JPH11241242A - Thick and thin yarn and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyester thick and thin yarn having a dry feeling, a smooth feeling, providing a light and shade contrast of short cycle by dyeing, having a natural melange-like uneven feeling and excellent stretchability. SOLUTION: This thick and thin yarn is a multifilament yarn substantially comprising a polypropylene terephthalate having 1.5-15% Uster normal U% in the direction of yarn length and a thickness unevenness of >=10/m thickness variation peaks with >=4.0 %. The multifilament yarn has <=30 g/d Young's modulus.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a marbled chic and thin yarn made of polyester which is excellent in stretchability, has a dry feeling and a smooth feeling, and has a short cycle length when dyed, and a method for producing the same. About.

[0002]

2. Description of the Related Art It has been known that a thick yarn can be obtained when an undrawn polyester yarn or a highly oriented undrawn yarn is incompletely drawn. Naturally, the thick and thin yarn has characteristics such as a feeling as the thick and thin ratio is large. However, if the thick and thin ratio is emphasized, the constant stress elongation region is likely to remain due to the inclusion of the undrawn portion. For this reason, there is a dilemma that permanent distortion is likely to occur in a processing stage or in a fabric product, and handleability and functionality deteriorate. Therefore, there is a problem that a product with good characteristics is inferior in function, and a product with no problem in functionality is hard to have characteristics.

In order to improve this functionality, a method of dispersing thick and thin between filaments and mixing them in constituent filaments is disclosed in JP-B-51-7207 and JP-A-58-5858.
-203113, JP-A-59-94617, JP-A-59-94643, JP-B-6-946.
No. 09 publication. In this method, the undrawn yarn having a spinning speed of less than 1700 m / min is used,
Before drawing, the undrawn yarn is subjected to a tension heat treatment at a temperature near or higher than the secondary transition temperature, and then a thick and thin yarn is obtained by incomplete drawing. In addition, there was an effect in reducing the residual shrinkage, but there was a problem of thermal embrittlement of the thick portion, and there was a problem that the thick portion dropped off at the processing stage or in a fabric product, and fluff was easily generated. . On the other hand, Japanese Patent Publication No. 7-3012 discloses that a highly oriented unstretched yarn is used and a stretching system having three heating elements and a frictional resistor in the same stretching system cannot be stretched at a stretching ratio higher than the natural stretching ratio. There has been proposed a method for obtaining a thick and thin yarn by complete drawing. Although this method was effective in solving the problem of thermal embrittlement of the thick part, the contrast of shading due to dyeing became unclear, and the friction coefficient between the friction resistor and the yarn changed due to dirt and abrasion of the friction resistor. It was difficult to obtain a thick and thin yarn stably because the thick and thin pattern greatly changed between the yarns and over time.

On the other hand, polypropylene terephthalate fiber is excellent in elongation elastic recovery, low in Young's modulus, good in dyeability, chemically stable, and suitable for clothing. No. 5320 and JP-A-52-81.
It has been known for a long time, as seen in Japanese Patent Publication No. 24 and the like. However, since 1,3 propanediol as a raw material is relatively expensive, it has not been used as a fiber until now.

[0005]

SUMMARY OF THE INVENTION The present invention provides a dry feeling,
To provide a thick and thin yarn made of polyester which has a smooth feeling, provides a light and dark contrast with a short cycle length by dyeing, has a natural frosty tone, and has excellent stretchability, and a method for producing the same. It is intended for.

[0006]

A thick and thin yarn which achieves the above object of the present invention has a wister normal U% of 1.5 to 15% in the length direction of the yarn, and a thickness of 4%. A multifilament substantially composed of polypropylene terephthalate having thickness unevenness in which the number of thickness fluctuation peaks of 0.0% or more is 10 / m or more, and the multifilament has a Young's modulus of 30 g / d or less. It is characterized by the following.

Further, according to the method for producing a thick and thin yarn of the present invention, the birefringence obtained by melt spinning is 20 × 10 ^−3.
When a multifilament unstretched yarn made of polypropylene terephthalate having a size of ６０60 × 10 ^-3 is drawn at a low magnification to produce a thick and thin yarn, the drawing is performed simultaneously at a rate of 1.05 to 1.7 times between a supply roller and a drawing roller. False twist, 80-18
It is characterized by heat setting at 0 ° C.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Polypropylene terephthalate in the present invention comprises terephthalic acid as a main acid component,
Polyester obtained by using 1,3 propanediol as a main glycol component. However, it may contain another copolymer component capable of forming an ester bond at a ratio of 20 mol%, more preferably 10 mol% or less.

Examples of the copolymerizable compound include isophthalic acid, cyclohexanedicarboxylic acid, adipic acid,
Dicarboxylic acids such as dimer acid and sebacic acid, and on the other hand, examples of the glycol component include, but are not limited to, ethylene glycol, diethylene glycol, butanediol, neopentyl glycol, cyclohexanedimethanol, polyethylene glycol, and polypropylene glycol. Not something.

[0010] Titanium dioxide as a matting agent, silica or alumina fine particles as a lubricant, hindered phenol derivatives, coloring pigments and the like as antioxidants can be added as required.

In the present invention, by setting the value of Uster normal U% in the length direction of the yarn to 1.5 to 15%, the cloth using the multifilaments made of the polypropylene terephthalate can be dyed naturally by dyeing. By having a feeling of fineness on the surface of the fabric,
A tactile dry material can be obtained. The Uster normal U% is preferably 2 to 12%, particularly preferably 3 to% 10.

Further, the number of peaks with a thickness variation of 4.0% or more when the Worcester spots were measured by the normal test was found to be 1% of the yarn length.
It is indispensable that the number is 10 or more per m in order to achieve the target texture of the present invention. Here, the number of thickness fluctuation peaks of 4.0% or more is a value obtained by reading the size of each peak in the U% chart as the difference between the upper end and the lower end of the peak, and counting the peaks whose difference is 4% or more. It is. The higher the number of thickness variation peaks, the greater the width and width of thin and fine pitches. Therefore, the effect of the neck (constriction) at the boundary between the thick portion and the fine portion gives a dry and smooth texture. The number of thickness variation peaks is preferably at least 12 / m, more preferably at least 15 / m.

The thick and thin yarn of the present invention, having a Young's modulus of 30 g / d, can be a fabric which is soft when formed into a fabric but does not easily suffer from elbow slippage. Young's modulus is preferably 25 g / d or less.

Further, the thick and thin yarn of the present invention is excellent in elastic recovery after 10% elongation, so that when it is made into a garment, it has high stretchability and is excellent in wearing comfort. The elastic recovery after 10% elongation is preferably 60% or more, more preferably 70% or more.

Next, a preferred method for producing a thick and thin yarn comprising the polypropylene terephthalate of the present invention will be described.

The thick and thin yarn made of polypropylene terephthalate of the present invention is a low-filament multifilament yarn made of polypropylene terephthalate having a birefringence of 20 × 10 ^{−3 to} 60 × 10 ⁻³ obtained by melt spinning. In producing a thick and thin yarn by stretching at a draw ratio, it can be produced by performing simultaneous false twisting at 1.05 to 1.7 times between a supply roller and a stretching roller and heat setting at 80 to 180 ° C. .

The method of the present invention is extremely effective in obtaining a thick and thin thread having a short cycle length. Further, it is extremely effective in obtaining a thick and thin yarn in which thick portions and details are mixed in the cross-sectional direction of the multifilament.

Here, by setting the birefringence of the undrawn polypropylene terephthalate yarn to 20 × 10 ^{−3 to} 60 × 10 ⁻³ , stable quality can be obtained in mass production. A more preferable range of the birefringence is 25 × 10 ^{−3 to} 5.
It is 0 × 10 ⁻³ .

The present invention is to produce a thick and thin yarn in which thick portions and details are substantially mixed, and is to draw at a low draw ratio of 1.05 to 1.7 times. The draw ratio is set to the above range, and in combination with the vibration of the yarn in the false twisting device, non-uniform stretching is caused on a heat setting device installed on the downstream side of the false twisting device. Can be produced. Further, a more preferable range of the stretching ratio is 1.1 to 1.6 times.

As a method of false twisting, a generally known false twisting device can be used, but a fluid swirling nozzle using compressed air as a working fluid is particularly preferably used. Since the fluid swirl nozzle has extremely small damage to the yarn while traveling in the drawing zone, it is generally possible to produce a thin and thick yarn without breaking the yarn even when obtaining a thin and thick yarn, and also to obtain the physical properties of the yarn. Is small and excellent in continuous productivity. Further, dirt and abrasion are extremely small, and the thick and thin pattern does not change between the yarns and with the passage of time, so that a thick and thin yarn can be stably obtained. The form of the thick and thin yarn of the present invention thus obtained mainly has thick details finely dispersed at a short pitch, but substantially no crimp due to false twist.

That is, by using a fluid swirling nozzle to generate high-speed rotation ballooning on the yarn traveling in the stretching zone, the yarn intermittently contacts and stretches with the heat setting device in synchronization with the ballooning rotation speed. Therefore, the thick yarn portion and the fine yarn portion are finely dispersed in the length direction of the multifilament and in the direction between the single yarns. For this reason, a thick and thin yarn having a short cycle length can be obtained without being affected by the length of the drawing zone. This gives a marbling-like heather effect,
A natural plaque is obtained. As described above, the actions of false twisting and ballooning are important to obtain a thick and thin yarn having a short cycle length. In order to stably apply the false twist and ballooning, it is preferable to use a yarn path guide before and after the fluid swirl nozzle to regulate the running position of the yarn.

In the present invention, the method of heat setting is not particularly limited, but as the heat setting device, it is preferable to perform tension heat setting using, for example, a heat stretching roller or a hot plate. By the tension heat setting, the relaxation of the orientation of the molecular chains during the heat setting is suppressed, and the washing fastness when the dyed fabric is washed can be greatly improved. The method of tension heat setting is not particularly limited, but a contact type or non-contact type hot plate is used,
A heated stretching roller on the satin surface can be used.

[0023] The heat setting temperature is preferably from 80 ° C to 180 ° C. More preferably, it is 100 ° C to 160 ° C. Here, the heat setting temperature is a surface temperature of the heat setting device in contact with the yarn in the contact heat setting device, and is an ambient temperature of the yarn passing portion in the non-contact heat setting device. When the heat setting temperature is less than 80 ° C,
The stretching point is not fixed on the heat setting device, so that it is not possible to form the short pitch thick and thin, which is the object of the present invention.
On the other hand, when the heat setting temperature exceeds 180 ° C., partial fusing occurs on the heat setting device, and yarn breakage occurs, resulting in extremely poor yarn-making properties and low mechanical properties of the obtained yarn, making it impractical. Will be.

Next, the manufacturing method of the present invention will be described with reference to an embodiment shown in the drawings.

FIG. 1 shows a method for producing a thick and thin yarn using an undrawn yarn that has been once melt-spun and wound. A multifilament unstretched yarn 1 made of polypropylene terephthalate having a birefringence of 20 × 10 ^{−3 to} 60 × 10 ⁻³ is supplied with an operating air pressure between a first delivery roller 3 and a second delivery roller 5 via a feed roller 2. Using a fluid swirl nozzle 4 of 0.5 to ⁵ kg / cm ² ,
While generating an articulated balloon on the running yarn,
The film is stretched at a low magnification of 1.7 times, and then the second delivery roller 5
After heat-setting at 80 ° C. to 180 ° C., a thick and thin yarn 7 is wound.

The stretching tension is not particularly limited.
It is good to be 0.3-1.0 g / d. If it is 1.0 g / d or more, ballooning due to the use of the fluid swirl nozzle 4 is less likely to occur, and it is difficult to control a thick and thin cycle length.

The length of the stretching zone is not particularly limited. There is no particular limitation on the installation position of the fluid swirl nozzle in the stretching zone. That is, by using the fluid swirl nozzle 4, a thick and thin yarn having a short cycle length can be obtained without being affected by the length of the stretching zone or the installation position of the fluid swirl nozzle.

FIG. 2 shows a method for producing a thick and thin yarn by directly drawing a melt-spun undrawn yarn without first winding it. The birefringence index melt-spun from the spinneret 8 is 20 × 10 ^{−3 to} 60 × 10 ^−3.
After applying an oil agent to the multifilament undrawn yarn 10 made of polypropylene terephthalate by the oiling device 9,
Between the first delivery roller 11 and the second delivery roller 13, while using a fluid swirl nozzle 12 having an operating air pressure of 0.5 to 5 kg / cm ² , while generating a knotted balloon on the running yarn, 1.05 to 1 The sheet is stretched at a low magnification of 0.7 times, subsequently heat-set at 80 ° C. to 180 ° C. with the second delivery roller 13, and wound up as a thick and thin yarn 14.

Here, the cross-sectional shape of the multifilament made of polypropylene terephthalate is not only round but also multi-filament.
It may be a three-lobed, hollow, polygonal, H-shaped, π-shaped, C-shaped, flat type, flat multi-lobed type or any other known cross section. Further, it may be a mixed fiber of a multifilament made of polypropylene terephthalate and another melt-spinnable thermoplastic polymer, or a composite fiber. The fabric form can be appropriately selected depending on the purpose, such as a woven fabric, a knitted fabric, or a nonwoven fabric.

[0030]

The present invention will be described in more detail with reference to the following examples. Each characteristic value in the examples was obtained by the following method.

A. Intrinsic viscosity [η] 0.10 g of sample per 10 ml of orthochlorophenol
Was dissolved and measured at 25 ° C. using an Ostwald viscometer.

B. U% and number of thickness fluctuation peaks
It was measured with STER MONITOR C (Zellweger USTER). Yarn speed 8m / min, TWIST Z 1.5, YARN TENTION 1.
5. EVALUTION TIME 2.5 minutes, RANGE 100%, measurement mode is normal, measure average deviation rate U%, and record waveform on chart. The measured value is measured at any three points of the sample, and the average value is used. From the recorded waveform, the magnitude of each peak was read as the difference between the upper end and the lower end of the peak, the peak having a difference of 4% or more was counted, and the number of peaks per 1 m of yarn length was defined as the number of peaks of thickness variation. .

C. Strong elongation Strong elongation and Young's modulus were measured using Orientec Tensilon UCT-100 according to JIS L1013.

D. Elastic recovery rate after 10% elongation The sample was subjected to 20 c under an initial load of 1/30 g per denier using a constant-speed elongation type tensile tester equipped with a self-recording device.
m, and set the pulling speed to 1
Stretch to 0% and elongation to 10%. Immediately, from the stress-strain curve recorded at the same speed and recorded, the constant elongation up to an elongation of 10% was α, and the recovery elongation when the stress was reduced until the stress became equal to the initial load was β. .

E. Elastic recovery after 10% elongation (%) = (β / α) × 100 Dry heat shrinkage 1/30 per denier using a measuring machine with a frame circumference of 0.5 m
With an initial load of 60 turns / min and a number of turns of 1
Make a small knives 0 times and apply a load of 20 times the initial load to measure the knurl length. Next, the load was removed, the sample was suspended in a dryer at 160 ° C., left to stand for 15 minutes, and then taken out. After cooling to room temperature, a load was applied again to measure the length of the shell, and the hot water shrinkage was calculated by the following equation.

Dry heat shrinkage (%) = {(L0−L1) / L0} × 100 where L0: length before drying (mm) L1: length after drying (mm) Boiling water shrinkage 1/30 per denier using a measuring machine with a frame circumference of 0.5 m
With an initial load of 60 turns / min and a number of turns of 1
Make a small knives 0 times and apply a load of 20 times the initial load to measure the knurl length. Next, the load was removed, and the sample was immersed in hot water at 100 ° C. for 15 minutes, taken out, air-dried, and re-loaded to measure the length of the scab. The hot water shrinkage was calculated by the following equation.

Hot water shrinkage (%) = {(L0−L1) / L0} × 100 where L0: length before immersion (mm) L1: length after air drying (mm) Birefringence Measured by a compensator method using a BH-2 polarizing microscope manufactured by OLYMPUS.

H. Washing Fastness After treating according to the method described in JIS-L0844 “Testing method for dyeing fastness to washing” A-2 method, the degree of fading before and after washing is determined by gray scale according to the following criteria.

5th grade: no fading is observed 4th grade: almost no fading 3rd grade: slight fading is observed 2nd grade: fading is observed 1st grade: severe fading Lightfastness According to JIS-L0842 "Dyeing fastness test method with carbon arc lamp light". The 10-hour irradiation is classified as 3rd grade, the 20-hour irradiation is classified as 4th grade, and the 40-hour irradiation is classified as 5th grade. Based on the blue scale fading as a reference, the fading of the sample is determined by gray scale.

The staining conditions are as follows.

Dye Terra Sirane Perfume SGL (manufactured by CIBA-GEIGY); 0.4% owf assistant Tetrocin PEG (manufactured by Yamakawa Pharmaceutical Company); 5% owf Sun Salt # 1200 (manufactured by Sanyo Chemical); 1% owf Bath ratio; 1: 100 Temperature × time; 90 ° C. × 20 minutes Example 1 19.4 kg of dimethyl terephthalic acid, 15.2 kg of 1,3-propanediol, tetrabutyl titanate as a catalyst, and methanol at 140 ° C. to 230 ° C. Was distilled out, and further subjected to polymerization for 3 hours at a constant temperature of 250 ° C. to obtain polypropylene terephthalate having an intrinsic viscosity [η] of 0.89.

Using the polypropylene terephthalate polymer produced by the above-described method, a spinning temperature of 26 is used by a usual spinning machine.
Using a die having a diameter of 0.3 mmφ × 36 holes at 0 ° C. and discharging at a discharge rate of 35.2 g / min, 3000 m / min.
At a spinning speed of 105 denier, 3
A highly oriented polypropylene terephthalate undrawn yarn having 6 filaments and a birefringence of 45 × 10 ⁻³ was obtained. An air pressure of 2 kg is applied to the highly oriented unstretched yarn between a first delivery roller (hereinafter sometimes referred to as a supply roller) 3 and a second delivery roller (hereinafter sometimes referred to as a stretch roller) 5 by a stretching apparatus shown in FIG. / with fluid swirling nozzles 4 cm ^2, while generating a Yufushi balloon running yarn was stretched to 1.4 times, the second delivery roller 5 continues peripheral speed 800 m / minute
At 120 ° C. to obtain a thick and thin yarn. Table 1 shows the drawing conditions and yarn quality of the thick and thin yarn. Next, the thick and thin yarn is woven into a plain woven fabric at a woven density of 90 × 75 yarns / inch, scoured in a usual manner, set on a greige machine at 150 ° C., dyed with a disperse dye, and finished set with a 150 ° C. tenter. A fabric sample was prepared. Table 1 shows the color fastness of the fabric sample.

Table 1 shows the drawing conditions, yarn quality and color fastness of Example 1. The thickness unevenness in the length direction of the multifilament was 6% in Uster normal U%, and was 4.0%.
% Or more, the number of thickness variation peaks was 15 / m. In addition, the Young's modulus was 27 g / d, and the elastic recovery after elongation at 10% was 74%, exhibiting good soft feeling and stretchability.

The woven fabric sample made of the thick and thin yarn of Example 1 had fine irregularities on the woven fabric surface, and was soft and rich in dry feeling, smooth feeling and stretchability. In addition, a difference in shading with a short cycle length was exhibited by the dyeing, and a natural spot feeling in a span tone was obtained by a synergistic effect with the surface unevenness. The dyeing fastness of this woven fabric sample was 5th in both washing fastness and light fastness, and good results were obtained.

Comparative Examples 1, 2, 3 In Comparative Example 1, a fabric sample was stretched in the same manner as in Example 1 except that no articulated balloon was generated on the running yarn without using the fluid swirl nozzle. Created.

Table 1 shows the drawing conditions, yarn quality and color fastness of the thick and thin yarns. The thick and thin yarn of Comparative Example 1 had a thickness unevenness U% in the length direction of the multifilament of 15% and 4.0%.
The number of thickness fluctuation peaks described above was 7 / m. Further, the Young's modulus is 30 g / d, and the elastic recovery after 10% elongation is 75%.
% And good soft feeling and stretchability.

The woven fabric sample of Comparative Example 1 had unevenness on the woven fabric surface, and thus was a product having a good dry feeling, smooth feeling, and stretchability. , Lacked marbling.

In Comparative Example 2, a woven fabric sample was prepared by stretching in the same manner as in Example 1 except that the stretching roller temperature was 70 ° C.

Table 1 shows the drawing conditions, yarn quality and color fastness of the thick and thin yarns. 3. The thick and thin yarn of Comparative Example 2 had a thickness unevenness U% in the length direction of the multifilament of 18%, and
The number of thickness fluctuation peaks of 0% or more was 8 / m. In addition, the Young's modulus was 25 g / d, the elastic recovery after 10% elongation was 70%, and had a good soft feeling and stretchability, but the dry heat shrinkage at 160 ° C was as high as 15.2%. Therefore, the texture of the woven fabric sample was coarse and hard, and the shading had a long cycle length due to dyeing. In addition, the color fastness to washing was 3 to 4 grades, and the light fastness was 3 grades. The color fastness was poor, and the quality as a product was poor.

In Comparative Example 3, stretching was carried out in the same manner as in Example 1 except that the temperature of the stretching roller was 190 ° C.

Table 1 shows the drawing conditions of the thick and thin yarns. In the case of the thick and thin yarn of Comparative Example 3, yarn breakage frequently occurred during stretching, and a product could not be obtained.

Example 2, Comparative Examples 4 and 5 Using the polypropylene terephthalate polymer produced in Example 1, a spinning temperature of 260 using a direct spinning and stretching apparatus shown in FIG.
At a spinning speed of 3000 m / min, a draw ratio of 1.3 times, and a heat setting temperature (the temperature of the second delivery roller 13) and an air pressure of a swirl nozzle were changed to obtain a thick and thick 75-denier, 36-filament polypropylene terephthalate. I got Shin Yan. Table 2 shows the spinning conditions and yarn quality of the thick and thin yarn. Next, the thick and thin yarns shown in Table 2 are woven into a plain woven fabric at a woven density of 90 × 75 yarns / inch, scoured by a conventional method, set on a greige machine at 150 ° C., dyed with a disperse dye, and finished set with a 150 ° C. tenter. And a fabric sample was prepared. Table 2 shows the color fastness of the fabric sample.

Table 2 shows the spinning conditions, yarn quality and color fastness of Example 2. The thickness unevenness U% in the length direction of the multifilament was 4%, and the number of thickness variation peaks of 4.0% or more was 17 / m. The Young's modulus is 25g
/ D, the elastic recovery after elongation at 10% was 74%, which was a good soft feeling and stretchability.

The woven fabric sample of Example 2 had fine irregularities on the woven fabric surface, and was therefore a soft, dry, smooth and stretchable product. In addition, a difference in shading with a short cycle length was exhibited by the dyeing, and a natural spot feeling in a span tone was obtained by a synergistic effect with the surface unevenness.
The dyeing fastness of this fabric sample was 5th in both washing fastness and light fastness, and good dyeing fastness was obtained.

Comparative Example 4 was performed in the same manner as in Comparative Example 4 except that the fluid swirl nozzle was not used and no articulated balloon was generated on the running yarn.
Direct spinning and stretching were performed in the same manner as in Example 2 to prepare a woven fabric sample. Table 2 shows the spinning conditions, yarn quality and color fastness of the thick and thin yarn. In the thick and thin yarn of Comparative Example 4, the thickness unevenness U% in the length direction of the multifilament was 12%, and the number of thickness variation peaks of 4.0% or more was 8 / m. In addition, the Young's modulus was 20 g / d, the elastic recovery rate after 10% elongation was 75%, and it had softness and stretchability.

For this reason, the fabric sample of Comparative Example 4 was a product having irregularities on the fabric surface and rich in soft feeling, dry feeling and stretchability, but the shading having a long cycle length was developed by dyeing. , Lacked marbling.

In Comparative Example 5, a woven fabric sample was prepared by directly spinning and drawing in the same manner as in Example 2 except that the heat setting temperature (the temperature of the second delivery roller 13) was not heated.
Table 2 shows the spinning conditions, yarn quality and color fastness of the thick and thin yarn. In the thick and thin yarn of Comparative Example 5, the thickness unevenness U% in the length direction of the multifilament was 16%, and the number of thickness variation peaks of 4.0% or more was 6 / m. In addition, the Young's modulus was 24 g / d, the elastic recovery rate after 10% elongation was 65%, and it had a soft feeling and stretchability. However, the texture of the woven fabric sample was rough and hard, and the cycle length was longer due to dyeing. The difference in shading appeared, and the quality as a product was inferior.

Examples 3 and 4, Comparative Examples 6 and 7 Using the undrawn yarn of Example 1, the drawing apparatus shown in FIG.
First delivery roller 3 at 40 ° C., second delivery roller 5
At 150 ° C. and the air pressure of the swirling nozzle at 3 kg / cm ^2.
By changing the stretching ratio, a thick and thin yarn was obtained at a stretching speed of 800 m / min.

Table 3 shows the drawing conditions and yarn quality of the thick and thin yarn. Next, the multifilament thick and thin yarns shown in Table 3 are woven into a plain fabric at a woven density of 90 × 75 yarns / inch, scoured by a conventional method, set on a greige fabric at a 150 ° C. tenter, dyed with a disperse dye, and treated at a 150 ° C. A finishing set was applied to make a fabric sample. Table 3 shows the color fastness of the fabric sample.

Table 3 shows the spinning conditions, yarn quality and color fastness of Example 3 in which the draw ratio was 1.15. The thickness unevenness in the length direction of the multifilament is Uster Normal U.
% And 2.3%, and the number of thickness variation peaks of 4.0% or more was 20 peaks / m. In addition, the Young's modulus is 20 g /
d) It had an elastic recovery rate of 63% after elongation of 10%, soft feeling, and stretchability.

The woven fabric sample made of the thick and thin yarn of Example 3 had fine irregularities on the woven fabric surface, and was soft and rich in dry feeling, smooth feeling and stretchability. In addition, a difference in shading with a short cycle length was exhibited by the dyeing, and a natural spot feeling in a span tone was obtained by a synergistic effect with the surface unevenness. The dyeing fastness of the fabric sample of Example 3 was 4 for both washing fastness and light fastness.
And good dyeing fastness was obtained.

Table 3 shows the spinning conditions, yarn quality and dyeing fastness of Example 4 in which the draw ratio was 1.6 times. The thickness unevenness in the length direction of the multifilament is Uster Normal U%
Was 1.7%, and the number of thickness variation peaks of 4.0% or more was 11 / m. The Young's modulus is 27 g /
d. The woven fabric sample comprising the thick and thin yarn of Example 4, which had an elastic recovery rate of 85% after 10% elongation, a soft feeling, and a stretch property, had fine irregularities on the woven fabric surface. The product was rich in dryness, smoothness and stretch. In addition, a minute difference in shading with a short cycle length was exhibited by dyeing, and a natural span-like spot was obtained due to a synergistic effect with surface irregularities. The dyeing fastness of the fabric sample of Example 4 was 5th in both the washing fastness and the light fastness, and good dyeing fastness was obtained.

Table 3 shows the stretching conditions, yarn quality and dyeing fastness of Comparative Example 6 in which the stretching ratio was 1.8 times. Comparative Example 6
The thickness unevenness U% in the length direction of the multifilament is 0.5
%, And the number of thickness fluctuation peaks of 4.0% or more was 0 / m. The Young's modulus is 35 g /
d) The elastic recovery after 10% elongation was 93%, which was a stretch property, but the softness was somewhat low.

For this reason, the woven fabric of Comparative Example 6 had a washing fastness and a light fastness of class 5 in all of the dyeing fastness. The product lacked smoothness and marbling, and was inferior in quality as a product.

Table 3 shows the stretching conditions, yarn quality and dyeing fastness of Comparative Example 7 in which the stretching ratio was 1.04. Comparative Example 7
In Example 1, the thickness unevenness U% in the length direction of the multifilament was as small as 0.8%, and the number of thickness variation peaks of 4.0% or more was 1 / m. In addition, the Young's modulus is 1
The elastic recovery rate after 8 g / d and 10% elongation was 55%, which was soft, but low in stretchability. In addition, the color fastness to washing was 3 and the light fastness was 3 for both.
It was class. In the woven fabric sample of Comparative Example 7, although the difference in shade of lightness due to heat set spots was obtained, the unevenness of the woven fabric surface was extremely small. Further, since the stress at the yield point is low, there is a problem that permanent set tends to remain during weaving and wearing the fabric.

[0066]

[Table 1]

[Table 2]

[Table 3]

[0067]

Industrial Applicability According to the present invention, the fabric has excellent stability in the spinning process, has a frost-like tone contrast by dyeing, has a natural spot feeling, and has a fine uneven feeling on the fabric surface. Polyester thick and thin yarns that have a dry and smooth feel visually and tactilely and have excellent stretchability can be obtained, and it is possible to provide multifilament products made of polypropylene terephthalate with good dyeing fastness. Becomes

[Brief description of the drawings]

FIG. 1 is a process diagram showing an example of a drawing apparatus for producing a thick and thin yarn of the present invention using an undrawn yarn.

FIG. 2 is a process diagram showing an example of a yarn-making apparatus for producing the thick and thin yarn of the present invention by direct spinning.

[Explanation of symbols]

 1, 10: undrawn yarn 2: feed roller 3, 11: first delivery roller 4, 12: fluid swirling nozzle 5, 13: second delivery roller 6, third delivery roller 7, 14: thick and thin yarn 8: spinneret 9 : Refueling equipment

Claims (4)

[Claims] (1) A wister normal U% has a value of 1.5 to 15% in the length direction of the yarn, and a number of thickness fluctuation peaks of 4.0% or more is 10 / m or more. A thick and thin yarn comprising a multifilament substantially composed of polypropylene terephthalate having unevenness, wherein the multifilament has a Young's modulus of 30 g / d or less. 2. The thick and thin yarn according to claim 1, wherein the elastic recovery after 10% elongation is 60% or more. 3. The birefringence Δn obtained by melt spinning is 20 × 1.
When a multifilament undrawn yarn made of polypropylene terephthalate having a size of 0 ^{-3 to} 60 × 10 ^-3 is drawn at a low magnification to produce a thick and thin yarn, 1.05 to 1.7 is applied between a supply roller and a drawing roller. Draw at the same time and false twist, 80
A method for producing thick and thin yarn, comprising heat setting at -180 ° C. 4. A false-twisting device using a fluid swirling nozzle using compressed air as a working fluid when false-twisting between a supply roller and a stretching roller.
A method for producing the described thick and thin yarn.