JPH09324321A - Highly oriented undrawn polyester yarn - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject undrawn yarn having a birefringence, a boiling water shrinkage, etc., falling within respectively specific ranges and useful as a yarn for supplying a spontaneously stretchable yarn to give a woven or knit fabric having light-weight, high bulkiness, excellent springiness and resilience and exhibiting the feeling of worsted yarn fabric. SOLUTION: This highly oriented undrawn polyester yarn has a birefingence of 45×10<-3> to 75×10<-3> , a C% value of <=4%, a boiling water shrinkage of 40-70% and a variation of the boiling water shrinkage of <=6%. This undrawn yarn can be produced by setting the L/D ratio to 2,900<=V<=3,200, 1.0<=L/D<=2.5, 0.22<=X/V<=0.31 and 750<=X<=900 wherein V is the spinning speed, L is the length of the nozzle and D is the diameter of the nozzle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spontaneous stretchable yarn which, when knitted or knitted, has a feeling of swelling which is light in weight, has a feeling of swelling, and has a combed-like feel which is excellent in elasticity and resilience. The present invention relates to a polyester highly oriented undrawn yarn which is a supply yarn.

[0002]

2. Description of the Related Art In order to improve the comfort and appearance of a fabric using polyester yarns and to obtain a wool-like swelling, spontaneous stretching yarns that are stretched by heat treatment after weaving and knitting and heat-shrinkable yarns are used. Different hetero-shrink mixed filament yarns have been proposed in Japanese Patent Laid-Open Nos. 2-91734 and 4-24234.

The use of a heterogeneous shrinkage mixed yarn composed of a spontaneously stretchable yarn and a heat-shrinkable yarn allows the fabric to have a swelling feeling and a soft texture.
Further, the loop formed by the elongated and protruding filaments can give a feeling of wetness. However, the spontaneously stretched yarn has uneven thickness distribution in the longitudinal direction thereof, and when dyed, the thick portion is deeply dyed, resulting in a defect-like dirty surface feeling, resulting in poor quality. .

[0004]

SUMMARY OF THE INVENTION The present invention solves the above problems, and when it is knitted and woven by mixing fibers with a heat-shrinkable yarn, it has a truly satisfactory wool-like lightweight feeling and swelling feeling. Therefore, the self-stretching yarns that have coreless elasticity (there is no core and you can feel the elasticity with a light force), and the surface looks uniform, and become a good-quality fabric, can be subjected to shrinkage heat treatment. It is a technical object to provide a polyester highly oriented undrawn yarn that can be obtained.

[0005]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have reached the present invention. That is, the present invention has a birefringence of 45 × 10 ⁻³ to 75 × 10 ^3.
-3 , C% value is 4% or less, boiling water shrinkage ratio is 40 to 70%, and fluctuation value of boiling water shrinkage ratio is 6% or less, which is a gist of highly oriented polyester unoriented yarn of polyester. .

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

The polyester highly oriented undrawn yarn of the present invention comprises
When subjected to shrinkage heat treatment, it becomes a spontaneously stretchable yarn that will be stretched in the subsequent heat treatments.
It must be ^-3 to 75 x 10 ^-3 . Birefringence is 45 ×
If it is less than 10 ^-3 or exceeds 75 × 10 ^-3 , even if this highly oriented undrawn yarn is subjected to shrinkage heat treatment at a temperature above the glass transition point, it spontaneously expands by receiving heat above the crystallization temperature. It cannot be an extensible thread.

[0008] That is, in order to obtain the characteristic that the yarn after the shrinkage heat treatment of the highly oriented undrawn yarn is elongated by receiving heat, the molecular chain segment of the highly oriented undrawn yarn has an undrawn structure. However, it needs to have a slight orientation. Further, it is necessary that the crystal axis (C axis) of the lamella layer formed by the folded structure of the molecular chain segment when subjected to the shrinkage heat treatment is oriented in the fiber axis direction. It is considered that the thermal elongation phenomenon is due to the so-called lamella thickening phenomenon, in which the folded molecular chain structure extends in the crystal axis direction by heat reception. Therefore, in the structure where the molecular chain segment of the highly oriented undrawn yarn is fully extended, thermal extensibility is not obtained even when shrinkage heat treatment is applied, and the oriented lamella layer of the folded structure is oriented in the fiber axis direction. The undrawn yarn must have a birefringence of 45 × 10 ⁻³ to 75 × 10 ⁻³ .

The highly oriented undrawn yarn of the present invention has a C% value of 4% or less. If the C% value exceeds 4%,
When this highly oriented undrawn yarn is subjected to shrinkage heat treatment, thickness unevenness due to excessive C% value is amplified, and when dyed, the dye is excessively exhausted in the thick portion, so the yarn after shrinkage heat treatment is applied. Alternatively, if a composite yarn in which this yarn and other yarns are mixed is woven and knitted and dyed, the thick part is extremely deeply dyed, and the quality of the fabric is significantly reduced, and the product can be obtained. Disappear.

Next, the highly oriented undrawn yarn of the present invention is required to have a boiling water shrinkage of 40 to 70% and a variation of the boiling water shrinkage of 6% or less. When the boiling water shrinkage is less than 40%, sufficient elongation of the molecular chain segment cannot be obtained even if the shrinkage heat treatment is followed by heat treatment. On the other hand, when the boiling water shrinkage rate exceeds 70%, the shrinkage amount during shrinkage heat treatment is too large, and the probability that the crystal axis of the lamella layer extending in the fiber axis direction due to the subsequent heat reception is too small. However, even if thickening occurs in each lamella layer, it does not lead to the actual elongation of the yarn. Moreover, even if the amount of shrinkage during shrinkage heat treatment is reduced, thermal extensibility is not obtained. Therefore, in order to obtain spontaneous elongation by shrinkage heat treatment, the boiling water shrinkage must be 40 to 70%.

Further, when the fluctuation value of the boiling water shrinkage ratio exceeds 6%, the fluctuation of the shrinkage amount during the shrinkage heat treatment is too large, and even if the highly oriented undrawn yarn itself has no thickness unevenness, A noticeable thickness unevenness is formed on the yarn. Therefore, C% is 4%
When the cloth is dyed as in the case of exceeding, the difference in shade due to the difference in dye exhaustion between the thick part and the detail is enlarged, and the quality of the cloth is extremely deteriorated, and the product cannot be obtained.

Next, an example of a method for producing the highly oriented polyester unoriented yarn of the present invention will be described. The polyester highly oriented undrawn yarn of the present invention has a distance X (mm) between the spinneret and a focusing guide for initially focusing the spun filament and a spinning speed V (m).
/ Min), the ratio of the discharge hole length L to the discharge hole diameter D (L / D), which is related to the shearing force that the filament receives at the spinneret.
Can be obtained by appropriately setting and performing melt spinning.

That is, spinning speed V and discharge hole L / D
Has a direct effect on the orientation (birefringence) and boiling water shrinkage of highly oriented undrawn yarn, with birefringence of 45 × 10 ^-3 to 75 × 10 ^-3 and boiling water shrinkage of 40 to 70%. For this purpose, it is necessary to satisfy the two expressions of 2900 ≦ V ≦ 3200 1.0 ≦ L / D ≦ 2.5. In order to set the C% value to 4% or less and the fluctuation value of the boiling water shrinkage ratio to 6% or less, it is possible to set 0.22 ≦ X / V ≦ 0.31 750 ≦ X ≦ 900 for spinning. is necessary.

The inventors of the present invention are not well aware of the relationship between the distance X between the spinneret and the focusing guide and the spinning speed V. However, the running starch syrup-like melted filament is thick due to vibration and resonance. Since unevenness or contraction unevenness in the longitudinal direction occurs, the distance X between the spinneret and the focusing guide and the spinning speed V are appropriately set to suppress this vibration or resonance phenomenon, and further, L / By defining D,
It is presumed that the polyester highly oriented undrawn yarn of the present invention can be obtained.

As the polyester highly oriented undrawn yarn in the present invention, a homopolyester represented by polyethylene terephthalate or a copolyester containing a third component is preferably used.

Next, a method of measuring each physical property value in the present invention will be described. (1) C% value Using an EVEN TESTER (manufactured by Keisokuki Kogyo Co., Ltd.), the sample was run at a yarn speed of 50 m / min, and while imparting false twist, a slot was selected according to the fineness (denier) of the sample, Measure in a normal test for 2 minutes and draw a chart at 2.5 cm / min. Next, the chart is divided into 2.5 cm intervals, and the maximum values H ₁ and H ₂ and the minimum values L ₁ and L ₂ of each section are read and calculated by the following formula.

[0017]

[Equation 1]

(2) Shrinkage rate of boiling water and its fluctuation value Using an epsilon meter manufactured by Toyobo Engineering Co., Ltd., while applying 0.02 g / d load to the yarn and running at 3 m / min, hot water of 98 ° C every 10 cm The shrinkage rate x was measured at 50 points by applying shrinkage treatment for 10 seconds, and calculated by the following formula.

[0019]

[Equation 2]

(3) Birefringence The birefringence is measured by an interference fringe measuring method using a polarization microscope compensator.

[0021]

Next, the present invention will be described in detail with reference to examples. The relative viscosity is measured at a concentration of 0.5 g / dl and a temperature of 20 ° C using an equal weight mixed solvent of phenol and ethane tetrachloride.

Example 1 Polyethylene terephthalate having a relative viscosity of 1.385 was used at a spinning nozzle having a discharge hole L / D of 2.0 (D = 0.15 mm) at a spinning speed of 3100 m / min and a distance between the spinning nozzle and the focusing guide of 800 mm. The highly oriented undrawn yarn 60d / 72f of the present invention was obtained by spinning. The birefringence of this yarn was 58.6 × 10 ⁻³ , the boiling water shrinkage was 57.2%, the boiling water shrinkage was 2.49%, and the C% was 3.9%. This highly oriented unstretched yarn has a non-contact heater temperature of 425 ℃ and a relaxation rate of 27.5
%, Boiling heat shrinkage-
A yarn having spontaneous elongation with dry heat shrinkage at -160% at 3.0% and -5.5% was obtained. The relaxation rate (%) was calculated by multiplying the value obtained by dividing the difference between the feeding speed (m / min) and the take-up speed (m / min) by the take-up speed by 100 times.

Then, the obtained spontaneously stretched yarn and 30d / 12
Polyethylene terephthalate drawn yarn of f (boiling water shrinkage rate 8.
3%, boiling water contraction rate variation value 0.4%, C% value 1.2%), and using a commercially available interlacer (manufactured by Heberline), relaxation rate 2.0%, pressure 3.0. Entangling treatment was performed at 0 kg / cm ² to obtain a composite mixed yarn.

The number of twists (Z) 500 T /
The yarn twisted with M was used for the warp and the weft, woven with a 2/2 twill design, and subjected to the usual dyeing finish processing with a disperse dye. The obtained woven fabric is light in weight, has a feeling of bulging, is excellent in elasticity and resilience, and has no defect due to partial deep dyeing, and its quality is good with a uniform surface. It was a thing.

Comparative Example 1 Polyethylene terephthalate having a relative viscosity of 1.385 was used at a spinneret having a discharge hole L / D of 2.0 (D = 0.15 mm) at 3100 m / m.
Spinning was performed at a spinning speed of 1 minute and a distance between the spinneret and the focusing guide of 1200 mm to obtain a highly oriented undrawn yarn of 60d / 72f. The birefringence of this yarn was 60.6 × 10 ^-3 , the boiling water shrinkage was 48.8%, the boiling water shrinkage was 7.52%, and the C% was 3.0%.

This yarn was subjected to shrinkage heat treatment and aligning and entanglement treatment under the same conditions as in Example 1 to obtain a composite mixed yarn,
A woven fabric was created and dyed and finished. The resulting fabric is
It was light in weight, had a bulge, and was excellent in elasticity and resilience, but the fine dark color areas were unevenly distributed on the surface of the fabric, and the surface was extremely dirty, and its quality was It was something that could not be handled as a product.

Comparative Example 2 A highly oriented undrawn yarn of 60d / 72f was obtained in the same manner as in Comparative Example 1 except that a spinneret having a discharge hole L / D of 2.6 (D = 0.10 mm) was used. . The birefringence of this yarn is 59.6 × 10 ^-3 , boiling water shrinkage is 57.5%, boiling water shrinkage is 3.01% and C% is 7.
8%.

This yarn was subjected to shrinkage heat treatment and aligning and entanglement treatment under the same conditions as in Example 1 to obtain a composite mixed yarn,
A woven fabric was created and dyed and finished. The resulting fabric is
It was light in weight, had a feeling of bulging, and was excellent in elasticity and resilience, but rough dark-colored streaks were unevenly distributed on the surface of the fabric, and the surface feeling was extremely dirty. It was something that could not be handled as a product.

[0029]

EFFECTS OF THE INVENTION The polyester highly oriented undrawn yarn of the present invention becomes a so-called spontaneously elongated yarn in which the filament elongates when subjected to heat when subjected to shrinkage heat treatment, and this highly oriented undrawn yarn undergoes shrinkage heat treatment. Even if it is received, it does not cause excessive thickness unevenness, and with the single yarn of the yarn after shrinkage heat treatment,
Alternatively, if a composite mixed yarn with other yarns is used for knitting, weaving, and dyeing, a highly air-containing fabric with bulges can be obtained, and even if dyed, defects such as dark streaks do not occur.
It is possible to obtain a good quality product having a substantially uniform surface.

Claims (1)

[Claims] 1. The birefringence is 45 × 10 ⁻³ to 75 × 10 ⁻³ , the C% value is 4% or less, the boiling water shrinkage rate is 40 to 70%, and the fluctuation value of the boiling water shrinkage rate is 6% or less. Highly oriented polyester undrawn yarn characterized by the following.