; the fibers are composed of a hardly-eluting component and an easily-eluting component; the hardly-eluting component of the fibers has 3 to 20 recesses continuous in a fiber axis direction; and a ratio of the maximum depth of the recesses of the hardly-eluting component between the fibers is 1.1 to 5.0. Further provided is a woven / knit fabric comprising a multifilament in which modified cross-section fibers having different cross-sectional shapes are dispersed and mixed, said fabric having a static friction coefficient of a fabric surface of 0.5 to 2.0, and a variation of a dynamic friction coefficient of 1.0×10-2 to 5.0×10-2.　Provided are the multifilament, the woven / knit fabric, and a fiber product which are suitable for comfortable clothing, in which patches of unevenness can be formed on the fabric surface and patches of voids can be formed inside the fabric, which have a mild gloss with a squeaky and luxurious feeling peculiar to silk, and which also have functionality such as water absorbing and diffusing properties.

Description

Multifilament, woven and knitted fabrics and textile products

[0001] The present invention relates to multifilaments, woven and knitted fabrics and textile products suitable for obtaining comfortable clothing that combines the properties of natural materials with functionality.

[0002] Synthetic fibers made from polyester, polyamide, etc. have excellent mechanical properties and dimensional stability, and are therefore widely used in a variety of applications, from clothing to non-clothing. However, as people's lives have become more diverse and they are seeking a better quality of life, advanced textures and functions not found in conventional synthetic fibers are required for many applications, including clothing.

[0003] Natural fibers such as linen, wool, cotton, and silk have excellent texture and functionality, and the complex luster and texture they create are considered to be both attractive and luxurious. Accordingly, it is no exaggeration to say that the elemental technologies related to synthetic fibers have evolved with the motivation of imitating the characteristics of natural materials.

[0004] In the history of synthetic fibers that have imitated natural materials, there have been proposals for a wide range of fiber technologies, including polymer technology to design fiber cross-sectional shapes and blending different fibers, particularly for silky materials that aim to achieve the properties of silk, the finest natural material.

[0005] For example, it is known that when the cross section of a polyester fiber is made into a multi-lobed irregular cross section, the irregularities of the multi-lobed shape amplify the reflection of light, resulting in a fiber with a high-brightness luster like silk, and this fiber is produced in large quantities as a representative example of a silky material. However, simply making the cross section into a modified cross section may not be sufficient to achieve a luxurious luster like silk, and it may also be difficult to satisfy texture other than luster.

[0006] Therefore, various textile technologies have been disclosed that further pursue the luster and texture unique to silk by making the cross-sectional form of the fiber more complex, such as a composite cross-section.

[0007] Patent Documents 1 and 2 propose composite fibers having a multilobal cross section, with easily soluble components arranged at the apexes of the multilobal shape in a tapered shape toward the interior of the fiber. In the composite fibers, grooves are formed at the apexes of the multilobal shape when the easily soluble components are subjected to a dissolution treatment, and the grooves cause diffused reflection of light and increase frictional force, resulting in a luxurious luster like silk and a tactile feel unique to silk, known as a creaky feel, when made into a woven or knitted fabric.

[0008] Furthermore, Patent Document 3 proposes a composite fiber in which a multi-lobed, poorly soluble component is completely coated with an easily soluble component in the cross section of the fiber. In this composite fiber, the elution of the easily soluble component forms irregularities on the fiber surface due to the multi-lobed shape, imparting a silk-like luster and a squeaky feel. In addition, large inter-fiber voids are formed in the recesses of the multi-lobed shape where the easily soluble component is thick, thereby imparting a fluffy texture.

[0009] Japanese Patent Application Laid-Open No. 58-98425 Japanese Patent Application Laid-Open No. 60-75638 International Publication No. 2021 / 070740

[0010] As in Patent Documents 1 to 3, by forming a special cross-sectional shape using eluted components, it may be possible to reproduce to some extent the texture unique to silk, such as a luxurious luster, a creaky feeling, and a moderate volume, by controlling light reflection, frictional force, and inter-fiber voids.

[0011] However, in Patent Documents 1 to 3, when the fabric is made into a woven or knitted fabric, the unevenness formed on the surface of the fabric is not uniform, and the resulting texture and appearance are uniform in some cases. As a result, the silk-like creaking feeling and luxurious mild luster are insufficient, and when the fabric is made into clothing, the characteristics of silk, such as a good feel against the skin and resistance to becoming wrinkled, are not obtained in some cases.

[0012] Furthermore, the composite fibers are packed closely together, resulting in a lack of inter-fiber voids, which can result in insufficient volume to provide a comfortable garment.

[0013] As described above, although various techniques have been proposed to date for producing silky materials using synthetic fibers, it is difficult to say that any technique exists that fully expresses the feel and appearance characteristic of silk. Therefore, an object of the present invention is to solve the problems of the prior art described above and to provide multifilaments, woven or knitted fabrics, and textile products that are suitable for obtaining comfortable clothing that has the characteristic creaky feel and luxurious, mild luster of silk, and also has functionality such as water absorption and diffusion.

[0014] The object of the present invention is achieved by the following means: (1) A multifilament in which modified cross-section fibers having different cross-sectional shapes are dispersed and mixed, the modified cross-section fibers have 3 to 20 recesses continuous in the fiber axis direction, and the ratio of the maximum depth of the recesses between the modified cross-section fibers is 1.1 to 5.0, (2) The multifilament according to (1), in which the degree of irregularity of the modified cross-section fibers is 1.1 to 2.5, (3) A textile product at least partially containing the multifilament according to (1) or (2), (4) A textile product comprising a multifilament in which modified cross-section fibers having different cross-sectional shapes are dispersed and mixed, in which the static friction coefficient of the fabric surface is 0.5 to 2.0 and the variation in the dynamic friction coefficient is 1.0 x 10 －２ ~5.0 x 10 －２ (5) A woven or knitted fabric according to (4), having a contrast gloss of 1.0 to 2.5 on the fabric surface; (6) A garment at least partially comprising the woven or knitted fabric according to (4) or (5); (7) A multifilament in which conjugated fibers having different conjugated cross sections are dispersed and mixed, the conjugated fibers being composed of a hardly soluble component and an easily soluble component, the hardly soluble component of the conjugated fiber having 3 to 20 continuous recesses in the fiber axial direction, and the ratio of the maximum depth of the recesses of the hardly soluble component between the conjugated fibers being 1.1 to 5.0; (8) The multifilament according to (7), having a ratio of the irregularities between the conjugated fibers being 1.1 to 2.0; (9) A multifilament from which the easily soluble component has been removed from the conjugated fiber according to (7) or (8); (10) A textile product at least partially comprising the multifilament according to (9).

[0015] The multifilament, woven or knitted fabric, and textile product of the present invention can form uneven spots on the surface of the fabric and void spots inside the fabric, so that comfortable clothing can be obtained that has the characteristic rustling feel and luxurious, mild luster of silk, and also has functionality such as water absorption and diffusion properties.

[0016] (a), (b), (c), and (d) of Figure 1 are schematic diagrams showing an example of a composite cross section in a composite fiber of the present invention. (a), (b), (c), and (d) of Figure 2 are schematic diagrams showing an example of a composite cross section in a composite fiber of the present invention. Figure 3 is a schematic diagram showing an example of the cross-sectional structure of a multifilament made of the composite fiber of the present invention. 3-(a) and (b) of Figure 3 are diagrams for understanding that composite fibers are connected adjacently, and 3-(c) of Figure 3 is a diagram for understanding groups of adjacent filaments in a composite fiber of the present invention. (a), (b), (c), and (d) of Figure 4 are schematic diagrams showing an example of the cross-sectional shape in a modified cross-section fiber of the present invention. (a), (b), (c), and (d) of Figure 5 are schematic diagrams showing an example of the cross-sectional shape in a modified cross-section fiber of the present invention. Figure 6 is a schematic diagram showing an example of the cross-sectional structure of a multifilament made of a modified cross-section fiber of the present invention. 6-(a) and 6-(b) in Fig. 6 are diagrams for understanding that the modified cross-section fibers are adjacently connected, and Fig. 6-(c) is a diagram for understanding adjacent filament groups of the modified cross-section fiber in the present invention. Fig. 7 is a cross-sectional view of a spinneret for explaining the method for producing a multifilament made of a composite fiber of the present invention.

[0017] The present invention will be described in detail below together with preferred embodiments.

[0018] In pursuit of the mechanism behind the unique feel of silk, we reconsider its structure and find that numerous fibrils are bundled together to form irregular triangular cross sections. In other words, in silk, in addition to the large irregularities caused by the irregular cross section, the fine irregularities created by the fibrils increase friction, which is thought to create the characteristic squeaky feel of silk.

[0019] Even in conventional silky materials, a method of forming fine irregularities on the surface of the modified cross-section fiber by dissolving easily soluble components using a chemical such as alkali is sometimes used. However, when the inventors of the present invention performed a detailed evaluation of the frictional force between silk fabrics and silky materials made by conventional technology, they discovered that there are large differences in the fluctuations in the static and dynamic friction coefficients between silk and conventional materials.

[0020] In other words, with conventional materials, all fibers have the same cross-sectional shape, so when woven or knitted, the unevenness formed on the surface of the fabric is uniform, whereas with silk, being a natural material, the cross-sectional shape of each individual fiber and the size of the fibrils vary, so when woven or knitted, unevenness forms on the surface of the fabric. This makes the unevenness more likely to catch on fingertips, increasing the static friction coefficient and also increasing the fluctuation in the dynamic friction coefficient, resulting in the characteristic squeaky feel of silk. Furthermore, the diffuse reflection of light due to the unevenness and the light diffusion due to the unevenness combine to create a luxurious, mild luster.

[0021] The present invention is based on this idea, and for the purpose of forming the complex unevenness exhibited by silk described above, it is important that in the multifilament of the present invention, composite fibers with different composite cross sections are dispersed and mixed, the composite fibers are composed of a hardly-soluble component and an easily-soluble component, the hardly-soluble component of the composite fiber has 3 to 20 recesses that are continuous in the fiber axis direction, and the ratio of the maximum depths of the recesses of the hardly-soluble components among the composite fibers is 1.1 to 5.0 (hereinafter, this may be referred to as a "multifilament made of composite fibers"); or that modified cross-section fibers with different cross-sectional shapes are dispersed and mixed, the modified cross-section fibers have 3 to 20 recesses that are continuous in the fiber axis direction, and the ratio of the maximum depths of the recesses among the modified cross-section fibers is 1.1 to 5.0 (hereinafter, this may be referred to as a "multifilament made of modified cross-section fibers").

[0022] As the polymers constituting the multifilament of the present invention, thermoplastic polymers are preferred because they have excellent processability. For example, polymers constituting the fiber are preferably polyester, polyethylene, polypropylene, polystyrene, polyamide, polycarbonate, polymethyl methacrylate, polyphenylene sulfide, and copolymers thereof. From the viewpoint of imparting particularly high interfacial affinity and obtaining fibers without composite cross-section abnormalities, it is preferable that all thermoplastic polymers used in the composite fiber are from the same polymer group and copolymers thereof. Furthermore, polyester-based combinations are particularly preferred from the viewpoints of not only achieving a bending rigidity similar to that of silk, but also improving the appropriate fluffiness and quick-drying properties of the fibers under friction, as described below. The polymers may also contain various additives, such as inorganic substances such as titanium oxide, silica, and barium oxide; colorants such as carbon black, dyes, and pigments; flame retardants; fluorescent brighteners; antioxidants; and ultraviolet absorbers.

[0023] Furthermore, with environmental issues receiving increasing attention, the use of plant-derived biopolymers and recycled polymers in the present invention is also preferable from the viewpoint of reducing the environmental impact, and the polymers used in the present invention described above can be recycled polymers recycled by any of chemical recycling, material recycling, and thermal recycling methods. Even when using biopolymers or recycled polymers, polyester resins can accentuate the features of the present invention as their polymer properties. As described above, it is more preferable to use biopolyesters or recycled polyesters from the viewpoint of obtaining bending rigidity and good color development similar to that of silk.

[0024] <Multifilament made of composite fiber> In the multifilament made of the composite fiber of the present invention, in order to create unevenness in the unevenness formed on the fabric surface and to accentuate the creaky feeling and the luxurious, mild luster, it is necessary for composite fibers with different composite cross sections to be dispersed and mixed.

[0025] The term "composite fiber" as used herein refers to a single fiber composed of two or more polymers. Furthermore, "different composite cross sections" refers to fibers with different cross-sectional shapes or interfacial shapes between polymers in their transverse cross sections. Fibers with different cross-sectional areas but similar cross-sectional shapes or interfacial shapes are considered to be the same composite cross section.

[0026] In the present invention, the state in which conjugate fibers having different conjugate cross sections are dispersed and mixed means that, when the cross section of the multifilament is observed, the multifilament is composed of conjugate fibers having different conjugate cross sections, and at least one type of conjugate fiber is present without bias. The presence or absence of this bias can be evaluated by the adjacent filament group ratio of the conjugate fiber, which will be described later.

[0027] In the present invention, the adjacent filament group of composite fibers refers to a collection of five or more composite fibers having the same composite cross section that are adjacently connected in the cross section of the multifilament. The adjacent filament group ratio of composite fibers is expressed as Ns / N, where Ns is the total number of composite fibers constituting the adjacent filament group and N is the total number of multifilaments. Adjacently connected composite fibers refer to the absence of any composite fiber having the same composite cross section between any composite fiber and the closest composite fiber having the same composite cross section, as shown in 3-(a) and 3-(b) in Figure 3. Furthermore, when five or more of these fibers are adjacently connected, as shown in 3-(c), the collection is defined as an adjacent filament group. Furthermore, when there are multiple adjacent filament groups in the cross section of the multifilament, the total number of composite fibers constituting them is the total number Ns of composite fibers constituting the adjacent filament groups.

[0028] That is, the adjacent filament group ratio of the composite fiber referred to in the present invention refers to a value measured by the following method. Specifically, the multifilament is embedded in an embedding agent such as epoxy resin, and 10 images of the cross section are randomly taken using a scanning electron microscope (SEM) or the like at a magnification that allows observation of 20 or more composite fibers with different composite cross sections. In this case, if metal staining is applied, the dyeing difference between the polymers can be utilized to clarify the contrast of the composite cross section. In each captured image, the number of composite fibers constituting adjacent filament groups is counted. From this measurement result, the adjacent filament group ratio = (number of composite fibers constituting adjacent filament groups) / (total number of composite fibers photographed) × 100 (%) is calculated. This procedure is performed for the 10 captured images, and the simple number average, rounded to the nearest whole number, is the adjacent filament group ratio of the composite fiber referred to in the present invention.

[0029] When composite fibers with different composite cross sections are not mixed evenly in the multifilament, as in general post-mixed yarns, but are unevenly present, the ratio of adjacent filament groups becomes greater than 80%, and composite fibers of the same type tend to be crowded together, which may make it difficult to create the unevenness in the unevenness formed on the fabric surface that is the objective of this invention.

[0030] On the other hand, the present invention is characterized in that conjugate fibers with different conjugate cross sections are dispersed and mixed. When this state is evaluated in terms of the adjacent filament group ratio, an adjacent filament group ratio of the conjugate fibers constituting the multifilament of 0 to 80% represents the intended dispersed and mixed state of the conjugate fibers of the present invention.

[0031] Pursuing this idea, it is preferable that the adjacent filament group ratio of the composite fiber is low, and it is preferable that the adjacent filament group ratio is 0 to 60%. Within this range, composite fibers having different composite cross sections are present around the composite fibers dispersed in the multifilament, making it possible to suppress interlocking of the unevenness between the fibers. As a result, the unevenness caused by the different composite cross sections can be maximized, and when the fabric is made into a woven or knitted fabric, unevenness is created in the unevenness of the fabric surface, allowing for the characteristic rustling feel of silk and a luxurious, mild luster to be expressed.

[0032] In the multifilament made of the conjugated fiber of the present invention, from the viewpoint that the irregularities formed on the fiber surface are not caught during advanced processing such as weaving and knitting and that irregularities can be produced on the surface of the fabric when it is made into a fabric, it is necessary that the conjugated fiber is made of a hardly soluble component and an easily soluble component, and that the hardly soluble component of the conjugated fiber has 3 to 20 continuous recesses in the fiber axial direction.

[0033] The terms "hardly soluble component" and "easily soluble component" used herein refer to components that have different elution rates in a solvent. The polymer component that has the fastest elution rate among the polymer components constituting the composite fiber is the easily soluble component, and the other polymer components are hard to elute.

[0034] The multifilament made of the conjugate fiber of the present invention is intended to be obtained by subjecting the easily soluble components to elution after advanced processing such as weaving and knitting to obtain a multifilament made of only the hardly soluble components.

[0035] Therefore, the greater the dissolution rate ratio of the hardly soluble component to the easily soluble component in the solvent, the more preferable the combination. Regarding the dissolution rate of the polymer forming the easily soluble component, taking into consideration the simplification and time reduction of the dissolution treatment in advanced processing, the dissolution rate ratio (hardly soluble component / easily soluble component) is preferably 100 or more, and more preferably 1,000 or more, when the polymer forming the hardly soluble component has the fastest dissolution rate as the reference. Setting the dissolution rate ratio to 1,000 or more allows the dissolution treatment to be completed in a short time, thereby increasing the process speed and preventing unnecessary deterioration of the polymer of the hardly soluble component, thereby enabling the production of a higher quality fabric. From this perspective, the greater the dissolution rate ratio, the more preferable it is, but the practical upper limit is 10,000 or less due to the stability of the polymer forming the easily soluble component.

[0036] The polymer forming the easily soluble component is preferably selected from polymers that are melt-moldable and exhibit greater solubility than other components, such as polyesters and copolymers thereof, polylactic acid, polyamides, polystyrene and copolymers thereof, polyethylene, and polyvinyl alcohol.

[0037] Furthermore, from the viewpoint of simplifying the elution process of the easily eluted component, the polymer forming the easily eluted component is preferably a copolymer polyester, polylactic acid, polyvinyl alcohol, or the like, which is easily soluble in aqueous solvents or hot water. In particular, polyester copolymerized with 5 mol % to 15 mol % of 5-sodium sulfoisophthalic acid and polyester copolymerized with the aforementioned 5-sodium sulfoisophthalic acid and 5% to 15% by mass of polyethylene glycol having a weight-average molecular weight of 500 to 3,000 are preferred. These polymers are easily soluble in aqueous solvents such as alkaline aqueous solutions while maintaining their crystallinity, and are therefore preferred from the viewpoint of passability in advanced processing, in that fusion between composite fibers does not occur even in false twisting and other processes in which abrasion is applied under heat.

[0038] In the multifilament made of the conjugated fiber of the present invention, in order to obtain the static friction coefficient required to produce the creaky feeling characteristic of silk, it is important that the hardly soluble component of the conjugated fiber has three or more recesses that are continuous in the fiber axis direction.

[0039] The recesses continuous in the fiber axis direction in the present invention mean recesses having a length in the fiber axis direction of 100 μm or more.

[0040] If the hardly-soluble component of the composite fiber has three or more continuous recesses in the fiber axis direction, when the readily soluble component is eluted after advanced processing such as weaving or knitting to form a multifilament composed of the hardly-soluble component, unevenness can be stably formed on the fabric surface, increasing the static friction coefficient, and the unevenness can also diffuse light and provide a mild luster. For example, it is preferable that the hardly-soluble component of the composite fiber has a multilobal shape as shown in Figures 1(a) to 1(c). Furthermore, if the cross-sectional shape is multilobal as shown in Figures 1(d) and 2(a) to 2(d), and the protrusions have grooves at their tips, it is easy to form recesses of different depths in the hardly-soluble component, and it is possible to provide variation in the unevenness of the hardly-soluble component in each composite fiber. Furthermore, as described below, when the composite fiber is made into a woven or knitted fabric, unevenness is easily formed on the fabric surface, which can increase the variation in the dynamic friction coefficient and provide a mild luster, and is therefore a particularly preferred example.

[0041] From the viewpoint of frictional force and gloss, the more recesses there are in the hardly soluble component, the better, but if the number of recesses is too large, the static friction coefficient becomes excessively large, and the hardly soluble component may catch on the skin too strongly, causing discomfort, so that the number of recesses in the hardly soluble component in the present invention is preferably 20 or less.Furthermore, if the number of recesses in the hardly soluble component is 15 or less, the frequency of fluffing that occurs when the recesses and protrusions are peeled off by friction falls within an appropriate range, and good abrasion resistance can also be achieved, which is more preferable.

[0042] In the multifilament made of the conjugated fiber of the present invention, in order to obtain the variation in dynamic friction coefficient required to produce the creaking feeling characteristic of silk, it is important to set the ratio of the maximum depths of the recesses of the hardly soluble components between the conjugated fibers to 1.1 to 5.0.

[0043] The depth of the recesses of the hardly soluble components and the ratio of the maximum depth of the recesses of the hardly soluble components between composite fibers referred to in the present invention refer to values ​​measured by the following method. That is, a multifilament is embedded in an embedding agent such as epoxy resin, and an image of the cross section is taken using a scanning electron microscope (SEM) or the like at a magnification such that 20 or more composite fibers can be observed. In this case, if metal staining is applied, the dye difference between the polymers can be utilized to clarify the contrast of the composite cross section. For composite fibers randomly sampled from the captured image, for example, as shown in FIG. 1( a), a line m is drawn that intersects the periphery of the hardly soluble components at only two points (point j, point k). Of the points on the periphery of the hardly soluble components that intersect with a line perpendicular to line m between the two points, the distance s (μm) between the line m and the point farthest from line m is rounded to one decimal place, and this value is taken as the depth (μm) of the recesses of the hardly soluble components. This procedure is also performed for all lines that intersect with the periphery of the hardly soluble components at only two points, and the largest of the obtained distances s is taken. ｍａｘ The value of s is rounded off to two decimal places and the value is taken as the maximum depth (μm) of the recess of the hardly soluble component. ｍａｘ The obtained s ｍａｘ The maximum value is divided by the minimum value, and the value is rounded to one decimal place to obtain the ratio of the maximum depth of the recesses of the hardly soluble component between the composite fibers.

[0044] If the ratio of the maximum depths of the recesses of the hardly-soluble components between the composite fibers is 1.1 or more, when the readily soluble components are eluted to form a multifilament composed of the hardly-soluble components after advanced processing such as weaving or knitting, variations in the recesses formed on the surface of the multifilament will occur. As a result, unevenness will be formed on the fabric surface, allowing for significant variations in the dynamic friction coefficient, and the unevenness will diffuse light, resulting in a mild luster. The greater the ratio of the maximum depths of the recesses of the hardly-soluble components, the more preferable this variation in the dynamic friction coefficient will be. A maximum depth ratio of 1.5 or more is preferable because unevenness can be exhibited regardless of the weaving or knitting structure, allowing for greater variations in the dynamic friction coefficient. Furthermore, a maximum depth ratio of 2.0 or more is even more preferable because it allows for the formation of unevenness of large and small voids within the fabric, thereby enabling sufficient water absorption and diffusion due to capillary action.

[0045] However, if the ratio of the maximum depths of the recesses of the hardly soluble components between the composite fibers becomes too large, the effect of the recesses with a small maximum depth becomes small, which may result in suppression of fluctuations in the dynamic friction coefficient and mild gloss, and therefore the substantial upper limit of the ratio of the maximum depths of the recesses between the modified cross-section fibers in the present invention is 5.0.

[0046] In a multifilament made of the composite fiber of the present invention, from the viewpoint of generating variations in the recesses formed on the surface of the multifilament, forming unevenness on the fabric surface, and increasing the fluctuation in the dynamic friction coefficient, it is preferable that the hardly soluble component of the composite fiber has recesses that are continuous in the fiber axis direction and have different depths.

[0047] If the hardly-soluble component of the composite fiber has continuous recesses of different depths in the fiber axis direction, not only can the unevenness of the hardly-soluble component vary among the composite fibers, but also the unevenness of the hardly-soluble component can be varied in each individual composite fiber. Therefore, when the resulting fabric is made into a woven or knitted fabric, unevenness is likely to form on the fabric surface, which can increase the variation in the dynamic friction coefficient and a mild gloss. In addition, the continuous presence of recesses of different depths in the fiber axis direction can increase the diffusion rate of water adhering to the fabric, thereby improving water absorption and diffusibility.

[0048] In the multifilament made of the conjugated fiber of the present invention, the irregularity ratio between the conjugated fibers is preferably 1.1 to 2.0, from the viewpoint that the irregularities formed on the fiber surface are not caught during advanced processing such as weaving and knitting, and irregularities can be expressed on the fabric surface when the fabric is made into a fabric.

[0049] The irregularity and the irregularity ratio between composite fibers in the present invention refer to values ​​measured by the following method. That is, a multifilament is embedded in an embedding agent such as epoxy resin, and an image of the cross section is taken using a scanning electron microscope (SEM) or the like at a magnification that allows observation of 20 or more composite fibers. For composite fibers randomly sampled from the photographed image, the inscribed circle diameter r of the composite fiber is A (diameter of A in Figure 2(a)) and circumscribed circle diameter r B (the diameter of B in Figure 2(a)) and calculate the circumscribed circle diameter r B The inscribed circle diameter r A The value r divided by B / r A The value obtained by rounding off to the second decimal place is the irregularity degree. This operation is also performed for all composite fibers present in the photographed image, and the obtained r B / r A The maximum value is divided by the minimum value, and the value is rounded to one decimal place to determine the ratio of the degree of irregularity between the composite fibers.

[0050] If the irregularity ratio between conjugate fibers is 1.1 or more, the difference in irregularity between adjacent conjugate fibers will create interfiber voids, and the irregularities on the fiber surface formed after the elution of the easily soluble components will not get caught, so that when fabric is made, unevenness can be sufficiently expressed on the fabric surface. Furthermore, if the irregularity ratio is 1.3 or more, unevenness of large and small voids will be formed inside the fabric, and water absorption and diffusion properties due to capillary action will be sufficiently expressed, which is more preferable.

[0051] However, if the irregularity ratio is too large, the irregularities formed on the surface of the fabric will be dominated by the irregularities on the highly irregular side, and unevenness due to different composite cross sections between composite fibers may not be obtained, so the substantial upper limit of the irregularity ratio is 2.0.

[0052] Furthermore, from the viewpoint of generating inter-fiber voids due to differences in the irregularity between adjacent conjugate fibers, it is preferable that the conjugate fiber on the low irregularity side is closer to a circular shape, so that the irregularities between the conjugate fibers do not interlock with each other, and the inter-fiber voids generated from the depressions of the hardly soluble components of the conjugate fiber can be maximized. Therefore, in the multifilament made of the conjugate fiber of the present invention, the irregularity of at least one type of conjugate fiber is preferably 1.0 to 1.5, and more preferably 1.0 to 1.2, since the inter-fiber voids are further increased and the increased voids inside the fabric also result in swelling.

[0053] In the multifilament made of the conjugate fiber of the present invention, the depth of the recesses of the hardly soluble component in the conjugate fiber is preferably 0.5 to 5.0 μm.

[0054] If the depth of the recesses is 0.5 μm or more, when the fabrics start to rub against each other, not only will the unevenness created by the recesses of the hardly soluble component of the composite fiber on the fabric surface interlock with each other, increasing the static friction coefficient, but also the unevenness created by the recesses of the hardly soluble component of the composite fiber peeling off due to friction, forming fuzz that is unevenly distributed in combination with the unevenness on the fabric surface, thereby further increasing the fluctuation in the dynamic friction coefficient on the fabric surface. From this perspective, the deeper the recesses, the more preferable, and if the depth of the recesses is 1.0 μm or more, the water absorption and diffusion properties can be improved by capillary action due to the voids in the recesses, making it even more preferable.

[0055] On the other hand, from the viewpoint of obtaining good abrasion resistance without deterioration of appearance quality due to fine fluff even when the irregularities peel off due to friction, the depth of the recesses is preferably 5.0 μm or less.Furthermore, if it is 4.0 μm or less, whitening due to fluff when dyed in a dark color can be suppressed, which is more preferable.

[0056] In the multifilament made of the conjugated fiber of the present invention, the ratio of fiber diameters between the conjugated fibers is preferably 1.1 to 2.0.

[0057] Here, the fiber diameter of the composite fiber and the fiber diameter ratio between composite fibers referred to in the present invention refer to values ​​measured by the following method. That is, the multifilament is embedded in an embedding agent such as epoxy resin, and an image of the fiber cross section perpendicular to the fiber axis is taken with a scanning electron microscope (SEM) at a magnification that allows observation of 20 or more composite fibers. The taken image is analyzed using image analysis software to calculate the cross-sectional area of ​​the fiber cross section of the composite fiber. From the obtained cross-sectional area, the diameter (μm) is calculated in terms of a perfect circle, and the value rounded to the nearest whole number is used as the fiber diameter of the composite fiber. In addition, the fiber diameters of all composite fibers are calculated, and the maximum value of the obtained fiber diameters is divided by the minimum value to obtain a value, and the value rounded to one decimal place is used as the fiber diameter ratio between composite fibers.

[0058] If the fiber diameter ratio between the composite fibers is 1.1 or more, when the multifilament of the present invention is spun by the blended spinning method described below, differences in fiber diameters will cause differences in fiber shrinkage after drawing, and when heat is applied to the fabric for dyeing, etc., the interfiber voids will increase, making it difficult for irregularities formed when the easily soluble components are eluted to interlock with each other, allowing for sufficient irregularities to appear on the fabric surface. However, if the fiber diameters differ significantly, yarn interference may occur during the blended spinning method, which may cause deterioration in spinnability, so the fiber diameter ratio is preferably 2.0 or less.

[0059] The multifilament made of the conjugate fiber of the present invention can be first made into various sheet-like fiber structures such as woven or knitted fabrics, nonwoven fabrics, and paper, and then the easily soluble components can be eluted to obtain a multifilament made of a less easily soluble component. In the multifilament from which the easily soluble components have been eluted, fibers with different irregularities are dispersed and mixed within the multifilament, which can form irregularities on the surface of the fabric and voids within the fabric. As a result, it is possible to obtain comfortable clothing that has the characteristic rustling feel and luxurious, mild luster of silk, as well as functionality such as water absorption and diffusion.

[0060] <Multifilament made of modified cross-section fibers> In the multifilament made of modified cross-section fibers of the present invention, it is necessary for modified cross-section fibers with different cross-sectional shapes to be dispersed and mixed together in order to create irregularities in the unevenness formed on the fabric surface and to accentuate the creaky feeling and luxurious mild luster.

[0061] Here, the modified cross-section fiber in the present invention is a fiber having a circumscribed circle diameter R B The inscribed circle diameter R A The term "different cross-sectional shapes" refers to single fibers having a value of 1.1 or more when divided by . Furthermore, "different cross-sectional shapes" means that the outer periphery of the fiber is different in the cross section of the fiber, and when the cross-sectional areas are different but the outer periphery shapes are similar, they are considered to have the same cross-sectional shape.

[0062] In the present invention, the state in which modified cross-section fibers having different cross-sectional shapes are dispersed and mixed means that, when the cross section of the multifilament is observed, the multifilament is composed of groups of modified cross-section fibers having different cross-sectional shapes, and at least one type of modified cross-section fiber is present without bias, and this can be evaluated by the ratio of adjacent filament groups of modified cross-section fibers described later.

[0063] In the present invention, the adjacent filament group of modified cross-section fibers refers to a collection of five or more adjacently connected modified cross-section fibers having the same cross-sectional shape in the cross section of the multifilament. The adjacent filament group ratio of modified cross-section fibers is expressed as Ns / N, where Ns is the total number of modified cross-section fibers constituting the adjacent filament group and N is the total number of multifilaments. The adjacently connected modified cross-section fibers mean that, as shown in 6-(a) and 6-(b) in Figure 6, there are no modified cross-section fibers with other cross-sectional shapes between any modified cross-section fiber and the modified cross-section fiber having the same cross-sectional shape that is closest to it. Furthermore, when five or more of these fibers are adjacently connected, as shown in 6-(c), the collection is defined as an adjacent filament group. Furthermore, when there are multiple adjacent filament groups in the cross section of the multifilament, the total number of modified cross-section fibers constituting them is the total number Ns of modified cross-section fibers constituting the adjacent filament groups.

[0064] The adjacent filament group ratio of the modified cross-section fiber referred to in the present invention refers to a value measured by the following method. Specifically, a multifilament is embedded in an embedding agent such as epoxy resin, and 10 images of the cross-section are randomly taken using a scanning electron microscope (SEM) or the like at a magnification such that 20 or more modified cross-section fibers with different cross-sectional shapes can be observed. In each of the images taken, the number of modified cross-section fibers constituting adjacent filament groups is counted. From the measurement results, the adjacent filament group ratio = (number of modified cross-section fibers constituting adjacent filament groups) / (total number of modified cross-section fibers photographed) × 100 (%) is calculated. This procedure is performed for the 10 photographed images, and the simple number average, rounded to the nearest whole number, is the adjacent filament group ratio of the modified cross-section fiber referred to in the present invention.

[0065] When irregular cross-section fibers with different cross-sectional shapes are not mixed evenly in the multifilament as in general post-blended yarns but are unevenly present, the ratio of adjacent filament groups becomes larger than 80%, and irregular cross-section fibers of the same type tend to be crowded together, which may make it difficult to produce the unevenness formed on the fabric surface as intended by the present invention.

[0066] On the other hand, the present invention is characterized in that modified cross-section fibers having different cross-sectional shapes are dispersed and mixed. When this state is evaluated by the adjacent filament group ratio, if the adjacent filament group ratio of the modified cross-section fibers constituting the multifilament is 0 to 80%, it represents the desired dispersed and mixed state of the modified cross-section fibers of the present invention.

[0067] Pursuing this idea, it is preferable that the adjacent filament group ratio of the modified cross-section fiber is low, and the adjacent filament group ratio is preferably 0 to 60%. Within this range, modified cross-section fibers having different cross-sectional shapes are present around the modified cross-section fibers dispersed in the multifilament, and it is possible to suppress the interlocking of the irregularities between the fibers. Therefore, the unevenness caused by the different cross-sectional shapes can be maximized, and when the fabric is made into a woven or knitted fabric, unevenness is created on the surface of the fabric, allowing it to exhibit the characteristic rustling feel and luxurious, mild luster of silk.

[0068] In the multifilament made of the modified cross-section fiber of the present invention, in order to obtain the static friction coefficient necessary to express the creaking feeling characteristic of silk, it is important that the modified cross-section fiber has three or more continuous recesses in the fiber axis direction.

[0069] The recesses continuous in the fiber axis direction in the present invention mean recesses having a length in the fiber axis direction of 100 μm or more.

[0070] If the modified cross-section fiber has three or more continuous recesses in the fiber axis direction, it is possible to stably form unevenness on the surface of a fabric obtained by weaving, knitting, etc., thereby increasing the static friction coefficient, and furthermore, from the viewpoint that the unevenness diffuses light and gives a mild gloss, it is preferable that the cross-sectional shape is multi-lobed, for example, as shown in Figures 4(a) to (c).Furthermore, if the multi-lobed shape has grooves at the tips of the protrusions, as shown in Figures 4(d) and 5(a) to (d), it is possible to form recesses of different depths on the fiber surface, and it is possible to give variation to the unevenness of each modified cross-section fiber.In addition, as will be described later, when the fabric is made into a woven or knitted fabric, unevenness is easily formed on the surface of the fabric, which can also increase the variation in the dynamic friction coefficient and give a mild gloss, and is therefore a particularly preferred example.

[0071] From the viewpoint of frictional force and gloss, the more recesses there are in the modified cross-section fiber, the better. However, if the number of recesses is too large, the static friction coefficient becomes excessive, and the fiber may catch on the skin strongly, causing discomfort. Therefore, it is preferable that the number of recesses in the modified cross-section fiber of the present invention is 20 or less. Furthermore, if the number of recesses of the hardly soluble component is 15 or less, the frequency of fluffing that occurs when the recesses are peeled off by friction falls within a moderate range, and good abrasion resistance can also be achieved, which is more preferable.

[0072] In the multifilament made of the modified cross-section fibers of the present invention, in order to obtain the variation in dynamic friction coefficient necessary to produce the creaking feeling characteristic of silk, it is important that the ratio of the maximum depths of the recesses between the modified cross-section fibers be 1.1 to 5.0.

[0073] The depth of the recesses of the modified cross-section fiber and the ratio of the maximum depth of the recesses between the modified cross-section fibers referred to in the present invention refer to values ​​measured by the following method. That is, a multifilament is embedded in an embedding agent such as epoxy resin, and an image of the cross-section is taken using a scanning electron microscope (SEM) or the like at a magnification such that 20 or more modified cross-section fibers can be observed. For the modified cross-section fibers randomly selected from the image, a line M is drawn that intersects with the periphery of the modified cross-section fiber at only two points J and K, as shown in Figure 4(a), and the distance S (μm) between the point on the periphery of the modified cross-section fiber that intersects with a line perpendicular to the line M between the two points and the point farthest from the line M is rounded to one decimal place, and this value is taken as the depth of the recesses (μm) of the modified cross-section fiber. This operation is also performed for all the lines that intersect with the periphery of the modified cross-section fiber at only two points, and the largest S among the obtained distances S is taken. ｍａｘ The value obtained by rounding off the value to the second decimal place is defined as the maximum depth (μm) of the recess of the modified cross-section fiber. ｍａｘ The obtained S ｍａｘ The maximum value is divided by the minimum value, and the value is rounded to one decimal place to obtain the ratio of the maximum depth of the recesses between the modified cross section fibers.

[0074] If the ratio of the maximum depths of the recesses between the modified cross-section fibers is 1.1 or more, variations in the recesses formed on the multifilament surface occur. As a result, unevenness is formed on the surface of the fabric obtained by weaving, knitting, etc., allowing for large variations in the dynamic friction coefficient. In addition, the unevenness diffuses light, resulting in a mild luster. The greater the ratio of the maximum depths of the recesses between the modified cross-section fibers, the more preferable this variation in the dynamic friction coefficient is. A maximum depth ratio of 1.5 or more is preferable because unevenness can be exhibited regardless of the weaving or knitting structure, allowing for greater variations in the dynamic friction coefficient and an enhanced mild luster. Furthermore, a maximum depth ratio of 2.0 or more is even more preferable because it forms unevenness of large and small voids inside the fabric, allowing for sufficient water absorption and diffusion due to capillary action.

[0075] However, if the ratio of the maximum depths of the recesses between the modified cross-section fibers becomes too large, the effect of the recesses with a small maximum depth becomes small, which may suppress fluctuations in the dynamic friction coefficient and mild gloss, and therefore the substantial upper limit of the ratio of the maximum depths of the recesses between the modified cross-section fibers in the present invention is 5.0.

[0076] In the multifilament made of the modified cross-section fiber of the present invention, it is preferable to have continuous recesses in the fiber axis direction with different depths, from the viewpoint of generating variations in the recesses formed on the multifilament surface, forming unevenness on the fabric surface, and increasing the fluctuation in the dynamic friction coefficient.

[0077] If the modified cross-section fibers have continuous recesses of different depths in the fiber axis direction, it is possible to provide variations in the recesses among the modified cross-section fibers. Therefore, when the modified cross-section fibers are made into a woven or knitted fabric, unevenness is easily formed on the surface of the fabric, which not only increases the variation in the dynamic friction coefficient and the mild gloss, but also increases the diffusion rate of water adhering to the fabric due to the continuous presence of recesses of different depths in the fiber axis direction, thereby improving the water absorption and diffusion properties.

[0078] In the multifilament made of the modified cross-section fiber of the present invention, from the viewpoint that the irregularities formed on the fiber surface are not caught and irregularities can be produced on the fabric surface, it is preferable that the irregularity ratio between the modified cross-section fibers is 1.1 to 2.0.

[0079] The irregularity and the irregularity ratio between modified cross-section fibers in the present invention refer to values ​​measured by the following method. That is, a multifilament is embedded in an embedding agent such as epoxy resin, and an image of the cross section is taken using a scanning electron microscope (SEM) or the like at a magnification such that 20 or more modified cross-section fibers can be observed. In the modified cross-section fibers randomly sampled from the photographed image, the inscribed circle diameter R of the modified cross-section fiber is A (diameter of A in Figure 5) and circumscribed circle diameter R B (diameter of B in Figure 5) and calculate the circumscribed circle diameter R B The inscribed circle diameter R A The value R divided by B / R AThe value obtained by rounding off to the second decimal place is the irregularity degree. This operation is also performed for all composite fibers present in the photographed image, and the obtained R B / R A The maximum value is divided by the minimum value, and the value is rounded off to one decimal place to determine the ratio of the irregularity between the irregular cross-section fibers.

[0080] If the irregularity ratio between the modified cross-section fibers is 1.1 or more, the difference in irregularity between adjacent modified cross-section fibers will create inter-fiber voids, preventing the irregularities on the fiber surface from getting caught, and allowing unevenness to be fully expressed on the fabric surface. Furthermore, if the irregularity ratio is 1.3 or more, unevenness of large and small voids will be formed inside the fabric, allowing water absorption and diffusion properties to be fully expressed by capillary action, which is more preferable.

[0081] However, if the irregularity ratio is too large, the irregularities formed on the fabric surface will be dominated by the irregularities on the highly irregular side, and unevenness due to the different cross-sectional shapes between the irregular cross-section fibers may not be obtained, so the substantial upper limit of the irregularity ratio between the irregular cross-section fibers is 2.0.

[0082] In the multifilament made of the modified cross-section fiber of the present invention, it is preferable that the degree of irregularity of the modified cross-section fiber is 1.1 to 2.5, from the viewpoint that gloss irregularities such as glare that are unique to synthetic fibers can be suppressed and that a luxurious, mild gloss like silk can be enhanced.

[0083] In the modified cross-section fiber of the present invention, if the degree of modification of the modified cross-section fiber is 1.1 to 2.5, the cross-sectional shape is low, so the slope of the recesses is gentle, and specular reflection of light by the slope of the recesses can be suppressed. This is preferable because it can suppress gloss spots such as glare that are unique to synthetic fibers and enhance a luxurious, mild gloss like silk.

[0084] Furthermore, if the irregularity degree is 1.1 to 2.0, in addition to the above-mentioned glossiness, the gradient of the recesses is sufficiently gentle, so that when the fabrics start to rub against each other, sufficient pressure is applied, so that the irregularities caused by the irregular cross-sections on the fabric surface interlock with each other, increasing the static friction coefficient. On the other hand, if the pressure weakens during rubbing, the irregularities caused by the irregular cross-sections become less likely to interlock, reducing the dynamic friction coefficient. This increases the difference between the static and dynamic friction coefficients, and enhances the moist feel unique to natural materials, including silk, which was difficult to achieve with conventional synthetic fibers, making this more preferable.

[0085] In the multifilament made of the modified cross-section fiber of the present invention, the depth of the recesses of the modified cross-section fiber is preferably 0.5 to 5.0 μm.

[0086] If the depth of the recesses is 0.5 μm or more, when the fabrics start to rub against each other, not only will the irregular cross-sections on the fabric surface mesh with each other to increase the static friction coefficient, but the irregular cross-section fibers will peel off due to friction to form fluff, which will be unevenly distributed in combination with the irregular surface irregularities on the fabric, thereby further increasing the fluctuation in the dynamic friction coefficient on the fabric surface, which is preferable. From this perspective, the deeper the recesses, the more preferable, and if the depth of the recesses is 1.0 μm or more, it is even more preferable because the water absorption and diffusion properties can be improved by the capillary phenomenon caused by the voids in the recesses.

[0087] On the other hand, from the viewpoint of obtaining good abrasion resistance without deterioration of appearance quality due to fine fluff even when the irregularities peel off due to friction, the depth of the recesses is preferably 5.0 μm or less, and more preferably 4.0 μm or less, since whitening due to fluff can be suppressed when dyed in a dark color.

[0088] In the multifilament made of modified cross-section fibers of the present invention, the ratio of fiber diameters between the modified cross-section fibers is preferably 1.1 to 2.0.

[0089] Here, the fiber diameter of the modified cross-section fiber and the fiber diameter ratio between modified cross-section fibers in the present invention refer to values ​​measured by the following method. That is, the multifilament is embedded in an embedding agent such as epoxy resin, and an image of the fiber cross-section perpendicular to the fiber axis is taken with a scanning electron microscope (SEM) at a magnification such that 20 or more modified cross-section fibers can be observed. The taken image is analyzed using image analysis software to calculate the cross-sectional area of ​​the fiber cross-section of the modified cross-section fiber. From the obtained cross-sectional area, the diameter (μm) is calculated in terms of a perfect circle, and the value rounded to the nearest whole number is used as the fiber diameter of the modified cross-section fiber. In addition, the fiber diameters of all modified cross-section fibers are calculated, and the maximum value of the obtained fiber diameters is divided by the minimum value to obtain a value, and the value rounded to one decimal place is used as the fiber diameter ratio between modified cross-section fibers.

[0090] If the fiber diameter ratio between the modified cross-section fibers is 1.1 or more, when the multifilament of the present invention is spun by the blended spinning method described below, differences in fiber diameters will result in differences in fiber shrinkage after drawing, and the inter-fiber voids will increase when heat is applied to the fabric for dyeing, etc. Therefore, irregularities due to the modified cross-sections will not easily interlock with each other, and unevenness can be fully expressed on the fabric surface. However, if the fiber diameters differ significantly, yarn interference may occur during the blended spinning method, which may cause deterioration in spinnability, so the fiber diameter ratio is preferably 2.0 or less.

[0091] In the fibers constituting the multifilament of the present invention, from the viewpoint of softness of texture, it is preferable that the fiber diameter is 30 μm or less. Furthermore, by making the fiber diameter 18 μm or less, it becomes suitable for general clothing applications such as innerwear, shirts, blouses, etc. that come into contact with the skin. However, if the fiber diameter is too small, bending recovery is reduced, and not only the resilience, which is one of the textures of silk, is impaired, but also color development may be reduced. Therefore, it is preferable that the fiber diameter is 8 μm or more.

[0092] <Textile Products> When a textile product contains at least a part of the multifilament of the present invention, uneven spots can be formed on the surface of the fabric and spots of voids can be formed inside the fabric, so that the fabric has the characteristic rustling feel of silk and a luxurious, mild luster, while also providing functionality such as water absorption and diffusion. Therefore, the multifilament of the present invention can be suitably used for a wide range of textile products, from general clothing such as jackets, skirts, pants, and underwear to clothing applications such as sportswear and clothing materials, and, taking advantage of its comfort, for interior products such as carpets and sofas, vehicle interior parts such as car seats, and daily uses such as cosmetics, cosmetic masks, and health products.

[0093] Furthermore, from the viewpoint of being able to reproduce the characteristic creaking feeling and luxurious mild luster of silk, it is particularly preferable to use it for clothing applications such as Western and Japanese clothing, which are primarily made of silk.

[0094] The multifilament of the present invention can be used for various textiles such as nonwoven fabrics and woven and knitted fabrics, but from the viewpoint of suitability for the above-mentioned clothing applications, it is preferable to use the multifilament of the present invention in a woven or knitted fabric at least in part.

[0095] The weave of the woven or knitted fabric of the present invention is not particularly limited. Examples of weaves for woven fabrics include plain weave, twill weave, satin weave, varied plain weave, varied twill weave, varied satin weave, variegated weave, patterned weave, single-layer weave, double weave, multiple weave, warp pile weave, weft pile weave, and leno weave. Examples of knitted fabrics include circular knit, weft knit, warp knit (including tricot knit and raschel knit), pile knit, plain knit, jersey knit, rib knit, smooth knit (double knit), rib knit, pearl knit, Denbigh knit, cord weave, atlas weave, chain weave, and insertion weave. While any weave is acceptable for both woven and knitted fabrics, a weave that is more likely to produce unevenness, such as a twill weave, is preferred over a plain weave, as it is more likely to form unevenness on the fabric surface. Furthermore, when blended with other fibers, a weave in which the multifilament of the present invention is more prominent on the fabric surface is desirable.

[0096] <Woven / knitted fabric> In the woven / knitted fabric of the present invention, in order to create a mottled texture on the surface of the fabric and to accentuate the characteristic rustling feel of silk and the luxurious, mild luster, it is important that the fabric contains multifilaments in which modified cross-sectional fibers with different cross-sectional shapes are dispersed and mixed.

[0097] The woven or knitted fabric of the present invention contains multifilaments in which modified cross-section fibers having different cross-sectional shapes are dispersed and mixed, which means that when a cross section of the woven or knitted fabric is observed perpendicular to the length direction (MD direction) of the fabric and perpendicular to the fiber axis direction of the multifilaments, the multifilaments contain multifilaments made of modified cross-section fibers having different cross-sectional shapes, and at least one type of modified cross-section fiber is present without bias in the multifilaments. The presence or absence of this bias can be evaluated by the adjacent filament group ratio of the modified cross-section fibers described above.

[0098] When irregular cross-section fibers with different cross-sectional shapes are not mixed evenly in the multifilament as in general post-blended yarns but are unevenly present, the ratio of adjacent filament groups becomes larger than 80%, and irregular cross-section fibers of the same type tend to be crowded together, which may make it difficult to produce unevenness on the surface of the woven or knitted fabric as intended by the present invention.

[0099] On the other hand, the woven or knitted fabric of the present invention is characterized in that modified cross-section fibers having different cross-sectional shapes are dispersed and mixed. When this state is evaluated in terms of the adjacent filament group ratio, if the adjacent filament group ratio of the modified cross-section fibers constituting the multifilament is 0 to 80%, it represents the desired dispersed and mixed state of modified cross-section fibers of the present invention.

[0100] Pursuing this idea, it is preferable that the adjacent filament group ratio of the modified cross-section fiber is low, and the adjacent filament group ratio is preferably 0 to 60%. Within this range, modified cross-section fibers having different cross-sectional shapes are present around the modified cross-section fibers dispersed in the multifilament, and it is possible to suppress the interlocking of the irregularities between the fibers. Therefore, the unevenness caused by the different cross-sectional shapes can be maximized, and when the fabric is made into a woven or knitted fabric, unevenness is created on the surface of the fabric, allowing it to exhibit the characteristic rustling feel and luxurious, mild luster of silk.

[0101] The woven or knitted fabric of the present invention contains multifilaments in which fibers with different cross-sectional shapes are dispersed and mixed, which creates unevenness on the surface of the fabric, and can produce the characteristic squeaky feel of silk. As for the friction performance, the static friction coefficient of the fabric surface is 0.5 to 2.0, and the variation of the dynamic friction coefficient is 1.0 × 10 －２ ~5.0 x 10 －２ It is important that

[0102] The static friction coefficient, dynamic friction coefficient, and variation in dynamic friction coefficient of the fabric surface referred to in the present invention are values ​​measured by the following measurement method. ２ An element with a geometric fingerprint pattern applied to urethane with a hardness equivalent to that of a fingertip is set on a contact terminal with an area of ​​1 mm. Next, a 20 g load is applied and the surface of the object is traced 30 mm at a speed of 10 mm / sec, and a friction curve representing the friction force (gf) versus the distance traveled is measured. Based on the obtained friction curve, the static and kinetic friction coefficients are calculated with reference to JIS K7125 (1999), and the values ​​rounded to one decimal place are used as the static and kinetic friction coefficients, respectively. In addition, the standard deviation of the kinetic friction coefficient values ​​in the range of 5 to 25 mm is calculated, and the value rounded to three decimal places is used as the variation in the kinetic friction coefficient.

[0103] The static friction coefficient of the fabric surface is 0.5 or more, and the fluctuation of the dynamic friction coefficient is 1.0 x 10 －２ If the coefficient of static friction is greater than or equal to this, the resistance when the fabrics are rubbed together is greater, and the fluctuation in the coefficient of dynamic friction is greater, resulting in the stick-slip characteristic of silk, making it possible to reproduce the creaky feeling characteristic of silk. From this perspective, the larger the fluctuations in the coefficient of static friction and the coefficient of dynamic friction, the more preferable it is. A coefficient of static friction of 0.8 or more and a fluctuation in the coefficient of dynamic friction of 1.5 × 10 －２ If the coefficient of static friction is 1.2 or more and the variation of the coefficient of dynamic friction is 2.0×10 or less, it is more preferable because the resulting fabric has a silk-like feel when made into clothing. －２ This is particularly preferable because it can also reproduce the characteristic of silk fabrics that are required for Japanese clothing and the like, such as their resistance to becoming unshaven.

[0104] On the other hand, if the fluctuations in the static friction coefficient and the dynamic friction coefficient become too large, the skin may feel uncomfortable due to the strong grip. Therefore, the static friction coefficient is set to 2.0 and the fluctuations in the dynamic friction coefficient are set to 5.0 × 10 －２ This is the practical upper limit.

[0105] In the woven or knitted fabric of the present invention, from the viewpoint of being able to obtain the moist feel that is unique to natural materials, in addition to the range of the static friction coefficient described above, it is preferable that the difference between the static friction coefficient and the dynamic friction coefficient of the fabric surface be 0.2 to 1.0.

[0106] In addition to the high static friction coefficient, a difference between the static and dynamic friction coefficients of 0.2 or more is preferable because the friction changes significantly from high at the start of rubbing the fabric to the friction during rubbing, thereby providing the moist feel that is unique to natural materials including silk, which has been difficult to achieve with conventional synthetic fibers.Furthermore, a difference between the static and dynamic friction coefficients of 0.5 or more provides a moist feel when the fabric touches the skin without applying pressure, such as by pinching the fabric with fingers, making this a more preferable range for clothing applications.

[0107] However, if the difference between the static friction coefficient and the kinetic friction coefficient becomes too large, the static friction coefficient becomes excessively large or the kinetic friction coefficient becomes excessively small. If the static friction coefficient is excessively large, the surface may catch on the skin too strongly, causing discomfort, while if the kinetic friction coefficient is excessively small, friction may not be felt during rubbing. Therefore, the practical upper limit of the difference between the static friction coefficient and the kinetic friction coefficient is 1.0.

[0108] In the woven or knitted fabric of the present invention, the contrast gloss of the fabric surface is preferably 1.0 to 2.5, from the viewpoint that the unevenness of the fiber surface diffuses light, thereby providing a luxurious, mild luster like silk.

[0109] The contrast gloss of the fabric surface referred to here refers to a value measured using an automatic variable-angle photometer (for example, the GONIOPHOTOMETER GP-200 manufactured by Murakami Color Research Laboratory). Light is incident on each sample at an incident angle of 60°, and the light intensity at acceptance angles of 0° to 90° is determined in 0.1° increments by two-dimensional reflected light distribution measurement. The maximum light intensity (specular reflection) near an acceptance angle of 60° is divided by the minimum light intensity (diffuse reflection) near an acceptance angle of 0° to calculate the value. This process is performed three times per location, and a simple number average of the results for a total of 10 locations is calculated. The value rounded to one decimal place is used as the contrast gloss.

[0110] A specific gloss of the fabric surface of 2.5 or less is preferable because it minimizes the difference between specular reflection and diffuse reflection, resulting in a luxurious, mild gloss like silk. From this perspective, a lower specific gloss is more preferable, and a specific gloss of 2.0 or less is more preferable because it reduces the viewing angle dependency of gloss. In particular, a specific gloss of 1.5 or less is even more preferable because it allows for a uniform gloss to be obtained regardless of the viewing angle. Furthermore, although a lower specific gloss is more preferable, the lower limit is when there is no difference between specular reflection and diffuse reflection, so the actual lower limit is 1.0.

[0111] In the woven or knitted fabric of the present invention, the frequency of fluff having a width of 0.5 to 5.0 μm on the surface of the fabric after a pilling test (JIS L 1076 (2012) C method) is 100 to 5,000 pieces / mm ２ It is preferable that:

[0112] The term "fuzz frequency" as used herein refers to a value measured by the following method. That is, after a woven or knitted fabric is subjected to a pilling test (JIS L 1076 (2012) Method C), an image of the fabric surface rubbed in the pilling test is taken with a scanning electron microscope (SEM) or the like at a size of 200 μm x 200 μm at a location where 10 or more fibers can be observed. The number of fuzz particles with a width of 0.5 to 5.0 μm is measured from the photographed image, and this value is multiplied by 25 to obtain the number of fuzz particles of 1 mm. ２ This operation is carried out at 10 different locations, and the simple average value is rounded off to the nearest decimal point to calculate the frequency of fluff (numbers / mm ２ )

[0113] Fluff frequency is 100 pieces / mm ２ If the frequency of the fluff is 500 pieces / mm or more, the fine fluff having a width of 0.5 to 5.0 μm formed by peeling off the irregularities of the modified cross-section fiber is unevenly distributed in combination with the irregularities on the surface of the fabric, and therefore the variation in the dynamic friction coefficient of the surface of the fabric can be further increased. ２ If this is the case, the proportion of fluff on the surface of the fabric will be large, which is more preferable since it will provide a soft feel due to the fluff, like that of natural materials.

[0114] On the other hand, from the viewpoint of obtaining good abrasion resistance without deteriorating the appearance quality of the fabric surface due to pilling caused by fluff, the frequency of fluff is 5,000 pieces / mm ２ It is preferable that the number of particles is 3,000 or less per mm. ２ It is more preferable to set the value to the range below, since whitening due to fluffing can be suppressed when dyed in a dark color.

[0115] <Production Method> An example of a method for producing the multifilament and woven or knitted fabric of the present invention will be described in detail below.

[0116] The multifilament of the present invention must be formed in a state in which conjugated fibers with different conjugated cross sections or fibers with different cross-sectional shapes are dispersed and mixed. This yarn bundle configuration can be achieved by precisely controlling so-called post-mixing, in which separately spun yarns are mixed using an air nozzle or the like. However, it is preferable to use a spinning-mixing method in which multiple types of single fibers are discharged from the same spinneret and wound simultaneously. In this spinning-mixing method, multiple types of single fibers are simultaneously bundled during winding, so that each single fiber is easily dispersed within the multifilament. It is also possible to change the degree of dispersion within the multifilament by changing the number and arrangement of discharge holes corresponding to each single fiber on the spinneret. Furthermore, spinning-mixing can eliminate post-processing steps. That is, to create the yarn bundle configuration required in the present invention using the post-mixing method, it is necessary, for example, to spray excess air or the like to rearrange the fiber arrangement within the entanglement nozzle and mix the fibers. During this process, the yarn may be subjected to unnecessary abrasion, resulting in single fiber breakage. On the other hand, in the case of the blended spun yarn preferably used in the present invention, multifilaments can be obtained without such concerns, and the quality of the fabric is also excellent.

[0117] Furthermore, in the multifilament of the present invention, it is preferable that the multifilament is composed of a conjugated fiber consisting of a hardly soluble component and an easily soluble component, and that after advanced processing such as weaving or knitting, the easily soluble component is eluted to obtain a modified cross-section fiber consisting of the hardly soluble component. This prevents the irregularities formed on the fiber surface from being caught during advanced processing such as weaving or knitting, and allows the unevenness to be maximized on the fabric surface when made into a fabric.

[0118] To obtain a multifilament made from the modified cross-section fiber of the present invention, the easily soluble component of the multifilament made from the conjugated fiber of the present invention may be composed of a known polymer soluble in a solvent or hot water, and the conjugated fiber may be immersed in a solvent or the like in which the polymer of the easily soluble component is soluble to remove the polymer of the easily soluble component. For example, when the polymer of the easily soluble component is a copolymerized polyethylene terephthalate copolymerized with 5-sodium sulfoisophthalic acid, polyethylene glycol, or the like, or polylactic acid, an alkaline aqueous solution such as a sodium hydroxide aqueous solution can be used. A method for treating the conjugated fiber of the present invention with an alkaline aqueous solution may involve, for example, immersing the conjugated fiber in an alkaline aqueous solution after forming a woven or knitted fabric or fiber structure from the conjugated fiber. Heating the alkaline aqueous solution to 50°C or higher is preferable because it can accelerate the progress of hydrolysis. Furthermore, using a fluid dyeing machine or the like allows for large-scale processing at one time, which is preferable from an industrial perspective.

[0119] When a multifilament made of the conjugated fiber of the present invention is produced by a blended spinning method, it is necessary to adjust the flow rate of the polymer flowing into each hole in the spinneret depending on the discharge holes so that single fibers with different cross-sectional forms can be produced using the same spinneret. From this viewpoint, it is preferable to use, for example, the composite spinneret described in JP 2011-208313 A.

[0120] The composite spinneret of the present invention shown in Figure 7 is assembled into a spin pack and used for spinning, with three major components stacked from top to bottom: a metering plate 1, a distributor plate 2, and a discharge plate 3. This allows the polymer flow rate to be adjusted at each of the metering plate 1, the distributor plate 2, and the discharge plate 3, and single fibers with different cross-sectional forms can be stably discharged from the same spinneret, making it preferable. Incidentally, Figure 7 shows an example in which three types of polymers, i.e., polymer A, polymer B, and polymer C, are used. It is difficult to composite three or more types of polymers with conventional composite spinnerets, and therefore it is preferable to use a composite spinneret utilizing fine flow channels as exemplified in Figure 7.

[0121] In the spinneret member exemplified in FIG. 7, the metering plate 1 measures the amount of polymer per discharge hole and per distribution hole and allows it to flow in, the distribution plate 2 controls the composite cross section and cross-sectional shape of the single fiber, and the discharge plate 3 compresses the composite polymer flow formed by the distribution plate 2 and discharges it.

[0122] Although not shown in the figure to avoid complicating the explanation of the composite spinneret, the components stacked above the metering plate 1 may be components with flow paths formed to match the spinning machine and spin pack. By designing the metering plate 1 to match existing flow path components, it is possible to utilize the existing spin pack and its components as they are. Therefore, there is no need to dedicate a spinning machine specifically to this spinneret. In practice, it is also advisable to stack multiple flow path plates between the flow path and the metering plate or between the metering plate 1 and the distributor plate 2. The purpose of this is to provide a flow path that efficiently transports the polymer in the cross-sectional direction of the spinneret and the cross-sectional direction of the single fiber, and to configure it so that it is introduced into the distributor plate 2.

[0123] The polymer stream thus formed into a cross section by the distributor plate 2 is contracted by the discharge plate 3 and discharged. At this time, the discharge holes are intended to re-meter the flow rate of the composite polymer stream, i.e., the discharge rate, and to control the draft (=take-up speed / discharge linear velocity) on the spinning line. The hole diameter and hole length are preferably determined taking into consideration the viscosity of the polymer and the discharge rate.

[0124] The multifilament of the present invention can be produced by melt spinning, which is intended to produce continuous fibers, wet and dry solution spinning, or melt-blowing and spunbonding, which are suitable for obtaining sheet-like fiber structures. However, from the viewpoint of increasing productivity, melt spinning is preferred. Furthermore, melt spinning can be performed using a composite spinneret, which will be described later. The spinning temperature is preferably set to a temperature at which the polymers used, primarily those with high melting points or high viscosity, exhibit fluidity. The temperature at which fluidity is exhibited varies depending on the molecular weight, but stable production is possible when it is set between the melting point of the polymer and melting point + 60°C.

[0125] Furthermore, in the multifilament of the present invention, it is preferable to set the melt viscosity ratio of the polymers constituting the composite fiber to less than 5.0 and the difference in solubility parameter values ​​to less than 2.0, since this allows a composite polymer flow to be stably formed and a fiber with a good composite cross section to be obtained.

[0126] The multifilament of the present invention can be stably produced when the output per hole of the spinneret is 0.1 g to 10 g / min / hole. In this case, the output is preferably determined according to the desired fiber diameter, taking into consideration the winding conditions, draw ratio, etc.

[0127] The polymer stream discharged from the discharge holes is cooled and solidified, and then an oil is applied thereto, and the polymer stream is taken up by rollers set to a specified peripheral speed. Here, this take-up speed is determined based on the discharge rate and the target fiber diameter. In the present invention, from the viewpoint of stably producing multifilaments, the take-up speed of the rollers during spinning is preferably about 500 to 6000 m / min, and can be changed depending on the physical properties of the polymer and the intended use of the fiber. In particular, from the viewpoint of achieving high orientation and improving mechanical properties, a speed of 500 to 4000 m / min and subsequent drawing is preferred, since this promotes uniaxial orientation of the fiber.

[0128] During drawing, for example, in a drawing machine consisting of one or more pairs of rollers, fibers made of a polymer exhibiting thermoplasticity that can be melt-spun are naturally stretched in the fiber axis direction by a peripheral speed ratio between a first roller set at a preheating temperature and a second roller set at a temperature equivalent to the crystallization temperature, and then the fibers are heat-set by the second roller and wound up. The preheating temperature is preferably set appropriately based on a temperature at which the polymer can be softened, such as its glass transition temperature. The upper limit of the preheating temperature is preferably set to a temperature at which spontaneous elongation of the fiber does not cause yarn path disturbance during the preheating process. For example, in the case of PET, which has a glass transition temperature around 70°C, the preheating temperature is usually set to about 80 to 95°C. In addition, in the case of a polymer that does not exhibit a glass transition, the dynamic viscoelasticity (tan δ) of the composite fiber is measured, and the preheating temperature can be selected to be equal to or higher than the higher-temperature peak temperature of the obtained tan δ.

[0129] Regarding drawing, the spun multifilament may be drawn after being wound up, or may be drawn immediately after spinning without being wound up, but it is more preferable to carry out yarn processing accompanied by drawing. By carrying out yarn processing, the unevenness of the fabric surface, which is a feature of the present invention, becomes more complex, and furthermore, the voids inside the fabric can be increased by controlling the fiber shape through yarn processing.

[0130] Here, when performing yarn processing involving drawing, it is preferable to use a highly oriented undrawn yarn obtained by high-speed spinning. Highly oriented undrawn yarn has a structure containing oriented amorphous material and moderate crystal nuclei, has a fast crystallization rate, and is suitable for yarn processing because it can suppress yarn breakage by preventing fusion in the heater and suppress fuzz due to a decrease in drawing tension. Methods for producing such highly oriented undrawn yarn vary somewhat depending on the fiber diameter, polymer type, and viscosity, but in the studies of the present inventors, a composite fiber with good yarn processability can be obtained by selecting a take-up speed during spinning from the range of 2000 to 4000 m / min.

[0131] The yarn processing is not particularly limited as long as it is a normal yarn processing technique such as false twisting or non-uniform stretching. However, from the viewpoint of changing the crimp form into a non-uniform form and making the resulting texture and feel more complex, it is more preferable to apply false twisting or non-uniform stretching.

[0132] The method of false twisting is not particularly limited as long as it is a commonly used method, but in consideration of productivity, it is preferable to use a friction false twisting machine using a disk or belt. False twisting adds unevenness due to mechanical crimping, making the unevenness on the fabric surface, which is a feature of the present invention, more complex, and furthermore, by controlling the fiber shape through yarn processing, the voids inside the fabric become larger, thereby imparting volume to the fabric.

[0133] In order to stably produce the multifilament of the present invention by false twisting, it is preferable to control the crimp form by the number of actual twists of the multifilament in the twisting region.

[0134] That is, it is preferable to set the false twist conditions, such as the rotation speed of the twisting mechanism and the processing speed, so as to satisfy the following condition: the number of twists T (unit: turns / m), which is the number of twists of the multifilament in the twisting region, is determined according to the total fineness Df (unit: dtex) of the multifilament after the false twist processing.

[0135] 20000 / Df ０．５ ≦T≦40000 / Df ０．５ Here, the false twist number T is measured by the following method. That is, a multifilament running in the twisting region of the false twisting process is sampled to a length of 50 cm or more so as not to untwist immediately before the twister. The sampled yarn sample is then attached to a twist detector, and the number of twists is measured by the method described in JIS L1013 (2010) 8.13, which is the false twist number T. When the false twist number satisfies the above-mentioned conditions, the unevenness caused by mechanical crimping can make the unevenness of the fabric surface more complex.

[0136] Furthermore, under the above-mentioned false twist conditions, it is advisable to adjust the draw ratio in the twisting region. The draw ratio here is calculated as Vd / V0, where V0 is the peripheral speed of the roller supplying the yarn to the twisting region and Vd is the peripheral speed of the roller installed immediately after the twisting mechanism. When a drawn yarn is used as the supply yarn, Vd / V0 can be set to 0.9 to 1.4. When a highly oriented undrawn yarn is used as the supply yarn, Vd / V0 can be set to 1.2 to 2.0, and drawing can be performed simultaneously with the false twisting. By setting the draw ratio in this range, crimps can be imparted to all of the single fibers in the multifilament without causing excessive tension or slack in the twisting region.

[0137] Furthermore, from the viewpoint of firmly fixing the crimp obtained in the false twisting step, it is preferable to determine the false twisting temperature in the range of Tg + 50 to Tg + 150°C, with the Tg of the higher Tg polymer in the composite polymers as the reference. The false twisting temperature here refers to the temperature of the heater installed in the twisting region. By setting the false twisting temperature in this range, the polymer that has been significantly twisted within the cross section of the composite fiber can be sufficiently fixed in structure, thereby improving the dimensional stability of the crimp obtained in the false twisting step.

[0138] The mechanical crimp imparted in the false twisting step preferably has a crimp development rate of 5% or more. If this range is set, the mechanical crimping adds unevenness, and when the fabric is made into a textile, the unevenness of the fabric surface, which is a feature of the present invention, becomes more complex, thereby enhancing the creaky feel and luxurious, mild luster characteristic of silk. Furthermore, if the crimp development rate is set to 10% or more, the voids inside the fabric become larger, which can impart volume to the fabric, and this is considered a more preferable range.

[0139] However, from the viewpoint of texture and volume, the higher the crimp expression rate, the better. However, if the voids inside the fabric become too large, the water absorption and diffusion properties due to capillary action caused by the recesses may decrease. Therefore, the crimp expression rate is preferably 30% or less, and a crimp expression rate of 25% or less is an even more preferable range, as it allows for high water absorption and quick-drying properties to be exhibited without being affected by the fabric structure, such as woven or knitted fabric.

[0140] The crimp development rate referred to in the present invention is determined by applying an initial load of 0.0018 cN / dtex to a measuring instrument (frame circumference 1 m) equipped with a tension adjuster to prepare a 10 m long, 10-wound multifilament skein. This skein was then immersed in water at 90°C for 20 minutes without load (0 cN / dtex) and air-dried for 24 hours under standard conditions of 20°C and 65% RH. Subsequently, a load of 0.0018 cN / dtex and a load of 0.09 cN / dtex were applied, and the skein length L0 was measured after 2 minutes. The 0.09 cN / dtex load was then removed, and the skein length L1 after 2 minutes was measured. The crimp development rate (%) is calculated from the values ​​obtained by the following formula, rounded to the nearest whole number: Crimp development rate (%) = [(L0 - L1) / L0] × 100 (%). In addition, if it is difficult to create a multifilament hank with a 10 m hank length and 10 windings due to yarn removal from the fabric, etc., a sample is treated in water at 90°C for 20 minutes without load (0 cN / dtex), the top of the sample is fixed with a clamp, and the sample is allowed to hang down under loads of 0.0018 cN / dtex and 0.09 cN / dtex. After 2 minutes, 20 cm (L0) from the upper clamp is measured and marked. Next, the 0.09 cN / dtex load is removed, and the length L1 from the upper clamp to the mark after 2 minutes is measured. The crimp development rate (%) is calculated from the obtained L0 and L1. It is also preferable to perform non-uniform drawing processing at a draw ratio that does not exceed the natural draw ratio of the undrawn yarn, thereby obtaining a thick and thin yarn in which drawn and undrawn parts appear randomly in the fiber axis direction (thick and thin). Non-uniform drawing processing results in differences in dyeability between the drawn and undrawn parts in addition to differences in dyeability between the single fibers, which further emphasizes the color shading and allows the fabric to have a mottled texture like natural materials. Furthermore, false twisting processing performed consecutively after non-uniform drawing processing can produce a material that combines a mottled texture with the texture due to the crimp morphology, which is a more preferable range.

[0141] The multifilament of the present invention may be mixed with other fibers before or after processing. The method of mixing is not particularly limited, and general mixing methods such as interlace mixing and taslan mixing can be used.

[0142] When the multifilament of the present invention is used as a textile product, after the multifilament of the present invention is made into a textile, it can be subjected to water repellency, antistaticity, flame retardancy, moisture absorption, antibacterial, softening finish, and other known post-processing in combination as needed, but in textile products, particularly woven and knitted fabrics, which partially contain the multifilament of the present invention, water absorption processing is particularly preferred as a post-processing because it can further improve water absorption and diffusion due to capillary action in the recesses. Furthermore, the presence of irregularities on the fiber surface can also improve the washing durability of functional finishing agents such as water repellency, antistaticity, flame retardancy, moisture absorption, antibacterial, and softening finish.

[0143] The method for weaving or knitting the woven or knitted fabric comprising the multifilament of the present invention is not particularly limited, and the fabric can be woven or knitted by a conventional method. When the woven or knitted fabric is a woven fabric, examples of the method include a water jet loom, an air jet loom, a rapier loom, and a jacquard loom. When the woven or knitted fabric is a knitted fabric, examples of the method include a circular knitting machine and a warp knitting machine.

[0144] The conjugate fiber, modified cross-section fiber, and multifilament according to the present invention will be specifically described below with reference to examples.

[0145] The following evaluations were carried out for the Examples and Comparative Examples.

[0146] A. Melt viscosity of polymer Chip-shaped polymer was dried to a moisture content of 200 ppm or less using a vacuum dryer, and the melt viscosity was measured using a Toyo Seiki Capillograph while changing the strain rate stepwise. The measurement temperature was the same as the spinning temperature, and the time from when the sample was placed in a heating furnace under a nitrogen atmosphere to when the measurement started was 5 minutes. The shear rate was 1216 s －１ The value was evaluated as the melt viscosity of the polymer.

[0147] B. Fineness The weight of 100 m of the multifilament was measured, and the weight was multiplied by 100. This procedure was repeated 10 times, and the average value was rounded to one decimal place to obtain the fineness (dtex) of the multifilament.

[0148] C. Crimp Development Rate Using a measuring scale (frame circumference 1 m) equipped with a tension adjuster, a 10 m skein of multifilament yarn was prepared with an initial load of 0.0018 cN / dtex applied, with a skein length of 10 m and 10 turns. This skein was treated in water at 90°C for 20 minutes without load (0 cN / dtex) and then air-dried for 24 hours under standard conditions of 20°C and 65% RH. Subsequently, a load of 0.0018 cN / dtex and a load of 0.09 cN / dtex were applied, and the skein length L0 was measured after 2 minutes. Next, the 0.09 cN / dtex load was removed, and the skein length L1 after 2 minutes was measured. The value obtained from L0 and L1 was calculated using the following formula, and the value obtained was rounded to the nearest whole number, and was taken as the crimp development rate (%). Crimp development rate (%) = [(L0 - L1) / L0] × 100 (%). In addition, when it was difficult to prepare a hank with a length of 10 m and 10 windings due to thread removal from the fabric, the upper part of a sample treated in water at 90°C for 20 minutes without load (0 cN / dtex) was fixed with a clamp, and the sample was allowed to hang down under loads of 0.0018 cN / dtex and 0.09 cN / dtex. After 2 minutes, 20 cm (L0) from the upper clamp was measured and marked. Next, the 0.09 cN / dtex load was removed, and the length L1 from the upper clamp to the mark after 2 minutes was measured. The crimp development rate (%) was calculated from the obtained L0 and L1.

[0149] D. Adjacent Filament Group Ratio of Composite Fibers The multifilament was embedded in an embedding agent such as epoxy resin, and 10 random images of its cross section were taken using a scanning electron microscope (SEM) or the like at a magnification that allowed observation of 20 or more composite fibers with different composite cross sections. In this case, metal staining can be used to utilize the dyeing differences between polymers to clarify the contrast of the composite cross section. In each captured image, the number of composite fibers constituting adjacent filament groups, which are collections of five or more adjacently connected composite fibers with the same composite cross section, was counted. From this measurement result, the adjacent filament group ratio = (number of composite fibers constituting adjacent filament groups) / (total number of composite fibers photographed) × 100 (%) was calculated. This procedure was performed for the 10 captured images, and the simple number average, rounded to the nearest whole number, was used as the adjacent filament group ratio (%) of the composite fiber.

[0150] E. Depth of the recess of the hardly soluble component, and the ratio of the maximum depth of the recess of the hardly soluble component between composite fibers. A multifilament was embedded in an embedding agent such as epoxy resin, and an image of the cross section was taken using a scanning electron microscope (SEM) or the like at a magnification such that 20 or more composite fibers could be observed. In this case, if metal staining is applied, the contrast of the composite cross section can be made clear by utilizing the dye difference between the polymers. In composite fibers randomly sampled from the captured image, for example, as shown in FIG. 1(a), a line m was drawn that intersects with the periphery of the hardly soluble component at only two points (point j, point k). Among the points on the periphery of the hardly soluble component that intersect with a line perpendicular to line m between the two points, the distance s (μm) between the point furthest from line m and line m was rounded to one decimal place, and this value was used as the depth (μm) of the recess of the hardly soluble component. This operation was also performed for all lines that intersect with the periphery of the hardly soluble component at only two points, and the largest s among the obtained distances s was selected. ｍａｘ The value obtained by rounding off the value to one decimal place was taken as the maximum depth (μm) of the recessed portion of the hardly soluble component.

[0151] Furthermore, for all composite fibers present in the captured image, s ｍａｘ The obtained s ｍａｘ The maximum value was divided by the minimum value, and the value was rounded to one decimal place to obtain the ratio of the maximum depth of the recesses of the hardly soluble component between the composite fibers.

[0152] F. Degree of irregularity of composite fiber, ratio of degree of irregularity between composite fibers Multifilaments were embedded in an embedding agent such as epoxy resin, and images of the cross section were taken using a scanning electron microscope (SEM) or the like at a magnification such that 20 or more composite fibers could be observed. For composite fibers randomly extracted from the photographed image, the inscribed circle diameter r of the composite fiber was A (diameter of A in Figure 2) and circumscribed circle diameter r B (diameter of B in Figure 2) and calculate the circumscribed circle diameter r B The inscribed circle diameter r A The value r divided by B / r A The value obtained by rounding off to one decimal place was taken as the irregularity of the composite fiber.

[0153] This operation was also performed for all composite fibers present in the captured image, and the obtained r B / rA The maximum value was divided by the minimum value, and the value was rounded to one decimal place to obtain the ratio of the degree of irregularity between the composite fibers.

[0154] G. Fiber diameter of composite fiber, fiber diameter ratio between composite fibers The multifilament was embedded in an embedding agent such as epoxy resin, and an image of the fiber cross section perpendicular to the fiber axis was taken with a scanning electron microscope (SEM) at a magnification such that 20 or more composite fibers could be observed. The taken image was analyzed using image analysis software to calculate the cross-sectional area of ​​the fiber cross section of the composite fiber, and the diameter (μm) was calculated in terms of a perfect circle from the obtained cross-sectional area. The value rounded off to the nearest whole number was used as the fiber diameter of the composite fiber.

[0155] In addition, the fiber diameters of all the composite fibers were calculated, and the maximum fiber diameter obtained was divided by the minimum fiber diameter to obtain a value, which was rounded to one decimal place to obtain the fiber diameter ratio between the composite fibers.

[0156] H. Adjacent filament group ratio of modified cross-section fibers The multifilament was embedded in an embedding agent such as epoxy resin, and 10 images of the cross-section were randomly taken using a scanning electron microscope (SEM) or the like at a magnification such that 20 or more modified cross-section fibers with different cross-sectional shapes could be observed. In each image, the number of modified cross-section fibers constituting adjacent filament groups, which are collections of five or more adjacent modified cross-section fibers having the same cross-sectional shape, was counted. From this measurement result, the adjacent filament group ratio = (number of modified cross-section fibers constituting adjacent filament groups) / (total number of modified cross-section fibers photographed) × 100 (%) was calculated. This procedure was performed for the 10 photographed images, and the simple number average, rounded to the nearest whole number, was used as the adjacent filament group ratio (%) of modified cross-section fibers.

[0157] I. Depth of the recess of the modified cross-section fiber, ratio of the maximum depth of the recess between the modified cross-section fibers The multifilament was embedded in an embedding agent such as epoxy resin, and an image of the cross-section was taken using a scanning electron microscope (SEM) or the like at a magnification such that 20 or more modified cross-section fibers could be observed. For the modified cross-section fibers randomly selected from the image, as shown in FIG. 4(a), a line M was drawn that intersects with the periphery of the modified cross-section fiber at only two points J and K. Among the points on the periphery of the modified cross-section fiber that intersect with a line perpendicular to the line M between the two points, the distance S (μm) between the line M and the point farthest from the line M was rounded to two decimal places, and the value was taken as the depth of the recess (μm) of the modified cross-section fiber. In addition, this operation was performed for all the lines that intersect with the periphery of the modified cross-section fiber at only two points, and the maximum S among the obtained distances S was taken. ｍａｘ The value obtained by rounding off the value to one decimal place was defined as the maximum depth (μm) of the recess of the modified cross section fiber.

[0158] Furthermore, for all the irregular cross-section fibers present in the photographed image, S ｍａｘ The obtained S ｍａｘ The maximum value was divided by the minimum value, and the value was rounded off to one decimal place to obtain the ratio of the maximum depth of the recesses between the modified cross section fibers.

[0159] J. Degree of irregularity of modified cross-section fiber, ratio of degree of irregularity between modified cross-section fibers Multifilaments were embedded in an embedding agent such as epoxy resin, and images of the cross-section were taken using a scanning electron microscope (SEM) or the like at a magnification such that 20 or more modified cross-section fibers could be observed. For modified cross-section fibers randomly extracted from the photographed image, the inscribed circle diameter R of the modified cross-section fiber was A (diameter of A in Figure 5) and circumscribed circle diameter R B (diameter of B in Figure 5) and calculate the circumscribed circle diameter R B The inscribed circle diameter R A The value R divided by B / R A The value obtained by rounding off to one decimal place was taken as the irregularity degree of the irregular cross section fiber.

[0160] This operation was also performed for all composite fibers present in the photographed image, and the obtained R B / R AThe maximum value was divided by the minimum value, and the value was rounded to one decimal place to obtain the ratio of the irregularity between the irregular cross section fibers.

[0161] K. Fiber diameter of irregular cross-section fiber, fiber diameter ratio between irregular cross-section fibers Multifilaments were embedded in an embedding agent such as epoxy resin, and images of the fiber cross-section perpendicular to the fiber axis were taken with a scanning electron microscope (SEM) at a magnification such that 20 or more irregular cross-section fibers could be observed. The taken images were analyzed using image analysis software to calculate the cross-sectional area of ​​the fiber cross-section of the irregular cross-section fiber, and the diameter (μm) was calculated in terms of a perfect circle from the obtained cross-sectional area. The value rounded off to the nearest whole number was used as the fiber diameter of the irregular cross-section fiber.

[0162] In addition, the fiber diameters of all the modified cross-section fibers were calculated, and the maximum value of the obtained fiber diameters was divided by the minimum value to obtain a value, which was rounded to one decimal place to obtain the fiber diameter ratio between the modified cross-section fibers.

[0163] L. Evaluation of friction of woven and knitted fabrics (squeakiness, moist feeling) Using a static and dynamic friction measuring instrument TL201Tt manufactured by Trinity Lab, a 10 cm x 10 cm area of ​​a 20 cm x 20 cm woven and knitted fabric was measured by 1 cm ２ An element with a geometric fingerprint pattern on urethane with a hardness equivalent to that of a fingertip was attached to a contact terminal with an area of ​​1.5 mm. Next, a 20 g load was applied while tracing the surface of the object for 30 mm at a speed of 10 mm / sec, and a friction curve representing the friction force (gf) versus the distance traveled was measured. Based on the obtained friction curve, the static and kinetic friction coefficients were calculated with reference to JIS K7125 (1999), and the values ​​were rounded to one decimal place to obtain the static and kinetic friction coefficients. The standard deviation of the kinetic friction coefficient values ​​in the range of 5 to 25 mm was also calculated, and the value rounded to three decimal places was used as the variation in the kinetic friction coefficient.

[0164] The creaking sensation was evaluated based on the obtained static friction coefficient and the change in the dynamic friction coefficient, and rated on a four-point scale based on the following criteria: S: Excellent creaking sensation (1.2≦[static friction coefficient]≦2.0 and 2.0×10 －２ ≦[Variation in dynamic friction coefficient]≦5.0×10 －２ A: Good creaking sensation (0.8≦[static friction coefficient]≦2.0 and 1.5×10－２ ≦[Variation in dynamic friction coefficient]≦5.0×10 －２ B: There is a creaking sensation (0.5≦[static friction coefficient]≦2.0 and 1.0×10 －２ ≦[Variation in dynamic friction coefficient]≦5.0×10 －２ C: Poor creaking sensation ([static friction coefficient] ≦ 0.4, or 2.1 ≦ [static friction coefficient], or [variation in dynamic friction coefficient] ≦ 0.9 × 10 －２ , or 5.1 × 10 －２ ≦[variation in dynamic friction coefficient]).

[0165] The moist feeling was also evaluated based on the static friction coefficient and dynamic friction coefficient obtained and rated on a three-point scale according to the following criteria: S: Excellent moist feeling (0.5≦[static friction coefficient−dynamic friction coefficient]≦1.0) A: Good moist feeling (0.2≦[static friction coefficient−dynamic friction coefficient]≦0.4) C: Poor moist feeling ([static friction coefficient−dynamic friction coefficient]≦0.1 or 1.1≦[static friction coefficient−dynamic friction coefficient]).

[0166] M. Surface Evaluation of Woven and Knit Fabrics (Abrasion Resistance, Fluffiness) After subjecting the woven and knit fabrics to a pilling test (JIS L 1076 (2012) Method C), the degree of pilling was assessed using a standard photograph and graded from 1 to 5 in increments of 0.5. From the grade results obtained, the abrasion resistance was graded on a four-level scale based on the following criteria: S: Excellent abrasion resistance (Grade: 4.5 or 5) A: Good abrasion resistance (Grade: 3.5 or 4) B: Abrasion resistant (Grade: 3) C: Poor abrasion resistance (Grade: 2.5 or less).

[0167] In addition, the surface of the fabric rubbed in the pilling test was photographed with a scanning electron microscope (SEM) or the like at a size of 200 μm x 200 μm at a location where 10 or more fibers could be observed. The number of fluffs with a width of 0.5 to 5.0 μm was measured from the photographed image, and the value was multiplied by 25 to obtain a value of 1 mm. ２ This operation was carried out at 10 different locations, and the simple number average was rounded off to the nearest decimal point to obtain the frequency of fluff (numbers / mm ２The fluffiness was evaluated based on the obtained fluff frequency and rated into three levels according to the following criteria: S: Excellent fluffiness (500≦[fluff frequency]≦3000) A: Good fluffiness (100≦[fluff frequency]≦499 or 3001≦[fluff frequency]≦5000) C: Poor fluffiness ([fluff frequency]≦99 or 5001≦[fluff frequency]).

[0168] N. Evaluation of Gloss (Glossiness) of Woven and Knitted Fabrics Using an automatic variable angle photometer (GONIOPHOTOMETER GP-200 model) manufactured by Murakami Color Research Laboratory, light was incident on the woven and knitted fabric at an incident angle of 60°, and the light intensity at acceptance angles of 0° to 90° was determined by two-dimensional reflected light distribution measurement in 0.1° increments. The maximum light intensity (specular reflection) near an acceptance angle of 60° was divided by the minimum light intensity (diffuse reflection) near an acceptance angle of 0° to calculate the value. This procedure was performed three times per location, and a simple number average of the results for a total of 10 locations was calculated. The value rounded to one decimal place was used as the contrast gloss. From the obtained contrast gloss, the glossiness was evaluated on a four-level scale based on the following criteria. S: Excellent gloss (1.0≦[contrast gloss]≦1.5) A: Good gloss (1.6≦[contrast gloss]≦2.0) B: Glossy (2.1≦[contrast gloss]≦2.5) C: Poor gloss (2.6≦[contrast gloss]).

[0169] O. Functional Evaluation of Woven and Knit Fabrics (Moisture Absorption and Quick-Drying Property) After 0.1 cc of water was dropped onto a 10 cm x 10 cm woven or knitted fabric, the fabric was weighed every 5 minutes in an environment with a temperature of 20°C and a relative humidity of 65% RH, and the time (minutes) until the residual moisture content reached 1.0% or less was determined. This procedure was performed at a total of three locations, and the simple average of the results was calculated and rounded to the nearest whole number to obtain the moisture diffusion time (minutes). The moisture absorption and quick-drying property was evaluated based on the obtained moisture diffusion time in four stages according to the following criteria: S: Excellent moisture absorption and quick-drying property ([moisture diffusion time] ≦ 20); A: Good moisture absorption and quick-drying property (21 ≦ [moisture diffusion time] ≦ 30); B: Moisture absorption and quick-drying property (31 ≦ [moisture diffusion time] ≦ 40); C: Poor moisture absorption and quick-drying property (41 ≦ [moisture diffusion time]).

[0170] Example 1 As an easily eluted component, polyethylene terephthalate copolymerized with 8 mol % of 5-sodium sulfoisophthalic acid and 9 wt % of polyethylene glycol (SSIA-PEG copolymerized PET, melt viscosity: 100 Pa·s) was prepared, and as a difficult-to-elute component, polyethylene terephthalate (PET, melt viscosity: 130 Pa·s) was prepared.

[0171] These polymers were melted separately at 290°C, and then weighed so that the easily soluble component / hardly soluble component weight ratio was 10 / 90. The polymers were introduced into a spinning pack equipped with the composite spinneret shown in Figure 7, and the introduced polymers were discharged from the discharge holes to form two types of composite fiber A (Figure 1(d)) and composite fiber B (Figure 2(c)), each having different composite cross sections. The spinneret used had 18 holes for each of the discharge holes to form composite fiber A and composite fiber B.

[0172] The discharged composite polymer stream was cooled and solidified, and then an oil was applied thereto. The stream was taken up at a spinning speed of 3,000 m / min and false twisted on a heater heated to 140°C to produce a multifilament consisting of 100 dtex-36 filament composite fibers (fiber diameter of composite fiber A: 16 μm, fiber diameter of composite fiber B: 17 μm, crimp development rate: 28%).

[0173] In the obtained multifilament, the hardly soluble components of composite fibers A and B had 6 and 12 recesses, respectively, and the ratio of the maximum depth of the recesses between composite fibers A and B was 2.4 and the ratio of the irregularities was 1.3. In addition, the adjacent filament group ratio was 28%, and composite fibers A and B were dispersed and mixed, confirming that the multifilament was made of the composite fiber of the present invention.

[0174] Furthermore, the irregularity of composite fiber A on the low irregularity side was 1.2, and since it was close to a circular shape, the irregularities between the composite fibers did not interlock, and the interfiber voids obtained after the easily soluble components were eluted could be maximized.

[0175] Using the multifilaments made of the obtained composite fibers as warp and weft, the number of composite fibers was adjusted so that the cover factor (CFA) in the warp direction was 800 and the cover factor (CFB) in the weft direction was 1200, to obtain a 2 / 1 twill fabric. The CFA here is calculated by multiplying the warp density (counts / 2.54 cm) by the total warp fineness (dtex). １／２ , CFB is the weft density [count / 2.54 cm] x (total weft size [dtex]) １／２ This is the value calculated from the formula.

[0176] The resulting woven fabric was treated for 10 minutes in 80°C warm water containing a surfactant as a scouring process, and then heated to 90°C using a 1% by mass aqueous solution of sodium hydroxide in a jet dyeing machine as a weight reduction process to remove 99% or more of the easily soluble polymer, Polymer 1. Next, the fabric was subjected to heat setting at 180°C for 1 minute at a tentering ratio of 5% as a heat setting process.

[0177] Next, as a dyeing process, the woven fabric was immersed in an aqueous solution containing a disperse dye (black) and a dyeing assistant at 130°C for 60 minutes, followed by rinsing with water. Next, the woven fabric was immersed in an aqueous solution containing a reducing detergent at 80°C for 20 minutes, followed by reduction cleaning, rinsing with water, and air drying.

[0178] The obtained woven fabric was composed of a multifilament consisting of two types of modified cross-section fiber A (FIG. 4(d), fiber diameter: 15 μm) and modified cross-section fiber B (FIG. 5(c), fiber diameter: 16 μm, crimp development rate: 27%) with different cross-sectional shapes. The modified cross-section fibers A and B had 6 and 12 recesses, respectively, and the ratio of the maximum recess depths between the modified cross-section fibers A and B was 2.4 and the ratio of the irregularities was 1.3. In addition, the adjacent filament group ratio was 28%, meaning that the modified cross-section fibers A and B were dispersed and mixed, confirming that the multifilament was composed of the modified cross-section fiber of the present invention.

[0179] In addition, the irregularity degrees of the modified cross-section fibers A and B were 1.5 and 1.9, respectively, both below 2.5. Since the cross-sectional shapes were less irregular, the slope of the recesses was gentle, which made it possible to suppress specular reflection of light caused by the slopes of the recesses, and to suppress gloss spots such as glare that are unique to synthetic fibers.

[0180] The fabric made of the multifilament has a complex uneven surface formed by the dispersion and mixing of irregular cross-sectional fibers with different cross-sectional shapes, and has an excellent silk-like creaking feel (static friction coefficient: 1.2, variation in dynamic friction coefficient: 2.0 × 10 －２ The fabric had a good moist feel (static friction coefficient - dynamic friction coefficient: 0.4), as well as an excellent glossiness with a luxurious, mild luster (contrast gloss: 1.5). Furthermore, the fabric also had good moisture absorption and quick-drying properties (moisture diffusion time: 30 minutes) due to the formation of interfiber voids within the fabric.

[0181] Furthermore, due to the presence of recesses with a depth of 0.5 to 5.0 μm, the fluff formed by the irregular cross-section fibers peeling off due to friction is unevenly distributed along with the unevenness of the fabric surface, resulting in an excellent fluffiness like that of natural materials (fluff frequency: 1250 pieces / mm ２ ), and because the fluff was fine with a width of 0.5 to 5.0 μm, it also had good abrasion resistance (pilling grade: grade 4), and was a woven fabric that combined a feeling of fluff and resistance to friction that was not found in conventional materials. The results are shown in Table 1.

[0182] Comparative Example 1 Polyethylene terephthalate (PET, melt viscosity: 130 Pa·s) was prepared as a hardly soluble component.

[0183] The polymer was melted at 290°C and then introduced into a spin pack equipped with a conventional spinneret. The polymer was discharged from the nozzle holes to form round and hexapalloy fibers (Fig. 4(b)). The spinneret had 18 holes each for forming round and hexapalloy fibers.

[0184] The discharged composite polymer stream was cooled and solidified, and then an oil was added thereto. The stream was taken up at a spinning speed of 3,000 m / min and false twisted on a heater heated to 180°C to produce a 90 dtex-36 filament multifilament (crimp development rate: 37%).

[0185] The resulting woven fabric was treated in warm water at 80°C containing a surfactant for 10 minutes as a scouring process, and then heat set at 180°C for 1 minute at a tentering ratio of 5% as a heat setting process.

[0186] Next, as a dyeing process, the woven fabric was immersed in an aqueous solution containing a disperse dye (black) and a dyeing assistant at 130°C for 60 minutes, followed by rinsing with water. Next, the woven fabric was immersed in an aqueous solution containing a reducing detergent at 80°C for 20 minutes, followed by reduction cleaning, rinsing with water, and air drying.

[0187] In Comparative Example 1, the multifilament was composed of fibers without recesses, so the unevenness of the fabric surface was uniform and small, and not only was it unable to achieve a silky, squeaky feel or a moist feel, but it also did not achieve a mild luster. Furthermore, because the unevenness of the fabric surface was small, it was unable to achieve a fluffy feel due to the unevenness peeling off during friction. Furthermore, because there were no easily soluble components, the inter-fiber voids were closely packed, which resulted in few voids within the fabric and insufficient moisture absorption and quick-drying properties. The results are shown in Table 1.

[0188] Comparative Example 2: As an easily eluted component, polyethylene terephthalate copolymerized with 8 mol% of 5-sodium sulfoisophthalic acid and 9 wt% of polyethylene glycol (SSIA-PEG copolymerized PET, melt viscosity: 100 Pa s) was prepared, and as a difficult-to-elute component, polyethylene terephthalate (PET, melt viscosity: 130 Pa s) was prepared.

[0189] These polymers were melted separately at 290°C, and then weighed so that the easily soluble component / hardly soluble component weight ratio was 10 / 90. The resulting mixture was introduced into a spinning pack equipped with the composite spinneret shown in Figure 7, and the incoming polymers were discharged from the discharge holes so as to form a composite cross section as shown in Figure 1(d).

[0190] The discharged composite polymer stream was cooled and solidified, and then an oil was added thereto. The stream was taken up at a spinning speed of 3,000 m / min and false twisted on a heater heated to 140°C to produce a multifilament (fiber diameter: 16 μm, crimp development rate: 28%) consisting of composite fibers of 94 dtex-36 filaments.

[0191] Using the multifilaments as warp and weft, the number of conjugated fibers was adjusted to obtain a 2 / 1 twill fabric so that the cover factor (CFA) in the warp direction was 800 and the cover factor (CFB) in the weft direction was 1200. The obtained fabric was subjected to scouring, weight reduction, heat setting, and dyeing under the same conditions as in Example 1.

[0192] In Comparative Example 2, the fabric obtained was composed of multifilaments consisting of fibers with modified cross-sections all having the same cross-sectional shape, so the unevenness of the fabric surface was uniform, and not only was it unable to achieve a silky, squeaky feel, but it also failed to achieve a mild luster. The results are shown in Table 1.

[0193] Comparative Example 3: As an easily eluted component, polyethylene terephthalate copolymerized with 8 mol% of 5-sodium sulfoisophthalic acid and 9 wt% of polyethylene glycol (SSIA-PEG copolymerized PET, melt viscosity: 100 Pa s) was prepared, and as a difficult-to-elute component, polyethylene terephthalate (PET, melt viscosity: 130 Pa s) was prepared.

[0194] These polymers were melted separately at 290°C, and then weighed so that the easily soluble component / hardly soluble component weight ratio was 10 / 90. These were then introduced into a spin pack incorporating the composite spinneret shown in Figure 7, and the incoming polymers were discharged from the discharge holes so as to form a composite cross section as shown in Figure 1(d). The spinneret had 18 discharge holes each with a different amount of incoming polymer.

[0195] The discharged composite polymer stream was cooled and solidified, and then an oil was applied thereto. The stream was taken up at a spinning speed of 3,000 m / min and false twisted on a heater heated to 180°C to produce a multifilament consisting of 100 dtex-36 filament composite fibers (fiber diameter of composite fiber A: 12 μm, fiber diameter of composite fiber B: 20 ​​μm, crimp development rate: 37%).

[0196] Using the multifilaments as warp and weft, the number of conjugated fibers was adjusted to obtain a 2 / 1 twill fabric so that the cover factor (CFA) in the warp direction was 800 and the cover factor (CFB) in the weft direction was 1200. The obtained fabric was subjected to scouring, weight reduction, heat setting, and dyeing under the same conditions as in Example 1.

[0197] In Comparative Example 3, the fabric obtained was composed of multifilaments made of fibers with modified cross-sections all having the same cross-sectional shape, although the fiber diameters were different, so the unevenness of the fabric surface was insufficient and the silk-like squeaky feel was not obtained. The results are shown in Table 1.

[0198] Comparative Example 4: As an easily eluted component, polyethylene terephthalate copolymerized with 8 mol% of 5-sodium sulfoisophthalic acid and 9 wt% of polyethylene glycol (SSIA-PEG copolymerized PET, melt viscosity: 100 Pa s) was prepared, and as a difficult-to-elute component, polyethylene terephthalate (PET, melt viscosity: 130 Pa s) was prepared.

[0199] These polymers were melted separately at 290°C, and then weighed so that the easily soluble component / hardly soluble component weight ratio was 10 / 90. The resulting mixture was introduced into a spinning pack equipped with the composite spinneret shown in Figure 7, and the incoming polymers were discharged from the discharge holes so as to form a composite cross section as shown in Figure 1(d).

[0200] The discharged composite polymer stream was cooled and solidified, and then an oil was added thereto. The stream was taken up at a spinning speed of 3,000 m / min and false twisted on a heater heated to 140°C to produce a multifilament (fiber diameter: 16 μm, crimp development rate: 28%) consisting of composite fibers of 46 dtex-18 filaments.

[0201] In addition, a multifilament (fiber diameter: 17 μm, crimp development rate: 28%) made of a 54 dtex-18 filament composite fiber was produced in the same manner as above, except that the composite cross section was changed to have the composite cross section shown in FIG. 2(c).

[0202] The two types of multifilaments obtained were mixed using a known air nozzle, and then the mixed yarn was used as the warp and weft to obtain a 2 / 1 twill fabric by adjusting the number of conjugated fibers so that the cover factor (CFA) in the warp direction was 800 and the cover factor (CFB) in the weft direction was 1200. The obtained fabric was subjected to scouring, weight reduction, heat setting and dyeing under the same conditions as in Example 1.

[0203] The obtained woven fabric was composed of a multifilament consisting of two types of modified cross-section fiber A (FIG. 4(d), fiber diameter: 15 μm) and modified cross-section fiber B (FIG. 5(c), fiber diameter: 16 μm, crimp development rate: 27%), each having a different cross-sectional shape. The modified cross-section fibers A and B had 6 and 12 recesses, respectively, and the ratio of the maximum depth of the recesses between the modified cross-section fibers A and B was 2.4, and the ratio of the degree of irregularity was 1.3.

[0204] In Comparative Example 4, the adjacent filament group ratio was 89%, and the modified cross-section fibers A and B were not dispersed and mixed, resulting in insufficient unevenness on the fabric surface and a silky, squeaky feel. The results are shown in Table 1.

[0205] [Examples 2 and 3] The same procedures as in Example 1 were repeated except that the maximum and minimum depths of the recesses of the hardly soluble component of composite fiber A were changed to 1.6 μm and 1.3 μm (Example 2), and 2.3 μm and 1.9 μm (Example 3).

[0206] In Examples 2 and 3, the increased depth of the recesses resulted in increased fluffing caused by friction causing the irregular cross-section fibers to peel off, giving the fabric a more natural-looking fluffiness. The increased voids within the fabric also resulted in excellent water absorption and diffusion. The results are shown in Tables 1 and 2.

[0207] Comparative Example 5 The same procedures as in Example 1 were repeated except that the maximum and minimum depths of the recesses of the hardly soluble component of composite fiber A were changed to 0.6 μm and 0.5 μm.

[0208] In Comparative Example 5, the ratio of the maximum depth of the recesses was too large, so that the unevenness formed on the surface of the fabric was small, and the silky squeaky feeling was not obtained. The results are shown in Table 2.

[0209] Comparative Example 6 The same procedures as in Example 1 were repeated except that the maximum and minimum depths of the recesses of the hardly soluble component of composite fiber B were changed to 6.4 μm and 2.2 μm.

[0210] In Comparative Example 6, the ratio of the maximum depth of the recesses was too large, resulting in small unevenness on the surface of the fabric, and the fabric did not have a silky, squeaky feel. Furthermore, the irregularity of the modified cross-section fiber B was too large, resulting in a steep slope of the recesses, which caused strong specular reflection of light at the slopes of the recesses, resulting in the generation of glossy spots such as glare that are unique to synthetic fibers. Not only was the luxurious, mild luster like silk not obtained, but the steep slope of the recesses also increased the coefficient of dynamic friction, resulting in a lack of moist feel. The results are shown in Table 2.

[0211] Example 4 The same procedures as in Example 1 were repeated except that the composite cross section of composite fiber A was changed to that shown in FIG. 1(a) and the composite cross section of composite fiber B was changed to that shown in FIG. 2(a).

[0212] In Example 4, the number of recesses in the modified cross-section fibers A and B was reduced, and in particular, the modified cross-section fiber A had only one type of recess, which prevented the unevenness from peeling off due to friction, resulting in excellent abrasion resistance. The results are shown in Table 2.

[0213] Example 5 The same procedures as in Example 1 were repeated except that the composite cross section of the composite fiber B was changed to that shown in FIG. 2(d).

[0214] In Example 5, the number of recesses in the modified cross-section fiber B was increased, which diffused light and further emphasized the glossiness, such as the luxurious, mild luster. Furthermore, the number of voids inside the fabric was increased, which improved the moisture absorption and quick-drying properties. The results are shown in Table 2.

[0215] Example 6 The same procedure as in Example 1 was repeated except that the composite cross section of the composite fiber A was changed to that shown in FIG. 2(d).

[0216] In Example 6, the number and depth of the recesses in the modified cross-section fiber A were increased, and as a result, the irregular cross-section fiber A's recesses were peeled off due to friction, forming more fluff, and the fluffing texture was enhanced, similar to that of natural materials. The results are shown in Table 2.

[0217] [Example 7] The same procedures as in Example 1 were repeated, except that the fiber diameter of composite fiber A was changed to 12 μm (maximum and minimum depths of the recesses of the hardly-soluble components were 0.9 μm and 0.8 μm), and the fiber diameter of composite fiber B was changed to 20 μm (maximum and minimum depths of the recesses of the hardly-soluble components were 3.5 μm and 1.2 μm).

[0218] In Example 7, the difference in fiber diameter between the fibers caused a difference in fiber shrinkage after drawing, and the interfiber voids increased when the fabric was heated for dyeing or the like, allowing for sufficient irregularities to appear on the fabric surface, increasing not only the silk-like squeaky feel and mild glossiness, but also improving water absorption and quick-drying properties due to the increased interfiber voids. The results are shown in Table 3.

[0219] [Example 8] The same polymers and spinneret as those in Example 1 were used to discharge the inflow polymer from the discharge holes, and the composite polymer stream was cooled and solidified, after which an oil agent was applied, and the composite polymer stream was taken up at a spinning speed of 1,500 m / min. The resulting composite fiber was stretched between rollers heated to 90°C and 130°C, thereby producing a multifilament composed of 84 dtex-36 filament composite fibers (composite fiber A fiber diameter: 16 μm, composite fiber B fiber diameter: 17 μm, crimp development rate: 0%).

[0220] In Example 8, the straight fibers made it difficult for the irregular cross-sections to interlock during rubbing, increasing the difference between the static and dynamic coefficients of friction, enhancing the moist feel that is characteristic of natural materials. In addition, the presence of continuous, straight recesses in the fiber axis direction increased the diffusion rate of water adhering to the fabric, resulting in excellent water absorption and diffusion properties. The results are shown in Table 3.

[0221] [Example 9] Multifilaments made of composite fibers were produced in the same manner as in Example 1, and a smooth knitted fabric was obtained using the fibers on a 28G circular knitting machine. The resulting knitted fabric was scoured for 10 minutes in 80°C warm water containing a surfactant, and then heated to 90°C using a 1% by mass aqueous sodium hydroxide solution in a jet dyeing machine to remove 99% or more of the easily soluble polymer, Polymer 1. Next, as a dyeing process, the fabric was immersed in an aqueous solution containing a disperse dye (black) and a dyeing assistant at 130°C for 60 minutes, followed by rinsing. Next, the fabric was immersed in an aqueous solution containing a reduction detergent at 80°C for 20 minutes, followed by reduction cleaning, rinsing, and air drying.

[0222] The obtained knitted fabric was composed of a multifilament consisting of two types of modified cross-section fiber A (FIG. 4(d), fiber diameter: 15 μm) and modified cross-section fiber B (FIG. 5(c), fiber diameter: 16 μm, crimp development rate: 29%) with different cross-sectional shapes. The modified cross-section fibers A and B had 6 and 12 recesses, respectively, and the ratio of the maximum recess depths between the modified cross-section fibers A and B was 2.4 and the ratio of the irregularities was 1.3. In addition, the adjacent filament group ratio was 28%, meaning that the modified cross-section fibers A and B were dispersed and mixed, confirming that the multifilament was composed of the modified cross-section fiber of the present invention.

[0223] The knitted fabric composed of this multifilament has a structure that emphasizes the unevenness of the fabric surface compared to woven fabrics, allowing the unevenness to be fully expressed on the fabric surface, not only enhancing the silky squeaky feel and mild luster, but also improving water absorption and quick-drying properties due to increased interfiber voids. Furthermore, compared to woven fabrics, the fabric structure weakens the fiber constraint, dispersing the force applied to the fibers during friction and improving abrasion resistance. The results are shown in Table 3.

[0224] Example 10: As an easily eluted component, polyethylene terephthalate copolymerized with 8 mol% of 5-sodium sulfoisophthalic acid and 9 wt% of polyethylene glycol (SSIA-PEG copolymerized PET, melt viscosity: 100 Pa s) was prepared, and as a difficult-to-elute component, nylon 6 (N6, melt viscosity: 190 Pa s) was prepared.

[0225] The procedures of Example 1 were repeated except that these polymers were melted separately at 290°C, and then the easily soluble component / hardly soluble component were weighed out to a weight ratio of 12 / 88 to produce a multifilament consisting of composite fibers in the same manner as in Example 1.

[0226] In Example 10, the nylon used was low in elasticity, and therefore the nylon was not easily scraped off during wear, resulting in excellent flexibility and excellent abrasion resistance. The results are shown in Table 3.

[0227] [Examples 11 and 12] The same procedures as in Example 1 were repeated, except that the heater temperature for false twisting was changed to 180°C and 120°C, thereby changing the crimp development rate of the multifilament made of composite fiber to 37% (Example 11) and 20% (Example 12), respectively.

[0228] In Examples 11 and 12, the smaller the crimp development rate, the finer the voids inside the fabric, and the more improved the water absorption and diffusion properties due to capillary action caused by the recesses. The results are shown in Table 3.

[0229]

[0230]

[0231]

[0232] The multifilament, woven / knitted fabric, and textile product of the present invention have fibers with different unevenness dispersed and mixed within the multifilament, which allows uneven spots to be formed on the surface of the fabric and void spots to be formed inside the fabric, making it possible to obtain textile products that have the characteristic rustling feel and luxurious, mild luster of silk, as well as functionality such as water absorption and diffusion properties.

[0233] Therefore, it can be suitably used for a wide range of textile products, from general clothing such as jackets, skirts, pants, and underwear to sportswear, clothing materials, and the like, and also for lifestyle applications such as interior products such as carpets and sofas, car seats, and other vehicle interior parts, cosmetics, cosmetic masks, and health products, taking advantage of its comfort. However, from the viewpoint of being able to reproduce the creaky feel and luxurious, mild luster that are characteristic of silk, it is particularly preferred to use it for clothing applications such as Western and Japanese clothing, in which silk is mainly used.

[0234] x Difficult-to-extract component y Easily soluble component A Perfect circle inscribed in the fiber cross section at two or more points (inscribed circle) B Perfect circle circumscribed in the fiber cross section at two or more points (circumscribed circle) m Straight line intersecting the periphery of the difficult-to-extract component at only two points j, k Intersection points of line m and the periphery of the difficult-to-extract component l Point on the periphery of the difficult-to-extract component that is furthest from line m s Shortest distance between line m and point l M Straight line intersecting the periphery of the irregular cross-section fiber at only two points J, K Intersection points of line M and the periphery of the difficult-to-extract component L Point on the periphery of the irregular cross-section fiber that is furthest from line M S Shortest distance between line M and point L 1 Metering plate 2 Distribution plate 3 Discharge plate

Claims

1. A multifilament in which irregular cross-section fibers with different cross-sectional shapes are dispersed and mixed, the irregular cross-section fibers have 3 to 20 continuous recesses in the fiber axis direction, and the ratio of the maximum depth of the recesses between the irregular cross-section fibers is 1.1 to 5.

0.

2. The multifilament according to claim 1, wherein the degree of deformation of the modified cross-section fiber is 1.1 to 2.

5.

3. A textile product containing at least a portion of the multifilament according to claim 1 or 2.

4. The fabric contains multifilaments in which fibers with different cross-sectional shapes are dispersed and mixed, and the static friction coefficient of the fabric surface is 0.5 to 2.0, and the variation of the dynamic friction coefficient is 1.0 x 10 －２ ~5.0 x 10 －２ That is, woven and knitted fabrics.

5. The woven or knitted fabric according to claim 4, wherein the contrast gloss of the surface of the fabric is 1.0 to 2.

5.

6. Clothing comprising at least a portion of the woven or knitted fabric according to claim 4 or 5.

7. A multifilament in which composite fibers with different composite cross sections are dispersed and mixed, the composite fibers consist of a hardly soluble component and an easily soluble component, the hardly soluble component of the composite fiber has 3 to 20 continuous recesses in the fiber axis direction, and the ratio of the maximum depth of the recesses of the hardly soluble component between the composite fibers is 1.1 to 5.

0.

8. The multifilament according to claim 7, wherein the ratio of the degree of deformation between the composite fibers is 1.1 to 2.

0.

9. A multifilament obtained by removing easily soluble components from the composite fiber according to claim 7 or 8.

10. A textile product at least partly comprising the multifilament according to claim 9.

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