Polyether ester elastic fibers and yarns thereof, as well as fabrics and garments containing such fibers.

Abstract

This invention provides a polyether ester elastic fiber, a yarn containing the fiber, and fabrics and garments comprising the fiber. The polyether ester elastic fiber exhibits good stretchability and elastic recovery, and possesses heat resistance that effectively suppresses the reduction of tensile stress and the formation of fabric wrinkles due to shrinkage even after dyeing processes. Furthermore, it has good aesthetic appeal as a fabric. The total fineness of the polyether ester elastic fiber of this invention is 5 dtex to 80 dtex, the phase separation index measured using a small-angle X-ray scattering device is 0.20 to 0.65, and the alignment index of the fiber axis direction in the hard chain segment region measured using Raman spectroscopy is 10.00 or less.

Description

[Technical Field]

[0001] This invention relates to a polyether ester elastic fiber and a yarn of the fiber, as well as fabrics and clothing containing the fiber. [Previous Technology]

[0002] Elastic fibers are widely used in clothing such as socks, underwear, sportswear, and swimwear, as well as in non-clothing fields such as diapers, bandages, body protectors, and masks. In particular, among elastic fibers used in clothing, in addition to the need for stretch recovery and elasticity, elastic fibers also need to minimize the appearance of streaks, wrinkles, mesh, and blockages caused by the disorder of knitted or woven structures during fabric processing and dyeing. Polyurethane elastic fibers are widely known to possess these properties.

[0003] On the other hand, polyether ester elastic fibers include hard segments comprising aromatic polyester units and soft segments comprising polyalkylene ether glycol units. Due to the balance between the cohesive force of the same components and the repulsive force against phase growth, these segments form a microphase separation structure comprising hard segment regions, soft segment regions, and a phase mixture of soft segment regions and hard segment regions. Since the hard segment regions function as physical crosslinking points and the soft segment regions function as stretching sites, the balance of the microphase separation structure comprising each region results in properties such as stretching compliance, stretching recovery, and heat resistance.

[0004] As shown in Figure 1, stretch conformability is represented by R / S, which is the ratio of the stress during elongation (S-modulus) to the stress during recovery (R-modulus) when the polyether ester elastic fiber recovers from elongation. The larger the R / S of the polyether ester elastic fiber, the better the stretch conformability, and the better the fit of the fabric. Furthermore, as shown in Figure 2, stretch recovery is represented by the recovery rate when the polyether ester elastic fiber recovers from elongation. The larger the recovery rate of the polyether ester elastic fiber, the better the stretch recovery, and the less likely the fabric is to loosen. Additionally, heat resistance refers to the change in tensile stress of the polyether ester elastic fiber during the dyeing process, or the degree of shrinkage, and whether filament breakage occurs.

[0005] Generally speaking, the stretchability, stretch recovery, and heat resistance of polyether ester elastic fibers are worse than those of polyurethane elastic fibers. If the stretchability and stretch recovery of polyether ester elastic fibers are improved by reducing the content of hard chain segments and increasing the content of soft chain segments, the melting point of polyether ester elastic fibers will be significantly reduced. Therefore, there are problems such as reduced tensile stress, shrinkage, wrinkling of the fabric, and fiber breakage in the fabric due to the heat applied during the dyeing process.

[0006] Patent Document 1 discloses a polyether ester elastic fiber that increases the melting point of the polymer by increasing the content of hard segments to 50% or more, and improves the orientation and crystallinity of the hard segment regions along the fiber axis by directly heat-treating it in the form of yarn packages, resulting in good stretch recovery. However, the stretch follow-through of the polyether ester elastic fiber described in Patent Document 1 is not good. It is presumed that this is because, since the hard segment regions are highly oriented along the fiber axis, the hard segment regions are damaged due to elongation stress when the polyether ester elastic fiber is stretched and recovered. Furthermore, the polyether ester elastic fiber described in Patent Document 1 suffers from shrinkage or decreased physical properties during the dyeing process, presumably because the hard segment regions oriented along the fiber axis relax during the dyeing process.

[0007] Furthermore, Patent Document 2 discloses a manufacturing method in which the speed of the take-up roller and the extension roller is controlled to perform melt spinning at an extremely high speed of 3000 m / min or higher, so that the hard chain segment regions are highly aligned along the fiber axis, thereby exhibiting the stretch recovery property of polyether ester elastic fibers. However, the stretch following property of the polyether ester elastic fibers described in Patent Document 2 is not good. It is presumed that the reason is that, due to the high alignment of the hard chain segment regions, the hard chain segment regions are damaged due to elongation stress when the polyether ester elastic fibers are stretched and recovered. Furthermore, the polyether ester elastic fibers described in Patent Document 2 shrink significantly or experience a significant decrease in physical properties during the dyeing process, presumably because the hard chain segment regions aligned along the fiber axis relax during the dyeing process.

[0008] Furthermore, Patent Document 3 discloses a polyether ester elastic fiber that, through a stretching treatment after spinning, improves the alignment of the hard chain segment regions along the fiber axis, resulting in good stretch follow-through and stretch recovery. However, the polyether ester elastic fiber described in Patent Document 3 is prone to shrinkage during the dyeing process. This is presumably because, since the hard chain segment regions in the polyether ester elastic fiber described in Patent Document 3 are highly aligned along the fiber axis, the alignment of the hard chain segment regions loosens during the dyeing process. Thus, the industry has not yet developed a polyether ester elastic fiber with good stretch follow-through and stretch recovery, and which can effectively suppress the reduction of tensile stress and the formation of fabric wrinkles during the dyeing process. [Prior Art Documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. Hei 11-107042 [Patent Document 2] Japanese Patent Application Publication No. 2019-210571 [Patent Document 3] Japanese Patent Application Publication No. 2009-167541 [Summary of the Invention]

[0010] [Problem to be Solved by the Invention] In view of the problems of the prior art described above, the problem to be solved by the present invention is to provide a polyether ester elastic fiber and a yarn of the fiber, as well as fabrics and garments containing the fiber, wherein the polyether ester elastic fiber has good stretch conformability and stretch recovery, and has heat resistance that sufficiently suppresses the reduction of tensile stress and the formation of fabric wrinkles due to shrinkage even after dyeing processing, and has good aesthetic appeal as a fabric. [Technical Means for Solving the Problem]

[0011] The inventors of this invention have made efforts to study and repeatedly conducted experiments to solve the above problems. As a result, they unexpectedly found that the above problems can be solved by increasing the ratio of hard chain segment regions to soft chain segment regions and / or controlling the alignment of the fiber axis direction of the hard chain segment regions to a lower level, thereby completing the present invention.

[0012] That is, the present invention is as follows. [1] A polyether ester elastic fiber having a total fineness of 5 dtex or more and 80 dtex or less, a phase separation index measured by a small-angle X-ray scattering device of 0.20 or more and 0.65 or less, and an orientation index of the fiber axis direction of the hard chain segment region measured by Raman spectroscopy of 10.00 or less. [2] The polyether ester elastic fiber as described in [1] above, wherein 80 mol% or more of the low molecular weight diol units constituting the polyether ester are selected from the group consisting of 1,4-butanediol, 1,6-hexanediol, 1,3-propanediol and ethylene glycol, and 50 mol% or more of the polymer polyol units are PTMG or a copolyol containing tetrahydrofuran (THF) and neopentyl glycol. [3] The polyether ester elastic fiber described in [1] or [2] above has a specific viscosity of 2.00 dL / g or more and 6.00 dL / g or less. [4] The polyether ester elastic fiber described in any one of [1] to [3] above has an orientation index of 2.50 or more and 5.00 or less in the fiber axis direction of the mixed portion of the soft segment region and the hard segment region as measured by Raman spectroscopy. [5] The polyether ester elastic fiber described in any one of [1] to [4] above has an orientation index of 1.50 or more and 4.00 or less in the fiber axis direction of the soft segment region as measured by Raman spectroscopy. [6] A spun yarn, which is a spun yarn of the polyether ester elastic fiber described in any one of [1] to [5] above. [7] A fabric comprising the polyether ester elastic fiber described in any one of [1] to [5] above. [8] A garment comprising polyether ester elastic fibers as described in any one of [1] to [5] above. [Effects of the Invention]

[0013] The polyether ester elastic fiber of the present invention, by having the above-described structure, possesses excellent stretchability and elastic recovery, and even after dyeing, it can sufficiently suppress the reduction of tensile stress and the formation of fabric wrinkles. Furthermore, the fiber of the present invention can sufficiently suppress the formation of fabric wrinkles, thus making it suitable for fabrics and clothing that can enhance their aesthetic appeal. Moreover, as one embodiment of the present invention, the yarn of the above-described fiber exhibits good unwinding properties and excellent migration stability during processing, and can uniformly form a greige fabric structure, thus resulting in excellent aesthetics. Furthermore, as another embodiment of the present invention, fabrics and clothing containing the above-described fiber experience suppression of stress reduction and wrinkle formation during dyeing, resulting in good elasticity and fit when worn, and excellent aesthetics.

Implementation Method

[0015] Hereinafter, embodiments of the present invention (hereinafter referred to as "this embodiment") will be described in detail. The present invention is not limited to the following embodiment, and various changes can be made within its scope.

[0016] [Polyether ester elastic fiber] One embodiment of the present invention is a polyether ester elastic fiber with a total fineness of 5 dtex or more and 80 dtex or less, a phase separation index measured by a small-angle X-ray scattering device of 0.20 or more and 0.65 or less, and / or an alignment index of the fiber axis direction of the hard chain segment region measured by Raman spectroscopy of 10.00 or less.

[0017] In this invention, the polyether ester elastomer constituting the polyether ester elastic fiber is not particularly limited as long as it has a structure formed by copolymerization of dicarboxylic acid units, low molecular weight diol units, and polymeric polyol units. Furthermore, the polymerization method is also not particularly limited. Carboxylic acid units and diol units with trifunctionality or higher can be used within the scope that does not impair the desired effect of this invention.

[0018] Examples of dicarboxylic acid units include aromatic dicarboxylic acids, alicyclic dicarboxylic acids, and aliphatic dicarboxylic acids. While not limited to the following, examples of aromatic dicarboxylic acids include phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, diphenyl-4,4'-dicarboxylic acid, diphenoxydicarboxylic acid, and 5-sulfoisophthalic acid.

[0019] Examples of alicyclic and aliphatic dicarboxylic acids include: sebacic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, dodecanoic acid, glutaric acid, succinic acid, oxalic acid, azelaic acid, dimethylmalonic acid, fumaric acid, citrate, allylmalonic acid, 4-cyclohexene-1,2-dicarboxylic acid, pimelic acid, octanoic acid, 2,5-diethylhexanoic acid, 2-ethyloctanoic acid, 2,2,3,3-tetramethylsuccinic acid, cyclopentenedicarboxylic acid, decahydro-1,5-(or 2,6-)naphthalenedicarboxylic acid, 4,4'-bicyclohexanedicarboxylic acid, 4,4'-methylenebis(cyclohexylcarboxylic acid), 3,4-furan dicarboxylic acid ester, and 1,1-cyclobutanedicarboxylic acid ester. These dicarboxylic acid units can be used alone or in combination of two or more. In particular, from the viewpoint of enabling elastic fibers to have good stretchability, stretch recovery, and heat resistance, the dicarboxylic acid unit is preferably an aromatic dicarboxylic acid, and more preferably terephthalic acid.

[0020] Low molecular weight diol units are diol compounds with a molecular weight of 500 or less. While not limited to the following, examples include: ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanediol, and 1,4-cyclohexanediol. One of these diol units may be used alone, or two or more may be used in combination. From the viewpoint of providing good stretchability, stretch recovery, and heat resistance of elastic fibers, ethylene glycol, 1,3-propanediol, and 1,4-butanediol are preferred as diol units.

[0021] In the polyether ester elastic fiber of this embodiment, from the viewpoint of further improving the stretch recovery and stretching follow-through during elongation recovery, and the effects of inhibiting the reduction of physical properties and shrinkage during the dyeing process, the low molecular weight diol unit constituting the polyether ester elastomer is preferably any one of 1,4-butanediol, 1,3-propanediol, or ethylene glycol at a rate of 80 mol% or more, more preferably 90 mol% or more, further preferably 95 mol% or more, and most preferably 98 mol% or more. Thus, by ensuring that at least 80 mol% of the low-molecular-weight diol units constituting the polyether ester elastomer are any one of 1,4-butanediol, 1,3-propanediol, or ethylene glycol, it is easy to control the orientation of the hard segment regions and the orientation of the mixed portion of the soft segment regions and hard segment regions to a lower level. This improves the stretch recovery and elongation compliance during stretching, as well as the suppression of property degradation and shrinkage during the dyeing process. Furthermore, the fabric is less prone to shrinkage during the dyeing process, thus reducing wrinkles and enhancing aesthetics.

[0022] As a polymer polyol unit, although not limited to the following, examples include: polyether diols, polyester diols, polycarbonate diols, and other polymer diols. From the viewpoint of improving the hydrolysis resistance of polyether ester elastic fibers, polyether polyols are preferred as polymer polyol units, and more preferably polyether diols.

[0023] Examples of polyether-based polyols include: polyethylene oxide, polyethylene glycol, polyethylene glycol derivatives, polypropylene glycol, polytetramethylene ether glycol (PTMG), modified PTMG (hereinafter also referred to as "PTXG") as a copolyol containing tetrahydrofuran (THF) and neopentyl glycol, and copolymer glycols containing THF and 3-methyltetrahydrofuran. These polyether-based polyols can be used alone or in combination of two or more. Furthermore, the average molecular weight of the polymeric polyol is preferably between 1000 and 8000. By using polymeric polyols within this range, elastic fibers with excellent elongation, stretch recovery, stretch conformation, and heat resistance can be easily obtained. From the viewpoint of achieving good stretch conformation, polytetramethylene ether glycol (PTMG) and copolyols containing tetrahydrofuran (THF) and neopentyl glycol (PTXG) are preferred polyether-based polyols.

[0024] In the polyether ester elastic fiber of this embodiment, from the viewpoint of further improving the effect of stretch recovery and stretch conformation, and the effect of suppressing the reduction of physical properties and shrinkage during the dyeing process, it is preferable to use either PTMG or PTXG at 50 mol% or more as the polymer polyol unit constituting the polyether ester elastomer, more preferably at 60 mol% or more. In this way, by making PTMG or PTXG at 50 mol% or more of the polymer polyol unit constituting the polyether ester elastomer, it is easier to control the orientation of the soft segment region and the orientation of the mixed portion of the soft segment region and the hard segment region to be lower, so as to improve the effect of stretch recovery and stretch conformation, and the effect of suppressing shrinkage during the dyeing process. Furthermore, the fabric is less likely to shrink during the dyeing process, so it is less likely to wrinkle, which can improve the aesthetics.

[0025] In the polyether ester elastomer constituting the polyether ester elastic fiber of this embodiment, the ratio of hard segments containing dicarboxylic acid units and low molecular weight diol units to soft segments containing polymer polyol units is preferably 15:85 to 50:50 by weight.

[0026] In the polyether ester elastic fiber of this embodiment, from the viewpoint of fully achieving improved stretch follow-through and stretch recovery during elongation recovery, as well as shrinkage suppression during the dyeing process, the total fineness needs to be 5 dtex or more and 80 dtex or less. Thus, by maintaining a total fineness of 5 dtex or more and 80 dtex or less, it is easier to control the temperature distribution of the yarn during the cooling process in the melt spinning step. It is also easier to control the fiber axis orientation of the hard segment region, soft segment region, and the mixed portion of the soft segment region and hard segment region of the polyether ester elastic fiber to be lower, thereby fully satisfying the effects of improved stretch follow-through and stretch recovery, and shrinkage suppression during the dyeing process. Furthermore, the fabric is less prone to shrinkage during the dyeing process, thus reducing the likelihood of wrinkles and maintaining aesthetic appeal.

[0027] Regarding the number of filaments of the polyether ester elastic fiber in this embodiment, there are no particular limitations as long as the desired effect of the present invention is not lost. From the viewpoint of suppressing the unevenness of physical properties or fineness between filaments and maintaining the bundled nature of filaments in the dyeing process, it is preferred to be 1 or more and 60 or less, and more preferably 1 or more and 20 or less.

[0028] In the polyether ester elastic fiber of this embodiment, from the viewpoint of fully achieving the effects of improved stretch recovery and improved stretch resistance during elongation recovery, as well as the suppression of property degradation and shrinkage during the dyeing process, the phase separation index measured by a small-angle X-ray scattering device is preferably 0.20 or higher and 0.65 or lower. By making the phase separation index measured by the small-angle X-ray scattering device 0.20 or higher, the composition ratio of the phase mixture between the soft segment region and the hard segment region can be reduced, and the composition ratio between the hard segment region and the soft segment region can be increased. When the polyether ester elastic fiber recovers its elongation, the functions of the hard segment region and the soft segment region can be fully utilized, thus satisfying the requirements for stretch recovery and stretch resistance. Furthermore, the composition ratio of the phase mixture between the soft segment region and the hard segment region, which is prone to changes in the phase separation structure during the dyeing process, is lower. Therefore, structural changes during the application of heat can be reduced during the dyeing process, thus satisfying the effects of property degradation and shrinkage suppression during the dyeing process. Furthermore, the fabric is less prone to shrinkage during the dyeing process, thus reducing wrinkles and enhancing aesthetics. The phase separation index, measured using a small-angle X-ray scattering device, is preferably above 0.25.

[0029] On the other hand, if the phase separation index measured using a small-angle X-ray scattering device exceeds 0.65, then during the elongation recovery of the polyether ester elastic fiber, the elongation stress is concentrated in the hard chain segment region, thus increasing the elongation stress and deteriorating the stretch recovery performance. Furthermore, the phase separation structure of the polyether ester elastic fiber is highly developed, so when the structure of the hard chain segment region is damaged due to elongation recovery, the impact of the change on the phase separation structure increases, and the structure will not return to its original state during recovery, thus deteriorating the stretch recovery performance. The phase separation index measured using a small-angle X-ray scattering device is preferably 0.55 or less.

[0030] In the polyether ester elastic fiber of this embodiment, from the viewpoint of fully combining the effects of improved stretch recovery and improved stretch recovery, as well as the suppression of physical property reduction and shrinkage during the dyeing and processing steps, the alignment index of the fiber axis direction of the hard segment region measured by Raman spectroscopy is preferably 10.00 or less. Furthermore, the alignment index of the fiber axis direction of the hard segment region is calculated by connecting 1550 cm⁻¹ and 1650 cm⁻¹ with a straight line for the parallel scattering spectrum and the perpendicular scattering spectrum, respectively, and the area enclosed by the Raman spectrum is calculated. It refers to the area of ​​the parallel scattering spectrum / the area of ​​the perpendicular scattering spectrum, and details will be explained later. By ensuring that the fiber axis alignment index of the hard segment region, measured by Raman spectroscopy, is below 10.00, the proportion of elongation stress applied to the hard segment region during elongation recovery can be reduced, thereby suppressing damage to the hard segment region. This satisfies the stretching and shrinkage recovery properties of the polyether ester elastic fiber. Furthermore, a lower fiber axis alignment in the hard segment region reduces structural relaxation even when heat is applied during dyeing, achieving the desired reduction in physical properties and shrinkage suppression during dyeing, while also maintaining the fabric's aesthetic appeal. Preferably, the fiber axis alignment index of the hard segment region, measured by Raman spectroscopy, is below 9.00, and more preferably below 8.00.

[0031] On the other hand, the alignment index of the fiber axis direction of the hard segment region of the polyether ester elastic fiber, measured by Raman spectroscopy, is preferably 5.00 or higher. If the alignment index of the fiber axis direction of the hard segment region measured by Raman spectroscopy is less than 5.00, the alignment index of the fiber axis direction of each hard segment region is low. Therefore, during elongation recovery, the hard segment region cannot function sufficiently as a crosslinking point, resulting in deterioration of stretch following and stretch recovery. Furthermore, the low alignment index of the fiber axis direction of the hard segment region of the polyether ester elastic fiber leads to structural relaxation when heat is applied during the dyeing process, resulting in a decrease in physical properties during the dyeing process. The alignment index of the fiber axis direction of the hard segment region measured by Raman spectroscopy is preferably 6.00 or higher, and more preferably 6.50 or higher.

[0032] In the polyether ester elastic fiber of the present invention, from the viewpoint of further improving the stretch recovery and elasticity improvement during elongation recovery, and the suppression of property degradation and shrinkage during the dyeing process, the specific viscosity is preferably 2.00 dL / g or higher, more preferably 3.00 dL / g or higher. By setting the specific viscosity to 2.00 dL / g or higher, molecular mobility can be reduced, thus making it less likely to cause damage to the hard chain segment regions during elongation recovery, thereby improving the stretch recovery and elasticity improvement during elongation recovery. Furthermore, with lower molecular mobility, even if heat is applied during the dyeing process, the structure of the hard chain segment regions is less likely to loosen, thus suppressing property degradation and shrinkage during the dyeing process. Furthermore, the fabric is less likely to shrink during the dyeing process, thus reducing the likelihood of wrinkles and improving aesthetics. On the other hand, there is no particular upper limit to the specific viscosity of polyether ester elastic fibers, but it is practically difficult to exceed 6.00 dL / g, and preferably below 5.00 dL / g. Polyether ester elastic fibers with a specific viscosity of below 6.00 dL / g can control the orientation of the soft segment region to a lower degree, thus improving the stretch recovery and shrinkage inhibition during dyeing and processing.

[0033] In the polyether ester elastic fiber of this embodiment, from the viewpoint of further improving the stretch recovery and elongation follow-through, and the effects of reducing physical properties and inhibiting shrinkage during the dyeing process, the alignment index of the fiber axis direction of the mixed portion of the soft segment region and the hard segment region, measured by Raman spectroscopy, is preferably 2.50 or more and 5.00 or less, more preferably 3.00 or more and 4.50 or less, and even more preferably 3.50 or more and 4.30 or less. Furthermore, the alignment index of the fiber axis direction of the mixed portion of the soft segment region and the hard segment region is calculated for parallel scattering and perpendicular scattering spectra, with respect to the line connecting 1650 cm⁻¹ and 1810 cm⁻¹, and a perpendicular line drawn from 1720 cm⁻¹, respectively. The area enclosed by the Raman spectrum on the low wavenumber side and the line and the perpendicular line is calculated, which refers to the area of ​​the parallel scattering spectrum / the area of ​​the perpendicular scattering spectrum. Details will be explained later. By achieving an alignment index of 2.50 or higher along the fiber axis in the mixed portion of the soft and hard segment regions, as measured by Raman spectroscopy, the hard and soft segment regions readily function as crosslinking points and stretching sites during elongation recovery, thus further enhancing stretch tracking and recovery properties. Furthermore, since a portion of the mixed portion of the soft and hard segment regions is aligned along the fiber axis, the degree of relaxation during heat application in the dyeing process is less, further improving the suppression of property degradation and shrinkage during dyeing. Consequently, the fabric is less prone to shrinkage during dyeing, reducing wrinkles and enhancing aesthetics. Furthermore, by achieving a lower alignment index (below 5.00) in the fiber axis direction of the mixed portion of the soft and hard segment regions, as measured by Raman spectroscopy, the fiber axis movement towards the mixed portion of the soft and hard segment regions becomes easier during elongation recovery. This suppresses damage to the mixed portion of the soft and hard segment regions, thus further improving the stretch follow-through and stretch recovery properties of the polyether ester elastic fiber during elongation recovery. Moreover, the lower alignment degree of the mixed portion results in less relaxation when heat is applied during the dyeing process, further suppressing the degradation of physical properties and shrinkage during the dyeing process, and further enhancing the fabric's aesthetic appeal.

[0034] In the polyether ester elastic fiber of this embodiment, from the viewpoint of further improving the stretch recovery and elongation follow-through, and the effects of reducing physical properties and inhibiting shrinkage during the dyeing process, the alignment index of the fiber axis direction of the soft segment region measured by Raman spectroscopy is preferably 1.50 or more and 4.00 or less, more preferably 2.00 or more and 3.50 or less, and even more preferably 2.50 or more and 3.30 or less. Furthermore, the alignment index of the fiber axis direction of the soft segment region is calculated for parallel scattering and perpendicular scattering spectra, with respect to the line connecting 1650 cm⁻¹ and 1810 cm⁻¹, and a perpendicular line drawn from 1720 cm⁻¹, by calculating the area enclosed by the Raman spectrum on the high wavenumber side and the line and perpendicular line, respectively. It refers to the area of ​​the parallel scattering spectrum / the area of ​​the perpendicular scattering spectrum, and details will be explained later. By achieving an alignment index of 1.50 or higher in the fiber axis direction of the soft segment region, as measured by Raman spectroscopy, the soft segment region readily functions as a stretching component during elongation recovery, further enhancing stretch tracking and recovery properties. Furthermore, since a portion of the soft segment region is aligned along the fiber axis, the degree of relaxation during heat application in the dyeing process is less, thus further improving the suppression of property degradation and shrinkage during dyeing, and enhancing the fabric's aesthetic appeal. Conversely, by achieving a lower alignment index (below 4.00) in the fiber axis direction of the soft segment region, movement towards the fiber axis direction during elongation recovery becomes easier, suppressing damage to the soft segment region, thereby further improving the stretch tracking and recovery properties of polyether ester elastic fibers during elongation recovery. Furthermore, the lower alignment of the fiber axis results in less relaxation when heat is applied during the dyeing process, thus further suppressing the reduction of physical properties and shrinkage during the dyeing process, and further enhancing the aesthetic appeal of the fabric.

[0035] The polyether ester elastic fiber of this embodiment can further improve the aesthetic appeal of the fabric by having a certain amount of fineness unevenness in the yarn length direction. The fineness unevenness in the yarn length direction of the polyether ester elastic fiber is preferably 3.00% to 11.50%, more preferably 3.50% to 11.00%, and even more preferably 4.00% to 10.50%. By ensuring that the fineness unevenness of the polyether ester elastic fiber is 3.00% or more, during knitting or weaving, the unevenness in the shape of the polyether ester elastic fiber causes a wider dispersion of the degree of blockage or mesh in the fabric structure, thereby improving the overall aesthetic appeal. On the other hand, if the fineness unevenness in the yarn length direction exceeds 11.50%, the tension variation during knitting or weaving is greater, and local blockage or mesh is more likely to occur in the fabric structure. This becomes more pronounced during the dyeing process, thus impairing the fabric's aesthetic appeal.

[0036] The polyether ester elastic fiber of this embodiment can further enhance the aesthetic appeal of the fabric due to the strain within a certain range of the single yarn cross-sectional shape. The diameters of the circumscribed circle (minimum diameter) and the inscribed circle (maximum diameter) completely encompassing the polyether ester elastic fiber cross-section are measured. The ratio of these diameters, i.e., the ratio of circumscribed circle diameter to inscribed circle diameter, is preferably 1.006 to 1.100, more preferably 1.008 to 1.090, and even more preferably 1.010 to 1.080. By setting the ratio of circumscribed circle diameter to inscribed circle diameter to 1.006 or higher, when using polyether ester elastic fiber for knitting or weaving, the uneven cross-sectional shape causes uneven morphology of the polyether ester elastic fiber, which can more widely disperse the degree of blockage or mesh in the fabric structure, thereby enhancing the aesthetic appeal of the fabric. On the other hand, if the ratio of the circumscribed circle diameter to the inscribed circle diameter exceeds 1.100, it becomes difficult to stably transfer the fabric onto the needles during knitting, thus making it impossible to uniformly form the loop structure of the fabric and damaging its aesthetic appeal.

[0037] The polyether ester elastic fiber of this embodiment can further improve the aesthetic appeal of the fabric by minimizing stress changes during elongation. The ratio of stress at 200% elongation to stress at 150% elongation of the polyether ester elastic fiber is preferably 1.06 to 1.40, more preferably 1.08 to 1.35, and even more preferably 1.10 to 1.30. By making the ratio of stress at 200% elongation to stress at 150% elongation 1.06 or higher, uneven fiber elongation is less likely to occur during the elongation-stretch ratio when the fabric is knitted, resulting in a more uniform yarn structure and thus improving the fabric's aesthetic appeal. On the other hand, if the ratio of stress at 200% elongation to stress at 150% elongation exceeds 1.40, the migration stress and elongation of the polyether ester elastic fibers will easily become uneven when the fibers are knitted or woven, which will easily cause blockage or mesh in the fabric structure and damage the aesthetics of the fabric.

[0038] The manufacturing method of the polyether ester elastic fiber in this embodiment is not particularly limited. The following describes a melt-spun sample. The polyether ester elastic system used as the raw material for the polyether ester elastic fiber is a polyether ester elastomer composed of dicarboxylic acid units, polymeric polyols, and low molecular weight diols in a molar ratio preferably of 1.00:0.05 to 0.40:0.60 to 0.95, more preferably 1.00:0.10 to 0.30:0.70 to 0.90.

[0039] To prevent thermal degradation of the polymer during the spinning process and coloring when using polyether ester elastic fibers, known additives such as hindered phenolic oxidation stabilizers, hindered amine oxidation stabilizers, phosphorus oxidation stabilizers, sulfur oxidation stabilizers, and triazole light stabilizers can be added to the polyether ester elastomer used as a raw material for polyether ester elastic fibers. One of these additives can be used alone, or two or more can be used in combination.

[0040] Furthermore, as long as the polyether ester elastic fiber does not lose the desired effect, it may contain polymers or additives other than polyether ester elastomers, such as gas-induced color change inhibitors, dyes, matting agents, crystal nucleating agents, lubricants, etc.

[0041] As a nucleating agent for crystallization, known agents can be used, such as: organic nucleating agents such as sodium, potassium, and lithium salts of aliphatic, alicyclic, or aromatic carboxylic acids with 3 to 40 carbon atoms, or inorganic nucleating agents such as talc, calcium carbonate, titanium dioxide, magnesium oxide, calcium sulfate, barium sulfate, and sodium silicate. The amount of nucleating agent added relative to polyether ester elastic fibers can be set to 0.01 parts by weight or less and 10 parts by weight.

[0042] Regarding the melt spinning method, there are no particular restrictions as long as the desired physical properties can be obtained. For example, fragments of polyether ester elastomer are fed into an extruder, heated and melted, metered by a gear pump and introduced into the spinning head. If necessary, metal wire mesh or glass beads are used to filter in the spinning head to remove foreign matter. After being ejected from the die, it is cooled by air in a cold air chamber and treated with a treatment agent. Then, it is wound up at a fixed speed by a winding machine via a guide roller.

[0043] From the viewpoint of suppressing hydrolysis in the extruder or spinning head, the polyether ester elastomer fragments fed into the extruder are preferably dried to a moisture content of less than 300 ppm using a dryer.

[0044] In the polyether ester elastic fiber of this embodiment, the total fineness can be adjusted by adjusting the balance between the amount of polymer ejected from the die during spinning and the winding speed of the winding machine.

[0045] The unevenness of the single yarn profile or fineness can be controlled by the following methods: using a non-circular spinning nozzle as the spinning nozzle shape used in melt spinning and increasing the diameter to generate tensile resonance; increasing the output to generate a sharkskin-like or melt fracture method; changing the cooling intensity in the spinning step to cause yarn oscillation, etc.

[0046] In the melt spinning step, the extrusion temperature, cold air velocity, cold air temperature, and spinning speed are adjusted to tightly control the fiber temperature distribution and spinning tension. The die temperature is preferably 180°C to 280°C, more preferably 200°C to 260°C. A common melt spinning cooling method is used, such as blowing cold air perpendicularly from directly below the spinning nozzle relative to the yarn movement direction. The cold air velocity is preferably 0.2 m / s to 3.0 m / s, more preferably 0.5 m / s to 1.5 m / s, and the cold air temperature is preferably 5°C to 25°C, more preferably 7°C to 20°C.

[0047] In the polyether ester elastic fiber of this embodiment, in the method of increasing the temperature at which the polyether ester elastomer is ejected from the die during spinning, the method of adding a nucleating agent to promote the formation of a microphase separation structure, and the method of extending the distance from the die to the winding machine, by promoting the formation of a microphase separation structure of the polyether ester elastic fiber or adjusting the applied thermal history, it is easy to make the phase separation index before and after elongation recovery, as measured by a small-angle X-ray scattering device, 0.20 or more and 0.65 or less.

[0048] In the polyether ester elastane of this embodiment, it becomes easy to control the alignment of the hard chain segment region, the soft chain segment region, the phase mixing portion of the soft chain segment region, and the hard chain segment region by providing a heating cylinder under the die nozzle to insulate the thread during the spinning step, or by strictly controlling the cold air temperature and speed. In polyether ester elastic fibers, the method of substantially reducing the cooling speed of the yarn directly below the die by keeping the temperature of the yarn at a point 10 cm directly below the die nozzle above 70°C, more preferably above 80°C, and further preferably above 90°C, and optimally above 100°C during the spinning step, is easy to make the 5.0 Furthermore, by strictly controlling the cold air temperature and speed from 10 cm to 50 cm below the die nozzle during the spinning step, and keeping the temperature of the yarn 50 cm below the die nozzle above 40°C, preferably above 45°C, and optimally above 50°C, it is easy to make the fiber axis measured above 5.50 Further, by strictly controlling the cold air temperature and speed from 50 cm to 100 cm below the die nozzle during the spinning step, and slow-cooling the temperature of the yarn 100 cm below the die nozzle to above 30°C, preferably above 35°C, and optimally above 40°C, it is easy to make the alignment index above 4.050 in the axial direction of the fibers measured using Raman spectroscopy. Also, in terms of the view that the temperature of the thread at the point 10 cm, the point at 50 cm, and the point at 100 cm directly below the die mouth is stably controlled in the above range by means of a heating cylinder or cold air temperature and speed during the spinning step, the curling speed of the winding machine is preferably set below 2000 m / min, preferably below 1500 m / min, and optimally below 1000 m / min.

[0049] In the polyether ester elastomer fiber of this embodiment, in the case of complex filaments with a filament number of 2 or more, the following method may be used in order to improve the clustering property: A dummy jig machine is set up between the die nozzle and the guide roller to propagate the filament from the lower part using the strength and weakness of the filament, so that the filaments cluster with each other and control the height of their cluster points. Methods of dummy A general method may be selected by using an air dummy utilizing a gas nozzle, or a ring dummy machine in contact with a rotating ring.

[0050] In the polyether ester elastic fiber of this embodiment, from the viewpoint of improving flexibility and processability, a treatment agent such as an oil can be applied to the polyether ester elastic fiber. The treatment agent is not limited to the following, but examples include: silicone-based oils such as dimethyl silicone, mineral oil-based oils, and combinations thereof. The coating method of the treatment agent is not particularly limited; for example, a coating method using an oiling roller can be used. The amount of treatment agent adhering to the polyether ester elastic fiber is preferably 0.5 parts by weight to 10 parts by weight relative to the fiber weight.

[0051] Another embodiment of the present invention is a yarn roll, which is the yarn roll of the above-mentioned polyether ester elastic fiber.

[0052] Another embodiment of the present invention is a fabric comprising the aforementioned polyether ester elastic fiber as an elastic fiber. The fabric in this embodiment refers to all woven fabrics with various knitted structures, such as circular knitted fabrics, weft knitted fabrics, and warp knitted fabrics, as well as woven fabrics, including both elastic and non-elastic fibers. As non-elastic fibers, all fibers can be used, including synthetic fibers such as polyamide fibers, polyester fibers, polypropylene, and acrylic fibers, cellulose fibers such as cupro rayon, rayon, cotton, and bamboo fiber, and animal hair fibers such as wool.

[0053] Furthermore, examples of knitted structures that can be used in weft-knitted fabrics include basic plain knit structures, tuck structures, float structures, semi-rib knit structures, lace mesh structures, yarn-padded structures, and jacquard structures. Examples of knitted structures that can be used in warp-knitted fabrics include basic structures such as chain knit structures, warp plain knit structures, warp pile structures, warp-knitted satin structures, and interlining structures, as well as variations obtained by combining these. When alternating between various fibers and the polyether ester elastic fiber of the present invention, the polyether ester elastic fiber can be knitted into the entire surface, or knitted into the required intervals, or even inserted.

[0054] In the knitting of circular knitted fabrics, knitting machines equipped with multiple yarn feeders capable of simultaneously feeding multiple yarns can be used, such as a typical circular single-jersey knitting machine with a single needle bed and a typical circular double-jersey knitting machine with a double needle bed. The machine size is typically from 5 to 50, and can be appropriately selected based on the intended use. In the knitting of weft-knitted fabrics, weft knitting machines such as large weft knitting machines, small weft knitting machines, flat double-sided knitting machines, double rib knitting machines, jacquard machines, single-needle machines, and double-needle machines can be used. The machine size is typically from 3 to 50, and can be appropriately selected based on the intended use.

[0055] In the knitting of warp-knitted fabrics, a warping step is performed using a Karl Mayer warping machine, a River warping machine, etc., to prepare the required number of polyether ester elastic fibers and / or coated polyether ester elastic fibers corresponding to the target product and wind them onto a warp beam. Subsequently, the warp beam of polyether ester elastic fibers and / or coated polyether ester elastic fibers is set on the knitting machine described later, and knitting is performed to obtain the desired warp-knitted fabric.

[0056] In the knitting of warp-knitted fabrics, Tricot warp knitting machines, Raschel warp knitting machines, and double-needle-bed Raschel warp knitting machines can be used. The appropriate machine should be selected based on the denier of the yarn used and the target product, along with the denier, machine type, and machine size. As for the knitting structure, the aforementioned basic knitting structures and variations thereof can be used. On a Tricot warp knitting machine, the desired warp-knitted fabric can be obtained using a two-reed structure (warp-pile plain weave, satin weave, jacquard weave, or variations thereof). On a Raschel warp knitting machine and a double-needle-bed Raschel warp knitting machine, the desired warp-knitted fabric can be obtained using an elastic mesh weave, satin mesh weave, jacquard weave, etc. Both Tricot and Raschel warp knitting machines can utilize three or more reed structures for knitting. The machine size is typically between 10 and 50; the appropriate size should be selected based on the intended use.

[0057] As a woven fabric, examples include woven fabrics obtained by weaving one or more of the following using conventional methods: natural fibers such as cotton and linen; regenerated cellulose fibers such as viscose rayon, cuprammonium rayon (product name Cupro), and specific cellulose fibers (trade name Tencel); and synthetic fibers such as polyester, polyamide, and PVA. The yarn arrangement method can be a commonly known method, as long as the arrangement method is appropriately determined according to the weave and density. Furthermore, previously known shuttle looms can be used in the weaving process, such as water-jet looms, air-jet looms, and rapier looms.

[0058] Another embodiment of the present invention is a garment fabric comprising the aforementioned polyether ester elastic fiber as an elastic fiber. In the fabric used in this embodiment, a general dyeing process can be applied, which involves opening the knitted fabric, performing a relaxation treatment, and then dyeing and finalizing the fabric, including resin processing. When it is desired to fix the shape before dyeing, pre-forming can be performed using dry heat within a temperature range below that of the polyether ester elastic fiber. Furthermore, the dyeing process can be performed using devices such as a Wenki dyeing machine, a roll dyeing machine, a beam dyeing machine, or a liquid flow dyeing machine, and can be carried out in either a batch or continuous manner. In addition to immersion dyeing, pad dyeing and printing methods can also be used. Regarding dyeing conditions, any commonly used dyeing conditions can be applied. The type and concentration of dyeing auxiliaries, dyeing pH value, dyeing liquor ratio, and dyeing time can be appropriately set considering the type of product being dyed, the processing equipment used, and the dyeing method. For example, when dyeing fabrics made from a blend of polyester and polyether ester elastic fibers, disperse dyes can be used. After dyeing at 135°C or below for 20 to 120 minutes, the dyeing process can be followed by a post-dyeing treatment. Alternatively, reducing agents such as sodium bisulfite and thiourea dioxide, as well as alkaline agents such as alkali metal hydroxides such as sodium hydroxide, alkaline earth metal hydroxides such as calcium hydroxide, alkali metal phosphates such as disodium hydrogen phosphate, and alkali metal carbonates such as sodium carbonate, can be used for reduction cleaning.

[0059] The clothing in this embodiment includes all kinds of clothing, such as: underwear, tops, women's short underwear, long slips, women's tight-fitting panties, briefs, sports pants, close-fitting shirts, corsets, bras, shoe covers, waistbands, pantyhose, tights, socks and other underwear; swimwear, training clothes, rhythmic clothing, ski suits, various competitive sportswear, outdoor clothing and other sportswear; T-shirts, jackets, sweaters, vests, shorts, skirts, knitwear, coats, work clothes and other outerwear; gloves, hats, scarves and other clothing accessories; pajamas, robes and other sleepwear; nursing clothing, etc., but not limited to these.

[0060] The polyether ester elastic fiber of this embodiment has good resilience and heat resistance, resulting in fewer fiber breaks during dyeing and processing. It also has high stretch recovery, thus enabling the manufacture of fabrics and clothing that provide a comfortable fit when worn. [Example]

[0061] The present invention will be described more specifically through the following embodiments and comparative examples, but the scope of the present invention is not limited to the embodiments. First, the evaluation method used in the following embodiments will be described.

[0062] <Test Method and Evaluation Method> <Determination of Fineness> The polyether ester elastic fiber is fed 50 m from the yarn package of the polyether ester elastic fiber using a feed roller while maintaining elongation, and then unwound. The weight (g) of the unwound yarn is measured. The fineness (dtex) of the polyether ester elastic fiber is calculated using the following formula: Fineness (dtex) = Total weight of unwound yarn (g) × 10000 / 50 (m).

[0063] <Determination of Small Angle X-ray Scattering (SAXS)> [Determination of Phase Separation Index] A test yarn is held in a metal frame with one side movable, allowing the yarn length to change freely, and is maintained at 10 mm intervals. This is defined as the state of the test yarn before elongation. Next, with the test yarn held at the metal frame at 10 mm before elongation reduced to 30 mm, one side of the metal frame is moved at a speed of 1000 mm / min and fixed, and left to stand for 30 minutes. Subsequently, with the test yarn reduced to 10 mm, one side of the metal frame is moved at a speed of 1000 mm / min and fixed, and left to stand for 30 minutes. When the test yarn relaxes due to elongation and becomes 10 mm longer than its initial length, one side of the metal frame is moved and fixed to the minimum length that does not relax. This is defined as the state of the test yarn after elongation recovery. The SAXS before elongation and after elongation recovery is measured under the following conditions, and the phase separation index is quantified in the following manner. [SAXS Measurement Conditions] The sample stage was set with the fiber axis of the polyether ester elastic fiber horizontal. The fiber was irradiated with X-rays perpendicularly, and measurements were performed using SAXS under the following conditions: Measurement Apparatus: NANOPIX, Rigaku Inc. Incident X-ray wavelength λ: 0.154 nm Detector: Two-dimensional detector "Hypix-6000" Measurement Time: 15 minutes Camera Length: 1312 mm Optical System: Point Collimation: First slit: 1.40 mmϕ, Guard slit: 0.85 mmϕ High-flux mode beam blocker: 4 mmϕ

[0064] The 12-point direction of the two-dimensional SAXS pattern I(2θ, ϕ) obtained by the two-dimensional detector is 0°. The azimuth angle ϕ is located in the clockwise direction, and the average scattering intensity I of the fan shape is calculated using the following formula (1): [Equation 1] {where ϕs: -10°, ϕe: 10°, θ: Bragg angle}.

[0065] For the obtained fan-shaped average scattering intensity I, the following formula (2) is used: [Equation 2] Formula (2) {where Ic(2θ): scattering intensity corrected by empty cell, Isample(2θ): scattering intensity of sample, Iempt(2θ): scattering intensity of empty cell, tsample: measurement time of sample, tempt: measurement time of empty cell, T: transmittance, C: device constant}, empty cell scattering correction is performed to calculate the one-dimensional scattering intensity Ic.

[0066] In the SAXS distribution, the absolute value q of the scattering vector is obtained using the following equation (3): [Equation 3] Equation (3) {where θ: Bragg angle, λ: incident X-ray wavelength}. Then, the Q value is obtained using the following equation (4): [Equation 4] Equation (4) {where q1: 0.20 nm-1, q2 = 1.00 nm-1}. Then, the phase separation index is calculated using the following equation (5): [Equation 5] Equation (5).

[0067] <Determination of Raman Spectroscopy> [Determination of Orientation Index] The test yarn is held in a metal frame that is movable on one side and allows the yarn length to change freely, and is held at 10 mm intervals. Next, the test yarn, before elongation, is held at 10 mm in the metal frame to 20 mm, one side of the metal frame is moved at a speed of 1000 mm / min and fixed, and left to stand for 30 minutes. Then, Raman spectroscopy is measured under the following conditions: the Raman spectrum measured by incident linearly polarized light parallel to the fiber axis is set as the parallel scattering spectrum, and the Raman spectrum measured by rotating the sample 90° and incident linearly polarized light perpendicular to the fiber axis is set as the perpendicular scattering spectrum. [Raman Spectroscopy Measurement Conditions] The polyether ester elastic fiber is placed on the sample stage, and Raman spectroscopy is performed under the following conditions. Measurement Apparatus: Horiba Manufacturing Co., Ltd. XploRA; Excitation Wavelength: 532 nm; Objective Lens: 10x; Exposure Time: 8 seconds; Number of Exposures: 4; Diffraction Grating: 2400 l / mm; Incident Polarized Light: Linear Polarization; Disc: Parallel Polarization Configuration

[0068] [Orientation index of fiber axis direction in hard chain segment region] For parallel scattering spectrum and perpendicular scattering spectrum, connect 1550 cm-1 and 1650 cm-1 with a straight line, calculate the area of ​​the part enclosed by the Raman spectrum, and set the area of ​​parallel scattering spectrum / area of ​​perpendicular scattering spectrum as the orientation index of fiber axis direction in hard chain segment region.

[0069] [Orientation index of fiber axis direction in the mixed portion of soft and hard segment regions] For parallel scattering and perpendicular scattering spectra, for the straight line connecting 1650 cm⁻¹ and 1810 cm⁻¹, draw a perpendicular line from 1720 cm⁻¹, and calculate the area enclosed by the Raman spectrum on the low wavenumber side, the straight line, and the perpendicular line, respectively. The area of ​​the parallel scattering spectrum / the area of ​​the perpendicular scattering spectrum is set as the orientation index of fiber axis direction in the mixed portion of soft and hard segment regions.

[0070] [Orientation index of fiber axis direction in soft chain segment region] For parallel scattering spectrum and perpendicular scattering spectrum, for the straight line connecting 1650 cm-1 and 1810 cm-1, draw a perpendicular line from 1720 cm-1, calculate the area enclosed by the Raman spectrum on the high wavenumber side and the straight line and perpendicular line respectively, and set the area of ​​parallel scattering spectrum / area of ​​perpendicular scattering spectrum as the orientation index of fiber axis direction in soft chain segment region.

[0071] <NMR Determination> [Qualitative and Quantitative Analysis of Low Molecular Weight Diols and Polymer Polyols] A specified amount of polyether ester elastic fiber, dried at 80°C for 5 hours under a vacuum of -0.1 MPa, was measured. The NMR was determined under the following conditions to qualitatively and quantitatively analyze the low molecular weight diols and polymer polyols. [NMR Determination Conditions] Measuring Apparatus: JEOL ECS400 Detection Nucleus: 1H Resonance Frequency: 400 MHz Number of Cycles: 256 Measurement Temperature: Room Temperature Solvent: Deuterated Chloroform Detection Concentration: 1.5% by Weight Chemical Shift Standard: Tetramethylsilane (0 ppm)

[0072] <Determination of specific viscosity> Accurately weigh about 1 g of polyether ester elastic fiber, place the accurately weighed yarn into a container containing 50 ml of petroleum ether, apply ultrasound for 5 minutes, discard the petroleum ether in the container, and dry at 80°C for 5 hours to remove the treatment agent from the polyether ester elastic fiber. Dissolve 0.3500 g of the polyether ester elastic fiber after removing the treatment agent in 40.0000 g of HFIP (1,1,1,3,3,3-hexafluoroisopropanol) to prepare a solution of 1.39 g / dL. Use an Ubbelohde viscometer to measure the batch flow time t (seconds) of the solution at 25.0°C. At this time, if the batch flow time of the solvent is set as t0 (seconds), the specific viscosity ηsp / c (dL / g) is calculated by the following formula (6): [Equation 6] Formula (6)

[0073] <Evaluation Method for Stretch Follow-up> Using a tensile testing machine (Orientec RTG-1210 Tensilon), at 20°C and 65% relative humidity, with the clamp distance set to 50 mm, repeated elongation tests from 0% to 200% were performed on a test yarn with a sample length of 50 mm at a speed of 500 mm / min. The stress during elongation was set as the S-modulus, and the stress during shrinkage was set as the R-modulus. The R-modulus was calculated using the following formula from the S-modulus and R-modulus of the third repeated test at 150% elongation: R / S (%) = S-modulus of the third repeated test at 150% elongation (cN) / R-modulus of the third repeated test at 150% elongation (cN) × 100 (%). The ratio of R-modulus to S-modulus is then obtained, i.e., R / S. For each test yarn, five measurements were performed, showing that the higher the average R / S ratio, the better the stretch follower properties of the polyether ester elastic fiber. In this invention, regarding the stretch follower properties of the polyether ester elastic fiber, a higher R / S ratio is better, preferably 63% or higher, more preferably 65% ​​or higher, more preferably 67% or higher, more preferably 69% or higher, and even more preferably 71% or higher, and most preferably 73% or higher.

[0074] <Evaluation Method for Stretch Recovery> Using a tensile testing machine (Orientec RTG-1210 Tensilon), at 20°C and 65% relative humidity, with a clamp distance of 50 mm, repeated elongation tests from 0% to 200% were performed on a test yarn with a sample length of 50 mm at a speed of 500 mm / min. The stress during elongation was set as the S-modulus, and the stress during shrinkage was set as the R-modulus. The recovery rate was calculated using the following formula: Recovery rate (%) = (200 - Elongation rate with R-modulus of 0 (cN) in the third repeated test) / 200 (%) × 100 (%). For each test yarn, five measurements were performed, and the average recovery rate was used to evaluate the stretch recovery. In this invention, regarding the stretch recovery of polyether ester elastic fibers, the higher the recovery rate, the better, preferably 80% or more, more preferably 82% or more, more preferably 84% or more, more preferably 86% or more, and even more preferably 88% or more, and most preferably 90% or more.

[0075] <Evaluation Method for Property Degradation During Dyeing Process> A test yarn is held in a metal frame with one side movable, allowing for free variation in yarn length, and held at 50 mm intervals. Markings are made at the 50 mm intervals between the held yarns to indicate the initial length of the test yarn. Next, one side of the metal frame is moved and fixed so that the test yarn held at 50 mm becomes 75 mm. Each metal frame is then subjected to a 30-minute hot water treatment at 130°C using a high-temperature, high-pressure dyeing machine (Orientec, Inc., Japan). After removing the metal frame from the high-temperature, high-pressure dyeing machine, one side of the metal frame is moved and fixed so that the test yarn becomes 50 mm, and the test yarn is removed. Due to the heat, the intervals between the marks at the initial 50 mm length of the removed test yarn are longer than 50 mm. Subsequently, at the marked positions before heat treatment, test yarns were mounted on a tensile testing machine (Orientec RTG-1210 Tensilon, with a clamping distance of 50 mm) and subjected to repeated elongation tests ranging from 0% to 200% at a speed of 500 mm / min under conditions of 20°C and 65% relative humidity. The 200% S-modulus of the first repeated test was measured. The 200% S-modulus after heat treatment, relative to the 200% S-modulus of the untreated test yarn, is called the heat treatment retention rate, serving as an indicator of the decrease in physical properties during the dyeing process. This shows that the higher the heat treatment retention rate, the less the physical properties of the polyether ester elastic fiber decrease during the dyeing process. For each test yarn, five heat treatments were performed, and the 200% R-modulus of the heat-treated test yarn was measured, with the average value used. In this invention, the higher the stress retention rate during the dyeing process of polyether ester elastic fibers, the better, preferably 89% or more, more preferably 94% or more, more preferably 100% or more, more preferably 104% or more, and even more preferably 109% or more, and most preferably 115% or more.

[0076] <Method for evaluating shrinkage during dyeing process> The test yarn is held in a metal frame that is movable on one side and allows the yarn length to change freely, and is held at 100 mm intervals. At this time, a mark is pre-marked at the 100 mm interval of the held yarn, which is taken as the initial length of the test yarn. Next, one side of the metal frame is moved and fixed so that the test yarn held in the metal frame at 100 mm becomes 50 mm. Using a high temperature and high pressure dyeing machine (Orientec (co.k.) of Japan), each metal frame is directly subjected to hot water treatment at 130°C for 30 minutes. Afterwards, the width of the metal frame is increased, and the width of the part where the relaxation of the test yarn disappears is recorded and denoted as L. At this time, the shrinkage rate is calculated using the following formula: Shrinkage rate (%) = 100 × (100 - L) / 100. In this invention, regarding the shrinkage during the dyeing process of polyether ester elastic fibers, the lower the shrinkage rate, the better. Preferably, it is below 22%, more preferably below 20%, more preferably below 18%, more preferably below 16%, and even more preferably below 14%, and most preferably below 12%.

[0077] <Method for Evaluation of Aesthetics of Fabric> [Knitting of embryo fabrics and dyeing processing of fabrics] Using a circular knitting machine of 28 G, the pseudo-pin filament and polyether ester elastane obtained by sham processing of a circular section polyester yarn of 84 dtex36 f were knitted to obtain a flat needle braid of 84% polyester and 16% polyurethane elastane. After refined relaxation of the blended braid at unfolded, 90°C, it was predetermined at 140°C under the dyeing conditions described below. [Dyeing conditions] Dye: CI dispersion blue 167 (benzene azo-based disperse dye) 7% owf dispersion homogenizer: NIKKA SUNSALT RM-340 (manufactured by Nikka Chemical Industries [Stock]) 0.5 g / liter Acetic acid: 0.5 cc / liter Sodium acetate: 1 g / liter Bath ratio: 1:20 Time Dyeing temperature, 3:20 30°C, 30°C. After the staining was completed, the autostaining machine drained the staining residue and added water to the staining machine to raise the temperature to 90°C. Under the following reducing cleaning conditions, a reduction cleaning bath at the following concentration was prepared by adding the following agents to it. [Reduction Cleaning Conditions] Thiourea dioxide: 2 g / L Caustic Sodium: 1 g / L Sunmol RC-700 (non-ionic cleaner; manufactured by Nikko Chemical Industries [Stock]): 0.5 g / L Bath ratio: 1:30. The reduction was cleaned, the residual liquid was drained, and the stain was adequately rinsed using hot water and water before final processing at a dry heat setting of 140°C for 30 seconds. [Assessment of Aesthetics of Fabric] The evaluation of the appearance of the braid is based on the evaluation benchmarks of the 5 grades described below, judged by 5 persons by resorting to visual evaluation and expressed as their average value. Evaluated as good-looking braid within the range of 4 to 5 points and assessed as qualified. [Evaluation Benchmark] Class 5: Braids with very good appearance without defects in warp and latitude sections Class 4: Braids with almost no defects in warp and latitude sections Class 3: Braids with a less obvious appearance of defects in warp and latitude sections Class 2: Braids with a slightly pronounced appearance with defects in warp, latitude sections

[0078] Using a dehumidifying dryer, fragments of polyether ester elastomer containing terephthalic acid, PTMG with a number average molecular weight of 2000, and 1,4-butanediol in a molar ratio of 1.00:0.81:0.19 and a specific viscosity of 4.00 dL / g are dried to a moisture content of less than 100 ppm at a temperature of 80°C. Polyether ester elastomer resin is then fed into the hopper and melted in an extruder. Metering and pressurization are performed using a gear pump located at the head, and the mixture is filtered before being extruded at a nozzle temperature of 210°C through a 0.50 mm diameter, single-hole nozzle at a rate of 44 dtex. Subsequently, cold air is blown from a self-adjusting cold air chamber with adjustable cold air distance and velocity, and then blown vertically onto the fibers to cool the yarn and perform melt spinning. The cooling chambers utilize three independent cooling chambers that can strictly control the temperature and speed of the cooling air. These three cooling chambers are: Cooling Chamber 1 (10 cm below the die), Cooling Chamber 2 (50 cm below the die), and Cooling Chamber 3 (100 cm below the die), which strictly controls the temperature of the yarn at 10 cm, 50 cm, and 100 cm below the die and blows cold air onto the fiber. Subsequently, while being treated with a treatment agent mainly composed of polydimethylsiloxane, the yarn is wound onto a paper tube at a speed of 700 m / min via a first guide roller at a speed of 600 m / min and a second guide roller at a speed of 700 m / min, to obtain a 44 dtex / 1 filament polyether ester elastic fiber ray. The polyether ester elastic fiber has an R / S ratio of 75%, a recovery rate of 92%, a stress retention rate of 120%, a shrinkage rate of 10%, and an aesthetic grade of 5.

[0079] [Examples 2 and 3] The resin ejection rate of the polyether ester elastomer was adjusted, and the total fineness was changed. Otherwise, polyether ester elastic fibers were obtained in the same way as in Example 1.

[0080] [Examples 4-7] For the yarn body of polyether ester elastic fiber, the temperature was adjusted to be between 60°C and 130°C to adjust the phase separation index. Otherwise, polyether ester elastic fiber was obtained by the same method as in Example 1.

[0081] [Examples 8-14] By adjusting the temperature of the yarn, the temperature of the cold air and the speed in the spinning step, the temperature of the yarn at a point 10 cm directly below the die nozzle is adjusted, and the orientation index of the fiber axis direction in the hard chain segment region is changed. Otherwise, polyether ester elastic fibers are obtained by the same method as in Example 1.

[0082] [Examples 15-19] Polyether ester elastomers obtained by polymerizing a resin in which a portion of 1,4-butanediol, a low molecular weight diol, is replaced with 1,6-hexanediol were spun, otherwise polyether ester elastic fibers were obtained by the same method as in Example 1.

[0083] [Examples 20-23] Polyether ester elastomers obtained by polymerizing a polyether ester elastomer by changing one part of PTMG, which is a polyol, to polyethylene glycol (PEG) with a number average molecular weight of 2000, were spun. Otherwise, polyether ester elastic fibers were obtained by the same method as in Example 1.

[0084] [Examples 24-29] Polyether ester elastomer resin with adjusted degree of polymerization by changing polymerization temperature and time was used to adjust the specific viscosity of polyether ester elastic fibers. Otherwise, polyether ester elastic fibers were obtained by the same method as in Example 1.

[0085] [Examples 30-37] In the spinning step, the temperature and speed of the cold air 10 cm to 50 cm below the die nozzle were changed, and the orientation index of the fiber axis direction of the mixed part of the soft chain segment region and the hard chain segment region measured by Raman spectroscopy was changed. Otherwise, polyether ester elastic fibers were obtained by the same method as in Example 1.

[0086] [Examples 38-45] In the spinning step, the temperature and speed of the cold air 50 cm to 100 cm below the die nozzle were changed, and the orientation index of the fiber axis direction of the soft chain segment region measured by Raman spectroscopy was changed. Otherwise, polyether ester elastic fibers were obtained by the same method as in Example 1.

[0087] [Comparative Examples 1 and 2] The resin ejection speed of the polyether ester elastomer and the winding speed of the winding machine were adjusted, and the total fineness was changed. Otherwise, polyether ester elastic fibers were obtained in the same way as in Example 1.

[0088] [Comparative Examples 3 and 4] For the spool of polyether ester elastic fiber, the temperature was adjusted to be between 40°C and 150°C to adjust the phase separation index. Otherwise, the polyether ester elastic fiber was obtained by the same method as in Example 1.

[0089] [Comparative Example 5] By adjusting the temperature of the yarn, as well as the temperature and speed of the cold air during the spinning process, the temperature of the yarn at points 10 cm, 50 cm, and 100 cm directly below the die nozzle was controlled, and the orientation index of the fiber axis direction in the hard chain segment region was changed. Otherwise, polyether ester elastic fibers were obtained by the same method as in Example 1.

[0090] [Comparative Examples 6 and 7] The ejection speed of the polyether ester elastomer resin was adjusted, and the winding speed of the winding machine was changed to more than 3000 m / min and less than 5000 m / min. Otherwise, polyether ester elastic fibers were obtained in the same way as in Example 1.

[0091] The manufacturing conditions and the measurement results of various properties of the obtained polyether ester elastic fibers in the above examples and comparative examples are shown in Tables 1 to 6 below.

[0092] [Table 1] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 raw material Dicarboxylic acid ratio of terephthalic acid (mol%) 100 100 100 100 100 100 100 100 100 100 low molecular weight diols The ratio of 1,4-butanediol (mol%) 100 100 100 100 100 100 100 100 100 100 The ratio of 1,6-hexanediol (mol%) 0 0 0 0 0 0 0 0 0 0 polyols PTMG ratio (mol%) 100 100 100 100 100 100 100 100 100 100 PEG ratio (number average molecular weight 2000) (mol%) 0 0 0 0 0 0 0 0 0 0 Spinning conditions winding speed (m / minute) 700 700 700 700 700 700 700 700 700 700 Total fineness (dtex) 44 5 80 44 44 44 44 44 44 44 Temperature of the thread at a point 10 cm directly below the nozzle (°C) 103 101 108 104 107 105 103 125 120 115 Temperature of the thread at a point 50 cm directly below the nozzle (°C) 52 50 54 51 50 53 51 52 51 50 Temperature of the thread at a point 100 cm directly below the nozzle (°C) 40 41 43 41 42 40 41 42 41 43 Phase separation index 0.30 0.30 0.30 0.20 0.25 0.55 0.65 0.30 0.30 0.30 Orientation index of fiber axis in hard segment region 7.50 7.50 7.50 7.50 7.50 7.50 7.50 4.00 5.00 6.00 Specific viscosity (η) sp / c) (dL / g) 4.00 4.00 4.00 4.00 4.00 4.00 4.00 4.00 4.00 4.00 The alignment index of the fiber axis in the mixed portion of the soft segment region and the hard segment region 4.00 4.00 4.00 4.00 4.00 4.00 4.00 4.00 4.00 4.00 Orientation index of fiber axis direction at the boundary of soft chain segment region 3.00 3.00 3.00 3.00 3.00 3.00 3.00 3.00 3.00 3.00 performance Stretch Follow (%) 75 73 73 71 73 73 67 58 68 72 Stretch and resilience (%) 92 90 90 82 90 91 84 75 85 89 The reduction of physical properties during the dyeing process (%) 120 117 115 94 117 115 115 97 117 115 Shrinkage during the dyeing process (%) 10 12 12 20 12 11 11 12 11 11 Aesthetics of Fabric (class) 5 5 5 4 5 5 5 5 5 5

[0093] [Table 2] Example 11 Example 12 Example 13 Example 14 Example 15 Example 16 Example 17 Example 18 Example 19 Example 20 raw material Dicarboxylic acid ratio of terephthalic acid (mol%) 100 100 100 100 100 100 100 100 100 100 low molecular weight diols The ratio of 1,4-butanediol (mol%) 100 100 100 100 75 80 90 95 98 100 The ratio of 1,6-hexanediol (mol%) 0 0 0 0 25 20 10 5 2 0 polyols PTMG ratio (mol%) 100 100 100 100 100 100 100 100 100 40 PEG ratio (quantity average molecular weight 2000) (mol%) 0 0 0 0 0 0 0 0 0 60 Spinning conditions Scroll speed (m / minute) 700 700 700 700 700 700 700 700 700 700 Total fiber (dtex) 44 44 44 44 44 44 44 44 44 44 Temperature of the thread at a point 10 cm directly below the nozzle (°C) 109 102 81 73 104 104 108 107 102 105 Temperature of the thread at a point 50 cm directly below the nozzle (°C) 52 51 53 51 51 50 52 51 50 51 Temperature of the thread at a point 100 cm directly below the nozzle (°C) 42 41 40 42 43 41 42 43 42 41 Phase separation index 030 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 Orientation index of fiber axis direction in hard segment region 6.50 8.00 9.00 10.00 7.50 7.50 7.50 7.50 7.50 7.50 Specific viscosity (η) sp / c) (dL / g) 4.00 4.00 4.00 4.00 4.00 4.00 4.00 4.00 4.00 4.00 The alignment index of the fiber axis in the mixed portion of the soft segment region and the hard segment region 4.00 4.00 4.00 4.00 4.00 4.00 4.00 4.00 4.00 4.00 Orientation index of fiber axis direction at the boundary of soft chain segment region 3.00 3.00 3.00 3.00 3.00 3.00 3.00 3.00 3.00 3.00 performance Stretch Follow (%) 74 73 71 65 56 64 67 71 73 56 Stretch and resilience (%) 91 90 88 84 72 80 84 88 90 73 The reduction of physical properties during the dyeing process (%) 117 115 109 97 64 89 100 112 115 70 Shrinkage during the dyeing process (%) 12 12 14 20 29 twenty one 17 14 12 29 Aesthetics of Fabric (class) 5 5 5 4 1 3 4 5 5 1

[0094] [Table 3] Example 21 Example 22 Example 23 Example 24 Example 25 Example 26 Example 27 Example 28 Example 29 Example 30 raw material Dicarboxylic acid ratio of terephthalic acid (mol%) 100 100 100 100 100 100 100 100 100 100 low molecular weight diols The ratio of 1,4-butanediol (mol%) 100 100 100 100 100 100 100 100 100 100 The ratio of 1,6-hexanediol (mol%) 0 0 0 0 0 0 0 0 0 0 polyols PTMG ratio (mol%) 50 60 90 100 100 100 100 100 100 100 PEG ratio (number average molecular weight 2000) (mol%) 50 40 10 0 0 0 0 0 0 0 Spinning conditions winding speed (m / minute) 700 700 700 700 700 700 700 700 700 700 Total fineness (dtex) 44 44 44 44 44 44 44 44 44 44 Temperature of the thread at a point 10 cm directly below the nozzle (°C) 105 103 106 102 101 105 108 105 104 104 Temperature of the thread at a point 50 cm directly below the nozzle (°C) 54 53 53 52 54 52 54 51 53 70 Temperature of the thread at a point 100 cm directly below the nozzle (°C) 41 41 43 40 40 42 42 42 42 41 Phase separation index 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 Orientation index of fiber axis direction in hard segment region 7.50 7.50 7.50 7.50 7.50 7.50 7.50 7.50 7.50 7.50 Specific viscosity (η) sp / c) (dL / g) 4.00 4.00 4.00 1.50 2.00 3.00 5.00 6.00 6.50 4.00 The alignment index of the fiber axis in the mixed portion of the soft segment region and the hard segment region 4.00 4.00 4.00 4.00 4.00 4.00 4.00 4.00 4.00 2.00 Orientation index of fiber axis direction at the boundary of soft chain segment region 3.00 3.00 3.00 3.00 3.00 3.00 3.00 3.00 3.00 3.00 performance Stretch Follow (%) 65 73 73 58 63 73 73 64 57 60 Stretch and resilience (%) 82 90 91 75 80 90 90 90 90 81 The reduction of physical properties during the dyeing process (%) 102 115 115 74 89 115 115 115 115 91 Shrinkage during the dyeing process (%) 20 12 11 27 twenty two 12 12 twenty one 28 twenty one Aesthetics of Fabric (class) 4 5 5 2 3 5 5 5 5 3

[0095] [Table 4] Example 31 Example 32 Example 33 Example 34 Example 35 Example 36 Example 37 Example 38 Example 39 Example 40 raw material Dicarboxylic acid ratio of terephthalic acid (mol%) 100 100 100 100 100 100 100 100 100 100 low molecular weight diols The ratio of 1,4-butanediol (mol%) 100 100 100 100 100 100 100 100 100 100 The ratio of 1,6-hexanediol (mol%) 0 0 0 0 0 0 0 0 0 0 polyols PTMG ratio (mol%) 100 100 100 100 100 100 100 100 100 100 PEG ratio (number average molecular weight 2000) (mol%) 0 0 0 0 0 0 0 0 0 0 Spinning conditions winding speed (m / minute) 700 700 700 700 700 700 700 700 700 700 Total fineness (dtex) 44 44 44 44 44 44 44 44 44 44 Temperature of the thread at a point 10 cm directly below the nozzle (°C) 106 103 107 105 105 102 107 103 106 104 Temperature of the thread at a point 50 cm directly below the nozzle (°C) 67 65 58 50 45 40 37 54 54 53 Temperature of the thread at a point 100 cm directly below the nozzle (°C) 41 43 42 42 41 41 40 53 53 51 Phase separation index 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 Orientation index of fiber axis direction in hard segment region 7.50 7.50 7.50 7.50 7.50 7.50 7.50 7.50 7.50 7.50 Specific viscosity (η) sp / c) (dL / g) 4.00 4.00 4.00 4.00 4.00 4.00 4.00 4.00 4.00 4.00 The alignment index of the fiber axis in the mixed portion of the soft segment region and the hard segment region 2.50 3.00 3.50 4.30 4.50 5.00 6.00 4.00 4.00 4.00 Orientation index of fiber axis direction at the boundary of soft chain segment region 3.00 3.00 3.00 3.00 3.00 3.00 3.00 1.00 1.50 2.00 performance Stretch Follow (%) 69 72 73 73 72 69 66 65 69 72 Stretch and resilience (%) 86 89 90 90 89 86 81 82 86 89 The reduction of physical properties during the dyeing process (%) 104 112 115 115 112 104 94 100 104 112 Shrinkage during the dyeing process (%) 16 13 12 12 13 16 twenty one 18 16 13 Aesthetics of Fabric (class) 4.5 5 5 5 5 4.5 3 4 4.5 5

[0096] [Table 5] Example 41 Example 42 Example 43 Example 44 Example 45 raw material Dicarboxylic acid ratio of terephthalic acid (mol%) 100 100 100 100 100 low molecular weight diols The ratio of 1,4-butanediol (mol%) 100 100 100 100 100 The ratio of 1,6-hexanediol (mol%) 0 0 0 0 0 polyols PTMG ratio (mol%) 100 100 100 100 100 PEG ratio (number average molecular weight 2000) (mol%) 0 0 0 0 0 Spinning conditions winding speed (m / minute) 700 700 700 700 700 Total fineness (dtex) 44 44 44 44 44 Temperature of the thread at a point 10 cm directly below the nozzle (°C) 102 101 105 103 102 Temperature of the thread at a point 50 cm directly below the nozzle (°C) 54 51 53 50 51 Temperature of the thread at a point 100 cm directly below the nozzle (°C) 49 40 35 30 twenty three Phase separation index 0.30 0.30 0.30 0.30 0.30 Orientation index of fiber axis direction in hard segment region 7.50 7.50 7.50 7.50 7.50 Specific viscosity (η) sp / c) (dL / g) 4.00 4.00 4.00 4.00 4.00 The alignment index of the fiber axis in the mixed portion of the soft segment region and the hard segment region 4.00 4.00 4.00 4.00 4.00 Orientation index of fiber axis direction at the boundary of soft chain segment region 2.50 3.30 3.50 4.00 4.50 performance Stretch Follow (%) 73 73 72 69 65 Stretch and resilience (%) 90 90 89 86 84 The reduction of physical properties during the dyeing process (%) 115 115 112 104 102 Shrinkage during the dyeing process (%) 12 12 13 16 20 Aesthetics of Fabric (class) 5 5 5 4.5 4

[0097] [Table 6] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 raw material Dicarboxylic acid ratio of terephthalic acid (mol%) 100 100 100 100 100 100 100 low molecular weight diols The ratio of 1,4-butanediol (mol%) 100 100 100 100 100 100 100 The ratio of 1,6-hexanediol (mol%) 0 0 0 0 0 0 0 polyols PTMG ratio (mol%) 100 100 100 100 100 100 100 PEG ratio (number average molecular weight 2000) (mol%) 0 0 0 0 0 0 0 Spinning conditions winding speed (m / minute) 700 700 700 700 700 3000 5000 Total fineness (dtex) 3 100 44 44 44 44 44 Temperature of the thread at a point 10 cm directly below the nozzle (°C) 68 68 101 102 67 63 60 Temperature of the thread at a point 50 cm directly below the nozzle (°C) 51 52 53 50 51 twenty three twenty one Temperature of the thread at a point 100 cm directly below the nozzle (°C) 41 41 40 41 40 20 18 Phase separation index 0.30 0.30 0.10 0.75 0.30 0.67 0.68 Orientation index of fiber axis direction in hard segment region 11.00 10.50 7.50 7.50 12.00 12.50 12.20 Specific viscosity (η) sp / c) (dL / g) 4.00 4.00 4.00 4.00 4.00 4.00 4.00 The alignment index of the fiber axis in the mixed portion of the soft segment region and the hard segment region 4.00 4.00 4.00 4.00 4.00 7.50 7.20 Orientation index of fiber axis direction at the boundary of soft chain segment region 3.00 3.00 3.00 3.00 3.00 5.50 5.30 performance Stretch Follow (%) 43 42 55 56 55 40 45 Stretch and resilience (%) 79 78 72 73 78 78 79 The reduction of physical properties during the dyeing process (%) 60 60 67 115 64 60 60 Shrinkage during the dyeing process (%) 30 30 30 11 30 25 30 Aesthetics of Fabric (class) 1 1 1 5 1 1 1 [Industrial Applicability]

[0098] The polyether ester elastic fiber and the yarn of the fiber of the present invention have good stretchability and elasticity recovery, and even after dyeing, they can effectively suppress the reduction of tensile stress and the formation of fabric wrinkles, and have good aesthetic appeal as fabrics. Furthermore, the fabrics and clothing of the present invention are less prone to wrinkling during the dyeing process, and have good elasticity and fit when worn. Therefore, the present invention, as an elastic fiber, can be suitable for use in various fields, including clothing. [Simplified Explanation of the Diagram]

[0014] Figure 1 is a schematic diagram of the measurement of stretch follower. Figure 2 is a schematic diagram of the measurement of stretch recovery.

Claims

1. A polyether ester elastic fiber having a total fineness of 5 dtex or more and 80 dtex or less, a phase separation index measured by a small-angle X-ray scattering device of 0.20 or more and 0.65 or less, and an orientation index of the fiber axis direction of the hard chain segment region measured by Raman spectroscopy of 10.00 or less.

2. The polyether ester elastic fiber as claimed in claim 1, wherein in the polyether ester elastomer constituting the above-mentioned polyether ester elastic fiber, 80 mol% or more of the low molecular weight diol units are selected from the group consisting of 1,4-butanediol, 1,6-hexanediol, 1,3-propanediol, and ethylene glycol, and 50 mol% or more of the polymer polyol units are PTMG, or a copolydiol containing tetrahydrofuran (THF) and neopentyl glycol.

3. The polyether ester elastic fiber as requested in item 1 or 2 has a specific viscosity of more than 2.00 dL / g and less than 6.00 dL / g.

4. For the polyether ester elastic fiber of claim 1 or 2, the orientation index of the fiber axis of the mixed portion of the soft segment region and the hard segment region, as measured by Raman spectroscopy, is 2.50 or more and 5.00 or less.

5. The polyether ester elastic fiber as requested in item 1 or 2, wherein the orientation index of the fiber axis direction of the soft segment region, as measured by Raman spectroscopy, is above 1.50 and below 4.

00.

6. A yarn body comprising a yarn body of a polyether ester elastic fiber as claimed in claim 1 or 2.

7. A fabric comprising polyether ester elastic fibers as claimed in claim 1 or 2.

8. A fabric comprising polyether ester elastic fibers as claimed in claim 1 or 2.

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