JP2002249926A - Polyester highly shrinkable fiber and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyester highly shrinkable yarn for combined filament yarns exhibiting sufficient heat shrinkage characteristics in a heat-treating and a dyeing steps with a sight extension residual strain in the final fabric and producing an excellent fullness feeling and to provide a method for stably and efficiently producing the polyester highly shrinkable yarn. SOLUTION: This polyester highly shrinkable yarn has >=15 and <35% S2-S1 and >=1 F2/F1 in which S1 denotes the dry heat shrinkage percentage under a constant load at 120 deg.C; S2 denotes the dry heat shrinkage percentage under a constant load at 190 deg.C; F1 denotes the dry heat shrinkage stress under a constant load at 120 deg.C; and F2 denotes the dry heat shrinkage stress under a constant load at 190 deg.C in the polyester highly shrinkable yarn comprising a polyester prepared by copolymerizing a third component in an amount of 8-40 mol% based on the whole acid component. Furthermore, the polyester highly shrinkable yarn is produced by melting, discharging and solidifying a copolyester, then taking off the resultant yarn with a preheating roller heated at 60-90 deg.C and with 1,700-4,000 m/min speed, drawing the taken off yarn between the preheating roller and a pair (two) of heat-setting rollers heated at 100-140 deg.C at a ratio of >=1.6 to <2.8, heat-setting the drawn yarn with the heat-setting rollers and then winding the heat-set yarn.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a highly shrinkable polyester yarn which exhibits sufficient heat shrinkage characteristics in a heat treatment / dyeing step and gives an excellent swelling feeling to a final fabric, and a method for efficiently producing the same.

[0002]

2. Description of the Related Art Polyester fibers are widely used as materials for clothing fabrics by taking advantage of their excellent properties. Along with the diversification, sophistication, and individualization of clothing life, attempts to realize natural and preferable characteristics of polyester fibers brought about by irregularities in fiber properties of natural fibers have been continued. In particular, a fabric woven using a mixed yarn composed of a plurality of polyester fibers having different shrinkage characteristics is subjected to a heat treatment in a process such as heat treatment and dyeing to cause a difference in shrinkage between the yarns, thereby providing a favorable swelling feeling to the final fabric. The method is widely adopted.

[0003] In such applications, there is an increasing demand for hetero-shrinkage mixed fiber yarns that can provide a fabric having a more excellent swelling feeling and a reduced elongation residual strain.

[0004] In the above-mentioned different shrinkage mixed fiber yarn, the shrinkage characteristic of the yarn having a higher shrinkage rate (hereinafter referred to as polyester high shrinkage yarn) controls the heat shrinkage behavior of the fabric in the heat treatment / dyeing step. In many cases, the swelling feeling and elongation residual strain of the final fabric are determined, and the present inventors have paid attention to such a point, and have studied a polyester high shrink yarn that can satisfy both characteristics.

Furthermore, the present inventors have studied a method for producing the above-mentioned polyester high shrinkage yarn. However, the conventionally proposed method cannot obtain the desired high shrinkage yarn, or the yarn cannot be obtained in the spinning / drawing process. There is a problem that vibrations are severe and thread breakage occurs and stable production cannot be achieved.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has an object to exhibit a sufficient heat shrinkage property in a heat treatment and dyeing process, to have a small residual tensile strain in a final fabric, An object of the present invention is to provide a polyester high shrinkage yarn for a mixed fiber, which provides an excellent swelling feeling, and to provide a method for stably and efficiently producing the polyester high shrinkage yarn.

[0007]

As a result of repeated studies by the present inventors, the above-mentioned object consists of a polyester obtained by copolymerizing a third component at a ratio of 8 to 40 mol% based on the total acid components. It has been found that this can be achieved by a polyester high shrink yarn having properties satisfying the expressions (1) and (2). (1) 35%> S2-S1 ≧ 15% (2) F2 / F1 ≧ 1 Here, S1 is 120 ° C., S2 is constant load dry heat shrinkage at 190 ° C., F1 is 120 ° C., and F2 is 190 ° C. Dry heat shrinkage stress.

[0008] Further, the above polyester high shrinkage yarn,
It can be manufactured by an efficient direct spinning / drawing method. At this time, by adopting a pair of (two) heat setting rollers, yarn sway can be extremely reduced, and there is no breakage and stable. It was found that spinning and stretching were possible.
Accordingly, as a result of further study, the polyester high shrinkage yarn was obtained by melting, discharging, cooling and solidifying a polyester obtained by copolymerizing the third component at a ratio of 8 to 40 mol% based on the total acid components, and then 60 to 90%. At a speed of 1700 to 4000 m / min by a preheating roller heated to 100 ° C., and a pair of (2) heated to 100 to 140 ° C.
) And stretched at a magnification of 1.6 or more and less than 2.8, and heat-set with the heat-set roller and wound up.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail. Polyester used in the present invention,
It is a polyester in which the main repeating unit is ethylene terephthalate and the third component is copolymerized at a ratio of 8 to 40 mol% based on the total acid components. Preferred examples of the third component include isophthalic acid, bisphenol A, bisphenol A ethylene oxide adduct, diethylene glycol, neopentyl glycol and the like. The intrinsic viscosity (measured at a temperature of 30 ° C. as an orthochlorophenol solvent) of such a polyester is not particularly limited, and is appropriately set according to the use of the obtained polyester yarn. For use in clothing, polyesters having an intrinsic viscosity of 0.5 or more, particularly 0.6 to 1.2 are preferred.

In the present invention, the constant load dry heat shrinkage and the dry heat shrinkage stress of the polyester high shrinkage yarn are as follows:
It is important that the expression and the expression (2) are simultaneously satisfied. As a result, after heat treatment and dyeing, a fabric having little residual elongation and excellent swelling feeling can be obtained. (1) 35%> S2-S1 ≧ 15% (2) F2 / F1 ≧ 1 Here, S1 is 120 ° C., S2 is constant load dry heat shrinkage at 190 ° C., F1 is 120 ° C., and F2 is 190 ° C. Dry heat shrinkage stress.

When the difference (S2-S1) between S2 and S1 of the polyester high shrinkage yarn is less than 15%, the shrinkage in the heat treatment / dyeing step becomes insufficient, and no excellent swelling feeling is exhibited. On the other hand, when S2-S1 is 35% or more, excessive shrinkage occurs in the heat treatment / dyeing step, and although the fabric has a swelling feeling, the residual strain due to elongation is large and is not practical. Here, when S2 is in the range of 25% to 40%, a higher swelling feeling is exhibited.

When the ratio of F2 to F1 (F2 / F1) is smaller than 1, the polyester high shrinkage yarn does not undergo a well-balanced shrinkage in the heat treatment / dyeing step, and the final fabric exhibits an excellent swelling feeling. do not do. More preferred F
The range of 2 / F1 is 1.1 to 1.5. When the range is set to such a range, the heat shrinkage of the fabric can be adjusted more accurately, and the fabric can have a more excellent swelling feeling.

Further, when a polyester high shrinkage yarn having a birefringence Δn of 0.13 or more and a specific gravity ρ of 1.37 or less is used, a more excellent swelling feeling is exhibited by the cloth.

The polyester highly shrinkable yarn of the present invention is obtained by melting, discharging and discharging a polyester obtained by copolymerizing a third component at a ratio of 8 to 40 mol% based on the total acid components.
After cooling and solidifying, take off with a preheating roller, stretch between the preheating roller and the heat setting roller, use a method of heat setting and winding up with the heat setting roller, at this time, the temperature of the preheating roller, the preheating roller Take-off speed, the temperature of the heat set roller, and the stretching ratio between the preheating roller and the heat set roller are performed under the following conditions, and a heat set roller including a pair (two) of rollers is used as the heat set roller. By adopting it, it can be manufactured stably and efficiently.

By setting the temperature of the preheating roller in the range of 60 to 90 ° C., it is possible to perform uniform drawing without performing flow drawing, and to stably produce a polyester high shrink yarn having physical properties that can withstand practical use. .

The take-up speed of the preheating roller is 1700 to 1700.
The range is 4000 m / min. Pickup speed is 40
If it exceeds 00 m / min, oriented crystals are promoted in the process of narrowing the flow of the discharged polymer, and the peak of the dry heat shrinkage stress shifts to the low temperature side, so that F2 / F1 cannot be 1 or more. Further, under the condition of the picking-up speed, S2
-It becomes difficult to set S1 to 15% or more. On the other hand, if the take-up speed is less than 1700 m / min, it is necessary to considerably increase the draw ratio in order to make the yarn practically usable,
It will be difficult to achieve a draw ratio of less than 2.8 described below.

The stretching ratio is 1.6 or more and less than 2.8.
When the draw ratio is 2.8 or more, the change in the heat shrinkage of the polyester high shrinkage yarn at 100 ° C. to 200 ° C. due to the temperature becomes small, and S2−S1 becomes less than 15%. Also,
The dry heat shrinkage stress at 190 ° C. is smaller than that at 120 ° C. On the other hand, if the stretching ratio is less than 1.6, 400
Even if the undrawn yarn drawn at 0 m / min is drawn, the elongation becomes too high, so that it is not a practical polyester high shrink yarn.

The temperature of the heat setting roller is from 100 ° C. to 14 ° C.
The range is 0 ° C. When the temperature of the heat setting roller is lower than 100 ° C., the dry heat shrinkage stress at 190 ° C. is larger than that at 120 ° C., but the constant load dry heat shrinkage at 190 ° C. is much larger than 120 ° C., and S2-S1
Is 35% or more. Further, such a polyester high shrinkage yarn undergoes excessive shrinkage in the heat treatment / dyeing step, and although the fabric swells, a large residual strain due to elongation is not enough for practical use. On the other hand, when the heat setting roller temperature exceeds 140 ° C., 100 ° C. to 200 ° C.
, The change of the heat shrinkage of the polyester high shrinkage yarn due to the temperature becomes small, and S2-S1 becomes less than 15%. Further, the dry heat shrinkage stress of the polyester high shrinkage yarn at 190 ° C. is smaller than that at 120 ° C.

At this time, the above-mentioned heat setting roller is a heat setting roller composed of two rollers,
Compared to a heat setting roller consisting of only one roller, the yarn sway of the running yarn on the preheating roller or the heat setting roller can be extremely reduced, and the polyester high shrinkage yarn of the present invention can be stably It can be spun and wound up.

[0020]

EXAMPLES The present invention will be described more specifically with reference to the following examples. The constant load dry heat shrinkage, dry heat shrinkage stress, feeling of swelling, and elongation residual strain described in the examples were measured by the following methods.

(1) Constant Load Dry Heat Shrinkage, Dry Heat Shrinkage Stress Toray Engineering Co., Ltd. Heat Shrink Spot System FTA-
Using 500, a polyester yarn is supplied from a feed roller at a speed of 10 m / min, and is passed through a heating zone having a length of 20 cm set at a constant temperature and a temperature of 120 ° C.
I took it with a draw roller. The tension between these rollers is detected by a tension sensor, the draw roller speed is controlled so that the tension of the polyester running yarn becomes a constant load (constant tension) of 0.5 g, and the speed is measured continuously for 2 minutes. And the constant load dry heat shrinkage S at 120 ° C.
1 was calculated. S1 = (10−V _DR ) / 10 × 100 where V _DR is a measured value of the draw roller speed (m / min).

Next, the speed of the draw roller is set to 10 m / mi.
n, and the tension between the rollers was continuously measured for 2 minutes to obtain a dry heat shrinkage stress F1 at 120 ° C.

Further, the temperature of the heating zone was set at 190 ° C., and the constant load dry heat shrinkage S2 and the dry heat shrinkage stress F2 at 190 ° C. were measured in the same manner, and the respective values were calculated.

(2) A feeling of swelling A polyester fiber having a high shrinkage and a polyester stretched yarn having a lower heat shrinkage than the polyester high shrinkage yarn are combined to form a tricotine structure (warp density: 155 / 37.9 m).
m, a weft density of 240 yarns / 37.9 mm). Subsequently, the obtained green fabric was subjected to a shrinkage heat treatment at 96 ° C. for 30 seconds, 130 ° C. for 10 minutes, and 190 ° C. for 45 seconds, and then subjected to a dyeing treatment at 135 ° C. for 20 minutes with a disperse dye to evaluate the feeling of swelling. It is a woven fabric. Five examiners perform sensory evaluation in the following three stages. Rank A: Swelling with moderate repulsion is felt Rank B: Swelling with poor repulsion is weak Rank C: Swelling is not felt with a flat feel

(3) Extensional residual strain rate Three test pieces of 5.5 × 60 cm each were taken from the vertical and horizontal sides of the woven fabric prepared in the evaluation of swelling, and the test pieces were taken from either side of the width. Approximately the same number of yarns are drawn out to form a 5 cm wide test specimen. Mark both ends of those 40 cm positions, measure exactly the length between the marks, and use it as the measurement test length L ₀ . 3-4c from the position of the mark of 40cm
m at a position spaced apart from the test piece by 39.2N (4k
gf) and suspend up and down for 120 minutes. After unloading immediately specimen was placed on a horizontal table, a length between the mark attached after 20 minutes the test piece was measured and L _20. The extension residual strain rate is measured by the following equation. Stretching residual strain ratio _{(%) = (L 20 -L} 0) / L 0 × 100

(4) Process condition This is expressed as the number of yarn breaks per day when the spinning / drawing machine with 6 weights is run for 3 days.

[Examples 1 to 4, Comparative Examples 1 to 3] Polyethylene terephthalate having an intrinsic viscosity of 0.64 obtained by copolymerizing 10% by mole of isophthalic acid was dried, and was dried with an apparatus shown in FIG. The running yarn (3) discharged through several dozen spinnerets (1) and cooled and solidified by the spinning cooling device (2) is bundled and oiled by the oiling device (4) and heated to 75 ° C. One pair (two pieces) (7 and 8) heated to the temperature shown in Table 1 while taking up the preheated roller (5) under the conditions shown in Table 1 and maintaining the distance between the traveling yarns via the separator (6). Alternatively, it is stretched at a magnification shown in Table 1 with one (7) heat setting roller, heat-set with the heat setting roller, and entangled with an air entanglement device (9) while winding the yarn (10). 56) decitex /
A 12 filament polyester high shrink yarn was obtained. The obtained polyester high shrinkage yarn, fineness 90 decitex,
Number of single yarns 36, strength 4.0 cN / decitex, elongation at break 40.1%, constant load dry heat shrinkage S1 8%, S2 11
%, A dry heat shrinkage stress F1 of 15 cN, and a drawn polyester yarn of F2 of 12 cN were blended, and after weaving and dyeing, the swelling feeling and elongation residual strain were evaluated. Table 1 summarizes the evaluation results and process conditions.

[0028]

[Table 1]

[0029]

According to the polyester high shrinkage yarn of the present invention, the fabric after heat treatment and dyeing can exhibit an excellent swelling feeling. Furthermore, the above-mentioned cloth also has an advantage that it has little elongation residual strain. Further, according to the production method of the present invention, the polyester high shrinkage yarn can be produced stably and efficiently by direct spinning and drawing.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating the steps for carrying out the production method of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 spinneret 2 spinning cooling device 3 running yarn 4 oil applying device 5 preheating roller 6 separator 7, 8 heat setting roller 9 air entanglement device 10 winder

Claims (4)

[Claims] 1. A highly shrinkable polyester yarn comprising a polyester obtained by copolymerizing a third component at a ratio of 8 to 40 mol% based on all acid components, and having characteristics satisfying the following formulas (1) and (2). (1) 35%> S2-S1 ≧ 15% (2) F2 / F1 ≧ 1 Here, S1 is 120 ° C., S2 is constant load dry heat shrinkage at 190 ° C., F1 is 120 ° C., and F2 is 190 ° C. Dry heat shrinkage stress. 2. Constant load dry heat shrinkage S2 at 190 ° C.
The polyester high shrinkage yarn according to claim 1, wherein is in the range of 25 to 40%. 3. The polyester highly shrinkable yarn according to claim 1, wherein the birefringence Δn is 0.13 or more and the specific gravity ρ is 1.37 or less. 4. A polyester obtained by melting, discharging, cooling and solidifying a polyester obtained by copolymerizing a third component at a ratio of 8 to 40 mol% based on all acid components, and then heating the polyester to 1700 to 4000 m by a preheating roller heated to 60 to 90 ° C. / Min at a speed of 1 min.
1.6 or more between a pair (two) of heat setting rollers
A method for producing a polyester highly shrinkable yarn, comprising drawing at a magnification of less than 8, heat setting with the heat setting roller, and winding up.