JP2006249624A - False-twist spun yarn and knitted or woven fabric using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new spun yarn for simultaneously satisfying lightweight, heat-retaining property and pill resistance by providing an air layer by using a spun yarn which is substantially twist-free in addition to a specific and specific and ideal hollow structure formation method carrying out removal of elution of a core component in dyeing after formation of fabric and a knitted or woven fabric composed of the spun yarn. <P>SOLUTION: The spun yarn comprises ≥20 wt% core-sheath type conjugate short fiber in which the sheath component is a polyamide and the core component is a polyester and the fineness is 0.5-7.0 dtex and the strength is 2.0 to 7.0 cN/dtex and the spun yarn is substantially twist-free. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a substantially non-twisted spun yarn composed of a core-sheath composite short fiber of polyamide and polyester excellent in properties such as heat retention and light weight, and a woven or knitted fabric (hereinafter referred to as these). Collectively called “woven or knitted fabric”).

  Synthetic fibers such as polyester and polyamide are used in a wide range of fields in terms of excellent strength and easy care. Since these synthetic fibers, particularly filaments, have a cold feel and are unsuitable as winter outer materials, many methods for incorporating a large air layer have been adopted.

  For example, in a filament, a technique is adopted in which a yarn is looped to make it bulky, or a multi-layer structure is used to increase the heat retention performance.

  On the other hand, polyester fibers have been mainly used for spun knitted fabrics, but since there is a dry feeling and crispness peculiar to polyester, in recent years a new texture, that is, a soft and moist feeling, and physical As a characteristic, nylon spun knitted fabrics have been reviewed from the standpoint of high strength.

  From the background described above, nylon spun knitted fabrics are widely used for sports clothing such as skiing, snowboarding, and casual sports, and cold clothing.

  However, since many of these are used in the cold season, there is a drawback that the material itself has a ground thickness or is layered, so that it becomes heavy when worn.

  As one means for solving such a problem, it can be considered that the yarn has a hollow structure.

  However, since ordinary polyamide fibers are manufactured by melt spinning, unlike polyester fibers, they are less likely to have a high hollow structure, and because the modulus of the polymer itself is low, it passes through the spinning process, weaving process, dyeing process, etc. In order to solve the problem in the post-processing step, a fabric composed of a core-sheath composite fiber using an alkali-resistant polymer as a sheath component and polyester as a core component is used. There is a method of providing a hollow portion by elution of polyester as a core component by alkali treatment (see, for example, Patent Document 1).

  However, in this method, when the obtained hollow fiber is made into a ring spun yarn by a normal spinning method, since the real fiber is imparted to the short fiber bundle, there are few voids between the fibers, and the fabric has high heat retention. There is a problem that it is difficult to fall.

  In addition, textiles using spun yarns made of nylon short fibers have the opposite effect of the physical properties of the fibers, that is, high strength, and like polyester, when wearing clothing, the fabric surface is rubbed and the fluff becomes entangled into pills. Growing, so-called pilling occurs, and it has the disadvantage of significantly impairing the appearance of the garment.

In view of these problems, there are also problems such as shrinkage characteristics of the ring yarn, and air spun yarn is more preferable. Moreover, even if it is a twin yarn processed product, these problems can be solved, but there is also a problem that the processing cost increases, which is not preferable.
JP 7-278947 A

  The present invention provides a spun yarn and a woven fabric that have a unique texture that is superior in comfort and cannot be obtained by the above-described conventional technology, and that is excellent in heat retention, light weight, and anti-pill properties, and that is soft and moist. The purpose is to provide knitting.

The present invention has the following configuration in order to solve the above problems. That is,
(1) A spun yarn having a single fiber fineness in a range of 0.5 to 7.0 dtex, a short fiber bundle including at least a thermoplastic synthetic fiber subjected to false twisting, and has a substantially untwisted structure. A spun yarn characterized by this.

  (2) A core-sheath-type composite short in which the sheath component is made of polyamide, the core component is polyester, the fineness is in the range of 0.5 to 7.0 dtex, and the strength is 2.0 cN / dtex to 7.0 cN / dtex. A spun yarn comprising 20% by weight or more of fibers and substantially non-twisted.

  (3) The spun yarn according to (2) above, wherein the composite ratio (% by weight) of the core component / sheath component of the short fiber is in the range of 25/75 to 60/40.

  (4) The spun yarn according to any one of (1) to (3), wherein the crimp rate (CR) is 30% or less.

  (5) A woven or knitted fabric comprising 20% by weight or more of the spun yarn according to any one of (2) to (4), and wherein the core component polyester is eluted by alkali treatment.

  (6) A garment comprising the spun yarn according to any one of (1) to (4).

  In the knitted fabric made of false twisted spun yarn using hollow nylon short fibers according to the present invention, the knitted fabric combines lightness, heat retention and anti-pilling properties not possible with the prior art, and is unique to nylon span. It can provide a new nylon spun knitted fabric that has a supple texture and has many functions such as soft stretch and glossiness.

  The spun knitted fabric according to the present invention is suitably used for winter underwear, sports, outdoor, casual use and the like because of its light weight and heat retention characteristics.

  Hereinafter, the present invention will be described in more detail.

  The present invention is a spun yarn in which a single fiber fineness is in a range of 0.5 to 7.0 dtex, a short fiber bundle including at least a thermoplastic synthetic fiber is subjected to false twisting, and has a false twist crimp. And a spun yarn having a substantially untwisted structure. The single fiber bundle may be blended with recycled fibers or natural fibers in addition to thermoplastic synthetic fibers.

  In addition, the present invention forms a fabric as a false-twisted spun yarn in which the core component is polyester and the sheath component is polyamide and the sheath component is substantially untwisted. By elution of the polyester in the core part to form a hollow structure, the hollow part of the core-sheath type composite raw cotton, and the presence of an air layer with low thermal conductivity between the short fiber bundles constituting the spun yarn, the unit A woven or knitted fabric with a light weight (weight per unit area) per area, light weight, and excellent heat retention, anti-pill properties, soft stretch, gloss and soft texture.

  Furthermore, in the woven or knitted fabric of the present invention, it is important that the area weight per unit weight (weight) is light and the CLO value indicating heat retention is 0.75 or more.

  In general, what is considered as a factor when clothes have high heat retention properties include low thermal conductivity of the material itself, a large thickness of the fabric, that is, a large amount of air layer, and the like. Therefore, in order to improve the heat retaining property, the fabric may be designed so that the basis weight is increased. However, the lightness is completely lost.

  The woven or knitted fabric made of the spun yarn according to the present invention achieves a lightweight feeling and light weight, and exhibits a high CLO value of 0.55 or higher, further 0.60 or higher, which indicates heat retention. The CLO value of 0.55 or more satisfies the heat retention required during light exercise in winter.

  For knitted products using 100% nylon short fiber spun yarn, products with high potential in terms of surface touch, texture, W / W (wash and wear) properties, physical properties, etc. can be realized in the inner and outer applications. The request from is also strong. However, the only drawback is that there is a problem that the quality deteriorates due to the occurrence of pills when wearing the product, and there are not many on the market at present.

  There are knitted products in which spun yarns consisting of polyester short fibers with reduced strength, that is, polyester fibers with reduced strength, are present as anti-pill materials, but these produce pilling within a few weeks after the start of wear. . However, there are also those that continue to wear and that are said to have anti-pill properties due to the formed pills falling off after a long period of time. However, consumers are never satisfied with products that generate pills when worn for a short period of time, and require that pills not occur regardless of whether they are worn for a short period of time. The knitted product using the spun yarn of the present invention satisfies the above requirements.

  As the substantially untwisted spun yarn in the present invention, a spun yarn obtained by using an air spinning machine as disclosed in, for example, Japanese Patent Application Laid-Open No. 2002-227042 in a spinning process using short fiber raw cotton. set to target.

  The spun yarn in the present invention is made of a short fiber raw material of core-sheath composite fiber, and the sheath component is preferably composed of a polyamide-based polymer and the core component is composed of a polyester-based polymer.

  In the present invention, the polyamide constituting the sheath is preferably a polyamide made of polyhexamethylenadipamide (nylon 66) or polyε-capramide (nylon 6), but sebacic acid, isophthalic acid, paraxylene gear. Polyamide containing imide or the like or a copolymerized polyamide thereof may be used.

  Moreover, it is important that the polyester constituting the core component is a readily soluble polymer in terms of the alkali treatment and elution removal in the dyeing process.

  As such a readily soluble polyester, for example, a sulfonated aromatic dicarboxylic acid-modified polyester, and a modified polyester in which a compound having a sulfonate group is contained in a part of a chain or a terminal of the polyester can be used. . More specifically, polyethylene terephthalate or polybutylene terephthalate, or a modified polyester obtained by copolymerizing a sulfonated aromatic dicarboxylic acid or a salt thereof with a copolyester having these as a main component may be used. It is preferable.

  A typical example of the sulfonated aromatic dicarboxylic acid is dimethyl 5-sodium sulfoisophthalate, which can be used as a preferable one in the present invention. The copolymerization is preferably in the range of 3.0 mol to 10 mol% by weight with respect to terephthalic acid. If this copolymerization is too low, the desired effect may not be sufficiently obtained. Conversely, if the copolymerization is too large, the crystal structure of the modified polyester may be disturbed, resulting in a significant decrease in mechanical properties.

  The composite ratio (% by weight) of the sheath portion and the core portion is important from the viewpoints of characteristics such as lightness and heat retention, and texture. The core-sheath composite ratio is preferably in the range of core: sheath = 25: 75-60: 40. More preferably, it is in the range of core: sheath = 30: 70-50: 50.

  The size of the core-sheath composite ratio is not so much a problem in the spinning and weaving process, but the polyester component is eluted by alkali treatment in the dyeing process to form a hollow structure in the fiber, and the ratio of the core component is large. That is, if the hollow ratio is increased, the lightness is improved, but if a physical force is applied in the state of the fabric, the hollow structure tends to be easily deformed. In general, the deformed portion has a flat shape and cannot exhibit desired functions and characteristics. From this point, the ratio of the core component is preferably 60% or less. On the contrary, if the ratio of the core component is small, the hollow structure is difficult to be deformed, but it is difficult to exhibit desired functions and characteristics. Regarding the preferable lower limit value of the ratio of the core component, if the core component ratio is too small, it takes a long time to remove the decomposition product by allowing the chemical solution to permeate the sheath portion during the step of elution and removal of the core component. From this point, the core-sheath component ratio is preferably in the range of core: sheath = 25: 75-60: 40. More preferably, it is in the range of core: sheath = 30: 70-50: 50.

  The fiber cross-sectional shape of the composite fiber (raw cotton) is not particularly limited, but a concentric core-sheath composite raw cotton is representative and preferable in production, but the core-sheath is relatively eccentric, May be a polygonal shape such as a triangular shape or a quadrangular shape, or an elliptical shape. Further, the core may be a multi-core shape instead of a single core.

  The crimp rate (CR) (%) of the spun yarn is important in terms of texture and gloss. The higher the value, the greater the number of crimps, and the less gloss is felt.

  In the false twisted yarn of the present invention, the crimp ratio (CR) is preferably 30% or less, and is very superior in glossiness and texture. When the numerical value is high, unpleasant dull feeling and desired texture are obtained. Since it cannot be obtained, it is not preferable. The crimp rate (CR) of such false twisted yarn is preferably in the range of 0.1 to 30%. More preferably, it is in the range of 5 to 30%, and further preferably in the range of 10 to 25%.

  Next, the yarn structure of the spun yarn of the present invention will be described.

  In the spun yarn of the present invention, it is important that the spun yarn itself is substantially untwisted in order to obtain a feeling of swelling and softness due to the hollow short fibers.

  Here, the substantially non-twisted spun yarn referred to in the present invention is one in which an actual twist of 4.0 T / Ls or less is applied, or an untwisted when the average fiber length of the short fiber component is Ls. It is a shape. When the number of twists is 4.0 T / Ls or less, there is no occurrence of untwisting due to the action of twisting torque, so it can be said to be a substantially untwisted structure yarn.

  That is, if it is a substantially untwisted structure yarn, it is treated with an alkali in the dyeing process, and after the core component of the short fiber is eluted to form a hollow structure, like a real twist yarn obtained by a general ring spinning machine There is no restriction between the short fiber bundles due to the twisting torque, and the short fiber bundle of the core component present relatively inside the spun yarn of the present invention has no twisting torque, that is, a free state. Not only that, but there are more air layers between short fiber bundles (increase in inter-fiber voids), so that the woven or knitted fabric made of the spun yarn of the present invention is lighter and has better heat retention. It becomes.

  The untwisted structure yarn is obtained by general air spinning, but considering the increase in inter-fiber voids, the sheath component positioned relatively outside of the untwisted short fiber bundle of the core component existing relatively inside is considered. It is more preferable that the short fiber bundle is wound at regular intervals.

  Furthermore, the air spinning machine used in the present invention can change the yarn form by changing the spinning speed, and the lower the spinning speed as the spinning condition, the higher the ratio of the core component of the spun yarn and the more the yarn binding. Although it is stable, on the contrary, it has a strong feeling of coarseness when it is made into a fabric, and the voids between the short fiber bundles are reduced by increasing the yarn bundling. Conversely, when the spinning speed is high, the gaps between the short fiber bundles are increased and the texture is soft, which is preferable from the viewpoint of heat retention, but since the yarn strength decreases and the fluff that causes pilling increases, the spinning speed increases. Is preferably 220 m / min to 350 m / min.

  The spun yarn obtained above is further passed through a pin false twisting process, which is a processed yarn process, and is also subjected to heater processing by a bulerial processing method, so that the spun yarn itself becomes closer to a perfect circle and becomes a spun yarn. A glossy feeling can be imparted. Moreover, by passing through the heater, the fluff of the spun yarn contracts and does not cause interference with other fluff, and exhibits high anti-pill properties. Furthermore, since the spun yarn itself exhibits dry heat shrinkage, the sprinkles peculiar to the spun yarn are alleviated, and a spun yarn closer to the filament yarn can be obtained.

  In addition, by applying pin false twisting, it is possible to provide the original texture and glossiness of the spun yarn by preparing the yarn of the spun yarn and making the fiber bundle uniform. The yarn strength of the spun yarn itself is improved by 20% or more. Can be made.

  Next, in the false twisting process of the false twisting machine used in the present invention, fluff can be greatly reduced by the number of false twists, and further, the heater temperature is raised to continue to reduce fluff. However, when the heater temperature is too high or the number of twists is excessively increased, the original texture of the spun yarn is impaired, and chattering is also undesirable. On the other hand, since the function by false twisting cannot be imparted when the temperature is lowered by sweet twisting, it is necessary to set appropriate conditions such as adjusting the 2nd heater temperature.

  From the above, the number of false twists in the false twisting process is in the range of 500 to 2,000 t / m, more preferably in the range of 800 to 1,200 t / m.

  About heater temperature, it is preferable to exist in the range of 80-250 degreeC, More preferably, it exists in the range of 150-210 degreeC. Further, when the 2nd heater is also adjusted within the range of 150 to 210 ° C., the torque is reduced and the number of fluffs can be greatly reduced to less than half of the original yarn.

  Next, the fineness of the short fibers constituting the spun yarn of the present invention is in the range of 0.5 to 7.0 decitex (dtex). More preferably, it is in the range of 0.6 to 3.0 dtex. When the fineness of the short fiber is less than 0.5 dtex, it causes the spun yarn quality to deteriorate, for example, a nep occurs in the spinning card process. On the other hand, if it exceeds 7.0 decitex, the short fiber bundle of the core component of the spun yarn and the short fiber bundle of the sheath component are poorly entangled, resulting in restrictions on the number setting, and further, the product has a hard texture. Resulting in restrictions on the use of the product.

  Further, the strength of the short fibers constituting the spun yarn of the present invention is preferably 2.0 cN / dtex to 7.0 cN / dtex. If it is less than 2.0 cN / dtex, there will be a problem during actual wearing due to deterioration of the strength of the product, such as a problem that the process passability in spinning, weaving and dyeing processes will be poor. On the other hand, when the wear rate is 7.0 cN / dtex or more, when wearing clothing, the fabric surface is rubbed and the short fibers are entangled with each other to grow into pills. When pilling, the pills fall off because the strength of the short fibers is too strong. As a result, the anti-pilling property that is the object of the present invention is hardly obtained. For the above reasons, the strength of the short fiber is in the above-mentioned preferable range.

  It is more effective to use the above-mentioned hollow short fibers in the spun yarn at 100% in order to sufficiently exhibit the characteristics such as heat retention and lightness which are the original aims of the present invention. In addition to the hollow short fibers used for the spun yarn to control the texture, it may be a mixture of cotton, rayon, wool, hemp natural fibers, polyester, acrylic, other synthetic fibers such as nylon, polyamide, polypropylene, or the like. From the viewpoint of lightness and heat retention, the ratio of the hollow short fibers to the spun yarn is preferably 40% by weight or more in terms of the weight before alkali treatment.

  Even when the spun yarn of the present invention is used after being knitted and woven, it is preferable that the spun yarn of the present invention is contained at least 20% by weight or more with respect to the weight of the woven or knitted fabric in order to satisfy the feeling of lightness and heat retention. . In the alkali treatment for elution and removal of the polyester component such as the modified polyester in the core portion performed in the dyeing processing step after forming the fabric in a normal knitting and weaving step, caustic alkali such as caustic soda and caustic potash is used as a chemical agent. Use it. The treatment conditions vary depending on the core-sheath composite ratio and the mixture ratio of the raw cotton constituting the fabric. Generally, the caustic alkali concentration is 10 to 80 g / liter, and the treatment temperature is 80 to 120 ° C. Use it. Dyeing may be performed using dyes and dyeing conditions that are usually used for polyamide dyeing.

  Hereinafter, the present invention will be described in more detail with reference to examples.

The evaluation method used in the present invention will be specifically described below.
[Heat retention (CLO value)]
Take two 50 cm × 50 cm test pieces. Using an ASTM heat retention tester, a test piece is attached to a hot plate having a hot plate temperature of 40 ° C. and left for 60 minutes. Read the energization time (seconds) of the integrating wattmeter after leaving the measurement time and the outside temperature (° C) of the measuring instrument. Read the energization time (seconds) of the integrating wattmeter with no test piece attached. The CLO value is obtained by the following formula from the energization time (seconds) when the test piece is not attached, the energization time (seconds) when the test piece is attached and the outside air temperature, and is expressed as an average value of the two pieces.

CLO value = (6.54 × (40−t)) / a / 0.18
Where a: energization time when the test piece is attached (sec / hr)
t: outside air temperature (° C) indicated by measuring instrument
This CLO value is a general numerical value indicating the heat retaining property of the fabric, and the larger the value, the better the heat retaining property.

As a guide, the CLO value of 1.0 represents the heat retention (heat resistance) of a fabric that can maintain the body skin temperature in a resting state in an indoor environment of 21 ° C., 50% RH or less and an airflow of 5 cm / sec.
[Unit weight]
Take a 25cm x 25cm fabric test piece, dry it well until it is below the equilibrium level ratio, leave it in a room at 20 ° C and 65% RH for 24 hours, and after balancing it, measure the weight of the test piece. To do. The weight of the obtained test piece is converted per 1 m ² and expressed as an average value for two pieces of fabric.
[Crimping rate (CR)%]
The wrap reel winds up 10 times and heat treatment is performed in 60 ° C. × 20 min warm water. After the treatment is completed, all the warm water is sucked up with filter paper and then left for 24 HR.

  After the heat treatment is completed, the sample is hung on the yarn, and the initial load of 2.0 mg / dtex and constant load of 1.0 g / dtex are added to the graduated cylinder filled with water. Is set to l, and after a lapse of time, only the constant load is removed in water, and the yarn length after another 2 minutes is set to l1.

Crimp rate (CR) (%) = [(l−l1) / l1] × 100
[Lightweight feeling]
The underwear of the same size was sewed, and the feeling of wearing lightness was sensory evaluated.

○: Clearly lightweight △: Slightly lightweight ×: No lightweight [ICI pill judgment (5 hr)]
This model evaluates the anti-pill performance in a model, and ranks the degree of pill generation in the 1st to 5th grades. The smaller the number, the less pilling occurs.
Conforms to JIS L1076 (Method A).
[Texture]
The texture of the woven fabric was subjected to the following sensory evaluation.

○: Tension, waist, soft feeling good △: Tension, waist, soft feeling slightly good ×: Tension, waist, soft feeling poor (Example 1)
Polyester copolymerized with 8.0 mol% of dimethyl 5-sodium sulfoisophthalate is used for the core component, nylon 66 is used for the sheath component, and the core-sheath composite raw cotton (% by weight) is core: sheath = 50: 50 After spinning at a spinning speed of 1300 m / min, normal stretching is performed at a magnification of 3.0, and after crimping, the core is cut with a single fiber fineness of 1.7 dtex, a fiber length of 38 mm, and a strength of 2.7 cN / dtex. A sheath composite raw cotton was obtained.

  Subsequently, a sliver having a thickness of 2.36 g / m was prepared using 100% of the core-sheath composite raw cotton using a normal spinning method. This sliver was put on an air spinning machine having a roller type draft mechanism, the draft rate of the air spinning machine was set to 120 times, and a spun yarn having a cotton count of 30 s was obtained at a spinning speed of 220 m / min. The spinnability was good and there was no yarn breakage.

  The yarn forming part of the air spinning machine used has a hollow air nozzle, and the core-sheath short fiber bundle of the sheath part is spaced apart from the untwisted core-sheath short fiber bundle of the sheath part by the swirling airflow in the air nozzle. By binding together, a mechanism for forming a spun yarn that is substantially untwisted is obtained.

  Further, using a pin false twisting machine for producing processed yarn, the spun yarn was false twisted at a spinning speed of 100 m / min, an overfeed of 3%, a false twist number of 1,000 t / m, a first heater 200 ° C.-2nd heater 180 ° C. processed. The false twist processability was good, and the amount of fluff generation was small and stable spinning was obtained.

  Tendon knitted fabric was knitted with a 28G single circular knitting machine using this non-twisted spun yarn.

  Next, after scouring and relaxing this knitted fabric in the dyeing process, the concentration of the caustic soda aqueous solution is 50 g / l, the processing temperature is 110 ° C., the processing time is 60 minutes, and the core polyester component is eluted and removed using a liquid dyeing machine It was.

Subsequently, normal nylon dyeing was performed at 100 ° C. for 45 minutes to obtain a knitted fabric with a finished basis weight of 145 g / m ² .

(Example 2)
A core / sheath composite raw cotton (weight%) was made core: sheath = 30: 70 using polyester obtained by copolymerizing 8.0 mol% of dimethyl 5-sodium sulfoisophthalate as the core component and nylon 66 as the sheath component. In the same manner as in Example 1, a fabric was prepared by spinning, false twisting, knitting, and dyeing processes.

(Example 3)
Nylon 66 is not 100%, ie, core / sheath composite, spun at a spinning speed of 1300 m / min, and then stretched at a normal speed of 3.0 times. After crimping, it was cut to a single fiber fineness of 1.7 dtex × A raw cotton having a fiber length of 38 mm was obtained.
Thereafter, in the same manner as in Example 1, a fabric was prepared by spinning, false twisting, knitting, and dyeing processes.

(Comparative Example 1)
A sliver with a thickness of 4.1 g / m was prepared using a normal spinning method using 100% core-sheath composite raw cotton similar to Example 1, and after passing through a roving process, a normal ring spinning machine was used. Thus, a spun yarn of cotton type count 30s was obtained.

  Thereafter, in the same manner as in Example 1, a fabric was prepared by false twisting, knitting, and dyeing processes.

Example 4
After preparing a sliver with a thickness of 2.36 g / m from 100% polyester raw cotton, a fabric was prepared in the same manner as in Example 1 by spinning, false twisting, knitting, and dyeing.

  Table 1 shows the results of the evaluation of the above-mentioned five span knitted fabrics.

Claims (6)

A spun yarn having a single fiber fineness in a range of 0.5 to 7.0 dtex, a false fiber bundle subjected to false twisting at least including a thermoplastic synthetic fiber, and having a substantially untwisted structure Spun yarn. 20 sheath-core composite short fibers having a sheath component of polyamide and a core component of polyester, a fineness in the range of 0.5 to 7.0 dtex, and a strength of 2.0 cN / dtex to 7.0 cN / dtex. A spun yarn comprising at least% by weight and substantially non-twisted. The spun yarn according to claim 2, wherein the composite ratio (wt%) of the core component / sheath component of the short fiber is in the range of 25/75 to 60/40. The spun yarn according to any one of claims 1 to 3, wherein the crimp rate (CR) is 30% or less. A woven or knitted fabric comprising the spun yarn according to any one of claims 2 to 4 in an amount of 20% by weight or more, wherein the core component polyester is eluted by an alkali treatment. A clothing comprising the spun yarn according to any one of claims 1 to 4.