JP2001303371A - Polyester conjugate fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a stretch-back raw yarn for high-quality woven and knitted fabrics having pleasant stretch-back properties by high-density crimping of raw yarn, excellent firmness, stiffness, resilient feeling and surface qualities. SOLUTION: This polyester conjugate yarn is characterized in that the yarn is a side-by-side type conjugate yarn comprising a high-viscosity polyester component (A) being a polyethylene terephthalate and a low-viscosity polyester component (B), the conjugate bond face shape in the fiber cross section satisfies formula (1), 0.6<=L2/L1<=1.0, the number of crimps after boiling water treatment is >=10.0 peaks/cm and satisfies formula (2), 2.0<=X/Y<=6.0 (L1 is the bond length (μm) of both the polyester components at the fiber cross section; L2 is the length (μm) of a line connecting two points at which the bond face of both the polyester components crosses the outer periphery of the fiber; X is a crimp percent (%) after boiling water treatment; and Y is the number of crimps after boiling water treatment).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester composite fiber for stretchable woven or knitted fabric, which has stretchback properties, bulkiness, tension and waist, and rebound.

[0002]

2. Description of the Related Art In order to obtain a woven or knitted fabric having a stretch function, it is well known to use a latently crimpable conjugate fiber in which two kinds of polyesters having different intrinsic viscosities are joined in a side-by-side type. When the latently crimpable conjugate fiber is subjected to a crimp development treatment in the state of a yarn or a woven or knitted fabric to develop a crimp, and used as a woven or knitted fabric having a stretch property, the three-dimensional crimped form of the yarn or The crimping performance has a significant effect when made into a fabric.

[0003] For example, Japanese Patent Application Laid-Open No. H11-241229 proposes a polyester composite fiber in which the joint surface shape in the fiber cross section is curved within a certain range. Certainly, the polyester composite fiber obtained according to the publication can increase the three-dimensional crimp shape, so that the swelling feeling and the soft feeling can be improved, but the discharge bend is large and stable yarn production is difficult. At the same time, the stabilization of the composite form is reduced, so that the crimped form becomes non-uniform, and it has been difficult to obtain a stretchable woven or knitted fabric having excellent surface quality.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems, and makes the bonding state of the side-by-side type conjugate fiber a specific state and at the same time performs high-density crimping, so that stretch-back property, tension and waist, An object of the present invention is to provide a stretchback yarn for high-grade woven or knitted fabric having excellent resilience and surface quality.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, by specifying the joint surface shape of both polyesters in the cross section of the fiber, the raw yarn develops a high-density crimp and is woven. It has been found that a polyester composite fiber can be obtained which can impart sufficient stretchability, bulkiness, tension and waist, and resilience to a fabric obtained by knitting.

That is, the present invention relates to a side-by-side type conjugate fiber comprising a high-viscosity polyester component (A) and a low-viscosity polyester component (B), which is a polyethylene terephthalate having 85 mol% or more of ethylene terephthalate repeating units, and has a fiber cross section. And the ratio of the straight line connecting two points where the joining surface of both polyester components and the outer periphery of the fiber intersect with each other satisfies the following expression (1), and the number of crimps after the boiling water treatment is 10.0. Mountain / cm
This is a polyester composite fiber characterized by having a crimp rate and a number of crimps after the boiling water treatment satisfying the following formula (2).

0.6 ≦ L ₂ / L ₁ ≦ 1.0 (1) 2.0 ≦ X / Y ≦ 6.0 (2) where L ₁ is a fiber both the length of the joint surface of the polyester component ([mu] m) L ₂ is a straight line connecting the joint surface and the fiber outer circumference and two points of intersection of the two polyester components in the fiber cross section length in cross section ([mu] m) X after boiling water treatment Crimp rate (%) Y is the number of crimps after the boiling water treatment (mount / cm)

[0008]

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

The polyester composite fiber of the present invention is a side-by-side type composite fiber comprising a high-viscosity polyester component (A) and a low-viscosity polyester component (B), which are polyethylene terephthalate having an ethylene terephthalate repeating unit of 85 mol% or more, The ratio of the length L ₁ (μm) of the joining surface of both polyester components in the fiber cross section to the length L ₂ (μm) of a straight line connecting two points where the joining surface of both polyester components intersects with the outer periphery of the fiber is 0.6 ≦. L ₂ / L ₁ ≦ 1.0
It is necessary to satisfy When L ₂ / L ₁ is less than 0.6, the three-dimensional crimp morphology of the crimp developed by the shrinkage treatment becomes too large, so that high-density crimping cannot be performed, and tension, waist, and resilience are imparted. I can't do it.
In addition, variation in the composite form between single yarns is likely to occur, and it is difficult to obtain a fabric having excellent surface quality. Tension, waist,
In order to obtain a resilience and an excellent surface quality, it is preferable to use 0.1%.
8 ≦ L ₂ / L ₁ ≦ 1.0.

The polyester composite fiber of the present invention needs to have a number of crimps after boiling water treatment of 10.0 peaks / cm or more. If the number of crimps after the boiling water treatment is less than 10.0 peaks / cm, the stretchability and resilience are lost, and the object of the present invention is not satisfied.

In the polyester composite fiber of the present invention, the relation X / Y between the crimp rate X (%) after the boiling water treatment and the number of crimps Y (peak / cm) after the boiling water treatment satisfies the following expression. is necessary.

2.0 ≦ X / Y ≦ 6.0 X / Y indicates the size of the crimped crimp, and the crimping rate X (%) after the boiling water treatment and the number of crimps after the boiling water treatment. Y
By setting the relationship of (mountain / cm) to 2.0 ≦ X / Y ≦ 6.0, when a fabric is formed, high stretchability can be exhibited, and a smooth and high-quality surface quality can be obtained. is there. When X / Y exceeds 6.0, the number of crimps is too small relative to the crimp rate, and the crimp diameter becomes too large, so that the fabric cannot have a smooth surface feeling. On the other hand, when X / Y is less than 2.0, the crimp becomes fine, so that the surface quality is improved, but the bulkiness and softness are reduced. Further, it is preferable that 2.5 ≦ X / Y ≦ 4.5 in order to maintain good surface quality and stretch back property.

The crimping ratio X (%) after the boiling water treatment defined in the present invention is determined by the following method.

The side-by-side conjugate fiber, which has been lapped 10 times with a measuring machine, is subjected to a boiling water treatment at 100 ° C. for 30 minutes in a free state. Then, air-dry for 30 minutes, 2.27 × 1
A load of 0 ^-3 cN / dtex is applied, and the length a is measured. Then, after removing the load of 2.27 × 10 ⁻³ cN / dtex, 5.6 ×
The length b is measured by applying a load of 10 ⁻³ cN / dtex.
Then, it is obtained from the following equation. Crimp rate (%) = [(ba) / b] × 100.

The number of crimps Y (peaks / cm) after the boiling water treatment defined in the present invention is determined by the following method.

The side-by-side type conjugate fiber cut to a length of 10 cm is subjected to a boiling water treatment at 100 ° C. for 15 minutes in a free state. Next, it is subjected to cold water treatment for 1 minute and then naturally dried for 5 hours. After drying, the sample is attached to a sample plate, covered with a slit plate having a width of 1 cm, transferred to a screen with a projector, and the number of peaks is read. The measurement is performed twice for each of 10 samples, and the average is defined as the number of crimps.

The cross-sectional shape of the polyester conjugate fiber of the present invention is not particularly limited, and may be an irregular cross-section other than a round cross-section. By making the cross section irregular, functionalities such as light weight, heat retention, glossiness, and water absorption can be imparted. Also, the three-dimensional crimp form can be controlled depending on the shape of the irregular cross section.

Further, as long as the object of the present invention is not impaired, isophthalic acid 2-2 bis @ 4- (β
Copolymer components such as -hydroxy) phenyl} propane,
A matting agent such as titanium oxide, an antioxidant such as a hindered phenol compound, a pigment, a twist-resistant agent, an antibacterial agent, and a conductivity imparting agent may be blended.

Further, the polyester composite fiber of the present invention comprises:
The composite ratio of the high-viscosity polyester component (A) and the low-viscosity polyester component (B) is preferably in the range of 60:40 to 40:60 from the viewpoint of stabilizing production and exhibiting crimp.

The conjugate fiber of the present invention can be obtained by spinning the high-viscosity polyester component (A) and the low-viscosity polyester component (B) using an ordinary conjugate spinning machine and stretching. At this time, if the intrinsic viscosity difference [ΔIV] of both polyester components is too large, the crimping characteristics become good, but the discharge bend becomes large due to the flow velocity difference of both components immediately below the die discharge hole, and yarn breakage during spinning frequently occurs. ΔIV is equal to 0.
It is preferably 40 or less, more preferably 0.30 or less. Conversely, if the difference in viscosity is too small, the spinning property is improved but the crimping property is reduced. Therefore, ΔIV is 0.15 or more, and more preferably 0.20 or more.
The above is preferred. Here, the intrinsic viscosity is a value measured in orthochlorophenol at 25 ° C.

The method for controlling the bonding surface between the high-viscosity polyester component (A) and the low-viscosity polyester component (B) of the polyester composite fiber of the present invention includes selecting the limiting viscosity difference of the polyester components to be bonded. This can be achieved by adjusting the merging position of both the high-viscosity polyester component (A) and the low-viscosity polyester component (B) in the used outlet of the die, that is, the distance from the merging to the discharge.

The breaking elongation of the polyester composite fiber is 15.
It is preferable that it is in the range of 0 to 40.0%. When the content is within this range, a yarn having good spinnability and good crimping properties can be obtained.

[0023]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to these Examples. In addition, the evaluation method in an Example is as follows.

1. Product texture A sensory evaluation was conducted by five skilled persons, taking into account the appropriate tension, waist and resilience, mainly based on stretchback properties, bulkiness, and surface quality, and evaluated by a four-level evaluation method.

○: Excellent ：: Good Δ: Acceptable ×: Not Acceptable Spinning was performed for 168 hours, and the spinning was evaluated according to the following method.

○: Thread breakage rate of less than 3.0% ：: Thread breakage rate of 3.0% or more and less than 6.0% Δ: Thread breakage rate of 6.0% or more and less than 10.0% X: Thread Cutting rate is 10.0% or more-: Not evaluated Example 1 Polyethylene terephthalate composed of 100% polyethylene terephthalate (PET) was used as the high viscosity polyester component (A) and P was used as the low viscosity polyester component (B).
[IV] was changed as shown in Table 1 using polyethylene terephthalate composed of 100% ET, and after combining at a composite ratio of 50:50, a spinneret having a distance to discharge of 4.2 mm was used at a spinning speed of 1750 m / min. Composite spinning was performed in a side-by-side manner at a winding speed to obtain an undrawn yarn. This undrawn yarn was subjected to a drawing heat setting so that the residual elongation was 30.0%, and a drawn yarn of 56 dtex-12 fil was obtained. The obtained drawn yarn was twisted at 1,000 times / m and used for warp and weft to obtain a plain fabric. The obtained woven fabric (Level 1) had excellent stretch-back properties, bulkiness, tension, waist, and resilience, and also had good spinning properties.

At level 2, although the stretch-back property was slightly inferior, the bulkiness and surface quality were good, and the yarn-making properties were also very good.

At level 3, although the bulkiness was good due to the excessively large three-dimensional crimp morphology, an excellent surface quality could not be obtained, and the yarn-making properties were somewhat poor.

Level 4 had a flat texture with excellent stretchback properties and surface quality but no bulkiness due to the excessively small three-dimensional crimp form.

Table 1 shows the evaluation results.

[0031]

[Table 1]

Example 2 Levels 5 to 8 were obtained by using a spinneret having a different distance from the time when both polyester components were merged in the spinneret until the ink was discharged, based on the spinning conditions of level 1.

In the case of level 5, the stretch back property and the bulkiness were good, and those having excellent surface quality were obtained.

In the case of level 6, the bulk height was very good, and the stretch back property and the surface quality were also good.

In the case of the level 7, although the stretch back property was slightly inferior, the bulk height was very good.

At level 8, the bulkiness was very good, but the number of crimps developed was too small, so that there was no firmness and resilience.

Table 2 shows the evaluation results.

[0038]

[Table 2]

Example 3 Level 9 to Level 12 were obtained using polymer specifications based on the level 1 spinning conditions and using a die having a different distance between the merging of both polyester components in the die and the discharge. .

In the case of level 9, the stretch back property, the stiffness / rebound property and the surface quality were very good.

In the case of level 10, although the three-dimensional crimp form was small, the bulk height was slightly inferior, but very excellent in stretchback properties, firmness and resilience, and surface quality were obtained.

At level 11, the bulk height was very good, but because of the large three-dimensional crimp shape, the stretchback properties and the firmness and resilience were slightly poor.

In the case of level 12, since the joining surface of both polyester components was excessively curved, the bulk height was good, but there was no stretch back property, no firmness / rebound, and the yarn-making properties were poor.

Table 3 shows the evaluation results.

[0045]

[Table 3]

Example 4 Levels 13 to 16 are experiments in which the residual elongation was changed.

At level 13, although some yarn breaks were observed, the crimp development was very good.

Levels 14 and 15 have good crimp development and
The spinnability was very stable.

At level 16, the stretch-back property was slightly weak, but the yarn-making property was very good.

Table 4 shows the evaluation results.

[0051]

[Table 4]

Example 5 Based on the yarn production conditions of level 1, the number of the discharge holes in the spinneret was reduced to 3 to obtain level 13.

Level 13 is stretch back,
Good resilience, excellent surface quality, and silky touch due to the irregular cross section were obtained.

Table 5 shows the evaluation results.

[0055]

[Table 5]

[0056]

EFFECTS OF THE INVENTION Stretch-back material for high-grade woven or knitted fabrics with excellent stretch-back properties, tension and waist, resilience, and surface quality by making the bonding state of the side-by-side type conjugate fibers specific and crimping at high density. You can get yarn.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4L041 AA07 AA25 BA02 BA05 BA09 BA38 BA59 BC05 BC13 BC17 BC20 BD14 CA06 DD01 DD04 DD10

Claims (1)

[Claims] An ethylene terephthalate repeating unit comprising 8 units
A side-by-side composite fiber comprising a high-viscosity polyester component (A) and a low-viscosity polyester component (B), which is 5 mol% or more of polyethylene terephthalate,
The ratio of the joining surface length of both polyester components in the fiber cross section and the ratio of a straight line connecting two points where the joining surface of both polyester components intersects the outer periphery of the fiber satisfies the following formula (1), and the number of crimps after boiling water treatment is A polyester composite fiber having 10.0 peaks / cm or more, and a crimp rate and a number of crimps after a boiling water treatment satisfying the following formula (2). 0.6 ≦ L ₂ / L ₁ ≦ 1.0 (1) 2.0 ≦ X / Y ≦ 6.0 (2) where L ₁ is the value of both polyester components in the fiber cross section. Bonding surface length (μm) L ₂ is the length of a straight line (μm) connecting two points where the bonding surface of both polyester components intersects the fiber periphery in the fiber cross section X is the crimping rate after boiling water treatment (%) Y Is the number of crimps after treatment with boiling water (mountain / cm)