JP2002061029A - Polyester conjugate fiber and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyester conjugate fiber having a good weaving processability and suitable for obtaining a cloth exhibiting an excellent stretching property and a bulky feeling. SOLUTION: This polyester conjugate fiber having <=15% existing crimping ratio and 20-50% total crimping ratio is obtained by conjugate spinning a polytrimethylene terephthalate having 0.9-1.5 intrinsic viscosity and a polyethylene terephthalate having 0.3-0.7 intrinsic viscosity in (3:7)-(7:3) wt. ratio as a side by side type or an eccentric sheath-core type fiber and taking up at 4000-8000 m/min speed.

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 conjugated to a side-by-side type or an eccentric core-sheath type. More specifically, the present invention relates to a polyester-based composite fiber comprising a polyethylene terephthalate-based polyester and a polytrimethylene terephthalate-based polyester, from which a fabric having good weaving properties, excellent stretchability, and good swelling is obtained.

[0002]

2. Description of the Related Art Conventionally, composite fibers obtained by laminating polytrimethylene terephthalate and polyethylene terephthalate in a side-by-side type have excellent latent crimp development,
It is known that a woven fabric obtained by manifesting the crimp by heat treatment after weaving the fiber has extremely good stretchability and swelling feeling as compared with other polyester-based composite fibers (see, for example, 11-1899
23, JP-A-11-158733).

[0003] However, although the composite fibers proposed in these publications are excellent in the ability to manifest the crimp by heat treatment (for example, the total crimp rate), the crimps (the manifest crimps) which are manifested in the fiber at the time of yarn production are known. (Shrinkage ratio) also tends to be very large, so that there is a problem in that the yarn permeability during weaving is deteriorated and it is difficult to stably weave.

As a means for remedying such a problem, a method of reducing the apparent crimp by suppressing the orientation by lowering the draw ratio can be considered, but such a method can reduce the apparent crimp. However, since the total crimp ratio becomes insufficient, it becomes impossible to obtain a fabric having high stretchability and swelling feeling, and mechanical performance such as strength becomes insufficient.

As another means, a method of adjusting the intrinsic viscosities of polytrimethylene terephthalate and polyethylene terephthalate can be considered. In this method, even if the apparent crimp rate can be reduced, the total crimp rate can be reduced as described above. Will be inadequate.

[0006]

SUMMARY OF THE INVENTION The present invention has been made on the basis of the above-mentioned prior art, and an object of the present invention is to provide a novel fabric having good weaving properties and excellent stretchability and swelling. An object of the present invention is to provide a polyester-based composite fiber and a method for producing the same.

[0007]

According to the study of the present inventors, the first object is to provide a polytrimethylene terephthalate-based polyester A having an intrinsic viscosity of 0.9 to 1.5,
Polyethylene terephthalate-based polyester B having an intrinsic viscosity of 0.3 to 0.7 is a composite fiber bonded to a side-by-side type or an eccentric core-sheath type, and the apparent crimp rate of the fiber is 15% or less. It has been found that this can be achieved by a polyester-based composite fiber characterized by having a total crimp ratio of 20 to 50%.

It is another object of the present invention to have an intrinsic viscosity of 0.9 to 1.
5. Polytrimethylene terephthalate polyester A
And a polyethylene terephthalate-based polyester B having an intrinsic viscosity of 0.3 to 0.7 by weight ratio (A: B) of 30:
It has been found that this can be achieved by a method for producing a polyester-based composite fiber, which is characterized in that it is composite-spun into a side-by-side type or an eccentric core-sheath type at 70 to 70:30 and drawn at a speed of 4000 to 8000 m / min. Was done.

[0009]

Embodiments of the present invention will be described below in detail. The polytrimethylene terephthalate-based polyester A used in the present invention is a polyester having a trimethylene terephthalate unit as a main repeating unit, while the polyethylene terephthalate-based polyester B is a polyester having an ethylene terephthalate unit as a main repeating unit.

The above-mentioned polyesters A and B may be used in a proportion of not more than 15 mol%, preferably not more than 5 mol%, based on the acid component, within a range not to impair the object of the present invention.
The components may be copolymerized. Examples of preferably used copolymerization components include acid components such as isophthalic acid, succinic acid, adipic acid, 2,6-naphthalenedicarboxylic acid, 5-sodium sulfoisophthalic acid, and tetrabutyl phosphonium salt of 5-sulfoisophthalic acid; Glycol components such as 4-butanediol, 1,6-hexanediol, and cyclohexanedimethanol; ε-caprolactone;
-Hydroxybenzoic acid, polyethylene glycol, polytetramethylene glycol and the like.

The polyesters A and B may optionally contain various additives such as matting agents, heat stabilizers,
Antifoaming agents, color regulants, flame retardants, antioxidants, UV absorbers,
An infrared absorber, a crystal nucleating agent, a fluorescent whitening agent and the like may be copolymerized or mixed.

Further, the intrinsic viscosity of the above-mentioned polytrimethylene terephthalate-based polyester A must be in the range of 0.9 to 1.5, preferably in the range of 1.0 to 1.2. B has an intrinsic viscosity in the range of 0.3 to 0.7, preferably 0.1 to 0.7.
It is necessary to be in the range of 4-0.6. When the intrinsic viscosity of the polytrimethylene terephthalate-based polyester A is less than 0.9, not only a conjugate fiber having a high stretch property cannot be obtained because sufficient shrinkage stress is not generated in the component, but also the aging after spinning. This is not preferable because the change is large and the strength and crimp characteristics of the fiber are reduced. On the other hand, when the intrinsic viscosity exceeds 1.5, the spinnability deteriorates and the spinning condition deteriorates, which is not preferable. On the other hand, when the intrinsic viscosity of the polyethylene terephthalate-based polyester B is less than 0.3,
If the molecular weight of the polymer is too low, the strength is lowered, which is not preferable. On the contrary, if it exceeds 0.7, the crimping performance (total crimp ratio) becomes insufficient, which is not preferable.

In the present invention, the difference between the intrinsic viscosities of the polyesters A and B is preferably 0.4 or more in order to obtain a higher crimp and a stable crimped form.
The following is preferable in order to suppress interfacial peeling between the polyesters A and B and to suppress the kneading phenomenon in which the yarn is deflected to a direction having a higher melt viscosity immediately below the discharge hole during the spinning. That is, the intrinsic viscosity difference is preferably in the range of 0.4 to 0.8, particularly preferably in the range of 0.5 to 0.7.

In the present invention, the above-mentioned polytrimethylene terephthalate-based polyester A and polyethylene terephthalate-based polyester B are joined in a side-by-side type or an eccentric core-sheath type to form a composite fiber.

The composite weight ratio of the polyesters A and B (A: B) is in the range of 30:70 to 70:30, especially 4:70.
It is preferable to set the range of 0:60 to 60:40. When the component A, which is a polytrimethylene terephthalate-based polyester, exceeds 70% by weight, the crimping performance (total crimp rate) is improved, but the strength as a conjugate fiber tends to be insufficient. %, It is difficult to obtain a material having high crimping performance.

The polyester-based composite fiber of the present invention has both a good weaving property and an excellent stretch property and a swelling effect to a fiber product such as a finally obtained fabric. Is 15% or less, preferably 10%
% Or less, and the total crimp ratio is 20 to 50%, preferably 3%.
It is important that it is in the range of 0-40%. That is,
In the conventional polyester-based composite fiber, there was a problem that the apparent crimping ratio was increased and the weaving property was deteriorated when trying to obtain a material having a high total crimping ratio. According to the spinning method, it can be seen that a composite fiber comprising a polytrimethylene terephthalate-based polyester and a polyethylene terephthalate-based polyester, which simultaneously satisfies the above requirements for the apparent crimp rate and the total crimp rate, can be obtained. Thus, a fabric having excellent stretchability and a good swelling feeling can be stably woven.

Here, when the apparent crimp rate exceeds 15%, the number of crimps is too large, so that the guideability of the weaving machine decreases, and weaving becomes difficult. On the other hand, the total crimp rate is 20
If the amount is less than 10%, the resulting fiber product such as a fabric has a poor stretchability, and the feeling becomes unsatisfactory in paper-like swelling. If the total crimp ratio exceeds 50%, the production becomes difficult, which is not preferable.

The above-described polyester composite fiber of the present invention can be produced, for example, by the following method. That is, a polytrimethylene terephthalate-based polyester A having an intrinsic viscosity of 0.9 to 1.5 and a polyethylene terephthalate-based polyester B having an intrinsic viscosity of 0.3 to 0.7 are combined with a conventionally known side-by-side type. Alternatively, using a spinneret for eccentric core-sheath composite spinning, melt spinning was performed at a melt spinning temperature of 270 to 290 ° C. so that the composite weight ratio was the above ratio, and the discharged yarn was solidified by blowing cooling air. Later take-off speed 4000-8000 m / min, preferably 5
It can be obtained by taking up at a speed of 000 to 6500 m / min and then once winding up or continuously without winding up, followed by stretching and heat treatment as required. In addition, the number of rollers at the time of taking off is not particularly limited, and may be a single or a plurality of two or more, but is usually taken over via a pair of rollers. At this time, the rotation speed (peripheral speed) of the first roller and the second roller may be different within a range that does not impair the spinning stability and does not hinder the object of the present invention, but usually the same speed. I do.

[0019]

The polyester composite fiber of the present invention is obtained by converting a high-viscosity polytrimethylene terephthalate-based polyester A having an intrinsic viscosity of 0.9 to 1.5 to an intrinsic viscosity of 0.3 to 1.5.
Since it has a larger heat shrinkage characteristic than the low viscosity polyethylene terephthalate-based polyester B of 0.7, when heat treatment is applied, crimps in which the polyester A is disposed inside and the polyester B is disposed outside are highly developed. . In addition, since it is a conjugate fiber drawn at a high speed of 4000 m / min or more, the detailed reason is not known, but compared to a normal low-speed spun undrawn yarn drawn, the conjugate fiber before heat treatment is There is little apparent crimp, and as a result, weaving can be performed stably.

Since the high viscosity side is made of polytrimethylene terephthalate-based polyester, the low viscosity side is made of polyethylene terephthalate-based polyester, so that the low viscosity side is made of polytrimethylene terephthalate. The problem of aging due to polyester is also suppressed.

[0021]

EXAMPLES The present invention will be described below more specifically with reference to examples. In addition, each evaluation item in an Example was measured by the following method.

(1) Intrinsic viscosity Using o-chlorophenol as a solvent, the intrinsic viscosity was determined at 35 ° C. according to a conventional method.

(2) Elongation at break and strength Using an autograph tensile tester manufactured by Shimadzu Corporation, a yarn length of 20
The measurement was performed at 0 mm, a tensile speed of 200 mm / min, and N = 3, and the average value was determined.

(3) Tensile elastic recovery The fiber was taken into a tensile tester at a distance of 250 mm between the chucks.
At a stretching rate of 10% and a pulling speed of 50 mm / min.
And then return to the original length at the same speed (L ₀), This
At the time of reading the moving distance (L) under stress
It was determined by the following equation. Elastic recovery rate = L / 25 × 100 (%)

(4) Actual Crimp Rate (VC) and Total Crimp Rate
(TC) Adjust the number of windings so that the total fineness is 3330 dtex
Make a skein. Apply a load of 5.88 cN (6 g) to this skein
And apply a load of 2.94 N (300 g).
The length at this time is L₀And Then 2.94N (300
g), and remove the load of 5.88 cN (6 g)
The length after 1 minute with L₁And Next, 5.88 cN (6
g) Boil this skein in boiling water for 20 minutes under load
Boil. After taking out the skein, dry it thoroughly and 2.94N
(300g) load and length L _TwoIs measured. afterwards
Remove the load of 2.94N (300g) and 5.88c
N (6g) Length L under load_ThreeIs measured. Overt crimp rate
And the total crimp rate is calculated by the following equation. Applicable crimp rate (VC) = (L₀-L₁) / L₀× 100 (%) Total crimp rate (TC) = (L_Two-L_Three) / L₀× 100 (%)

(5) Boiling water shrinkage (BWS) A 200 mm skein made by winding 10 times has a total fineness of 0.0
Length L ₀ when a load of 9 (cN / dtex) is hung
Is measured, and then immersed in boiling water at a temperature of 100 ° C. for 30 minutes with no load, sufficiently dried, and then the skein length L ₁ under the same load is measured again. The skein shrinkage before and after the boiling water treatment was defined as the boiling water shrinkage (BWS). BWS = (L ₀ −L ₁ ) / L ₀ × 100 (%)

(6) Stretch rate of woven fabric A woven fabric sample having a length of 150 mm and a width of 50 mm was subjected to an initial load of 196 mN (20 g) using a tensile tester.
Attachment with grip distance of 100mm, 14.7N
(1.5 Kg) Load elongation under load was measured and determined by the following equation. Those having a value of 15% or more were regarded as acceptable. Stretch rate = L / 100X100 (%)

(7) Feeling of swelling Sensory evaluation was conducted by 10 persons who were arbitrarily selected, and evaluated in three grades: good, slightly good, and poor.

Example 1 A polytrimethylene terephthalate chip having an intrinsic viscosity of 1.05 and a polyethylene terephthalate chip having an intrinsic viscosity of 0.4 were mixed at a weight ratio (A: B) of 50:50. And melt-spun at a temperature of 280 ° C. from a side-by-side type composite spinneret, and take up at a speed of 5500 m / min to obtain a composite fiber of 83.3 dtex / 24 filaments. Obtained. Table 1 shows the results of evaluating the physical properties, the apparent crimp rate (VC), the total crimp rate (TC), and the texture of the woven fabric of the obtained conjugate fiber.

Comparative Example 1 A chip of polytrimethylene terephthalate having an intrinsic viscosity of 1.05 and a chip of polyethylene terephthalate having an intrinsic viscosity of 0.4 were mixed at a weight ratio (A: B) of 50:50. The melt is spun at a temperature of 270 ° C. from a side-by-side type composite spinneret, taken up at a speed of 3000 m / min, and the undrawn composite fiber of 133 dtex / 24 filaments is supplied. Obtained. This undrawn fiber is treated at a preheating temperature of 80
C. and a set temperature of 180.degree. C. to obtain a composite fiber of 82.1 decitex / 24 filaments. Table 1 shows the results of evaluating the physical properties, the apparent crimp rate (VC), the total crimp rate (TC), and the texture of the woven fabric of the obtained conjugate fiber.

Comparative Example 2 A chip of polytrimethylene terephthalate having an intrinsic viscosity of 1.05 and a chip of polyethylene terephthalate having an intrinsic viscosity of 0.5 were mixed at a weight ratio (A: B) of 50:50. And melt-spun from a side-by-side type composite spinneret at a temperature of 270 ° C. at a speed of 1500 m /
Min, a first roller at a temperature of 80 ° C., and a speed of 4000 m /
The mixture was spun and drawn (straight drawing method) through a second roller at a temperature of 205 ° C. for 8 minutes to obtain a conjugate fiber of 83.1 dtex / 24 filaments. Physical properties and apparent crimp rate (V
Table 1 shows the results of evaluation of C), the total crimp rate (TC), and the feeling of the woven fabric.

[0032]

[Table 1]

[0033]

The polyester composite fiber of the present invention is excellent in weaving since the apparent crimp rate is small, while it is excellent in stretchability and heat-treated after weaving because the total crimp rate is sufficiently large, and the feeling of swelling is high. A good fabric can be obtained.
Therefore, it can be widely used not only in sports clothing requiring stretchability but also in fields such as outerwear.

Claims (3)

[Claims] 1. A side-by-side type of a polytrimethylene terephthalate-based polyester A having an intrinsic viscosity of 0.9 to 1.5 and a polyethylene terephthalate-based polyester B having an intrinsic viscosity of 0.3 to 0.7. Or a composite fiber bonded in an eccentric core-sheath type, wherein the fiber has an apparent crimp rate of 1
A polyester-based composite fiber having a total crimp ratio of 5% or less and 20 to 50%. 2. The polyester composite fiber according to claim 1, wherein the intrinsic viscosity difference between the polytrimethylene terephthalate-based polyester A and the polyethylene terephthalate-based polyester B is 0.4 to 0.8. 3. A weight ratio (A: B) of a polytrimethylene terephthalate-based polyester A having an intrinsic viscosity of 0.9 to 1.5 and a polyethylene terephthalate-based polyester B having an intrinsic viscosity of 0.3 to 0.7. ) 30: 70-70: 3
0. A method for producing a polyester-based conjugate fiber, comprising conjugate spinning into a side-by-side type or an eccentric core-sheath type at 0, and drawing at a speed of 4000 to 8000 m / min.