Woven and knitted fabrics

Abstract

In order to provide a woven / knitted article having excellent fabric / skin separation, the present invention provides a woven / knitted article including C-type cross-section fibers, wherein: the average standard deviation Sq of the surface roughness of at least one surface of the woven / knitted article is 5-100 µm, inclusive; and the ratio (Sqs / Sq) of the average standard deviation Sqs of the surface roughness of the one surface when the woven / knitted article is stretched by 10%, to the average standard deviation Sq, is 0.85-2.00, inclusive.

Description

[Technical Field]

[0001] The present invention relates to a woven or knitted fabric that is comfortable to wear and has a natural appearance. [Background technology]

[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 lifestyles have become more diverse and they are seeking a better quality of life, there is a demand for fibers with more advanced textures and functions.

[0003] There is a trend toward superior comfort when it comes to clothing textiles. In particular, underwear, shirts, and other items that come into contact with the human skin require sweat absorption, quick drying, good breathability, and the ability to move with the body, such as stretchability, and various technologies have been proposed to date.

[0004] Patent Document 1 describes that by using flat yarns with a flat cross section to form a knitted fabric, the surface area of ​​the fibers can be increased, thereby imparting excellent water absorption and moisture evaporation properties.

[0005] In addition, in Patent Document 2, the sticking of the dough is reduced by increasing the degree of surface irregularity and increasing the moisture retention rate in the dough.

[0006] Natural materials such as cotton, linen, wool, and Japanese paper have an uneven surface texture, which is a characteristic of natural materials and has been favored and used for both clothing and non-clothing applications. On the other hand, when synthetic fiber filaments are used, the fibers tend to be highly uniform, and it has been pointed out that it is not possible to obtain the uneven texture of natural materials. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-174067 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-303408 Summary of the Invention [Problem to be solved by the invention]

[0008] However, even Patent Documents 1 and 2 do not necessarily provide sufficient effects in terms of comfort when worn, particularly when exercising, and in particular, the ability of the fabric to stay away from the skin when sweating, and further improvements are desired.

[0009] Furthermore, with the recent high summer temperatures, sweating increases, and sweat absorbed from the skin surface tends to migrate to the surface. As office wear becomes more casual, there are more opportunities to wear a jacket directly over underwear or a T-shirt. In this case, sweat can seep from the underwear into the jacket, causing sweat stains on the lining and surface of the jacket, which can become a problem. This can be improved by increasing the thickness of the underwear to increase its absorbency, but thicker materials can also increase sweating and reduce comfort during exercise.

[0010] In view of the above-mentioned problems of the prior art, the present invention aims to improve the skin-releasing properties of fabrics when worn, particularly to solve the problem that this effect is reduced during exercise, etc. Another object of the present invention is to simultaneously achieve the reduction in perspiration seepage. In addition, an object of the present invention is to achieve a natural-like surface texture with synthetic fibers so that the fabrics can be suitably used as woven or knitted fabrics for clothing. [Means for solving the problem]

[0011] In order to achieve the above object, the present invention comprises the following configuration. (1) A woven or knitted fabric containing C-section fibers, wherein the average standard deviation Sq of surface roughness on at least one side of the woven or knitted fabric is 5 μm or more and 100 μm or less, and when the woven or knitted fabric is stretched by 10%, the ratio (Sqs / Sq) of the average standard deviation Sq of surface roughness on one side to the average standard deviation Sq is 0.85 or more and 2.00 or less. (2) The woven or knitted fabric according to (1), wherein the ratio (RB / RA) of the inscribed circle diameter RA to the circumscribed circle diameter RB in the C-cross section fiber is 1.2 or more and 5.0 or less. (3) The woven or knitted fabric according to (1) or (2), wherein the C-cross section fiber is a C-cross section fiber in which at least two different types of polymers are unevenly distributed on the left and right sides. (4) The woven or knitted fabric according to any one of (1) to (3), which has at least one weave selected from twill weave, multi-ply weave, rib knit, and pique knit. (5) A woven or knitted fabric according to any one of (1) to (4), which contains a water-absorbent polyester resin. (6) The woven or knitted fabric according to any one of (1) to (5), which has a water retention rate of 20% or more. (7) The woven or knitted fabric according to any one of (1) to (6), having an exudation rate of 40% or less. [Effects of the Invention]

[0012] The woven or knitted fabric of the present invention reduces sticking of the fabric to the skin and perspiration exudation when worn, thereby providing clothing that is comfortable to wear and has excellent appearance. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic diagram of the cross-sectional structure of a C-section fiber according to the present invention. [Figure 2] FIG. 2 is a schematic diagram of the cross-sectional structure of a conventional composite fiber. DETAILED DESCRIPTION OF THE INVENTION

[0014] The present invention will be described in detail below together with preferred embodiments.

[0015] The woven or knitted fabric of the present invention has a surface roughness average standard deviation Sq of 5 μm or more and 100 μm or less on at least one side. This may also be true for both sides of the woven or knitted fabric. The surface roughness average standard deviation Sq is calculated using the method described below. If Sq is less than 5 μm, the fabric surface will have no unevenness and the skin-releasing properties will be reduced. In addition, the surface of the woven or knitted fabric will become uniform, impairing the natural material-like appearance. On the other hand, if Sq is greater than 100 μm, the fabric surface will have too much unevenness, resulting in a garment that feels rough and uncomfortable against the skin when worn. By setting Sq to 5 μm or more and 100 μm or less, the appropriate unevenness and non-uniformity of the fabric surface can achieve both skin-releasing properties when worn and skin-releasing properties when sweating, and also achieve a natural-like surface feel. Furthermore, the contact area with the skin is reduced, thereby suppressing chill caused by sweat-absorbing fabrics. The lower limit is preferably 30 μm or more, and more preferably 40 μm or more. The upper limit is preferably 90 μm or less, and more preferably 80 μm or less.

[0016] Furthermore, the woven or knitted fabric of the present invention has a ratio Sqs / Sq of the average standard deviation Sqs of the surface roughness of at least one surface when stretched by 10% to the above-mentioned Sq on the same surface as Sqs, which is 0.85 or more and 2.00 or less. Sqs here is calculated by the method described below.

[0017] When investigating the reasons for the reduced release properties during exercise, etc., it was confirmed that the unevenness of the fabric surface is reduced when the fabric stretches due to body movement. It was also discovered that this reduced unevenness leads to a decrease in release properties, i.e., the fabric sticking to the shoulders, back, and elbows. In other words, this problem can be solved if the reduction in the unevenness of the fabric surface when the fabric stretches can be suppressed. Conventional woven and knitted fabrics have not focused on Sqs, and therefore have not been satisfactory in terms of release properties, particularly during exercise. To solve this problem, Sqs is preferably 5 μm or more and 200 μm or less. Setting it to 5 μm or more improves release properties. It is more preferably 30 μm or more. Furthermore, setting it to 200 μm or less provides a better feel against the skin when stretched. However, the relative value of Sqs, i.e., the ratio to Sq in an unstretched state, is a particularly important indicator of wearing comfort, rather than the absolute value. If the Sqs / Sq ratio is less than 0.85, the fabric will stick to the skin at the stretched portion due to exercise, reducing comfort. Conventional woven and knitted fabrics, even if they have surface irregularities, become smooth and uniform upon stretching, resulting in an Sqs / Sq ratio of less than 0.85, and the magnitude of this change is one of the causes of significant deterioration in comfort. Furthermore, if the Sqs / Sq ratio is greater than 2.00, the unevenness of the stretched portion of the fabric becomes too great, making the wearer feel a rough touch, again reducing comfort. By setting the Sqs / Sq ratio to 0.85 or more and 2.00 or less, comfort during exercise can be achieved. The lower limit is preferably 0.90 or more, more preferably 0.95 or more. The upper limit is preferably 1.70 or less, more preferably 1.60 or less.

[0018] To achieve the above-described ranges for Sq and Sqs / Sq, it is possible to appropriately combine the structure of the woven or knitted fabric, the properties of the yarn, and the like. Examples of woven or knitted structures that can be easily achieved within the scope of the present invention include twill and double weaves for woven fabrics, and rib knits and pique knits for knitted fabrics, and are therefore preferred. Twill weaves are a more preferred embodiment due to their excellent productivity and the ease with which surface roughness can be controlled by stretching the fabric. Furthermore, the properties of the constituent yarns include, for example, false-twisted yarns, sheath-core composite cross-section fibers, and side-by-side conjugate yarns. In the case of a flat cross-sectional shape, crimped yarns containing aligned portions can be used. In particular, flat yarns are preferred in the present invention, and it is more preferable for 10% or more of the multifilament yarns to be oriented in the same direction, as this facilitates achieving the above-described range for Sqs / Sq in the present invention. "Facing in the same direction" as used herein refers to a cross-sectional image containing 20 or more multifilament flat yarns, in which the angle between an arbitrary reference line and the major axis of the cross section of the flat yarn is measured at 0 to 180 degrees for 20 yarns each, and 10% or more of the flat yarns have an angle of 20 degrees or less. It is more preferable that 10% or more of the flat yarns have an angle of 10 degrees or less. Furthermore, as described below, a flat yarn refers to one with an RB / RA ratio of greater than 1, preferably 1.2 or greater. The use of a side-by-side conjugate yarn having a flat cross-sectional shape facilitates the production of phase-aligned crimped yarns, which is a preferred embodiment of the present invention. In this embodiment, highly flattened yarns within the ranges of Sq and Sqs / Sq of the present invention can be twisted into ribbon-like structures, enhancing the textured feel of the fabric surface. Furthermore, since the yarn bundles twist and move in the thickness direction when the fabric is stretched, this is preferable because it allows the Sq and Sqs / Sq to be within more preferred ranges. Note that when processing such as false twist crimping is performed, the phase tends to become less uniform. In false twist yarns, the developed crimps tend to be dispersed and the surface tends to become uniform, but they may be used as long as the ranges of Sq and Sqs / Sq in the present invention are satisfied.

[0019] The elongation percentage of the woven or knitted fabric of the present invention is preferably 10% or more, more preferably 20% or more, from the viewpoint of wearing comfort. Also, from the viewpoint of excellent skin-releasing properties when worn, it is preferably 50% or less, more preferably 40% or less. The elongation percentage in the present invention can be determined by the method described in the examples below.

[0020] The woven or knitted fabric of the present invention contains C-cross section fibers. The C-cross section fibers preferably account for 20% by weight or more, more preferably 90% by weight or more, of the woven or knitted yarns. For example, in the case of a woven fabric, the C-cross section fibers can be used in at least some or all of the warp and weft yarns as long as the range specified in the present invention is satisfied. While the C-cross section fibers may be used in only the warp or only the weft, it is preferred that the C-cross section fibers be used in at least some or all of the warp and weft yarns.

[0021] In the present invention, C-section fibers refer to yarns in which a portion of the hollow fiber wall is open in the fiber axis direction and the cross section is approximately C-shaped (including those that are modified to appear approximately V-shaped or approximately U-shaped). The inclusion of C-section yarns improves water absorbency through the C-shaped openings, keeping the skin surface dry. As mentioned above, surface roughness is an important indicator for improving skin release properties, and the water absorbency provided by these openings makes the effect extremely excellent, especially when sweating. The effect of the present invention cannot be achieved with either one alone. Even if the surface roughness is within the range of the present invention, the absence of the openings will result in poor skin release properties. Furthermore, even if the openings are present, the surface roughness will still be poor if it is outside the range of the present invention.

[0022] Furthermore, moisture absorbed by the skin side can be trapped in the hollow space inside the fiber, which helps prevent sweat from transferring to the outer layer when layered. This makes it possible to achieve both a comfortable feel against the skin and reduced sweat transfer.

[0023] In the present invention, it is preferable that the C-cross section fiber is obtained from a dissolving hollow fiber, since cross section deformation can be suppressed during processing steps such as false twisting and twisting. The dissolving hollow fiber referred to in the present invention is a fiber having a core-sheath structure consisting of a core component made of an easily soluble polymer and a sheath component made of a sparingly soluble polymer, and by removing the core component, a yarn having a C-cross section can be formed. In the cross section of the fiber, a part of the core component is exposed to the fiber surface through the opening of the sheath component, and the yarn preferably has a continuous portion that is continuous from the fiber center to the fiber surface.

[0024] The width of the interconnected portion (hereinafter sometimes simply referred to as "interconnected width") is preferably 10% or less of the fiber diameter. The fiber diameter is determined by embedding the composite fiber in an embedding agent such as epoxy resin and photographing the fiber cross section perpendicular to the fiber axis with a scanning electron microscope (SEM) at a magnification sufficient to observe 10 or more fibers. From each photographed image, the diameter of a fiber randomly selected within the same image is measured in μm units to the first decimal place. This is then performed for 10 filaments, and the simple number average is calculated. The value obtained by rounding to the nearest decimal place is used as the fiber diameter (μm). If the fiber cross section perpendicular to the fiber axis is not a perfect circle, its area is measured and the diameter calculated by converting it to a perfect circle is used. The interconnected width is measured by embedding the fiber in an embedding agent such as epoxy resin and photographing the fiber cross section perpendicular to the fiber axis with a transmission electron microscope (TEM) at a magnification sufficient to observe 10 or more fibers. When the readily soluble polymer is interconnected from the fiber center to the fiber surface, analysis is performed using known analytical software capable of measuring the length of an image. Referring to Figure 1, first, the shortest width W (e.g., W in Figure 1(b)) of the interconnected portion in the direction perpendicular to a line S (e.g., S in Figure 1(b)) that passes through the fiber center G and is parallel to the interconnected portion is calculated in μm units. This is then performed for 10 filaments, and the simple number average of the results obtained is calculated and rounded to the nearest tenth to obtain the interconnected width. The interconnected width calculated for each filament is then divided by the fiber diameter and multiplied by 100 to calculate the simple number average of the results obtained for 10 filaments, and the result is rounded to the nearest tenth to obtain the ratio (%) of the interconnected width to the fiber diameter.

[0025] By setting the interconnection width to 10% or less of the fiber diameter, collapse of the hollow space due to fiber bite or misalignment of the openings can be prevented without impairing water absorption or water retention. Furthermore, by setting the interconnection width to 5% or less of the fiber diameter, fibrillation due to fiber abrasion caused by the openings formed after the elution of the readily soluble polymer can be suppressed. Furthermore, when post-processing with a functional agent is performed, the functional agent that has entered the hollow space can be prevented from falling off during washing or the like, thereby significantly improving the washing durability of the functional agent, which is more preferable. In addition, it can also prevent retained moisture from seeping out when water absorption processing is performed. However, if the interconnection width is too narrow, it becomes difficult to remove the readily soluble polymer from the core, so the practical lower limit of the interconnection width is 1% of the fiber diameter.

[0026] C-cross-section fibers can have any irregular cross section, such as flat, multilobal, polygonal, gear-shaped, petal-shaped, or star-shaped. However, from the viewpoint of adequate skin release, flat or multilobal shapes are preferred. A flat shape facilitates the alignment of the crimp phase, making it easier to control the surface roughness within the range of the present invention. Furthermore, a multilobal shape imparts irregularities to the fiber surface, suppressing glare due to diffused reflection of light and enhancing water absorption and quick-drying properties through fine interfiber voids. Furthermore, the irregularities provide a dry touch when touched by the hand, as the irregularities catch the fingers. However, if the number of irregularities is too large, the spacing between the irregularities becomes finer, gradually reducing the effect. Therefore, the practical upper limit for the number of irregularities in the multilobal shape of the present invention is 20.

[0027] In the C-section fiber of the present invention, the ratio of the inscribed circle diameter RA to the circumscribed circle diameter RB (RB / RA) of the fiber cross section is preferably 1.2 or more and 5.0 or less. Here, the inscribed circle diameter RA and the circumscribed circle diameter RB in the present invention are determined by embedding the fiber in an embedding medium such as epoxy resin and photographing the fiber cross section perpendicular to the fiber axis with a scanning electron microscope (SEM) at a magnification that allows observation of 10 or more fiber filaments. Randomly selected fibers within each photographed image are analyzed using analysis software capable of measuring image lengths. The diameter of the largest possible circle (e.g., A in FIG. 1(a)) that inscribes the fiber surface at at least two points (e.g., a1 and a2 in FIG. 1(a)) and exists only within the fiber, where the circumference of the inscribed circle does not intersect with the fiber surface, is calculated. A simple number average of the results obtained for 10 filaments is calculated, and the value rounded to the nearest whole number is defined as the inscribed circle diameter RA. In addition, the diameter of a circle (for example, B in Figure 1(a)) that circumscribes the fiber surface at at least two points (for example, b1 and b2 in Figure 1(a)) and exists only outside the fiber, and has the smallest possible diameter within the range where the circumference of the circumscribed circle does not intersect with the fiber surface, is calculated, and the simple number average of the results obtained for 10 filaments is calculated and rounded to the nearest whole number, which is defined as the circumscribed circle diameter RB. RB / RA is calculated by dividing the RB obtained for each fiber above by RA, and the simple number average of the results obtained for 10 filaments is calculated and rounded to the nearest whole number, which is defined as RB / RA.

[0028] By making the RB / RA 1.2 or more, the skin separation property is improved due to the surface unevenness. It is more preferably 1.5 or more. Furthermore, by making the RB / RA 5.0 or less, glare due to flatness can be suppressed, and a woven or knitted fabric with excellent surface quality can be obtained. It is more preferably 4.0 or less. In the present invention, there are no particular limitations on the method for achieving the above range, but it can be obtained, for example, by using a spinneret described below.

[0029] The above-mentioned "easily soluble polymer" refers to a polymer that dissolves relatively quickly in a solvent used in the dissolution treatment, and the above-mentioned "slightly soluble polymer" refers to a polymer that dissolves slowly. In addition, the terms "dissolved" and "dissolved" in the present invention also include cases where the polymer is decomposed and appears to be dissolved.

[0030] The polymer constituting the C-section fiber of the present invention is preferably a thermoplastic polymer because of its excellent processability, such as polyester, polyethylene, polypropylene, polystyrene, polyamide, polycarbonate, polymethyl methacrylate, and polyphenylene sulfide polymers and their copolymers. From the viewpoint of imparting particularly high interfacial affinity and obtaining fibers without composite cross-section defects, it is preferable that all thermoplastic polymers used in the composite fiber of the present invention are from the same polymer group and their copolymers. Furthermore, the polymer may 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.

[0031] The readily soluble polymer is preferably selected from polymers that are melt-moldable and more readily soluble than other components, such as polyesters and their copolymers, polylactic acid, polyamide, polystyrene and its copolymers, polyethylene, and polyvinyl alcohol. From the viewpoint of simplifying the elution process of the readily soluble polymer, copolymerized polyesters, polylactic acid, polyvinyl alcohol, and the like that are readily soluble in aqueous solvents or hot water are preferred. In particular, due to their crystallinity, they do not cause fusion between composite fibers even in false twisting and other processes in which abrasion is applied under heat, and because they are readily soluble in aqueous solvents such as alkaline aqueous solutions, they are highly suitable for advanced processing. Therefore, polyesters copolymerized with 5 mol% to 15 mol% of 5-sodium sulfoisophthalic acid and polyesters copolymerized with 5 wt% to 15 wt% of polyethylene glycol having a weight-average molecular weight of 500 to 3000 are particularly preferred.

[0032] In the C-section fiber of the present invention, it is preferable that at least two different polymers are distributed unevenly on the left and right sides. The different polymers are not particularly limited as long as they differ in at least one of the following: chemical composition, presence or absence of copolymerization, copolymerization ratio, copolymer position (e.g., random copolymerization or block copolymerization), chemical structure, weight-average or number-average molecular weight, melting point, etc. However, polymers with different melting points are preferable in terms of ease of crimp development. Different chemical compositions usually result in different melting points, and multiple differences may exist. The distribution of different polymers unevenly on the left and right sides means, for example, that, in the case of a fiber consisting of two types of polymers, a line passing through the center of the fiber and dividing the fiber cross section into two equal areas is such that different polymers are predominantly distributed on the left and right fiber cross sections of the line. It is preferable that the area ratio of the different polymers on either the left or right fiber cross section is 100:0 to 70:30, and on the other fiber cross section is in the range of 30:70 to 0:100 (e.g., line I in Figure 2(b)). That is, the area ratio of each polymer is preferably in the range of 70 / 30 to 30 / 70.Within this range, the fabric is less susceptible to the hardening of texture that occurs when one of the polymers shrinks significantly during heat treatment, and the crimped form due to the shrinkage difference can be fully expressed.

[0033] The composite structure of the above-mentioned composite fiber is not particularly limited, and examples of such composite structures include a side-by-side type, an island-in-the-sea type, a core-sheath type, and a blend type. From the perspective of increasing the distance between centers of gravity to increase the crimp development potential, it is preferable that the hardly soluble polymers with different melting points, for example, a hardly soluble polymer on the relatively low melting point side and a hardly soluble polymer on the high melting point side, are bonded side-by-side, with the polymers being unevenly distributed to the left and right. By bonding the hardly soluble polymers side-by-side, the interface between the hardly soluble polymers with different melting points is small, and therefore the distance between the centers of gravity between the polymers in the composite cross section can be maximized. This not only maximizes the crimp development potential but also makes it possible to impart stretchability, resulting in a fabric with appropriate stretchability and a stress-free wearing comfort, and is therefore a more preferred range.

[0034] Examples of polymers include melt-moldable thermoplastic polymers and copolymers thereof, such as polyesters, polyethylenes, polypropylenes, polystyrenes, polyamides, polycarbonates, polymethyl methacrylates, and polyphenylene sulfide. In the case of polymers with different melting points, the difference between the melting points of the highest and lowest polymers to be combined is preferably 10°C or more, and more preferably 20°C or more.

[0035] The main reason why the C-section fiber of the present invention is preferably composed of at least two different polymers is that the crimp morphology is expressed by the difference in shrinkage. A combination of different polymers is preferably such that at least one is a high-shrinkage, low-melting-point polymer and at least one is a low-shrinkage, high-melting-point polymer. From the viewpoint of preventing peeling and imparting stability to advanced processing and durability to the fabric, it is more preferable to select the polymer combination from the same group of polymers having the same bonds in the main chain, such as polyesters with ester bonds and polyamides with amide bonds. Examples of such combinations of polymers from the same polymer family include, but are not limited to, polyester combinations such as copolymerized polyethylene terephthalate / polyethylene terephthalate, polybutylene terephthalate / polyethylene terephthalate, polytrimethylene terephthalate / polyethylene terephthalate, thermoplastic polyurethane / polyethylene terephthalate, polyester elastomer / polyethylene terephthalate, polyester elastomer / polybutylene terephthalate, polyamide combinations such as nylon 66 / nylon 610, nylon 6-nylon 66 copolymer / nylon 6 or 610, PEG copolymerized nylon 6 / nylon 6 or 610, and thermoplastic polyurethane / nylon 6 or 610, and polyolefin combinations such as ethylene-propylene rubber finely dispersed polypropylene / polypropylene and propylene-α-olefin copolymer / polypropylene. From the viewpoints of suppressing collapse of the hollow portion inside the fiber due to high bending rigidity and achieving good color development when dyed, it is more preferable to use polyester combinations for poorly soluble polymers with different melting points. Furthermore, examples of copolymerization components in copolymerized polyethylene terephthalate include succinic acid, adipic acid, azelaic acid, sebacic acid, 1,4-cyclohexanedicarboxylic acid, maleic acid, phthalic acid, isophthalic acid, and 5-sodium sulfoisophthalic acid. From the viewpoint of maximizing the difference in shrinkage from polyethylene terephthalate, it is preferable to use polyethylene terephthalate in which 5 to 15 mol % of isophthalic acid is copolymerized.

[0036] From the viewpoint of achieving a softer texture, the C-section fiber of the present invention preferably has a fiber diameter of 20 μm or less. Within this range, sufficient resilience can be obtained in addition to flexibility, making it suitable for clothing applications such as pants and shirts, which require a firm and resilient texture. If the fiber diameter is 15 μm or less, flexibility increases and the crimp morphology developed upon heat treatment becomes fine. Since the unevenness caused by the crimp catches the fingers when touched with the hand, a dry touch is also obtained, making it suitable for clothing applications such as innerwear and blouses that come into contact with the skin. From the viewpoint of maintaining bending recovery, obtaining a moderate resilience, and obtaining excellent color development, the fiber diameter is preferably 8 μm or more.

[0037] The woven or knitted fabric of the present invention preferably contains a water-absorbent resin or a hydrophilic group in order to further improve the skin separation property. water absorption Woven and knitted fabrics containing resins or hydrophilic groups can generally be obtained by subjecting woven and knitted fabrics to a water-absorbing treatment. Examples of such water-absorbing treatments include alkali weight reduction treatments for polyesters, and treatments using water-absorbing polyester resins such as polyethylene glycol and polyester-polyalkylene glycol copolymer resins, or treatments using hydrophilic finishing agents such as cellulose and hydrophilic silicones, attached to fibers. The inclusion of a water-absorbing polyester resin in the woven and knitted fabrics of the present invention is preferred because it provides a high water-absorbency improvement effect and high washing durability. Furthermore, the method for water-absorbing treatment of woven and knitted fabrics is not particularly limited, and can be carried out using dyeing equipment commonly used for processing woven and circular knitted fabrics. This water-absorbing treatment can be carried out simultaneously with or after dyeing during the dyeing process, or it can be applied to the woven and knitted fabric by a padding method during the finishing stage, etc. The knitted fabrics of the present invention may also be subjected to various additional functional treatments, including conventionally known stain-resistant treatments such as SR treatment, deodorizing treatment, antibacterial or antimicrobial treatment, UV protection treatment, friction melting treatment, electrostatic treatment, and skin care treatment.

[0038] Furthermore, the woven or knitted fabric of the present invention preferably has a water retention rate of 20% or more, more preferably 40% or more. The practical upper limit of water retention rate is approximately 80%. A water retention rate of 20% or more allows the fabric to sufficiently absorb sweat and inhibits sweat transfer to outerwear. There are no particular limitations on the method for achieving a water retention rate within the above range, but various methods can be employed, such as using crimped yarn or using a thicker weave for the woven or knitted fabric, such as a multiple weave or pique knit, to create a structure with adequate voids for absorbing moisture. The water retention rate in the present invention can be measured by the method described below.

[0039] Furthermore, the woven or knitted fabric of the present invention preferably has a seepage rate of 40% or less, more preferably 35% or less. The practical lower limit of the seepage rate is about 5%. By setting the seepage rate to 40% or less, the degree of sweat transfer to the outer layer can be accurately reproduced using the seepage rate evaluation method described below, and sweat transfer to the outer layer can be further suppressed. There are no particular restrictions on the method for setting the seepage rate within the above range, but for example, by appropriately adjusting the amount of C-cross-section fiber in the present invention, moisture can be retained in the hollow space inside the yarn to achieve the above range.

[0040] Next, a preferred method for producing the woven or knitted fabric of the present invention will be described.

[0041] The method for producing the C-cross section fiber of the present invention is not particularly limited, and can be a melt spinning method for producing continuous fibers, or a solution spinning method such as a wet or dry-wet method. From the viewpoint of increasing productivity, a melt spinning method is preferred. In addition, a composite spinneret, which will be described later, can also be used in the melt spinning method. The spinning temperature is set to a temperature at which the polymers used, primarily high-melting-point or high-viscosity polymers, 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.

[0042] The spinning speed 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. From the perspective of achieving high orientation and improving mechanical properties, a spinning speed of 500 to 4000 m / min followed by drawing is preferred, as this promotes uniaxial orientation of the fiber. During drawing, it is preferable to appropriately set the preheating temperature based on the softening temperature, such as the glass transition temperature of the polymer. 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, whose glass transition temperature is around 70°C, the preheating temperature is usually set to about 80 to 95°C.

[0043] Furthermore, when the output per hole of the spinneret for the C-section fiber of the present invention is set to about 0.1 to 10 g / min·hole, stable production becomes possible. After the extruded polymer flow is cooled and solidified, an oil agent is added, and the polymer is taken up by rollers set to a specified peripheral speed. The polymer is then drawn by heated rollers to form the desired fiber.

[0044] A suitable composite spinneret for producing a C-cross section fiber made of two or more polymers is, for example, the composite spinneret described in JP 2011-208313 A. This composite spinneret is comprised of three main components, a metering plate, a distributor plate, and a discharge plate, stacked from top to bottom, and is incorporated into a spinning pack for spinning.

[0045] The woven or knitted fabric of the present invention can be obtained by weaving, knitting, and dyeing the above-described C-crosssection fiber using a conventional method. As a method for producing the woven or knitted fabric of the present invention, an example of a dyeing process for a woven or knitted fabric made of C-crosssection fibers in which two different polymers are unevenly distributed on the left and right sides is shown below. First, the woven or knitted fabric is optionally scoured and subjected to a wet heat treatment, which causes crimping in the filaments due to the difference in thermal shrinkage between the two constituent polymers. This wet heat treatment can be performed using a jet dyeing machine or the like. The temperature and time can be set so as to maximize the potential shrinkage of the polymers contained therein. The higher the treatment temperature and the longer the treatment time, the greater the potential shrinkage of the polymers and the more micro-crimps are developed. After this wet heat treatment, it is preferable to perform an intermediate setting before dissolving the easily soluble polymer used to form the C-crosssection fiber. This intermediate setting allows the elongation of the resulting woven or knitted fabric to be controlled. The intermediate setting can be performed using equipment such as a pin tenter, and the surface condition and elongation of the woven or knitted fabric can be controlled by appropriately adjusting the tension, temperature, and width. Increasing the tension elongates the fabric, decreasing the elongation percentage, but tends to remove wrinkles and improve surface quality. Increasing the treatment temperature improves the setting property, but also increases the thermal shrinkage of the fabric, tending to decrease the elongation percentage. Therefore, the desired elongation percentage can be achieved by appropriately controlling these factors.

[0046] Thereafter, if necessary, a soluble polymer for forming a C-cross section fiber can be dissolved out to obtain a C-cross section shape. The soluble polymer can be dissolved out by processing the fiber in a liquid capable of dissolving the soluble polymer, such as an aqueous sodium hydroxide solution, using a jet dyeing machine or the like.

[0047] The woven or knitted fabric of the present invention may further be subjected to dyeing, functional processing, and finishing setting. Even after undergoing these post-processing steps, the crimp induced by the wet heat treatment is maintained, thereby imparting stretchability to the woven or knitted fabric.

[0048] The woven and knitted fabric of the present invention reduces the sticking of the fabric to the skin when worn and reduces the seepage of sweat into outerwear, resulting in excellent wearing comfort and appearance, and therefore can be suitably used for general clothing such as jackets, skirts, pants, and underwear, as well as sports clothing and clothing materials. [Example]

[0049] The woven or knitted fabrics of the present invention will be described in detail below with reference to Examples. The Examples and Comparative Examples were evaluated according to the following A to H.

[0050] A. Melting point Fibers and portions of fibers extracted from chip-shaped polymers or woven or knitted fabrics were vacuum dried to a moisture content of 200 ppm or less, and approximately 5 mg was weighed. Using a TA Instruments Q2000 differential scanning calorimeter (DSC), the sample was heated from 0°C to 300°C at a rate of 16°C / min, and then held at 300°C for 5 minutes for DSC measurement. The melting point was calculated from the melting peak observed during the heating process. Measurements were performed three times per sample, and the average value was used as the melting point. When multiple melting peaks were observed, the melting point was determined to be the top of the highest melting peak.

[0051] B. Fineness The weight of 10 cm of fiber taken from raw yarn or woven / knitted fabric before weaving / knitting was measured, and the weight was calculated by multiplying the weight by 100,000. This process was repeated 10 times, and the average value was rounded to one decimal place to obtain the fineness (dtex).

[0052] C. Average standard deviation of surface roughness (Sq) The woven or knitted fabric was fixed to a flat plate so that no load was applied, and the standard deviation of the surface roughness was measured 10 times using a Keyence One-Shot 3D Shape Measuring Instrument VR-3200 under the following conditions, changing the position, and the average value was taken as the average standard deviation Sq.

[0053] Magnification: 12x Measurement area: Full area (18cm long x 24cm wide) Correction: Surface shape correction, waviness removal, correction strength = 5 Filter type: Gaussian S-filter: None F-Operation: None L-filter: None.

[0054] D. Average standard deviation (Sqs) of surface roughness when the fabric is stretched by 10% Woven and knitted fabrics were fixed to a flat plate while stretched 10% in the direction of the C-section fibers. The standard deviation of the surface roughness was measured 10 times using a Keyence VR-3200 One-Shot 3D Shape Measuring Instrument under the following conditions: The average value of the standard deviation was calculated as Sqs. Note that the C-section fibers refer to the warp (weft) direction when they are present only in the warp (weft) yarns of a woven fabric; when they are present in both the warp and weft, they refer to the direction of greater elongation. For warp-knitted fabrics, this refers to the warp direction (the direction in which the loops are arranged vertically), and for weft-knitted fabrics, it refers to the weft direction (the direction in which the loops are arranged horizontally). The stress used to stretch a woven or knitted fabric must be 4.0 N / cm or less. Sqs measurements are not permitted for woven or knitted fabrics that do not stretch 10% under a stress of 4.0 N / cm.

[0055] Magnification: 12x Measurement area: Full area (18cm long x 24cm wide) Correction: Surface shape correction, waviness removal, correction strength = 5 Filter type: Gaussian S-filter: None F-Operation: None L-filter: None.

[0056] E. Water retention rate, seepage rate The water retention rate and seepage rate were calculated using the following method. (1) A woven or knitted fabric (test piece) that had been left in an environment of 20°C and 65% RH for 24 hours was cut into a piece measuring 10 cm x 10 cm, and two pieces of filter paper and three pieces of non-absorbent film of the same size were prepared. (2) The weight of the film (W0) and the weight of the test piece (W1) were measured. (3) Using a syringe, 0.3 cc of distilled water was placed on the film, and the test piece was placed on the water droplet with the front side facing up and the back side facing the water droplet. (4) After leaving it for 5 seconds, the weight (W2) of the test piece was immediately measured. (5) The weight (W3) of the film after water absorption was measured. (6) The weights of the two filter papers (w1, w3) before absorbing water were measured. (7) The test piece was sandwiched between weighed filter paper on both the front and back sides, and then sandwiched between the remaining two pieces of film not used in (3) above. (8) The pressure on the test piece is 5g / cm 2 After leaving it for 1 minute, the weights of the front and back surfaces of the filter paper (w2 (corresponding to w1 in (6) above) and w4 (corresponding to w3 in (6) above)) were immediately measured. (9) The water retention rate (%) and the seepage rate (%) were calculated using the following formula, and the average values ​​of 10 measurements were used as the water retention rate (%) and the seepage rate (%).

[0057] Water absorption rate (%)=100×(W2-W1) / ((W3-W0)+(W2-W1)) Total seepage rate (%) = 100 x ((w2-w1) + (w4-w3)) / ((W3-W0) + (W2-W1)) Water retention rate (%) = Water absorption rate (%) - Total seepage rate (%) Seepage rate (%) = 100 × 1 / 2 × ((w2-w1)+(w4-w3)) / (W2-W1).

[0058] F. Wearing evaluation (skin-freeness, ease of movement, sweat transfer, natural appearance) Identical shirts were made from woven and knitted fabrics, and the natural-looking appearance was evaluated using the following criteria while the shirt was worn on bare skin and a gray jacket was worn as an outer layer. The subjects then walked on a treadmill at 5 km / h for 20 minutes in an environment of 27°C and 75% RH. The shirt's release, ease of movement, and sweat transfer to the jacket while standing and moving were evaluated using the following criteria. This wear evaluation was conducted by 10 randomly selected subjects, and the release, ease of movement, and sweat transfer were evaluated using the average values.

[0059] Natural appearance: Natural appearance = 〇, Not natural appearance = × Release from the skin when stationary and moving: Excellent = ◎, Fairly good = 〇, Poor = × Ease of movement: Excellent = ◎, Somewhat excellent = 〇, Poor = × Sweat transfer: little = good, much = bad.

[0060] G. Fiber diameter The composite fiber was embedded in an embedding agent such as epoxy resin, and the fiber cross section perpendicular to the fiber axis was photographed using a scanning electron microscope (SEM) at a magnification that allowed observation of 10 or more filaments. The diameter of a randomly selected fiber within each photograph was measured in μm units to the first decimal place, and the simple number average of the results for 10 filaments was calculated and rounded to the nearest decimal place to obtain the fiber diameter (μm). If the fiber cross section perpendicular to the fiber axis was not a perfect circle, its area was measured and the value calculated by converting it to a perfect circle was used.

[0061] H. Elongation rate According to JIS L 1096 (2010) 8.16.1 A method, the elongation percentage was determined when the woven or knitted fabric was stretched in the thread direction of the approximately C-shaped cross-section fiber.

[0062] [Example 1] Polymer 1 was polyethylene terephthalate copolymerized with 8 mol% 5-sodium sulfoisophthalic acid and 9 wt% polyethylene glycol (SSIA-PEG copolymerized PET, melt viscosity: 100 Pa·s, melting point: 233°C). Polymer 2 was polyethylene terephthalate copolymerized with 7 mol% isophthalic acid (IPA copolymerized PET, melt viscosity: 140 Pa·s, melting point: 232°C). Polymer 3 was polyethylene terephthalate (PET, melt viscosity: 130 Pa·s, melting point: 254°C).

[0063] These polymers were melted separately at 290°C, and then weighed out to give a weight ratio of polymer 1 / polymer 2 / polymer 3 of 20 / 40 / 40. The inflowing polymers were extruded from the extrusion hole to form a flat composite fiber as shown in Figure 1(a), in which polymer 1 was located in the innermost layer and in the interconnected portion extending from the center of the fiber to the surface (x in Figure 1(a)), and polymer 2 and polymer 3 were bonded side-by-side in the outermost layer (y, z in Figure 1(a)).

[0064] After cooling and solidifying the extruded composite polymer stream, an oil agent was added, the stream was wound up at a spinning speed of 1500 m / min, and stretched between rollers heated to 90°C and 130°C to produce a composite fiber of 56 dtex-36 filaments (fiber diameter 12 μm).

[0065] The ratio RB / RA of the inscribed circle diameter RA to the circumscribed circle diameter RB of the obtained composite fiber was 1.8. It was also confirmed that the interconnected width was 0.5 μm, which was 4% of the fiber diameter of 12 μm.

[0066] Two of the obtained composite fibers were twisted together in the S direction at 300 T / M, and this twisted yarn was used as the warp and weft using a water jet loom to obtain a 2 / 2 twill fabric with a warp density of 135 threads / 2.54 cm and a weft density of 80 threads / 2.54 cm.

[0067] The resulting fabric was continuously scoured, subjected to a wet heat relaxation process in a jet dyeing machine at 130°C for 30 minutes, and then intermediately set at 180°C for 1 minute with a tentering ratio of 1%. The fabric was then heated to 100°C using a 1 wt% aqueous sodium hydroxide solution in a jet dyeing machine to remove Polymer 1 (weight loss: 22%). This was followed by a water-absorbing process using a polyester polyalkylene glycol copolymer resin (TM-SS21, manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd.) at 5% owf during standard dyeing and finishing, resulting in a fabric with a warp density of 180 threads / 2.54 cm and a weft density of 105 threads / 2.54 cm. The evaluation results of the resulting fabric are shown in Table 1. Note that more than 10% of the multifilament yarns in the resulting fabric were oriented in the same direction.

[0068] [Example 2] Two 56 dtex-36 filament (fiber diameter 12 μm) composite fibers described in Example 1 were paralleled and knitted on a single circular knitting machine to obtain a pique knit fabric with 42 threads / 2.54 cm in welting and 40 threads / 2.54 cm in course. This was then processed by the processing method described in Example 1 to obtain a pique knit fabric with 42 threads / 2.54 cm in welting and 45 threads / 2.54 cm in course. The evaluation results of the obtained knit fabric are shown in Table 1. In the obtained knit fabric, 10% or more of the multifilament yarns were oriented in the same direction.

[0069] [Example 3] A woven fabric with a warp density of 178 threads / 2.54 cm and a weft density of 103 threads / 2.54 cm was obtained in the same manner as in Example 1, except that two of the composite fibers of Example 1 were false-twisted at a twist ratio of 1.05 and used together as textured yarns of 53 dtex-36 filaments (fiber diameter 12 μm, continuous width 0.6 μm). The evaluation results of the obtained woven fabric are shown in Table 1. The obtained woven fabric had less than 10% multifilaments oriented in the same direction.

[0070] [Example 4] A woven fabric with a warp density of 175 threads / 2.54 cm and a weft density of 102 threads / 2.54 cm was obtained in the same manner as in Example 1, except that a taslan textured yarn (120 dtex-72 filaments) using the composite fiber of Example 1 as the core yarn and sheath yarn was used alone. The evaluation results of the obtained woven fabric are shown in Table 1. In the obtained woven fabric, 10% or more of the multifilament yarns were oriented in the same direction.

[0071] [Example 5] A woven fabric with a warp density of 180 threads / 2.54 cm and a weft density of 105 threads / 2.54 cm was obtained in the same manner as in Example 1, except that the composite fiber (fiber diameter 12 μm, interconnection width 0.5 μm) had a fiber cross section as shown in FIG. 1(c). The evaluation results of the obtained woven fabric are shown in Table 1. The obtained woven fabric had less than 10% multifilaments oriented in the same direction.

[0072] [Comparative Example 1] A woven fabric with a warp density of 160 threads / 2.54 cm and a weft density of 95 threads / 2.54 cm was obtained in the same manner as in Example 1, except that a composite fiber (56 dtex-36 filaments, fiber diameter 12 μm) with the cross section shown in FIG. 2(a) was used, using polymer 2 and polymer 3 from Example 1, and the weave was plain weave. The evaluation results of the obtained woven fabric are shown in Table 1. The fabric was poor in skin separation and water retention, and sweat transfer to the outerwear after exercise was significant. The fabric also did not have a natural appearance. In the obtained woven fabric, more than 10% of the multifilament threads were oriented in the same direction.

[0073] Comparative Example 2 A woven fabric with a warp density of 160 threads / 2.54 cm and a weft density of 95 threads / 2.54 cm was obtained in the same manner as in Comparative Example 1, except that a composite fiber (56 dtex-36 filaments, fiber diameter 12 μm) with the cross section shown in FIG. 2(b) was used, using polymer 2 and polymer 3 from Example 1. The evaluation results of the obtained woven fabric are shown in Table 1. The fabric was poor in skin separation and water retention, and sweat transfer to the outerwear after exercise was significant. The fabric also did not have a natural appearance. The obtained woven fabric had less than 10% of the multifilaments oriented in the same direction.

[0074] Comparative Example 3 A woven fabric with a warp density of 158 threads / 2.54 cm and a weft density of 95 threads / 2.54 cm was obtained in the same manner as in Example 5, except that Polymer 3 was used instead of Polymer 2. The evaluation results of the obtained woven fabric are shown in Table 1. The fabric had poor stretchability, and was poor in terms of skin-releasing properties and ease of movement. In addition, the fabric did not have a natural appearance. The obtained woven fabric had less than 10% multifilaments oriented in the same direction.

[0075] Comparative Example 4 The composite fiber of Comparative Example 3 was false-twisted in the same manner as in Example 3, and two 53 dtex-36 filament (fiber diameter 12 μm, continuous width 0.6 μm) textured yarns were combined to obtain a woven fabric with a warp density of 163 yarns / 2.54 cm and a weft density of 99 yarns / 2.54 cm in the same manner as in Example 1, except that the composite fiber of Comparative Example 3 was false-twisted in the same manner as in Example 3, and two 53 dtex-36 filament (fiber diameter 12 μm, continuous width 0.6 μm) textured yarns were combined to obtain a woven fabric with a warp density of 163 yarns / 2.54 cm and a weft density of 99 yarns / 2.54 cm. The evaluation results of the obtained woven fabric are shown in Table 1. The unevenness of the fabric surface was reduced due to fabric stretching, resulting in poor skin separation. Furthermore, the fabric did not have a natural appearance. The obtained woven fabric had less than 10% multifilaments oriented in the same direction.

[0076] Comparative Example 5 A woven fabric with a warp density of 180 threads / 2.54 cm and a weft density of 105 threads / 2.54 cm was obtained in the same manner as in Example 1, except that a composite fiber (56 dtex-36 filaments, fiber diameter 12 μm) with the cross section shown in Figure 2(c) was used, which was made from polymer 2 and polymer 3 of Example 1. The evaluation results of the obtained woven fabric are shown in Table 1. The fabric had low water absorbency and poor skin release properties, and sweat transfer to the outerwear after exercise was significant. In addition, more than 10% of the multifilament threads of the obtained fabric were oriented in the same direction.

[0077] Comparative Example 6 A woven fabric with a warp density of 160 threads / 2.54 cm and a weft density of 95 threads / 2.54 cm was obtained in the same manner as in Example 1, except that the same composite fiber as in Example 5 was used and the weave was changed to a plain weave. The evaluation results of the obtained woven fabric are shown in Table 1. Although non-uniform graining occurred and the Sq was large, the unevenness decreased with stretching of the fabric, and the skin-releasing properties were poor. In addition, the obtained woven fabric had less than 10% of the multifilaments oriented in the same direction. [Industrial Applicability]

[0078] The woven or knitted fabric of the present invention reduces sticking of the fabric to the skin when worn and reduces perspiration penetration into outerwear, resulting in excellent comfort and appearance. In addition, because it has a natural-looking appearance, it can be suitably used for general clothing such as jackets, skirts, pants, and underwear, as well as sportswear and clothing materials.

[0079] [Table 1] [Explanation of symbols]

[0080] x: Easily soluble polymer y: Low-melting point, poorly soluble polymer z: Low-solubility polymer with high melting point a1, 2: Intersection of the fiber surface and the inscribed circle b1, 2: Intersection of the fiber surface and the circumscribed circle A: A circle that is inscribed in the fiber surface at at least two points, exists only inside the fiber, and has the largest possible diameter within the range where the circumference of the inscribed circle does not intersect with the fiber surface. B: A fiber that circumscribes the fiber surface at at least two points and external A circle that exists only in the area and has the smallest possible diameter within the range where the circumference of the circumscribing circle does not intersect with the fiber surface. G: Fiber center I: A line that passes through the center of the fiber and divides the fiber cross section into two areas, and the area ratio of the hardly soluble polymer on the high melting point side to the hardly soluble polymer on the low melting point side on the left and right fiber cross sections of the line is 100:0 to 70:30 on one side of the fiber cross section, and 30:70 to 0:100 on the other side of the fiber cross section. S: A straight line that passes through the fiber center G and is parallel to the connecting part W: Width of the connecting part in the direction perpendicular to the line S

Claims

1. A woven or knitted fabric comprising a C-section fiber, wherein the ratio (RB / RA) of an inscribed circle diameter RA to a circumscribed circle diameter RB in the cross section of the C-section fiber is 1.2 or more and 5.0 or less; The C-section fiber is a C-section fiber in which at least two different types of polymers are unevenly distributed on the left and right sides, The woven / knitted fabric has a surface roughness average standard deviation Sq of 5 μm or more and 100 μm or less on at least one side thereof, and when the woven / knitted fabric is stretched by 10%, the ratio (Sqs / Sq) of the surface roughness average standard deviation Sqs on the one side thereof to the average standard deviation Sq is 0.85 or more and 2.00 or less.

2. 2. The woven or knitted fabric according to claim 1, wherein the C-shaped cross-section fiber is a multifilament, and 10% or more of the multifilament yarns are oriented in the same direction.

3. 3. The woven or knitted fabric according to claim 1, wherein the C-cross section fibers account for 20% by weight or more of the yarns of the woven or knitted fabric.

4. 4. The woven or knitted fabric according to claim 1, wherein the woven or knitted fabric has at least one weave selected from the group consisting of twill weave, multi-ply weave, rib stitch, and pique stitch.

5. The woven or knitted fabric according to any one of claims 1 to 4, which contains a water-absorbent polyester resin.

6. The woven or knitted fabric according to any one of claims 1 to 5, which has a water retention rate of 20% or more.

7. The woven or knitted fabric according to any one of claims 1 to 6, wherein the exudation rate is 40% or less.

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