JP2008069479A - Polyester fiber, woven knit fabric, car sheet and process for producing polyester fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester fiber being resistant to cyclic loading, excelling in surface softness and uniformity properties, having easy dyeability in combination and being free from unevenness or curling, especially a woven knit fabric suitable as a car sheet. <P>SOLUTION: The polyester fiber has 15-38 cN/dtex initial tensile resistance, degree 70% or higher elongation recovery ratio exhibited after 20% elongation, 0.3-1.4% shrink release ratio exhibited after a dry heat treatment at 160°C, 4-11% shrinkage percentage in boiling water, 4-15% dry heat shrinkage percentage at 160°C and 55-80°C temperature at 0.5 cN/dex stress in a shrinkage stress curve. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a polyester fiber that exhibits stable behavior after heat treatment and cooling. In particular, the present invention relates to a polyester fiber from which a fabric suitable as a car seat can be obtained.

  Conventionally, polyethylene terephthalate (hereinafter sometimes referred to as PET), which is a polyester fiber, has been studied as a center of synthetic fiber because of its high strength, good dyeability, and productivity. PET fibers are useful not only for clothing but also for vehicles, and have been developed mainly for car seats and ceiling materials. The PET fiber has a stable behavior after heat treatment, and it is easy to fit within the designed fabric width in the heat treatment step, which is the final step for obtaining a woven fabric or a knitted fabric (also referred to as a woven or knitted fabric). Therefore, a stable quality fabric can be obtained. In addition, since a car seat, a ceiling material, and the like can be given a high-class feeling by using a raised fabric, the fabric after heat treatment may be subjected to a raising treatment. Also in this raising process, the PET fiber is easy to obtain a stable quality.

  However, when PET fiber is used as a car seat, there is a problem that the fabric is stretched due to repeated load on the human body. This is due to the low stretch recovery property of the PET fiber, that is, the recovery rate after stretching is low.

  Furthermore, since the initial tensile resistance (sometimes referred to as Young's modulus or elastic modulus) of PET fibers is as high as about 90 cN / dtex, particularly when it is a raised fabric, it becomes stiff. There's a problem.

  On the other hand, polytrimethylene terephthalate (hereinafter sometimes referred to as 3GT) is characterized by high elongation recovery and low softness since it has a low initial tensile resistance when used as a fiber. In addition, due to its easy dyeability, recent studies have been actively conducted as an attractive polyester fiber that can compensate for the shortcomings of PET fibers.

  However, 3GT fiber is not universal and has disadvantages. In order to make up for this drawback, studies relating to 3GT fibers are actively conducted. For example, in order to compensate for the low strength of 3GT fiber, an elastic modulus that is too low depending on the application, and low dyeing fastness, a core-sheath composite fiber having 3GT as a sheath component and PET as a core component has been proposed (patent) Reference 1). According to this document, a core-sheath composite fiber having a strength of 3.9 to 4.7 g / d (3.5 to 4.2 cN / dtex) and an elastic modulus of 43 to 72 g / d (39 to 65 cN / dtex) was obtained. Yes. According to this technique, although the strength is higher than that of the conventional 3GT fiber, there is a problem that the low elastic modulus, which is the most important feature of the 3GT fiber, is impaired and the softness is lacking. Further, the stretch recovery property, which is an important attraction of 3GT fiber, is also greatly reduced, and it becomes insufficient as a car seat.

  On the other hand, when 3GT fiber is used for a car seat, the heat setting property is inferior. Therefore, when the tension state is released after finishing heat setting, it gradually contracts in the width direction, resulting in variations in quality in the width direction. This tendency is particularly noticeable in knitted fabrics with weak fabric binding force. After several days after heat setting, the smoothness of the surface is lost and the softness cannot be felt, and the end curls and withstands actual use. There was no problem.

  As a known technique that has improved the problem of shrinkage of 3GT fibers, for example, Patent Document 2 can be cited. In this document, it is proposed to control the thermal stress in order to suppress the high shrinkage ratio of the 3GT fiber and thereby further improve the softness. As a control method, spinning at high speed and winding without heat treatment are mentioned. However, with this technique, although the shrinkage rate and stress due to heat are low, it has been found that the shrinkage gradually occurs with time and the heat setting property is inferior. This is because the fiber spun at high speed has a low crystallinity and 3GT has a low glass transition temperature, so that crystallization gradually proceeds even after fiberization.

As described above, no fiber that can provide a fabric suitable as a car seat has been proposed yet.
JP-A-11-93021 (Claims, paragraph 0011, Examples) JP 2001-348729 A (Claims, Examples)

  The present invention proposes a polyester fiber that is strong against repeated loads, has excellent surface softness and uniformity, and is capable of obtaining a woven or knitted fabric having no irregularities or curls, particularly a fabric suitable as a car seat. is there.

  The present invention provides a polyester having an initial tensile resistance of 15 to 38 cN / dtex, an elongation recovery rate after 20% elongation of 70% or more, and a shrinkage rate after dry heat treatment at 160 ° C. of 0.3% to 1.4%. Fiber.

  Moreover, this invention includes the woven / knitted fabric which consists of said fiber.

  Moreover, this invention includes the car seat which consists of said woven or knitted fabric.

  Moreover, this invention includes the cheese-like package by which said fiber is wound, a bulge is -5-10% and a saddle is 0-10%.

  Moreover, this invention includes the method of manufacturing said polyester fiber.

  The present invention is a polyester fiber that takes advantage of the low initial tensile resistance and high stretch recovery of 3GT fiber and has improved heat setability. By using the polyester fiber of the present invention, it is possible to obtain a woven or knitted fabric that is strong against repeated loads, has excellent surface softness and uniformity, and has no irregularities or curls. In particular, a better car seat than the conventional one can be obtained.

  Hereinafter, the present invention will be described in detail.

  The polyester fiber of the present invention has an initial tensile resistance of 15 to 38 cN / dtex, an elongation recovery rate after 20% elongation of 70% or more, and a shrinkage rate after dry heat treatment at 160 ° C. of 0.3% to 1.4%. It is. It is a feature of the polyester fiber of the present invention that these three regulations are satisfied at the same time, and it is a polyester fiber that could not exist conventionally.

  The initial tensile resistance of the polyester fiber of the present invention is 15 to 38 cN / dtex. When this value is within this range, the fabric obtained from the fiber has good softness. When the initial tensile resistance of the fiber is larger than this range, the softness is deteriorated. A widely used PET fiber has a value of about 90 cN / dtex, so that a fabric obtained from the PET fiber has a stiff hardness. A 3GT fiber that has been studied in recent years is preferably about 20 cN / dtex. From the viewpoint of the softness of the fabric, the initial tensile resistance is preferably a lower value, more preferably 15 to 35 cN / dtex, and still more preferably 15 to 33 cN / dtex.

  The elongation recovery rate after 20% elongation of the polyester fiber of the present invention is 70% or more. Due to the measurement method, the upper limit is 100%. When this value is within this range, the fabric obtained from the fibers has good resistance to repeated loads. When this value is low, for example, when a car seat is used, the fabric is fully stretched due to the human body load, and the fabric structure is misaligned and talmi occurs. This elongation recovery rate is about 30% for PET fiber, and only a fabric with low resistance to repeated loads can be obtained with PET fiber alone. This value is preferable because 3GT fiber shows a value of 90% or more. From the viewpoint of resistance to repeated loads, the elongation recovery rate is more preferably 80% or more, and still more preferably 85% or more.

  The initial tensile resistance of the polyester fiber and the elongation recovery rate after 20% elongation can be controlled to some extent by the selection of the polyester polymer used. The polyester polymer preferably contains at least 3GT. Furthermore, other polyester polymers can be combined or blended as required. The other polyester polymer is preferably a polymer selected from PET and polybutylene terephthalate (hereinafter sometimes referred to as PBT).

  The polyester fiber of the present invention has a shrinkage rate of 0.3 to 1.4% after 160 ° C. dry heat treatment. The shrinkage rate after the 160 ° C. dry heat treatment is the rate of shrinkage under gravity after performing the heat treatment at 160 ° C. under a constant load and then removing the load at room temperature. Specifically, it is a value measured by the following method.

Take the fiber 1m x 10 times. The skein is subjected to a load of 9.1 × 10 ⁻³ cN / dtex, and the casket length is measured (L0). Next, a dry heat treatment is performed at 160 ° C. for 15 minutes under a load of 9.1 × 10 ⁻³ cN / dtex, and the skein length is measured immediately after the dry heat treatment (within 30 seconds) (L1). Further, after changing the load to 4.6 × 10 ⁻³ cN / dtex and leaving it at 20 ° C. for 30 minutes, the skein length is measured (L2). The shrinkage rate after 160 ° C. dry heat treatment is calculated by the following formula.
(Reduction rate after 160 ° C. dry heat treatment) = (L1−L2) / L0
This rate of shrinkage is a parameter representing the heat setting property of the fiber. When the fiber shrinkage rate is large, the fabric obtained from the fiber shrinks even after finishing heat setting, and the uniformity of the fabric is impaired. In addition, the shrinkage of the fabric causes a decrease in surface quality such as misalignment and tarmi of the fabric structure. In particular, a knitted fabric with a weak tissue binding force has a large influence, and cannot be practically used. In order to use the fiber for knitting without any problem, the shrinkage ratio needs to be 1.4% or less. More preferably, it is 1.1% or less. This release / shrinkage rate can be said to be the most important item for increasing the value as a fabric. This rate of shrinkage is about 0.3% for PET fibers and about 1.7-2.0% for conventional 3GT fibers.

  It is important for the polyester fiber of the present invention to satisfy all three items simultaneously, together with the initial tensile resistance and the elongation recovery rate after 20% elongation. With conventional PET fibers, the shrinkage rate after 160 ° C. dry heat treatment can be achieved, but the initial tensile resistance and the elongation recovery rate after 20% elongation cannot be satisfied. Further, with the conventional 3GT fiber, the initial tensile resistance and the elongation recovery rate after 20% elongation can be achieved, but the shrinkage rate after the 160 ° C. dry heat treatment cannot be satisfied. A specific method for producing the polyester fiber of the present invention satisfying all these three items will be described later.

  Next, the preferable range about the shrinkage | contraction characteristic of a fiber is described. The shrink property of the fiber is important in the subsequent process of obtaining the knitted or knitted fabric. It is preferable that the boiling water shrinkage of the fiber is 4 to 11%, the 160 ° C. dry heat shrinkage is 4 to 15%, and the temperature at the time of 0.5 cN / dtex stress in the shrinkage stress curve is 55 to 80 ° C.

  The boiling water shrinkage rate is important as a measure of shrinkage in the refining process among the processes of obtaining the woven or knitted fabric. The boiling water shrinkage is preferably suppressed to a low level, and if it is in the range of 4 to 11%, it is preferable because the fabric does not become hard. In the case of conventional 3GT fiber, the shrinkage is about 13%. When the boiling water shrinkage is large, the knitted or knitted fabric shrinks and becomes hard in the refining process or the like, and it becomes difficult to obtain a woven or knitted fabric utilizing the softness of 3GT. When the boiling water shrinkage is more preferably in the range of 4 to 10%, and still more preferably in the range of 4 to 9.5%, it becomes easy to obtain a fabric excellent in softness.

  The 160 ° C. dry heat shrinkage ratio is a value that serves as a standard for shrinkage during finish heat setting. The 160 ° C. dry heat shrinkage rate is also preferably kept low, and if it is 4 to 15%, the density of the woven or knitted fabric structure can be easily controlled. Further, even when the polyester fiber of the present invention is woven or knitted with other polyester fibers, there is little difference in shrinkage with other polyester fibers, so that surface unevenness and curling are avoided in the fabric after heat treatment. Can do. From the viewpoint of softness, the 160 ° C. dry heat shrinkage is preferably low. A more preferable value is 4 to 14%.

  Further, the temperature at the time of 0.5 cN / dtex stress in the shrinkage stress curve is a temperature at which stress starts to be applied when the fiber is heated at a heating rate of 100 ° C./min. The fabric is first given heat in the refining process and receives heat of 90 to 100 ° C. In this step, when the temperature at the time of 0.5 cN / dtex stress of the fiber is 55 to 80 ° C., rapid shrinkage of the fabric is suppressed, and there is no misalignment of the tissue, and it becomes easy to obtain a good fabric. Therefore, it is preferable. Moreover, it is preferable that the temperature at the time of 0.5 cN / dtex stress of the fiber is 55 ° C. or higher because it is difficult to be affected by the heat of the loom or knitting machine when a fabric is obtained from the fiber. The temperature at the time of 0.5 cN / dtex stress of the fiber is more preferably 60 ° C. or higher. In the case of conventional 3GT fibers, this temperature was 45-55 ° C.

  In addition, as a preferable characteristic of the polyester fiber in the present invention, the peak temperature of the shrinkage stress is preferably 130 to 170 ° C. The peak stress is preferably 0.15 to 0.3 cN / dtex. Within this range, when performing heat setting of the woven or knitted fabric, moderate stress is applied in the direction in which the fibers shrink uniformly until the finish heat setting is completed. A knitted fabric can be obtained. More preferably, the peak temperature is 140 to 160 ° C. and the peak stress is 0.15 to 0.25 cN / dtex. The peak temperature and peak stress of the shrinkage stress can be adjusted by the heat treatment temperature in fiber production and the yarn tension before and after the heat treatment.

  What is necessary is just to set the intensity | strength and elongation of a fiber in the range which is satisfactory in obtaining a fabric. If the strength is 2.5 cN / dtex or more and the elongation is 25 to 60%, yarn breakage during weaving or knitting is less likely to occur.

  3GT is a polyester obtained using terephthalic acid as the main acid component and 1,3-propanediol as the main glycol component. As for 3GT, it is preferable that 90 mol% or more consists of a repeating unit of trimethylene terephthalate. However, it may contain other copolymer components in a proportion of 10 mol% or less. Examples of the copolymerizable compound include dicarboxylic acids such as isophthalic acid, succinic acid, cyclohexanedicarboxylic acid, adipic acid, dimer acid, sebacic acid, 5-sodium sulfoisophthalic acid, ethylene glycol, diethylene glycol, butanediol, and neopentyl glycol. And diols such as cyclohexanedimethanol, polyethylene glycol, and polypropylene glycol, but are not limited thereto. Further, if necessary, titanium dioxide as a matting agent, silica fine particles or alumina fine particles as a lubricant, hindered phenol derivatives, coloring pigments as an antioxidant may be added.

  PET is a polyester obtained using terephthalic acid as the main acid component and ethylene glycol as the main glycol component. It is preferable that 90 mol% or more of PET is composed of repeating units of ethylene terephthalate. Similarly to 3GT, it may contain a copolymerization component as described above, or an additive such as a matting agent may be added. PBT is a polyester obtained using terephthalic acid as the main acid component and butylene glycol as the main glycol component. It is preferable that 90% mol or more of PBT is composed of a repeating unit of butylene terephthalate. Similarly to 3GT, it may contain a copolymerization component as described above, or an additive such as a matting agent may be added.

  The polyester fiber of the present invention preferably contains 3GT from the viewpoint of softness and elongation recovery rate. It may be a fiber composed only of 3GT (sometimes referred to as 3GT single fiber), or may be a fiber containing a polymer selected from PET and PBT in addition to 3GT. When PET or PBT is included, a so-called blended fiber obtained by blending a plurality of components into a yarn may be used, or a so-called composite fiber in which a plurality of components are combined in a core-sheath type or a side-by-side type. By blending or combining PET or PBT with 3GT, it is possible to compensate for the disadvantages of 3GT such as poor heat setability while taking advantage of the properties of 3GT such as good softness and elongation recovery rate. More preferably, a concentric core-sheath composite fiber (simply referred to as a core-sheath fiber) may be used. A polymer selected from PET and PBT as the core component and a core-sheath fiber using 3GT as the sheath component are preferable, and a core-sheath fiber using PET as the core component and 3GT as the sheath component is most preferable. In this case, it is preferable that the intrinsic viscosity of 3GT is 0.8 to 1.2 and the intrinsic viscosity of PET is 0.4 to 0.6, since the polyester fiber makes use of the characteristics of 3GT and compensates for the disadvantages of 3GT. . If the intrinsic viscosity of PET is higher than this, the properties of PET become too strong, and the softness and elongation recovery rate of 3GT are not utilized, which is not preferable. In addition, when PBT is used as a core component, it is preferable that the intrinsic viscosity of PBT is 0.5 to 0.9.

  The polyester fiber of the present invention is suitable for woven and knitted fabrics. By using the fiber of the present invention, it is possible to obtain a woven or knitted fabric that is resistant to repeated loads, has excellent surface softness and uniformity, and has no irregularities or curls. Since the woven or knitted fabric obtained from the polyester fiber of the present invention has high resistance to repeated loads, it is suitably used for car seats that are subject to human load. In addition, in a car seat, in order to give a high-class feeling, a raising process may be implemented. Since the polyester fiber of the present invention has a low initial tensile resistance, it has an excellent soft feeling when the obtained fabric is raised. In addition, since the surface state differs between the front and back of the fabric by raising, problems such as curling are likely to occur. However, since the polyester fiber of the present invention has a low release rate after 160 ° C. dry heat treatment, the occurrence of curling or the like can be suppressed even when the raising treatment is performed. In that sense, the polyester fiber of the present invention and the fabric obtained therefrom are the most desired fiber and fabric from the automobile industry.

  When obtaining a woven or knitted fabric from the polyester fiber of the present invention, it is preferable that the woven or knitted fabric is composed only of the polyester fiber of the present invention and does not contain other fibers, since the characteristics of the polyester fiber of the present invention can be maximized. . However, as long as the effects of the present invention are not impaired, composite processing with other polyester fibers or natural fibers, twisting yarn, or the like may be performed.

The polyester fiber of the present invention is wound around a paper tube or the like and supplied as a cheese-like package as shown in FIG. The cheese-like package preferably has a bulge of -5 to 10% and a saddle of 0 to 10%. As shown in FIG. 5, the maximum diameter (Dmax), minimum diameter (Dmin), maximum width (Wmax), and minimum width (Wmin) of the package are measured, and the saddle and bulge are calculated by the following equations.
Saddle (%) = {(Dmax−Dmin) / Dmin} × 100
Bulge (%) = {(Wmax−Wmin) / Wmin} × 100
If the saddle or bulge is large, unevenness occurs in the hardness of the fibers in the package. In particular, when the saddle is large, the fiber is hard at the maximum diameter portion, and conversely, the fiber tends to be soft at the minimum diameter portion. If there is unevenness in the hardness of the fiber, the uniformity of the fabric is impaired when a fabric is obtained using it, and the quality of the fabric surface is lowered. When the saddle and the bulge are in the above range, the unevenness of the fibers in the package is suppressed, and the deterioration of the fabric surface quality caused by this can be suppressed. A more preferable range of bulge is 0 to 8%, and a more preferable range of saddle is 0 to 8%.

  In order to make the saddle and the bulge within a preferable range, the package shape immediately after winding is improved by setting the tension at the time of winding to an appropriate range, and the shape of the package over time after winding is changed. It is important to reduce the change. In particular, in the case of a fiber containing 3GT, as described above, since the shrinkage with time is likely to occur, the package shape tends to be deteriorated. Since the polyester fiber of the present invention has little shrinkage over time after winding, the change in package shape after winding can be reduced, and the above-mentioned preferable package shape can be achieved.

  Next, the preferable manufacturing method of the polyester fiber of this invention is described.

  One of the preferred embodiments of the method for producing the polyester fiber of the present invention includes a step of melting a polytrimethylene terephthalate polymer, a step of discharging from a die having a die surface depth of 20 to 90 mm, and a discharged polymer having a spinning speed of 4500. It is a manufacturing method of the polyester fiber including the process of drawing at 7000 m / min, and the process of heat-treating the picked-up fiber at 120-180 degreeC, without extending | stretching. In this embodiment, 3GT single fiber is obtained.

In the case of 3GT single fiber, the intrinsic viscosity of 3GT polymer is preferably 0.8 to 1.2. The 3GT polymer is preferably melted so that the melt viscosity at a shear rate of 1216 sec ^-1 is 1000 to 2000 poise. An intrinsic viscosity of 0.8 or more is preferable because 3GT shrinkage characteristics and softness are good. An intrinsic viscosity of 1.2 or less is preferable because the resulting fiber does not shrink too much and spinning becomes easy.

  For the melting of the polymer, a method using an extruder or a pressure melter is generally used, but in order to ensure the melt viscosity, a method using an efficient extruder is preferable. Thereafter, as shown in FIG. 1, the melted polymer 1 is measured by a known method, and is discharged from the base 4 through the pipe 2. If the polymer residence time from entering the pipe to discharging the die is long, the polymer will deteriorate and the melt viscosity will decrease. In particular, since 3GT polymer is liable to cause polymer deterioration due to staying, it is preferable that the staying time from entering the pipe to discharging the die is 20 minutes or less. Further, since the viscosity is lowered depending on the spinning temperature, the spinning temperature is preferably 275 ° C. or lower. In order to sufficiently melt the 3GT polymer, the spinning temperature is preferably 240 ° C. or higher.

  Next, the polymer 7 discharged from the die 4 is cooled and solidified to become fibers. The base surface depth 6 that affects the cooling and solidification completion point is preferably 20 to 90 mm. The base surface depth in the present invention is a distance from the base surface to the lower surface of the heat retaining body 5. Generally, as the depth of the die surface is deeper, the strength of the fiber is improved by the slow cooling effect. However, in the present invention, the depth of the die surface is deliberately reduced, and the molten polymer discharged from the die is cooled and solidified as quickly as possible, thereby suppressing fiber shrinkage and further improving the heat setting property. In the case of 3GT, the temperature at which contraction stress starts to be applied during heating can be shifted upward, and the surface quality of the resulting fabric can be improved. This effect cannot be found at a base depth of 100 mm. The fibers are converged at the position of the oil supply device after cooling and solidification, but the convergence distance (distance from the base surface to the oil supply device) is preferably shortened. In order to improve the heat setting property, it is most preferable to shorten the focusing distance and lower the spinning tension by reducing the depth of the die surface. Specifically, the focusing distance is preferably 1000 to 1700 mm.

  The shallower the depth of the die surface, the better. The more preferable range is 20 to 80 mm, and further preferably 20 to 60 mm. However, when the depth is made shallower, the die surface is cooled, and the strength of the fiber is lowered. For this reason, it is preferable to control the temperature of the heat retaining body 5 under the base independently of the spinning temperature. That is, the temperature reduction of the die surface can be avoided by setting the temperature of the heat retaining body 5 to a temperature higher than the spinning temperature using a die heater. Specifically, the temperature setting of the heat retaining body 5 is 10 to 30 ° C. higher than the spinning temperature, and maintaining the relationship of (base surface temperature)> (spinning temperature−10 ° C.) does not generate low-strength fibers. (Refer to FIG. 1).

  Furthermore, in the present invention, the spinning speed is increased to 4500 to 7000 m / min, and then the drawn fiber is heat-treated at a high temperature of 120 to 180 ° C. without stretching, so that the shrinkage characteristics and heat setting of the fiber can be achieved. I found out that the sex is drastically improved.

  The combination of the high spinning speed and the shallow surface depth is important. By sufficiently orienting the fibers by the spinning tension, subsequent drawing becomes unnecessary. The spinning speed is preferably 4500 to 7000 m / min, more preferably 5000 to 7000 m / min.

The spun fiber is heat-treated without being drawn. The heat setting property of the fibers is improved by promoting crystallization by heat without stretching. Either non-contact heat treatment such as steam or contact heat treatment using a roller or plate can be used for the heat treatment, but contact heat treatment is preferred from the viewpoint of thermal efficiency. In order to avoid fiber damage due to abrasion, heat treatment with a roller is more preferable. The heat treatment temperature is preferably 120 to 180 ° C, but 140 to 180 ° C can be said to be a more preferable range in order to promote thermal crystallization. In addition, the heat treatment time is preferably 20 × 10 ^{−3 to} 100 × 10 ⁻³ seconds from the viewpoint of promoting thermal crystallization.

  Moreover, in order to further improve the heat setting property, it is effective to perform the heat treatment in a tension state. Specifically, the heat treatment roller can be a taper roll, and the heat treatment can be performed in a tension state by setting the roll outlet speed higher than the roll inlet speed. In addition, tension heat treatment is possible by arranging a plurality of rolls, installing the heating plate 22 between the rollers, and adjusting the roller speed (see FIG. 3).

  Other preferable embodiments of the method for producing the polyester fiber of the present invention include a step of melting polytrimethylene terephthalate having an intrinsic viscosity of 0.8 to 1.2, polyethylene terephthalate having an intrinsic viscosity of 0.4 to 0.6, or A step of melting polybutylene terephthalate having a viscosity of 0.5 to 0.9, a step of joining two molten polymers in a die, a step of discharging the joined polymer from a die having a die surface depth of 20 to 90 mm, and a discharged polymer Is a method for producing a polyester fiber, which includes a step of pulling the fiber at a spinning speed of 1400 to 3500 m / min, and a step of heat-treating the pulled fiber at 120 to 180 ° C. after drawing. With this method, it is possible to obtain fibers having favorable shrinkage characteristics without increasing the spinning speed.

  In this embodiment, a composite fiber or blend fiber of 3GT and PET or PBT is obtained. In the step of joining two molten polymers with a die and the step of discharging the joined polymer from the die, for example, when a die for composite spinning such as a core-sheath die is used, a composite fiber can be obtained. On the other hand, in the step of joining the two molten polymers in the die and the step of discharging the joined polymer from the die, for example, after mixing the polymers using a mixer such as a static mixer, and then discharging from the die, A blended fiber is obtained.

In these cases, it is preferable that the 3GT polymer is a polymer having an intrinsic viscosity of 0.8 to 1.2 as described above, and the melt viscosity at a shear rate of 1216 sec ⁻¹ is 1000 to 2000 poise. On the other hand, as the PET polymer, a polymer having an intrinsic viscosity of 0.4 to 0.6 is preferably selected, and the melt viscosity at a shear rate of 1216 sec ⁻¹ is preferably 300 to 900 poise. In the case of a PBT polymer, it is preferable to select a polymer having an intrinsic viscosity of 0.5 to 0.9 and set the melt viscosity at a shear rate of 1216 sec ⁻¹ to 300 to 900 poise. For the 3GT polymer, the residence time is preferably within 20 minutes as described above, and the spinning temperature is preferably as low as possible.

  When the core-sheath fiber is used, the composite ratio of the 3GT polymer and the other polymer is preferably such that the ratio of the 3GT polymer is 70 to 90% by mass in the fiber. When the blended fiber is used, the blend ratio of the 3GT polymer to the other polymer is preferably 60 to 80% by mass of the 3GT polymer in the fiber. By setting this ratio, it becomes easy to improve the heat setting property without impairing the advantages of 3GT.

  In the case of using 3GT polymer and PET polymer, since the melting point of PET is about 30 ° C. higher than that of 3GT, the spinning temperature is difficult, but a spinning temperature of 265 to 275 ° C. is preferable. When 3GT polymer and PBT polymer are used, the melting point of PBT is not significantly different from 3GT, so it is preferable to set the same conditions as for 3GT single fiber.

  Here, it is important to make the melt viscosity of PET or PBT lower than 3GT. By making the melt viscosity of PET or PBT lower than the melt viscosity of 3GT, taking advantage of the initial tensile resistance and the elongation recovery rate after 20% elongation, which are important characteristics of 3GT fiber, The shrinkage ratio after a certain 160 ° C. dry heat treatment can be suppressed. That is, the composite fiber or blend fiber manufactured under these conditions is superior in the properties of 3GT polymer in terms of initial tensile resistance and elongation recovery rate after 20% elongation, while on the other hand, it is released after 160 ° C. dry heat treatment. Regarding the reduction ratio, it was found that the properties of PET polymer or PBT polymer are superior. A more preferable range of melt viscosity of the PET polymer or PBT polymer is 400 to 800 poise. In order to make this melt viscosity range, the intrinsic viscosity of the PET polymer is preferably in the range of 0.4 to 0.6, and the intrinsic viscosity of the PBT polymer is preferably in the range of 0.5 to 0.9.

  In the case of a composite fiber or a blend fiber, the characteristics of the fiber can be adjusted by combining the polymers. Therefore, unlike the case of 3GT single fiber, a common manufacturing method using drawing after drawing the discharged polymer under the appropriate spinning conditions. Can be adopted. In the case of the above-described 3GT single fiber, the production conditions are very different from the common production conditions, so that it may be difficult to cope with common production equipment. In the case of a composite fiber or a blend fiber, a fiber having excellent heat setting properties can be obtained by using a common production facility. Furthermore, since the poor light fastness of 3GT can be compensated, it is preferable to use a composite fiber or a blend fiber.

  In the same manner as described above, in order to improve the shrinkage characteristics and the heat setting property, the depth of the die surface is preferably 20 to 90 mm, more preferably 20 to 80 mm, and further preferably 20 to 60 mm. Further, it is most preferable to improve the heat setting property by setting the focusing distance to 1000 to 1700 mm and lowering the spinning tension as in the case of single fibers.

  The spinning speed is preferably 1400 to 3500 m / min. Within this range, stable yarn production and appropriate strength can be obtained.

After taking up the spinning, the drawing is continued. Stretching may be appropriately set according to the balance between strength and elongation, and is preferably set so that the elongation is 25 to 60%. For this purpose, the draw ratio is preferably set in the range of 1.2 to 4.5 times. It is preferred to preheat the fiber before drawing. After stretching, heat treatment is performed at 120 to 180 ° C. The heat treatment time is preferably 20 × 10 ^{−3 to} 100 × 10 ⁻³ seconds. This heat treatment promotes fiber crystallization and improves shrinkage properties and heat setting properties.

  As a more preferable step, after heat treatment, the fiber cooling time is ensured to be equal to or longer than the heat treatment time through several rollers, and the tension is adjusted and wound (see FIG. 4). By doing in this way, since it becomes easy to keep the shape of a package favorable, it is preferable.

  In addition, in common with 3GT single fiber, blend fiber, and composite fiber, an oil agent may be applied by a known method before drawing with a roller and / or before winding. Moreover, in order to increase the number of confounding, it is also possible to perform confounding several times.

  Furthermore, when using the polyester fiber of the present invention as a woven or knitted fabric, false twist may be performed in order to impart stretchability.

Hereinafter, an example is given and it demonstrates concretely. In addition, the main measured value of the Example was measured with the following method.
(1) Intrinsic viscosity Intrinsic viscosity [η] is a value determined on the basis of the following definition, using orthochlorophenol as a solvent, measuring the viscosity at 30 ° C. Here, C is the concentration of the solution, and ηr is the relative viscosity (ratio of the viscosity of the solution at a certain concentration C to the viscosity of the solvent).

(2) Melt Viscosity Using a Capillograph 1B manufactured by Toyo Seiki Co., Ltd., measurement was performed three times at a shear rate of 1216 sec ⁻¹ under a nitrogen atmosphere, and the average value was taken as the melt viscosity (poise). The measurement temperature was the same as the spinning temperature in each example and comparative example, and the melt viscosity was measured after maintaining the same time as the polymer residence time in each example and comparative example. That is, the melt viscosity of 3GT in Example ¹ is a value measured at a shear rate of 1216 sec ⁻¹ after being held at a temperature of 270 ° C. for 15 minutes by the Capillograph 1B.
(3) Strength, elongation, initial tensile resistance, elongation recovery rate after 20% elongation Measured according to JIS L1013 (1999). The strength and elongation were measured according to JIS L1013 (1999) section 8.5 “Tensile strength and elongation” at a gripping interval of 20 cm and a tensile speed of 50% / min. The initial tensile resistance was measured according to JIS L1013 (1999) 8.10 at a gripping interval of 20 cm and a tensile speed of 50% / min. The elongation recovery rate after 20% elongation is the elasticity when the sample is stretched to 20% with a gripping interval of 20 cm and a tensile speed of 50% / min in accordance with 8.9 method of elongation modulus A in JIS L1013 (1999). The rate was determined.
(4) Release rate after 160 ° C. dry heat treatment The fiber is scraped 1 m × 10 times. The skein is subjected to a load of 9.1 × 10 ⁻³ cN / dtex, and the casket length is measured (L0). Next, a dry heat treatment is performed at 160 ° C. for 15 minutes under a load of 9.1 × 10 ⁻³ cN / dtex, and the skein length is measured immediately after the dry heat treatment (within 30 seconds) (L1). Further, after changing the load to 4.6 × 10 ⁻³ cN / dtex and leaving it at 20 ° C. for 30 minutes, the skein length is measured (L2). The shrinkage rate after 160 ° C. dry heat treatment is calculated by the following formula.
(Reduction rate after 160 ° C. dry heat treatment) = (L1−L2) / L0
(5) Boiling water shrinkage rate 1 m × 10 times of fiber. A load of 0.029 cN / dtex is applied to the skein, and the casket length is measured (L′ 0). Next, the skein is treated with boiling water at 100 ° C. for 15 minutes in an unloaded state, and after air drying, the skein length when a load of 0.029 cN / dtex is applied is measured (L′ 1). The boiling water shrinkage is calculated by the following formula.
Boiling water shrinkage (%) = {(L′ 0−L′1) / L′ 0} × 100
(6) 160 ° C. dry heat shrinkage The fiber is scraped 1 m × 10 times. The skein is subjected to a load of 0.029 cN / dtex and the scabbard length is measured (L "0). Next, the skein is treated in an oven at 160 ° C for 15 minutes with no load, and after air cooling, 0 Measure the skein length when a load of 029 cN / dtex is applied (L ″ 1). The 160 ° C. dry heat shrinkage is calculated by the following formula.
160 ° C. dry heat shrinkage (%) = {(L ″ 0−L ″ 1) / L ″ 0} × 100
(7) Shrinkage stress peak temperature, peak value, temperature at 0.5 cN / dtex stress A 200 mm sample was tied into an annular shape, and KE-2 manufactured by Kanebo Engineering Co., Ltd. was used, initial load 0.044 cN / dtex, initial temperature 30 The shrinkage stress was measured at a temperature of 100 ° C./minute, and the temperature at which the shrinkage stress becomes maximum (peak temperature) and the value of the shrinkage stress (peak value) at that time were determined. Further, the temperature is plotted on the horizontal axis and the shrinkage stress value is plotted on the vertical axis, and the temperature at the time of 0.5 cN / dtex stress is obtained.
(8) Saddle, bulge In each example and comparative example, when winding the fiber, it was wound around a paper tube having a diameter of 134 mm with a winding width of 114 mm to obtain an 8 kg package (winding diameter of about 340 mm). The obtained package was allowed to stand for 168 hours (7 days) in an atmosphere of 25 ° C. and 60% RH, and then the shape of the package was measured. As shown in FIG. 5, the maximum diameter (Dmax), minimum diameter (Dmin), maximum width (Wmax), and minimum width (Wmin) of the package were measured, and saddles and bulges were calculated according to the following equations.
Saddle (%) = {(Dmax−Dmin) / Dmin} × 100
Bulge (%) = {(Wmax−Wmin) / Wmin} × 100
(9) Fabric quality, fabric smoothness, light fastness, durability, comprehensive evaluation (i) Creation of evaluation raised knitted fabric Both the front yarn and the back yarn are made from the fibers obtained in each of the examples and comparative examples. Created a knitting machine with a tricot half structure. The obtained raw machine was refined at 95 ° C., preset at 140 ° C., and then brushed. Then, it dye | stained at 130 degreeC, the finishing set was performed at 160 degreeC using the pin tenter, and the raising knitted fabric was obtained.
(Ii) Fabric quality, fabric smooth feeling The obtained raised knitted fabric was cut into a 30 cm square, and four points of sensory evaluation were performed on one point of the knitted fabric by a consensus of three evaluators having three years of experience. The pass level is B or higher.

A: Excellent B: Excellent C: Although the effect is improved compared to the conventional product, it is not a significant improvement D: Same as the conventional product It is.
Fabric quality: The surface roughness of the fabric and the curl of the fabric were visually evaluated for comparison with a conventional product (3GT fiber, Comparative Example 7). The smaller the unevenness of the fabric surface and the curl of the fabric, the better, and the A evaluation was that the unevenness and curl of the fabric surface could not be confirmed visually.
Fabric smooth feeling: The softness and uniformity of the raised fabric was compared with a conventional product (PET fiber, Comparative Example 9) by tactile sensation. It is said that the higher the softness and the more uniform the sliding feeling, the better.
(Iii) Light fastness A high energy type xenon fade meter (SC700-1FA: manufactured by Suga Test Instruments Co., Ltd.) was used. The raised knitted fabric was sandwiched between urethane sheets and fixed to a holder. A glass filter was attached to the holder, and a xenon lamp was irradiated at a black panel temperature of 73 ° C. × 50% RH × 3.8 hours. About the sample after a test, the grade determination was performed using the gray scale for color fading prescribed | regulated to JISL0804. The pass level is B or higher.

A: 4th grade or higher B: 3.5th grade C: 3rd grade D: 2.5th grade or less (iv) Durability Cut the raised knitted fabric into 10 cm squares, fix only the four corners, and leave the central part floating. A cross-sectional area of 4 cm ² and a load of 300 g are placed on the center and held for 30 seconds. Remove weight and wait 30 seconds. After repeating the above load loading and release a total of 5 times, about the raised knitted fabric that was released from the fixation and placed on a flat surface, it was conventionally visually observed by three evaluators with 3 years of experience as in the above (ii). Comparative evaluation with a product (PET fiber, Comparative Example 9) was performed. The smaller the dent of the fabric due to the load, the better, and the A evaluation was that the dent was not visually confirmed.

A: Excellent B: Excellent C: Although the effect is improved as compared with the conventional product, it is not a significant improvement. D: The same or higher (v) evaluation of the fabric is performed. A comprehensive evaluation was conducted. If any one of the items is C or less, it was designated as comprehensive evaluation C. In all cases where B is greater than or equal to B, three or more items of A are designated as comprehensive evaluation A, and other items are designated as comprehensive evaluation B. Evaluation was performed in three stages, and B or higher was regarded as acceptable.

A: Very good B: Excellent C: Significant improvement is not seen in comparison with conventional products Examples 1-3 and Comparative Examples 1-3
Experiments were conducted with core-sheath fibers. The polyester used was as shown in Table 1, and the ratio between the core and the sheath was appropriately changed. In Example 1, a 3GT homopolymer having an intrinsic viscosity of 1.1 was used as the sheath component, and a PET homopolymer having an intrinsic viscosity of 0.51 was used as the core component, and the core-sheath fiber was spun at a spinning temperature of 270 ° C. At this time, a core-sheath spinning die was used, and a core-sheath shape was formed by the die. The polymer residence time from entering the pipe to discharging the die was 6 minutes for 3GT and 50 minutes for PET. The melt viscosity measured under these conditions was 1900 poise for 3GT and 480 poise for PET.

The spinning equipment shown in FIG. 4 was used. Spinning was performed at a die depth of 20 mm and a spinning speed of 1600 m / min. The polymer discharged from the base 27 was cooled by a cooling device 28 to become fibers, and after being focused in an oil supply device 29 installed at 1500 mm from the base surface, an oil was applied. Furthermore, after the fiber was entangled by the entanglement device 30, the fiber was wound around the first roller 31 at a speed of 1600 m / min. The first roller 31 was heated to 55 ° C. After winding the fiber around the first roller 31 seven times, the fiber was drawn to the second roller 32 having a speed of 4200 m / min, and a 2.625-fold drawing was performed. The second roller 32 was heated to 150 ° C. The fiber was wound around the second roller 32 6 times, and heat treatment was performed at 150 ° C. and 39 × 10 ⁻³ seconds. After the heat treatment, entanglement is again given by the entanglement device 33, and the package 37 is formed by the contact roller 36 and the winder 38 via the third roller 34 and the fourth roller 35 for cooling the fiber and adjusting the tension. Winding was performed at 3990 m / min to obtain 84 dtex 48 filament polyester fiber.

  For Example 2 and Comparative Examples 1 and 2, yarn production was performed under the same conditions as in Example 1 except that the ratio of the polymer, the core and the sheath was changed. The residence time in Example 2 is 7 minutes for 3GT, 17 minutes for PET, the residence time in Comparative Example 1 is 10 minutes for 3GT, the PET is 10 minutes, and the residence time in Comparative Example 2 is 8 minutes for 3GT. PET was 14 minutes.

  In Example 3, a PBT homopolymer having an intrinsic viscosity of 0.78 was used as a core component, and 84 dtex48 filament core-sheath fibers were obtained. The residence time was 7 minutes for 3GT and 17 minutes for PBT. Yarn production was carried out under the same conditions as in Example 1.

  In Comparative Example 3, a core-sheath fiber having a PBT homopolymer having an intrinsic viscosity of 0.78 as a sheath component and a PET homopolymer having an intrinsic viscosity of 0.51 as a core component was obtained. The residence time was 6 minutes for PBT and 50 minutes for PET. Yarn production was carried out under the same conditions as in Example 1.

  The production conditions and results are shown in Table 1. In Examples 1 to 3, the initial tensile resistance, the elongation recovery rate at 20% elongation, and the release rate after 160 ° C. dry heat treatment satisfied the scope of the present invention, and good results were also obtained in fabric evaluation. Particularly, in Example 2, the most excellent initial knitted resistance, the elongation recovery rate at 20% elongation, and the release / shrinkage rate after 160 ° C. dry heat treatment were excellent, and a particularly excellent raised knitted fabric was obtained. Furthermore, since PET and PBT having good light fastness are combined as a core, the light fastness is improved as a whole of the core-sheath fiber.

  On the other hand, in Comparative Examples 1 and 2, since the characteristics of PET are deeply colored, the shrinkage rate is low, but the initial tensile resistance, which is the characteristic of 3GT, and the elongation recovery rate at 20% elongation are hidden. Thus, a satisfactory fabric could not be obtained. In Comparative Example 3, PBT was used instead of 3GT. However, the initial tensile resistance and elongation recovery were insufficient, and only a fabric having a particularly inferior durability in terms of repeated load evaluation was obtained.

Examples 4-6, Comparative Example 4
Next, an experiment was conducted on the influence of spinning speed and heat treatment temperature on the core-sheath fiber. The conditions were the same as in Example 2 except for the spinning speed and the heat treatment temperature. Production conditions and results are shown in Table 2.

  In Examples 4 to 6 in which the spinning speed was within the range of the present invention, it was possible to achieve both heat setability and softness and to obtain a fabric with good stretch recovery. On the other hand, in Comparative Example 4 where the spinning speed was 1000 m / min, the shrinkage rate after 160 ° C. dry heat treatment was as high as 1.6%, so that only a fabric with poor surface quality was obtained.

Examples 7-10, Comparative Examples 5-6
The blend fiber experiment was then carried out. The residence times in the polyester and the base used were as shown in Table 3. A blend fiber of 84 dtex 48 filaments was obtained under the same temperature and speed conditions as in Example 1 except that the base was changed and the two polymers were kneaded with a mixer and then discharged to obtain blend fibers. The production conditions and results are shown in Table 3.

  It can be seen from a comparison between Example 1 and Comparative Example 5 that even if the polymer blend ratio is the same, the blend fiber remains 3GT characteristics as compared with the core-sheath fiber. In Comparative Example 5, since the shrinkage rate was high, the unevenness of the fabric was conspicuous and was not practical. Further, in Comparative Example 6, since the mixing ratio of PET was increased, the initial tensile resistance and elongation recovery rate were deteriorated, and only a fabric having poor softness and durability was obtained.

  On the other hand, in Examples 7-10, while utilizing the characteristics of 3GT, it succeeded in the reduction of a shrinkage rate and was able to obtain the outstanding raising | knitting fabric.

Examples 11-12, Comparative Examples 7-9
Next, 3GT single fiber experiment was conducted. In Example 11, a 3GT homopolymer having an intrinsic viscosity of 1.1 was used, and spinning was performed at a spinning temperature of 250 ° C. The residence time at the base was 10 minutes. The base surface depth was set to 20 mm, and the yarn was produced using the equipment of FIG. First, the polymer discharged from the base 8 is cooled by the cooling device 9, applied with an oil agent by the oil supply device 10, and entangled by the entanglement device 11, and then the first roller 12 at a speed of 5000 m / min. It was wrapped around The first roller 12 was unheated and had a surface temperature of 35 ° C. After winding the first roller 12 seven times, it was drawn to the second roller 13 having a speed of 5000 m / min. The second roller 13 was heated to 150 ° C. The fiber was wound around the second roller 13 6 times, and heat treatment was performed at 150 ° C. and 32 × 10 ⁻³ seconds. After the heat treatment, winding was performed as a package 15 at 4850 m / min with the contact roll 14 and the winder 16 to obtain a polyester fiber of 84 dtex 48 filaments.

  Also in Example 12, yarn production was performed in the same manner as in Example 11, and the first roller 12 and the second roller 13 were wound at speeds of 6000 m / min and 5800 m / min, respectively, and an 84 dtex 48 filament polyester fiber was wound. Obtained.

  In Comparative Example 7, the polymer used is the same as in Example 11, but the first roller 12 is heated to 55 ° C., the speed is 3000 m / min, and the second roller 13 is 4000 m / min. .33-fold stretching was performed. The second roller 10 was heat-treated at 150 ° C. and wound up at 3800 m / min to obtain 84 dtex 48 filament polyester fiber.

  In Comparative Example 8, spinning was performed in the same manner as in Example 11, but the second roller was not heated.

  Comparative Example 9 was carried out in the same manner as in Example 11 except that a PET homopolymer with an intrinsic viscosity of 0.65 was used, the spinning temperature was 290 ° C., and the heat treatment with the second roller 13 was not performed.

  Production conditions and results are shown in Table 4. In Examples 11 to 12, good fabrics were obtained. On the other hand, in Comparative Example 7 in which the stretching was performed, the release rate was increased, the fabric quality was lowered, and only the package foam was poor. In Comparative Example 8, yarn production was carried out under conditions similar to the examples of JP-A No. 2001-348729, but the suppression of the shrinkage rate was insufficient and only the package foam was poor. Moreover, in the comparative example 9 using PET, only the fabric inferior to softness and durability was obtained.

Examples 13-14, Comparative Example 10
An experiment was conducted on the influence of the depth of the base. Using the same polymer as in Example 2, the spinning temperature, spinning speed, other temperature conditions, etc. were the same as in Example 2, and only the base surface depth was changed from 20 mm in Example 2 to 60 mm, 90 mm, 110 mm, and obtained. The fabric was evaluated. The results are shown in Table 5. In Example 13 where the die depth was 60 mm, an excellent fabric could be obtained as in Example 2. Further, even in Example 14 where the surface depth was 90 mm, a sufficiently excellent fabric could be obtained. However, in Comparative Example 10 in which the depth of the die surface is 110 mm, although the strength is improved, the boiling water shrinkage rate and the dry heat shrinkage rate are high, and the shrinkage rate is 1.6%. However, only a fabric with a low light fastness was obtained.

Example 15 and Comparative Example 11
Further, using the same polymer as in Example 12, the spinning temperature, spinning speed, other temperature conditions, etc. were also the same as in Example 12, and only the base surface depth was changed from 20 mm in Example 12 to 90 mm, 110 mm, and obtained. The fabric was evaluated. The results are shown in Table 5. In Example 15 in which the depth of the die surface was 90 mm, an excellent fabric similar to that in Example 11 could be obtained. However, in Comparative Example 11 in which the depth of the die surface was 110 mm, although an improvement in strength was observed, the shrinkage rate after 160 ° C. dry heat treatment was high, and a satisfactory fabric could not be obtained.

  The polyester fiber of the present invention is suitable for woven and knitted fabrics. By using the polyester fiber of the present invention, it is possible to obtain a woven or knitted fabric that is strong against repeated loads, has excellent surface softness and uniformity, and has no irregularities or curls. Since the woven or knitted fabric obtained from the polyester fiber of the present invention has high resistance to repeated loads, it is suitably used for car seats that are subject to human load. In addition, in a car seat, in order to give a high-class feeling, a raising process may be implemented. Since the polyester fiber of the present invention has a low initial tensile resistance, it has an excellent soft feeling when the obtained fabric is raised. In addition, since the surface state differs between the front and back of the fabric by raising, problems such as curling are likely to occur. However, since the polyester fiber of the present invention has a low release rate after 160 ° C. dry heat treatment, the occurrence of curling or the like can be suppressed even when the raising treatment is performed. In that sense, the polyester fiber of the present invention and the fabric obtained therefrom are the most desired fiber and fabric from the automobile industry.

It is a schematic diagram which shows the relationship between a nozzle | cap | die and a nozzle | cap | die surface depth. It is a figure which shows an example of the preferable yarn making equipment of 3GT single fiber. It is a figure which shows an example of the preferable yarn making equipment of 3GT single fiber. It is a figure which shows an example of the preferable yarn-making equipment of 3GT core-sheath fiber and a blend fiber. It is a schematic diagram explaining the bulge and saddle which are the indicators of the package and package form.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Polymer 2 Piping 3 Spinning heating body (spinning temperature)
4 base 5 heat insulator 6 depth of base 7 discharged polymer 8 base 9 cooling device 10 refueling device 11 entanglement device 12 first roller 13 second roller 14 contact roller 15 package 16 winder 17 cooling device 19 oiling device 19 20 Entangling device 21 First roller 22 Heating plate 23 Second roller 24 Contact roller 25 Package 26 Winder 27 Cap 28 Cooling device 29 Refueling device 30 Entangling device 31 First roller 32 Second roller 33 Entangling device 34 Third roller 35 Fourth roller 36 Contact roller 37 Package 38 Winder

Claims (13)

  A polyester fiber having an initial tensile resistance of 15 to 38 cN / dtex, an elongation recovery rate after 20% elongation of 70% or more, and a release rate after dry heat treatment at 160 ° C. of 0.3% to 1.4%.   The polyester according to claim 1, which has a boiling water shrinkage of 4 to 11%, a 160 ° C dry heat shrinkage of 4 to 15%, and a temperature of 0.5 cN / dtex stress in the shrinkage stress curve of 55 to 80 ° C. fiber.   The polyester fiber according to claim 1, comprising polytrimethylene terephthalate.   The polyester fiber according to claim 3, further comprising a polymer selected from polyethylene terephthalate and polybutylene terephthalate.   The polyester according to claim 3, wherein the polyester is a concentric core-sheath composite fiber, the sheath is made of polytrimethylene terephthalate having an intrinsic viscosity of 0.8 to 1.2, and the core is made of polyethylene terephthalate having an intrinsic viscosity of 0.4 to 0.6. fiber.   A woven or knitted fabric comprising the fiber according to any one of claims 1 to 5.   A woven or knitted fabric comprising only the fibers according to any one of claims 1 to 5.   A car seat comprising the woven or knitted fabric according to any one of claims 6 to 7.   The car seat according to claim 8, which has been subjected to raising treatment.   A cheese-like package in which the fiber according to any one of claims 1 to 5 is wound, the bulge is -5 to 10%, and the saddle is 0 to 10%. A method for producing the polyester fiber according to claim 1, comprising:
Melting a polytrimethylene terephthalate polymer;
A step of discharging from a base having a base depth of 20 to 90 mm,
A step of drawing the discharged polymer at a spinning speed of 4500 to 7000 m / min, and
The manufacturing method of the polyester fiber including the process of heat-processing at 120-180 degreeC without extending | stretching the taken-up fiber.   The method for producing a polyester fiber according to claim 11, wherein the heat treatment is a tension heat treatment. A method for producing the polyester fiber according to claim 4,
Melting polytrimethylene terephthalate having an intrinsic viscosity of 0.8 to 1.2,
Melting polyethylene terephthalate having an intrinsic viscosity of 0.4 to 0.6 or polybutylene terephthalate having an intrinsic viscosity of 0.5 to 0.9;
A process of joining two molten polymers at the base,
Discharging the merged polymer from the die having a depth of 20 to 90 mm;
A step of drawing the discharged polymer at a spinning speed of 1400-3500 m / min, and
A method for producing a polyester fiber, comprising a step of heat-treating the taken-up fiber at 120 to 180 ° C. after drawing.

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