JP3719258B2 - Soft stretch yarn, production method and fabric - Google Patents

Description

  The present invention relates to a soft stretch yarn, a production method, and a fabric capable of imparting soft stretch properties to the fabric with excellent crimp expression.

  Synthetic fiber fabrics are widely used because they are superior to natural fiber fabrics and semi-synthetic fiber fabrics in terms of durability and easy care. However, compared with natural fiber cloth and semi-synthetic fiber cloth, since it is inferior in aesthetics and texture, various improvements have been added. By synthesizing these improvements, a fabric having a high level of texture even with synthetic fibers has been developed and popularized under the name of “new synthetic fiber”. This “new synthetic fiber” has a new texture that is completely different from conventional synthetic fiber fabrics, which was obtained by both the advancement of yarn production technology and the advancement of advanced processing technology for producing fabrics in the production of synthetic fiber fabrics. Have been accepted. However, even with this “new synthetic fiber”, it does not reach the aesthetics and texture of natural fiber fabrics and semi-synthetic fiber fabrics, and a new, high-quality product is demanded through the product cycle. Further improvements in functionality and the like were desired.

  To deal with this problem, for example, there is a method of using a pre-twisted false twisted yarn as a means of obtaining a fabric having a surface change. However, this method is insufficient to obtain a new surface feeling and the cost increases. There was a problem. Moreover, since the yarn is twisted, there is a problem that the stretchability cannot be imparted to the fabric. In addition, there is a method in which polyurethane-based elastic yarns are mixed in order to impart stretch properties to the fabric, but this is very expensive, and when used together with general-purpose synthetic fibers such as polyester, it does not stain with disperse dyes. There was a problem of roughening of the fabric surface and rough curing due to dullness during dyeing and poor heat resistance.

  For this reason, various polyester fibers using a side-by-side composite of polymers have been proposed as methods that do not use polyurethane fibers or false twisted yarns.

  For example, Japanese Patent Publication No. 44-2504 and Japanese Patent Laid-Open No. 4-308271 disclose a side-by-side composite yarn of polyethylene terephthalate (PET) having an intrinsic viscosity difference or an intrinsic viscosity difference, and Japanese Patent Laid-Open No. 5-295634 discloses a homo-PET. A side-by-side composite yarn of copolymer PET having a higher shrinkage than that is described. If such a latently crimpable polyester fiber is used, a certain degree of stretchability can be obtained, but the generated stress when the fabric is stretched is high, that is, the fabric has a strong feeling of tightening, It was not possible to fully exhibit the recovery property against elongation. This is because the present inventors have found that a side-by-side composite yarn of a PET combination having a large viscosity difference or shrinkage difference as employed in the publication has a high resistance to crimp elongation. It was. Furthermore, the side-by-side composite yarn as described above has a problem that the ability to develop crimps in a fabric restraint is low, or the crimps are liable to be loosened by an external force. Side-by-side composite yarns do not use the stretch properties of a polymer matrix like polyurethane fibers, but use the expression of crimp due to the inside of a polymer with a large difference in shrinkage between the composite polymers. Yes. For this reason, for example, when heat treatment is performed in a state where the shrinkage of the polymer is limited as in the case of fabric restraint, the heat fixing is performed as it is, and the above-mentioned problem is considered to occur because the shrinkage ability beyond that is lost.

Further, side-by-side composite yarns (Patent Document 1) using polypropylene terephthalate (PPT) and polybutylene terephthalate (PBT), which are polyesters having a slight stretch property, have also been proposed. Has a large elongation power. Actually, when estimated from the finish count of the plain weave that has been heat-treated, the stress generated for 30% elongation is considerably higher than 60 × 10 ⁻³ cN / dtex in the experiment number XV-d. It was large and still very tight. Furthermore, when the present inventors conducted a follow-up test, Worcester spots (U%) were poor, and there was a drawback that the dyed spots were large when made into a fabric.
Japanese Patent Publication No. 43-19108

  The present invention solves the problems of tightening feeling, fabric coarse-curing, and yarn spots, which have been a problem with conventional side-by-side composite yarns, and can provide a fabric that is superior in soft stretchability and uniform dyeability. A stretch yarn, a production method, and a fabric are provided.

In order to achieve the above object, the present invention adopts the following configuration. That is,
(1) A side-by-side composite yarn or an eccentric core-sheath composite yarn composed of two types of polyesters (except that both types are polypropylene terephthalate), wherein the polypropylene terephthalate forms the inside of the crimp and the Wooster spots are 2. A soft stretch yarn characterized by simultaneously satisfying 0% or less, a stress with respect to 50% elongation of the yarn of 30 × 10 ⁻³ cN / dtex or less, and a recovery rate of 60% or more simultaneously.
(2) The soft stretch yarn according to (1), wherein the two types of polyester are polypropylene terephthalate and polyethylene terephthalate.
(3) The soft stretch yarn according to (1) or (2) above, wherein the strength is 2.2 cN / dtex or more.
(4) The soft stretch yarn according to any one of (1) to (3), wherein a recovery rate with respect to 50% elongation of the yarn is 70% or more.
(5) The soft stretch yarn according to any one of (1) to (4) above, wherein a stress with respect to 50% elongation of the yarn is 10 × 10 ⁻³ cN / dtex or less.
(6) said that shrinkage stress is characterized in that at 0.25 cN / dtex or more (1) to the soft stretch yarn according to any one of (5).
(7) A soft stretch blend, wherein the soft stretch yarn according to any one of (1) to (6) and a low shrink yarn having a boiling water shrinkage of 10% or less are blended. yarn.
(8) A fabric comprising at least the soft stretch yarn according to any one of (1) to (7).
(9) The fabric according to (8) above, wherein natural fibers and / or semi-synthetic fibers are mixed.

  According to the present invention, there are provided a soft stretch yarn, a manufacturing method, and a fabric, which can solve the problems of the tightening feeling and the rough curing of the fabric, which have been problems in the past, and can provide a fabric that is superior in soft stretch properties than in the past. is there.

In the present invention, in order to achieve soft stretch properties, it is important that the resistance to elongation of the yarn is low and the recovery rate to elongation is high, and this characteristic is the stress when the yarn is stretched 50%. It is possible to evaluate by the recovery rate in the strong elongation curve hysteresis (FIG. 1). Actually, the yarn is first scraped and subjected to heat treatment for 15 minutes in boiling water under substantially no load, followed by air drying at 180 ° C. for 15 minutes after air drying. Then, this heat treated yarn was subjected to an initial tension of 4.4 × 10 ⁻³ cN / dtex (5 mgf / d) using an automatic tensile testing machine, from which the yarn was pulled at a pulling speed of 100% / min. % Elongation, immediately turn back and return to 0% elongation at the same speed, and draw a hysteresis curve (FIG. 1). The maximum ultimate stress based on the initial tension is defined as the stress for 50% elongation. In FIG. 1, the recovery rate is calculated as recovery rate (%) = [(50−a) / 50] × 100%. Here, a is the elongation rate at the point where the generated stress becomes the initial tension in the recovery process of the hysteresis curve.

In the soft stretch yarn of the present invention, it is important that the stress with respect to 50% elongation of the yarn is 30 × 10 ⁻³ cN / dtex or less, and thereby, a good soft stretch property is obtained, and there is no feeling of tightening and softness. A fabric can be obtained. On the other hand, in the conventional side-by-side composite yarn, the stress with respect to 50% elongation of the yarn is very high and exceeds 50 × 10 ⁻³ cN / dtex, so that only a fabric with a strong feeling of tightening and a strong hard feeling can be obtained. The stress for 50% elongation of the yarn is preferably 10 × 10 ⁻³ cN / dtex or less. Further, in order to obtain a sufficient stretch property, it is important that the recovery rate for 50% elongation of the yarn is 60% or more. The recovery rate is preferably 70% or more.

  Moreover, if the diameter of the crimp of the soft stretch yarn after heat treatment is 250 μm or less, the soft stretch property is easily developed, and when the fabric is made, the surface of the fabric is prevented from being rough and a high-quality fabric can be obtained. This is preferable. The crimped diameter of the soft stretch yarn is more preferably 200 μm or less.

  Further, if the crimp phases are uniform between the single yarns, a finely textured fabric with a beautiful surface can be obtained when the fabric is made. On the other hand, if the phase of crimp is shifted between single yarns, it becomes easy to form a fabric with a plain surface and a fabric with good slipperiness can be obtained.

Further, it is preferable that the crimp elongation ratio (E ₀ ) in a load-free state is 50% or more because the stretchability is further improved. Here, the crimp extension rate is an index indicating the degree of crimp extension, and the higher the value of the crimp extension rate, the higher the degree of crimp and the better the stretchability. E ₀ reflects the degree of crimping without load. However, when the soft stretch yarn of the present invention is used as a strongly twisted yarn or a woven fabric, the restraint force caused by the strong twist or the restraint force due to the woven structure works to express the crimp. May be difficult. Therefore, the crimp elongation under load is also important, and this characteristic can be estimated by the crimp elongation (E _3.5 ) when a load of 3.5 × 10 ⁻³ cN / dtex is applied. . In soft stretch yarn of the present invention E _3.5 is preferably 10% or more. On the other hand, in the polyethylene terephthalate side-by-side composite yarn described in JP-A No. 11-81069, etc., E _3.5 is about 0.5%. It will be scarce.

  In order to overcome the strong twist and the restraint of the woven fabric and develop crimps, the shrinkage stress is also important, and the maximum value of the shrinkage stress is preferably 0.25 cN / dtex (0.28 gf / d) or more. More preferably, the maximum value of the shrinkage stress is 0.30 cN / dtex (0.34 gf / d) or more. Moreover, it is preferable that the temperature which shows the maximum of shrinkage stress is 110 degreeC or more.

  Moreover, if the initial tensile resistance of the yarn is 60 cN / dtex or less, the fabric becomes softer, which is preferable. The initial tensile resistance of the yarn is more preferably 50 cN / dtex or less.

  Furthermore, in the high-order processing step of the fabric, if the fabric shrinks excessively, it is hardened, so that the dry heat shrinkage rate of the soft stretch yarn is preferably 20% or less.

  In the present invention, it is important that the Wooster spot which is an index of the fineness spot (thickness spot) of the yarn is 2.0% or less. As a result, not only the occurrence of dyed spots on the fabric can be avoided, but also the shrinkage spots of the yarn when made into a fabric can be suppressed, and a beautiful fabric surface can be obtained. Wooster spots are preferably 1.2% or less.

  In addition, the strength of the soft stretch yarn is preferably 2.2 cN / dtex (2.5 gf / d) or more from the viewpoint of ensuring the passability of the soft stretch yarn in the high-order processing step and the tear strength when it is made into a fabric. . The strength is more preferably 3.0 cN / dtex (3.4 gf / d) or more. Furthermore, it is preferable that the elongation of the soft stretch yarn is 20 to 45% from the viewpoint of handleability of the yarn.

The structure of the soft stretch yarn of the present invention is a side-by-side composite yarn or an eccentric core-sheath composite yarn made of two types of polyester (except that both types are polypropylene terephthalate), and the polypropylene terephthalate forms the inside of the crimp. In particular , when a side-by-side composite yarn or an eccentric core-sheath composite yarn made of polyethylene terephthalate (hereinafter abbreviated as PET) and polypropylene terephthalate (hereinafter abbreviated as PPT) is used, it is easy to reduce the stress for 50% elongation of the yarn and at the same time recover It is preferable to improve the rate. Furthermore, taking a large difference in melt viscosity between the two polymers is preferable because the stretch properties such as the recovery rate to 50% elongation of the yarn and the crimp elongation rate are improved. Moreover, when PPT is arranged inside the crimp, the stretchability is further improved, which is preferable.

  Also, the composite ratio of the polymer is not limited at all, but it is preferably 3/7 to 7/3 from the viewpoint of crimp expression. More preferably, it is 4/6 to 6/4, and further preferably 5/5.

  The PET in the present invention is a polycondensate using terephthalic acid as an acidic component and ethylene diol as a diol component, and PPT is a polycondensation using terephthalic acid as an acidic component and 1,3-propanediol as a diol component. Is the body. Further, a part of the diol component and the acid component may be substituted with other copolymerizable components within a range of 15 mol% or less. When the copolymerization component is polyethylene glycol, the content is 15% by weight or less. These may also contain other polymers, matting agents, flame retardants, antistatic agents, pigments and other additives.

However, if the difference in melt viscosity of the polymer to be combined becomes excessively large, the spinnability is remarkably lowered due to the occurrence of so-called yarn bending. For this reason, it is necessary to use an insertion-type complex base (FIG. 2B) as described in JP-A-11-43835, and because of the abnormal stagnation of the polymer in the pack or base, It may decrease significantly. Therefore, if the melt viscosity ratio of the two types of polymers is reduced to the contrary, a simple parallel merged composite die (FIG. 2 (a)) can be used. 54, P-173 (1998) as described, it is possible to avoid the problem of spinnability deterioration due to polymer bending at the die. Such a combination of melt viscosities has the advantage that operability can be greatly improved. Preferably, the melt viscosity ratio is 1.0 to 2.5. Here, the melt viscosity ratio is defined by the following formula. The measurement conditions for the melt viscosity were a temperature of 280 ° C. and a strain rate of 6080 sec ⁻¹ in accordance with the normal melt spinning conditions of polyester.

Melt viscosity ratio = V1 / V2
V1: Melt viscosity value (poise) of a polymer having a relatively large melt viscosity
V2: Melt viscosity value (poise) of a polymer having a relatively low melt viscosity
In the present invention, the fiber cross-sectional shape is not limited at all, but for example, a cross-sectional shape as shown in FIG. 3 is conceivable. Of these, the balance between crimp development and texture is a semi-circular side-by-side with a round cross-section, but it is suitable for applications such as a triangular cross-section when aiming for dry texture, and a hollow side-by-side when aiming for heat and warmth. The cross-sectional shape can be selected as appropriate.

  Although the manufacturing method of the soft stretch yarn of this invention is not specifically limited, For example, it can manufacture as follows.

  First, as a first preferred embodiment of the method for producing a soft stretch yarn of the present invention, a conventional spinning / drawing two-step method will be described. That is, a side-by-side composite yarn or an eccentric core-sheath composite yarn made of two types of polyesters (except that both types are polypropylene terephthalate) having a melt viscosity ratio of 1.0 to 2.5 is spun at a temperature of 250 to 280 ° C. , Spinning at a spinning speed of 1200 m / min or more, winding it once, and using a drawing machine having a hot roller, drawing at a drawing temperature of 50 to 80 ° C. and a draw ratio of 20 to 45%, and heat setting It is a method to do. Hereinafter, a specific description will be given with reference to the drawings. In FIG. 4, the melted polyester is filtered through the filter 2 and spun from the die 3. Then, the spun yarn is cooled by a cooling device, and after being lubricated by a lubrication device 6, entanglement is given by an air nozzle as necessary, and a first take-up roller (1GD) 8 and a second take-up roller (2GD) After being picked up by 9, it is wound up by a winder 10. Here, the peripheral speed of 1GD8 is the spinning speed. Next, the wound undrawn yarn 11 is drawn and heat set by a drawing device. For example, in FIG. 5, the undrawn yarn 11 is fed from the feed roller (FR) 12 and then the first hot Preheated by the roller (1HR) 13 and stretched between the 1HR13 and the second hot roller (2HR) 14. Then, after being heat set by 2HR 14, it is wound as drawn yarn 16 through cold roller 15.

Here, the combination of complex polymers, the melt viscosity ratio is improved spinnability if 1.0 to 2.5, PP T and Then stretch a high melt viscosity than the other polyester one polyester excellent PPT to form a inner crimp is Ino easiness to exhibit soft stretchability. In order to suppress yarn unevenness, it is important to select a spinning temperature and a spinning speed. Since PPT has a melting point lower by about 30 to 35 ° C. than PET, the spinning temperature is preferably set to 250 to 280 ° C. lower than the normal spinning temperature of PET. As a result, it is possible to suppress thermal degradation and excessive viscosity reduction of PPT, to prevent a decrease in yarn strength, and to reduce yarn unevenness. The spinning temperature is more preferably 255 to 275 ° C. Furthermore, by setting the spinning speed to 1200 m / min or more, the cooling process during spinning is stabilized, the fluctuation of the yarn swing and the solidification point of the yarn is greatly suppressed, and the yarn spots are reduced compared to the yarn spun at a lower speed. It can be greatly suppressed. This also has the advantage that the yarn strength can be increased. However, if the spinning speed is about 3000 m / min, the stretch characteristics of the soft stretch yarn may be deteriorated, which is preferable. However, at a spinning speed of 5000 m / min or higher, the stretch characteristics are improved, and therefore high speed spinning is preferably employed.

  In stretching and heat setting, it is preferable to consider that PPT has a lower glass transition temperature and lower melting point than PET and is inferior in heat resistance. In particular, in order to suppress yarn unevenness, selection of the stretching temperature is important, and the stretching temperature is preferably 50 to 80 ° C. Thereby, excessive crystallization and thermal deterioration of the yarn on 1HR13 are suppressed. For this reason, yarn fluctuations, yarn unevenness due to fluctuations in the drawing point, and yarn breakage are reduced, and the yarn strength is improved. The stretching temperature is preferably 65 to 75 ° C. Further, in order to reduce the dry heat shrinkage rate of the drawn yarn, heat setting is performed following drawing, but when a hot roller is used as a heat setting device, 120 to 160 ° C., and when a hot plate is used, 110 to 180. It is preferable to set the temperature at about 0 ° C. because the shrinkage rate can be 20% or less. In addition, it is preferable to use a hot plate as the heat setting device, because the heat setting can be performed in a state where the molecular chain is tensioned, so that the shrinkage stress of the yarn can be increased. Furthermore, in order to express the soft stretch property of the present invention, the draw ratio is important, and it is preferable to set the draw yarn elongation to 20 to 45%. This suppresses the occurrence of yarn breakage during the stretching process due to excessive high-stretch stretching, the deterioration of soft stretch properties, and the occurrence of yarn breakage during the fabric formation process, and further reduces the stretch properties due to low-stretch stretching, during the fabric formation process. This makes it possible to avoid troubles such as panicking. The setting of the draw ratio is more preferably 25 to 35% in terms of drawn yarn elongation.

  Next, as a second preferred embodiment of the method for producing a soft stretch yarn of the present invention, a method by a spinning direct drawing method in which a spun yarn is drawn without being wound once will be described. That is, after spinning a side-by-side composite yarn or an eccentric core-sheath composite yarn made of two types of polyester (except that both types are polypropylene terephthalate) at a spinning temperature of 250 to 280 ° C. and a spinning speed of 1200 m / min or more, This is a production method in which the film is wound after being stretched and heat set by a direct spinning method without winding, at a stretching ratio of 50 to 80 ° C. and a stretch rate of 20 to 45%. Hereinafter, a specific description will be given with reference to the drawings. In FIG. 8, the melted polyester is filtered through the filter 2 and spun from the die 3. Then, the spun yarn is cooled by a cooling device, and after refueling by a refueling device 6, entanglement is given by an air nozzle as required, and taken up by a first holon nelson roller (1HNR) 17. After being preheated, the film is stretched with a second hot nelson roller (2HNR) 18, further heat set with 2 HNR 18, and then wound by the winder 10. Here, the peripheral speed of 1HNR17 is the spinning speed, the temperature of 1HNR17 is the stretching temperature, and the temperature of 2HNR18 is the heat set temperature.

Here, the combination of complex polymers, the melt viscosity ratio is improved spinnability if 1.0 to 2.5, PP T and Then stretch a high melt viscosity than the other polyester one polyester excellent PPT to form a inner crimp is Ino easiness to exhibit soft stretchability. In order to suppress yarn unevenness, it is important to select a spinning temperature and a spinning speed. Since PPT has a melting point lower by about 30 to 35 ° C. than PET, the spinning temperature is preferably set to 250 to 280 ° C. lower than the normal spinning temperature of PET. As a result, it is possible to suppress thermal degradation and excessive viscosity reduction of PPT, to prevent a decrease in yarn strength, and to reduce yarn unevenness. The spinning temperature is more preferably 255 to 275 ° C. Furthermore, by setting the spinning speed to 1200 m / min or more, the cooling process during spinning is stabilized, the fluctuation of the yarn swing and the solidification point of the yarn is greatly suppressed, and the yarn spots are reduced compared to the yarn spun at a lower speed. It can be greatly suppressed. This also has the advantage that the yarn strength can be increased. However, if the spinning speed is about 3000 m / min, the stretch characteristics of the soft stretch yarn may be deteriorated, which is preferable. However, at a spinning speed of 5000 m / min or higher, the stretch characteristics are improved, and therefore high speed spinning is preferably employed.

  In stretching and heat setting, it is preferable to consider that PPT has a lower glass transition temperature and lower melting point than PET and is inferior in heat resistance. In particular, in order to suppress yarn unevenness, selection of the stretching temperature is important, and the stretching temperature is preferably 50 to 80 ° C. This suppresses excessive crystallization and thermal degradation of the yarn on 1HNR17. For this reason, yarn fluctuations, yarn unevenness due to fluctuations in the drawing point, and yarn breakage are reduced, and the yarn strength is improved. The stretching temperature is preferably 65 to 75 ° C. Moreover, in order to reduce the dry heat shrinkage rate of the drawn yarn, heat setting is performed subsequent to drawing, but a heat setting temperature of 120 to 160 ° C. is preferable because the shrinkage rate can be 20% or less. Furthermore, in order to express the soft stretch property of the present invention, the draw ratio is important, and it is preferable to set the draw yarn elongation to 20 to 45%. This suppresses the occurrence of yarn breakage during the stretching process due to excessive high-stretch stretching, the deterioration of soft stretch properties, and the occurrence of yarn breakage during the fabric formation process, and further reduces the stretch properties due to low-stretch stretching, during the fabric formation process. It is possible to avoid this trouble. The draw ratio is more preferably set to 25 to 35% in terms of the drawn yarn elongation. Thus, when the spinning direct drawing method is adopted instead of the spinning and drawing two-step method, the manufacturing process becomes efficient and the cost is reduced. However, the phase of crimp of the soft stretch yarn tends to be random, especially when the yarn is used without twisting, the yarn contracts randomly in the fabric, resulting in There is an advantage that it is easy to obtain a plain and slippery fabric.

  Next, as a third preferred mode of the method for producing a soft stretch yarn of the present invention, in FIG. 9, a non-contact heater 19 is provided on the spinning line between the die 3 and 1GD8, and high-speed spinning at a spinning speed of 4000 m / min or more is performed. By doing so, it is also possible to employ a simplified spinning direct drawing method in which heat setting is performed after drawing automatically occurs in the non-contact heater 19 due to air resistance. At this time, since the yarn passes through the non-contact heater in a non-focused state, the yarns are stretched and heat set apart from each other, and soft stretch is further performed than in the hot roller type direct spinning method described above. The phase of the crimp of the yarn is preferable because it tends to be random.

  Next, as a fourth preferred embodiment of the method for producing the soft stretch yarn of the present invention, in FIG. 4, by automatically setting the spinning speed to 5000 m / min or more, the air is automatically stretched between the die 3 and 1GD8 by air resistance. It is also possible to employ a more simplified manufacturing method in which heat is set by the heat of the yarn itself.

By the way, the soft stretch yarn of the present invention is preferable when twisted yarn of 100 turns / m or more is easily applied, and the crimp phase is easily aligned, and the stretch property is easily exhibited even in the fabric state. In general, when a strong twisting the side-by-side bicomponent filaments, although stretchability becomes crimp is defective is to decrease, E _3.5 is the soft stretch yarn of the present invention is significantly higher than the conventional PET-based side-by-side bicomponent filaments For this reason, sufficient stretchability is exhibited even as a strong twisted yarn. Here, the term “strong twist” means to apply a twisted yarn having a twist coefficient of 5000 or more. When the fineness of the yarn is 56 dtex, the number of twists is 700 turns / m or more. The twist coefficient is defined as the product of the square root of the number of twists (turns / m) and the fineness (dtex × 0.9).

  Further, the soft stretch yarn of the present invention can be used without twisting. In this case, if the phase of crimp is shifted between single yarns of the yarn, the surface of the fabric becomes plain, for example, slipperiness. It can be used for a stretch lining excellent in In addition, one of the advantages is that the bulkiness is higher than when crimps are aligned.

  Moreover, when the soft stretch yarn of the present invention is used for knitting, it can be made into an excellent stretch knitted fabric having soft stretch properties that could not be obtained by conventional knitting. Especially in the case of knitted fabrics, the fabric shrinks in a state where the binding force is weak in the high-order processing step, so that apparent shrinkage including shrinkage due to crimping is large and the stitches are clogged. Therefore, when stretch yarn is used, the fabric is likely to coarsely cure. . Therefore, the soft stretch property of the yarn itself is a particularly important parameter in knitting, and by using the soft stretch yarn of the present invention, it is possible to obtain a soft stretch knitted fabric that has never been obtained conventionally. In addition, when soft stretch yarns having the same crimp phase are used, fine crimps are likely to occur between the stitches, and fine wrinkles are formed, and a knitted fabric with high aesthetics can be obtained.

  Furthermore, when the soft stretch yarn of the present invention is used in combination with a low shrink yarn made of polyester or nylon having a boiling water shrinkage of 10% or less, not only the soft feeling is increased, but also the feeling of swelling and resilience is improved. And preferred. If the low shrinkage yarn is present on the relatively outer periphery of the soft stretch yarn, it functions as a cushion and further improves the soft feeling, and the yarn diameter as a multifilament increases, thereby improving the feeling of swelling. For this reason, it is advantageous that the low shrinkage yarn has a lower boiling water shrinkage rate. Preferably, the boiling water shrinkage rate is more preferably 4% or less, and even more preferably 0% or less. Further, it is advantageous that the initial tensile resistance of the low shrinkage yarn is low, and it is preferably 50 cN / dtex or less. Furthermore, since the softness of the low shrinkage yarn is improved when the single yarn fineness is thin, the single yarn fineness is preferably 2.5 dtex or less, more preferably 1.0 dtex or less.

  In addition, when the soft stretch yarn of the present invention is used in combination with natural fibers and / or semi-synthetic fibers, the natural fibers and semi-synthetic fibers have a poor texture such as moisture absorption and release, cool contact feeling, and resilience. It is preferable that stretchability can be added without any problems. The term “mixed use” as used herein means mixed fiber, union, union or the like. In order to balance the characteristics of the soft stretch yarn and the texture of natural fibers and semi-synthetic fibers, the total weight of natural fibers and / or semi-synthetic fibers is preferably 10 to 90% of the fabric weight.

  The soft stretch yarn of the present invention can be suitably used for socks, shirts, blouses, carding guns, pants, skirts, dresses, suits, blousons, linings and the like.

Hereinafter, the present invention will be described in detail with reference to examples. In addition, the measuring method in an Example used the following method.
A. Stress and Recovery Rate for 50% Elongation of Yarn First, the yarn is scraped and subjected to heat treatment for 15 minutes in boiling water under substantially no load, followed by air drying and dry heat at 180 ° C. for 15 minutes. Then, this heat treated yarn was subjected to an initial tension of 4.4 × 10 ⁻³ cN / dtex (5 mgf / d) using an automatic tensile testing machine, from which the yarn was pulled at a pulling speed of 100% / min. % Elongation, immediately turn back and return to 0% elongation at the same speed, and draw a hysteresis curve (FIG. 1). The maximum ultimate stress based on the initial tension is defined as the stress for 50% elongation. In FIG. 1, the recovery rate is calculated as recovery rate (%) = [(50−a) / 50] × 100%. Here, a is the elongation rate at the point where the generated stress becomes the initial tension in the recovery process of the hysteresis curve.
B. Crimp elongation (Figure 6)
Crimp elongation (%) = [(L1-L2) / L1] × 100%
L1: After skeining the fiber skein for 15 minutes, followed by a further 180 ° C. dry heat treatment for 15 minutes, then skein length when the load of 180 × 10 ⁻³ cN / dtex is suspended L2: after measuring L1, the suspended load is 180 × ^10-3 cN / dtex (0.2 gf / d) to 0.9 × 10 ⁻³ cN / dtex (1 mgf / d) skein length E ₀ : When heat-treated without load (no treatment load) Crimp elongation ratio E _3.5 : 3.5 × 10 ⁻³ cN / dtex (4 mgf / d) When subjected to heat treatment under a load, C. Crimp diameter The yarn after E ₀ measurement of the yarn obtained in the examples and comparative examples was sampled in a state where force was not applied as much as possible, and observed with a scanning electron microscope (FIG. 7). And 100 crimps were selected at random, the diameter (outer diameter) was measured, and the average value thereof was taken as the crimp diameter.
D. Wooster spot (U%)
The measurement was performed in the normal mode while feeding a yarn at a speed of 200 m / min using a Zellerweger USTER TESTER 1 Model C.
E. Shrinkage stress It was measured at a heating rate of 150 ° C./min with a thermal stress measuring instrument manufactured by Kanebo Engineering. The sample was a 10 cm × 2 loop, and the initial tension was fineness (decitex) × 0.9 × (1/30) gf.
F. Strength and elongation The initial sample length was 50 mm, the tensile speed was 50 mm / min (100% / min), and a load-elongation curve was obtained under the conditions shown in JIS L1013. Elongation was divided by the initial sample length to determine elongation.
G. Melt viscosity Measured in a nitrogen atmosphere using a Capillograph 1B manufactured by Toyo Seiki Co., Ltd. Measurement was performed three times at a measurement temperature of 280 ° C. and a strain rate of 6080 sec ⁻¹ , and the average value was taken as the melt viscosity.
H. Initial tensile resistance was measured according to JIS L1013.
I. Boiling water shrinkage and dry heat shrinkage Boiling water shrinkage (%) = [(L0′−L1 ′) / L0 ′)] × 100%
L0 ′: Original length of skein measured after initial yarn 0.18 cN / dtex (0.2 gf / d) after drawing the drawn yarn, and the skein measured L0 ′ boils in a substantially load-free state Treatment in water for 15 minutes, after air drying, skein length under initial load of 0.18 cN / dtex (0.2 gf / d) Dry heat shrinkage (%) = [(L0′−L2 ′) / L0 ′)] × 100%
L2 ′: The skein length of L1 ′ measured under a load-free condition with 180 ° C. dry heat for 15 minutes and then air-dried under an initial load of 0.18 cN / dtex (0.2 gf / d) J . Texture evaluation The fabrics obtained in the examples and comparative examples were subjected to sensory evaluation at 1 to 5 grades with respect to softness, swelling, rebound, stretchability, dyed spots, and surface feeling (aesthetics on the surface of the fabric). Grade 3 or higher was accepted.

Example 1
Homo PPT containing no titanium oxide having a melt viscosity of 400 poise and homo-PET containing 0.03% by weight of titanium oxide having a melt viscosity of 370 poise were melted separately at 260 ° C. and 285 ° C., respectively, and a stainless steel nonwoven fabric filter having an absolute filtration diameter of 15 μm was obtained. After performing filtration separately, it was discharged at a spinning temperature of 275 ° C. as a side-by-side composite yarn having a composite ratio of 1: 1 (FIG. 3B) from a parallel merged composite spinneret having 12 holes (FIG. 2A). . The melt viscosity ratio at this time was 1.08. Winding 168 dtex, 12 filaments of undrawn yarn at a spinning speed of 1500 m / min, and then using a drawing machine having a hot roller, the temperature of the first hot roller is 70 ° C. and the temperature of the second hot roller is 130 ° C. Drawing was performed at a magnification of 3.00. Both the spinning and the drawing had good yarn-making properties and no yarn breakage. The yarn making conditions are shown in Table 1, and the yarn physical properties are shown in Table 2. PPT entered the inside of the crimp and showed excellent crimp expression ability. Further, the crimp diameter developed by the heat treatment for measuring E ₀ was very fine as 200 μm, and the phases were aligned, so that the quality was very high. Further, the initial tensile resistance was sufficiently soft at 42 cN / dtex, and the dry heat shrinkage was 11%, which was sufficiently low. Moreover, the temperature showing the maximum of the shrinkage stress was a sufficiently high temperature of 128 ° C.

Example 2
Homo PPT containing no titanium oxide with a melt viscosity of 2900 poise and homo PET containing 0.03% by weight of titanium oxide with a melt viscosity of 370 poise were separately melted at 280 ° C. and 285 ° C. After performing filtration separately, a side-by-side composite yarn having a composite ratio of 1: 1 (FIG. 3 (b)) from an insertion type composite spinneret (FIG. 2 (b)) described in JP-A-9-157941 having 12 holes. ) At a spinning temperature of 275 ° C. Winding 190 dtex, 12 filaments of undrawn yarn at a spinning speed of 1350 m / min, and then using a drawing machine having a hot roller, the temperature of the first hot roller is 80 ° C. and the temperature of the second hot roller is 135 ° C. Drawing was performed at a magnification of 3.40. Both the spinning and the drawing had good yarn-making properties and no yarn breakage. The yarn making conditions are shown in Table 1 and the yarn physical properties are shown in Table 2. The high viscosity PPT entered the inside of the crimp and showed excellent crimp expression. Further, the crimp diameter developed by the heat treatment for measuring E ₀ was very fine as 175 μm, and the phases were aligned, so that the quality was very high. Further, the initial tensile resistance was sufficiently soft at 46 cN / dtex, and the dry heat shrinkage was 9%, which was sufficiently low. Moreover, the temperature showing the maximum of the shrinkage stress was a sufficiently high temperature of 130 ° C.

Example 3
Melt spinning was performed under the same conditions as in Example 1 except that the spinning speed was 3000 m / min and the fibers were 77 dtex. Using this undrawn yarn, drawing was performed under the same conditions as in Example 1 except that the draw ratio was 1.40. Both the spinning and the drawing had good yarn-making properties and no yarn breakage. The yarn making conditions are shown in Table 1, and the yarn physical properties are shown in Table 2. PPT entered the inside of the crimp and showed excellent crimp expression ability. Further, the crimp diameter developed by the heat treatment for measuring E ₀ was very fine as 220 μm, and the phases were aligned, so that the quality was very high.

Example 4
The melt spinning was performed under the same conditions as in Example 1 except that the side-by-side composite was changed to the eccentric core-sheath composite (FIG. 2 (h)), and the polymer and composite ratio were changed as follows. At this time, PET containing 0.40 wt% of titanium oxide having a melt viscosity of 400 poise was 60 wt% as a sheath polymer, and PPT not containing the melt viscosity of 700 poise titanium oxide was 40 wt% as a core polymer. Using this undrawn yarn, drawing was performed under the same conditions as in Example 1 except that the draw ratio was 2.60 and the second hot roller temperature was 140 ° C. Both the spinning and the drawing had good yarn-making properties and no yarn breakage. The yarn making conditions are shown in Table 1, and the yarn physical properties are shown in Table 2. The crimping ability was excellent. Further, the crimp diameter developed by the heat treatment for measuring E ₀ was very fine as 240 μm, and the phases were aligned, so that the quality was very high.

Example 5
Melt spinning was performed under the same conditions as in Example 1 except that the spinning speed was changed to 7000 m / min. This could be used in a wound state without being stretched. The physical property values thereof are shown in Table 1, and showed excellent crimp expression ability. Further, the crimp diameter developed by the heat treatment for measuring E ₀ was as very fine as 120 μm, and the phases were aligned, so that the quality was very high. Furthermore, the dry heat shrinkage was 5%, which was a sufficiently low shrinkage yarn.

Example 6
Melt spinning was performed under the same conditions as in Example 1 except that the fiber cross-sectional shape was a hollow cross-section (FIG. 3 (f)). Using this undrawn yarn, drawing was performed under the same conditions as in Example 2 except that the draw ratio was 2.95. The yarn making conditions are shown in Table 1, and the yarn physical properties are shown in Table 2. PPT entered the inside of the crimp and showed excellent crimp expression ability. Further, the crimp diameter developed by the heat treatment for measuring E ₀ was very fine as 240 μm, and the phases were aligned, so that the quality was very high.

Example 7
Homo PPT containing no titanium oxide with a melt viscosity of 700 poise and homo PET containing 0.03% by weight of titanium oxide with a melt viscosity of 370 poise were melted separately at 260 ° C. and 285 ° C., respectively, and a stainless steel nonwoven fabric filter having an absolute filtration diameter of 15 μm was obtained. After performing filtration separately, it was discharged at a spinning temperature of 275 ° C. as a side-by-side composite yarn having a composite ratio of 1: 1 (FIG. 3B) from a parallel merged composite spinneret having 12 holes (FIG. 2A). . Then, using the spinning direct drawing apparatus of FIG. 8, the peripheral speed of the first hot Nelson roller 17 is 1500 m / min, the temperature is 75 ° C., the peripheral speed of the second hot Nelson roller 18 is 4500 m / min, and the temperature is 130 ° C. Spinning was performed in the same manner, and 56 dtex, 12 filament soft stretch yarn was wound up. The physical property values of the obtained soft stretch yarn are shown in Table 2. PPT entered the inside of the crimp and showed excellent crimp expression ability. Further, the crimp diameter developed by the heat treatment for measuring E ₀ was as very fine as 200 μm, and the quality was very high. Further, the initial tensile resistance was sufficiently soft at 42 cN / dtex, and the dry heat shrinkage was 10%, which was sufficiently low. Moreover, the temperature showing the maximum of the shrinkage stress was a sufficiently high temperature of 128 ° C. Further, the crimp phase was randomized, and it was suitable for a lining having no twist and excellent slipperiness.

Example 8
Spinning was performed in the same manner as in Example 7 using the spinning direct drawing apparatus shown in FIG. 9, with the temperature of the non-contact heater 19 set to 190 ° C., the spinning speed set to 5000 m / min, and subjected to 100 ° C. steam heat treatment between the 2GD 9 and the winder 10. went. At this time, the yarn speed before entering the non-contact heater was 2200 m / min. The physical property values of the obtained soft stretch yarn are shown in Table 2. PPT entered the inside of the crimp and showed excellent crimp expression ability. Further, the crimp diameter developed by the heat treatment for measuring E ₀ was as very fine as 190 μm, and the quality was very high. Further, the phases of crimps were different between single yarns, and there was a feeling of bulk compared to Example 2. Further, the initial tensile resistance was sufficiently soft at 43 cN / dtex, and the dry heat shrinkage was 12%, which was sufficiently low. Further, the temperature showing the maximum of the shrinkage stress was sufficiently high as 126 ° C. Further, the crimp phase was randomized, and it was suitable for a lining having no twist and excellent slipperiness.

Comparative Example 1
The polymer combination is homo-PPT not containing titanium oxide with a melt viscosity of 400 poise and homo-PET containing 0.03% by weight of titanium oxide with a melt viscosity of 400 poise, the yarn speed is 900 m / min, the spinning temperature is 286 ° C., the discharge rate, the stretching Except for changing the magnification, melt spinning and drawing were performed under the same conditions as in Example 1 to obtain a drawn yarn of 56 dtex and 12 filaments. Table 1 shows the spinning conditions and Table 2 shows the physical properties of the yarns. Although some crimping ability was shown, the spinning temperature was high and the discharge became unstable due to PPT side thermal deterioration, and the spinning speed of the undrawn yarn was Because of its low value, yarn fluctuation and solidification point fluctuations during the spinning process increased. For this reason, the yarn strength of the drawn yarn was significantly reduced, and the Wooster spots were also deteriorated. Moreover, since the stress with respect to 50% elongation exceeded 30 × 10 ⁻³ cN / dtex and the recovery rate was less than 70%, the softness and stretchability did not reach those of Example 1.

Comparative Example 2
With the combination of the polymers of Comparative Example 1, spinning was performed in the same manner as in Comparative Example 1 at a spinning temperature of 280 ° C. and a spinning speed of 1500 m / min to obtain 146 dtex, 12-filament undrawn yarn. Then, melt spinning and stretching were carried out under the same conditions as in Example 1 except that the draw ratio was 2.70 times and the temperature of the first hot roller was 100 ° C. to obtain a drawn yarn. Table 1 shows the yarn production conditions and Table 2 shows the physical properties of the yarn. Although some crimping ability was shown, the temperature of the first hot roller was high, so that the PPT was thermally deteriorated and the yarn breakage occurred frequently. Moreover, the obtained drawn yarn also had low yarn strength, and the Wooster spots were also deteriorated. Moreover, since the stress with respect to 50% elongation exceeded 30 × 10 ⁻³ cN / dtex and the recovery rate was less than 70%, the stretchability did not reach Example 1.

Comparative Example 3
Homo PET containing 0.03% by weight of titanium oxide having a melt viscosity of 130 poise (intrinsic viscosity 0.46) and a melt viscosity of 2650 poise (intrinsic viscosity 0.77) was melted separately at 275 ° C. and 290 ° C., respectively, and the absolute filtration diameter was 15 μm. After separately filtering using a stainless steel nonwoven fabric filter, a side-by-side composite yarn (Fig. 2B) having a composite ratio of 1: 1 from an insertion type die (Fig. 2 (b)) described in JP-A-9-157941 having 12 holes. 3 (a)), the yarn was discharged at a spinning temperature of 290 ° C. The melt viscosity ratio at this time was 20.3. Winding 154 dtex, 12 filaments of undrawn yarn at a spinning speed of 1500 m / min, and then using a drawing machine having a hot roller, the first hot roller temperature is 90 ° C and the second hot roller temperature is 130 ° C. After stretching at a magnification of 3.11, 10% relaxation heat treatment was performed with a non-contact heater (heater temperature 160 ° C.). Both the spinning and the drawing were inferior in yarn production, and many yarn breaks occurred. The yarn making conditions are shown in Table 1 and the yarn physical properties are shown in Table 2. The stress for 50% elongation exceeded 50 × 10 ⁻³ cN / dtex, and the soft stretch yarn of the present invention could not be obtained. Further, E _3.5 = 0.5% and the crimp expression ability under restraint was low. Furthermore, the initial tensile resistance was 75 cN / dtex and lacked softness.

Comparative Example 4
Homo PET containing 0.03% by weight of titanium oxide having a melt viscosity of 2000 poise and copolymer PET containing 0.03% by weight of titanium oxide obtained by copolymerizing 10 mol% of isophthalic acid as an acid component having a melt viscosity of 2100 poise were obtained at 285 ° C. and 275 ° C., respectively. After being melted separately at 0 ° C. and filtered separately using a stainless steel nonwoven fabric filter having an absolute filtration diameter of 15 μm, a side-by-side ratio of 1: 1 from a parallel merged composite spinneret (FIG. 2A) having 12 holes. The composite yarn (FIG. 3B) was discharged at a spinning temperature of 285 ° C. Then, an undrawn yarn of 154 dtex, 12 filaments was wound at a spinning speed of 1500 m / min. Thereafter, using a stretching machine having a hot roller, stretching was performed at a temperature of the first hot roller of 90 ° C., a temperature of the second hot roller of 130 ° C., and a stretching ratio of 2.75. Both the spinning and the drawing had good yarn-making properties and no yarn breakage. The yarn making conditions are shown in Table 1 and the yarn physical properties are shown in Table 2. The stress for 50% elongation exceeded 50 × 10 ⁻³ cN / dtex, and the soft stretch yarn of the present invention could not be obtained. Moreover, _E3.5 = 0.4% and the crimp expression ability under restraint was low.

Example 9
The yarns obtained in Examples 1 to 6 and Comparative Examples 1 to 4 were used as raw yarns, and a twisted yarn having a twist number of 700 turns / m was applied thereto, and a set to be twisted was performed by 65 ° C. steam. Then, the knitted fabric was knitted with an interlock structure through 28 gauge circular knitting. According to a conventional method, this was subjected to relaxing scouring at 90 ° C., and then an intermediate set at 180 ° C. Then, according to a conventional method, after 10% by weight alkali reduction, dyeing was performed at 130 ° C. And the texture of the obtained fabric was sensory-evaluated (Table 3). The level at which the soft stretch yarns of Examples 1 to 6 were used was soft and excellent in stretch properties, and the fabric surface was rich in aesthetics. In the level using the raw yarns of Examples 1 to 6, the crimped diameter of the raw yarn is fine and the phases of the crimps are aligned. Therefore, a very beautiful wrinkle appears especially on the fabric surface, which is rich in aesthetics. It was. In addition, there was no staining spots and the quality was high. However, in Comparative Examples 1 and 2, stained spots occurred and the quality was inferior. In Comparative Examples 3 and 4, the texture was rough.

Example 10
The soft stretch yarns obtained in Examples 1 to 6 and Comparative Examples 1 to 4 were used as a raw yarn, and a twisted yarn having a twist number of 1500 turns / m was applied thereto, and a set to be twisted by 65 ° C. steam was performed. A plain weave was prepared using the same yarn for the warp and the weft. The yarn density at this time was 110 warps / inch (2.54 cm) and 91 wefts / inch (2.54 cm) for the wefts, and the torque balance was taken as an alternate arrangement of S twist / Z twist. The obtained raw machine was processed as follows. First, relaxing scouring was performed at 90 ° C., and then an intermediate set was applied by a pin tenter at a dry heat of 180 ° C. And after giving 15% alkali weight loss by a conventional method, it dye | stained at 130 degreeC by the conventional method again.

And the texture of the obtained fabric was sensory-evaluated (Table 4). In Examples 1-6 , the yarn had good stretch properties as expected from the yarn properties, but in Comparative Examples 3 and 4, the stretch properties were inferior. At the level where the raw yarns of Examples 1 to 6 were used, the crimped diameter of the raw yarn was fine and the phases of crimping were uniform, so that the fabric surface was not rough and was particularly aesthetic.

Example 11
A plain weave was prepared using the same yarn as the warp and weft while keeping the soft stretch yarns obtained in Examples 1, 7 , 8 and Comparative Examples 3, 4 untwisted. At this time, the yarn density was 110 warps / inch (2.54 cm) and 91 wefts / inch (2.54 cm). The obtained raw machine was processed as follows. First, scouring was performed at 90 ° C. using a softener, and then an intermediate set was applied using a pin tenter at a dry heat of 180 ° C. And after giving 15% alkali weight loss by a conventional method, it dye | stained at 130 degreeC by the conventional method again.

  And the texture of the obtained fabric was sensory-evaluated. Sufficient stretchability was obtained with the fabrics using Examples 1, 10, and 11. However, fine wrinkles remained on the surface of the fabric although Example 1 was not problematic. On the other hand, in Examples 10 and 11, there was no generation of wrinkles and the fabric surface was plain and slippery, which was suitable for a stretch lining. In Examples 10 and 11, Example 11 was more excellent in slipperiness. In the case of using Comparative Examples 3 and 4, the expression of the crimp of the yarn was weak due to the tension in the softer, and the stretchability was not obtained.

Example 12
Examples 1, 2, 4, the soft stretch yarn obtained in a ratio Comparative Examples 3, 4 and yarn, to produce combined filament yarn with low shrinkage yarn consisting of PET under the conditions shown in this and Table 5, 65 A twist set was made by steam at 0 ° C. Then, weaving and processing were performed in the same manner as in Example 13 for evaluation.

  The texture of the obtained fabric was subjected to sensory evaluation (Table 6). As expected from the yarn characteristics, the yarns of the examples were soft and the texture was soft and good stretch was developed. However, the yarns of Comparative Examples 3 and 4 had a strong feeling of coarseness. It became.

Example 13
The soft stretch yarn obtained in Example 2 was used as a raw yarn, and a twisted yarn having a twist number of 700 turns / m was applied thereto, and a twist-stop set was performed using 65 ° C. steam. Then, using this as the weft, a plain weave was produced using copper ammonia rayon “cupra” (83 dtex, 45 filament) manufactured by Asahi Kasei Kogyo Co., Ltd. as the warp. The yarn density at this time was 110 warps / inch (2.54 cm) and 91 wefts / inch (2.54 cm) for the wefts, and the torque balance was taken as an alternate arrangement of S twist / Z twist. The obtained raw machine was processed as follows. First, relaxing scouring was performed at 90 ° C., and then an intermediate set was applied with a pin tenter at 150 ° C. dry heat. And it dye | stained at 100 degreeC.

  The resulting woven fabric was soft and rich in stretch properties, and further developed a high dry feeling due to the large cold contact feeling peculiar to copper ammonia rayon. Moreover, the moisture absorption / release property and the slipperiness of the fabric surface were also good.

Example 14
A woven fabric was prepared in the same manner as in Example 10 except that viscose rayon “Silmax” (83 dtex, 38 filaments) manufactured by Asahi Kasei Kogyo Co., Ltd. was used as the warp. The resulting fabric was soft and rich in stretch properties. Moreover, a pre-tactile tactile sensation was obtained due to the excellent resilience peculiar to viscose rayon, and a high degree of dry feeling due to a greater contact cooling sensation was expressed. Moreover, the moisture absorption / release property was also good.

Example 15
The soft stretch yarn obtained in Example 2 was used as a base yarn, and a twisted yarn having a number of turns of 550 turns / m was applied thereto, and a twist-stop set was performed using 65 ° C. steam. This was combined with the copper ammonia rayon used in Example 13, and knitted with an interlock structure through a 24 gauge circular knitting. This was subjected to relaxation scouring at 90 ° C. according to a conventional method, followed by dyeing at 100 ° C.

  The obtained knitted fabric was soft and rich in stretch properties, and further developed a high dry feeling due to the large cold contact feeling peculiar to copper ammonia rayon. Moreover, the moisture absorption / release property and the slipperiness of the fabric surface were also good.

Example 16
A knitted fabric was produced in the same manner as in Example 15 except that the viscose rayon used in Example 14 was used instead of the copper ammonia rayon.

  The obtained knitting was soft and rich in stretch. Moreover, a pre-tactile tactile sensation was obtained due to the excellent resilience peculiar to viscose rayon, and a high degree of dry feeling due to a greater contact cooling sensation was expressed. Moreover, the moisture absorption / release property was also good.

It is a figure showing a strong elongation curve hysteresis. It is a figure which shows the example of a nozzle | cap | die for side-by-side composite spinning. It is a figure which shows the fiber cross-sectional shape example of a polyester fiber. It is a figure which shows an example of a spinning / winding apparatus. It is a figure showing an extending | stretching apparatus. It is a figure which shows the crimp expansion | extension rate measuring method. It is an electron micrograph which shows an example of the shape of the fiber of a soft stretch yarn. It is a figure which shows an example of a spinning direct drawing apparatus. It is a figure which shows another example of the spinning direct drawing apparatus.

Explanation of symbols

1: Spin block 2: Non-woven filter 3: Base 4: Chimney 5: Yarn 6: Refueling guide 7: Entanglement guide 8: First godet roller 9: Second godet roller 10: Winding yarn 11: Undrawn yarn 12: feed roller 13: first hot roller 14: second hot roller 15: cold draw roller 16: drawn yarn 17: first hot nelson roller 18: second hot nelson roller 19: non-contact heater 20: steam conditioner

Claims (9)

Side-by-side composite yarn or eccentric core-sheath composite yarn made of two types of polyester (except that both types are polypropylene terephthalate). Polypropylene terephthalate forms the inside of the crimp, and Wooster spots are 2.0% or less. A soft stretch yarn characterized by simultaneously satisfying a stress with respect to 50% elongation of the yarn of 30 × 10 ⁻³ cN / dtex or less and a recovery rate of 60% or more.   The soft stretch yarn according to claim 1, wherein the two kinds of polyesters are polypropylene terephthalate and polyethylene terephthalate.   The soft stretch yarn according to claim 1 or 2, wherein the strength is 2.2 cN / dtex or more.   The soft stretch yarn according to any one of claims 1 to 3, wherein a recovery rate with respect to 50% elongation of the yarn is 70% or more. The soft stretch yarn according to any one of claims 1 to 4, wherein a stress with respect to 50% elongation of the yarn is 10 x ^10-3 cN / dtex or less. Soft stretch yarn according to any one of claims 1 to 5, shrinkage stress is characterized in that at 0.25 cN / dtex or more. A soft stretch blended yarn comprising the soft stretch yarn according to any one of claims 1 to 6 and a low shrink yarn having a boiling water shrinkage of 10% or less. Fabric characterized by comprising using at least the soft stretch yarn according to any one of claims 1-7. The fabric according to claim 8 , wherein natural fibers and / or semi-synthetic fibers are mixed.