JP2002061030A - Method for producing polyester conjugate fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyester conjugate fiber capable of being dyed in a deep color and also suitable for obtaining a cloth exhibiting an excellent stretching property and a bulky feeling. SOLUTION: This polyester conjugate fiber is obtained by conjugating a polytrimethylene terephthalate having 0.9-1.3 intrinsic viscosity and a polyethylene terephthalate having 0.4-0.6 intrinsic viscosity as a side by side type or an eccentric sheath core type fiber taking up at 500-3500 m/min spinning speed and then continuously drawing in a ratio as so to obtain the fiber having 20-50% elongation without winding up the fiber.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polyester composite fiber conjugated in a side-by-side type or an eccentric core-sheath type. More specifically, the present invention relates to a method for producing a polyester composite fiber comprising a polyethylene terephthalate-based polyester and a polytrimethylene terephthalate-based polyester, which is excellent in dyeability, and has excellent stretchability and good swelling.

[0002]

2. Description of the Related Art Conventionally, two kinds of polymers having different shrinkage characteristics or different melt viscosities are joined to an eccentric core-sheath type or a side-by-side type, and subjected to composite spinning and drawing, and heat-treated in a relaxed state. A method for obtaining a crimped yarn by this is well known. In particular, composite fibers made of polyethylene terephthalate-based polyester have been used in a wide range of fields, taking advantage of their excellent mechanical properties, thermal stability, wash and wear properties, and the like. However, woven fabrics using these polyester-based composite fibers can provide good bulkiness, but have poor stretchability and insufficient elastic recovery, and have high rigidity and texture. There are drawbacks such as hardness and low dyeability.

As a method for remedying such a defect, for example, Japanese Patent Application Laid-Open No. 43-19108 discloses a method in which polytrimethylene terephthalate and polyethylene terephthalate are combined in a side-by-side manner. This method uses a high-molecular-weight polytrimethylene terephthalate as a high shrinkage component. Although a woven fabric composed of the composite fiber certainly exhibits good stretchability and swelling, the dyeability is insufficient and the dyeability is insufficient. There is a problem that it is difficult to dye into a color.

As means for solving this problem, Japanese Patent Laid-Open No.
No. 189923 discloses a polytrimethylene terephthalate having an intrinsic viscosity of 0.4 to 1.0 and a polytrimethylene terephthalate having an intrinsic viscosity of 200 to 200.
Polyester-based composite fibers in which a polyester having a melt viscosity of up to 500 poise is composited have been proposed. However, since the composite fiber uses low-viscosity polytrimethylene terephthalate as a low-shrinkage component, the dyeability of the woven fabric is improved as compared with that of the composite fiber, but the crimping property of the composite fiber is as described above. It is low in comparison with the above, and there is a limit to use in applications requiring high stretchability.
Further, since low-viscosity polytrimethylene terephthalate is used, there is also a problem that it tends to change with time, and the mechanical properties and crimping properties of the fiber deteriorate.

[0005]

SUMMARY OF THE INVENTION The present invention has been made on the background of the above-mentioned prior art, and has as its object to provide a fabric which can be easily dyed in a dark color and which exhibits excellent stretchability and swelling feeling. Is to provide a method for producing a polyester conjugate fiber that can be obtained.

[0006]

Means for Solving the Problems As a result of various studies to achieve the above object, the present inventors set the intrinsic viscosities of polyethylene terephthalate and polytrimethylene terephthalate to be in specific ranges, as well as spinning and drawing. The present inventors have found that the use of the so-called straight-rolling method, in which the above-mentioned steps are continuously performed, can simultaneously realize high stretchability, a soft feeling with swelling, and deep dyeing.

[0007] Thus, according to the present invention, a polytrimethylene terephthalate-based polyester A having an intrinsic viscosity of 0.9 to 1.3 and a polyethylene terephthalate-based polyester B having an intrinsic viscosity of 0.4 to 0.6 are side-coated. A fiber obtained by compounding into a by-side type or an eccentric core-sheath type, melt-discharging, cooling and solidifying the discharged yarn, taking up the yarn at a speed of 500 to 3500 m / min, and then continuously without winding once. And a method for producing a polyester composite fiber, characterized in that it is stretched at a rate at which the elongation of the polyester composite becomes 20 to 50%.

[0008]

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 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.

Next, the intrinsic viscosity of the polytrimethylene terephthalate-based polyester A must be in the range of 0.9 to 1.3, preferably in the range of 1.0 to 1.2. Polyester B has an intrinsic viscosity in the range of 0.4 to 0.6, preferably 0.1 to 0.6.
It is necessary to be in the range of 5 to 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. Conversely, when the intrinsic viscosity exceeds 1.3, the spinnability is lowered and the spinning condition is deteriorated, which is not preferable. On the other hand, when the intrinsic viscosity of the polyethylene terephthalate-based polyester B is less than 0.4,
The dyeability of the obtained conjugate fiber is reduced, so that it becomes difficult not only to dye it in a dark color, but also the strength is lowered, which is not preferable. Conversely, when the ratio exceeds 0.6, the crimping performance (total crimp ratio) is undesirably reduced.

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 more crimped and stable crimped form.
It is preferable that the ratio be 0.8 or less 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 0.4 to
A range of 0.8, particularly a range of 0.5 to 0.7 is preferred.

In the present invention, the above-mentioned polytrimethylene terephthalate-based polyester A and polyethylene terephthalate-based polyester B are combined into a side-by-side type or an eccentric core-sheath type and melt-spun. The composite weight ratio of polyesters A and B (A: B) is 30: 70-7.
It is preferably in the range of 0:30, particularly in the range of 40:60 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.

In order to composite spin the polyesters A and B into a side-by-side type or an eccentric core-sheath type, a conventionally known spinneret may be appropriately selected and used according to a desired composite structure. The spinning temperature at which each polymer is extruded from the spinneret is in the range of 270 to 290 ° C, especially 275 to 290 ° C.
When the spinning temperature is less than 270 ° C., the polyethylene terephthalate-based polyester B is less likely to be in a stable molten state. It is difficult to obtain strength and elongation. On the other hand, when the spinning temperature exceeds 290 ° C., the polytrimethylene terephthalate-based polyester A
Is easily thermally decomposed, and the strength and elongation of the resulting fiber are liable to decrease.

Next, the discharged yarn is solidified by spraying a cooling air, and then subjected to an oiling treatment to take off the yarn at a take-off speed of 500 to 35.
The fiber is drawn at a rate of 00 m / min, preferably 1,000 to 3,000 m / min, and then continuously stretched without being wound, so that the obtained fiber has an elongation of 20 to 50%, preferably 25 to 45%. .

The take-up is performed by winding the yarn around the first roll rotating at a constant speed several times so that the tension between the front and rear of the roll does not propagate. Next, stretching may be performed with the second roll installed. Here, the first roll and the second roll may be heated if necessary. In particular, the first roll is preferably set to 80 to 100 ° C. for heating the yarn for drawing. Is 140 for heat setting of the drawn yarn.
The temperature is preferably set to 200 ° C.

The draw ratio depends on the take-up speed and the degree of elongation of the conjugate fiber, and may be appropriately set as desired.

The conjugate fiber produced by the method described above preferably satisfies the following characteristics at the same time, especially when used for clothing. That is, the strength is practically 2.2 to 4.5 cN / dtex, particularly 3.1.
A suitable range is from 4.5 to 4.5 cN / dtex, a boiling water shrinkage ratio is from 5 to 10%, especially from 6 to 8%, and a total crimp ratio is from 15 to 55%, especially from 20 to 40%. The range is appropriate, and the maximum thermal stress is 0.09 to 0.27 cN / dte.
x, especially 0.13 to 0.22 cN / dtex, and a thermal stress peak temperature in the range of 190 to 220 ° C, particularly 200 to 210 ° C are suitable. When the physical properties of the conjugate fiber satisfy the above requirements, relaxation, pre-setting, dyeing, and shrinkage that are likely to occur in each step such as final setting in the woven fabric production process can be suppressed, and the texture of the obtained woven fabric is further improved. It can be prevented from becoming stiff.

[0019]

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: o-Chlorophenol was used as a solvent and determined at 35 ° C. according to a conventional method.

(2) Breaking elongation 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) Total crimping ratio (TC) The number of windings is adjusted so that the total fineness is 3330 dtex. A load of 5.88 cN (6 g) is applied to the skein, and a load of 2.94 N (300 g) is further applied.
The length at this time is defined as L ₀ . Then 2.94N (300
g) is removed, and the skein is boiled in boiling water for 20 minutes while keeping the load of 5.88 cN (6 g). After removing the skein, dry it sufficiently and 2.94N (300g)
Applying a load to measure the length L _1. Then 2.94N
(300g) and 5.88cN (6g)
Measuring the length L ₂ at a load condition. The actual crimp rate and the total crimp rate are determined by the following equations. Total crimp rate (TC) = (L ₁ −L ₂ ) / L ₀ × 100 (%)

(4) Boiling water shrinkage (BWS) A skein of 200 mm 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 (%)

(5) Evaluation of Stainability Using Macbeth spectrophotometer manufactured by Sakata Inx Co., Ltd.
Determine the values of L *, a *, b * before and after staining of the cylinder net sample,
ΔL * and ΔE were calculated as follows. Here, if L * of the tube net sample after dyeing is 40.0 or less and ΔE of the tube net sample before and after dyeing is 55.0 or more, it is determined that the dyeing property is good. ΔE = [(ΔL *) ² + (Δa *) ² + (Δb *) ² ] ^1/2 where ΔL * is the difference between lightness index L * before and after staining, Δa
* And Δb * are the chromaticity index a before and after staining, respectively.
The difference between * and b * is shown, and the values of L *, a * and b * are obtained by using the standard light C and tristimulus values X, Y and Z specified in JIS Z8722 by the following formula. It is. L * = 10Y ^1/2 a * = 17.5 (1.02 XY) / Y ^1/2 b * = 7.0 (Y-0.847Z) / Y ^{1/2 In} addition, dyeing of the tube net sample According to the following: A 4% by weight dye (Sumicaron Navy Blue) of a tube net sample, 2 cc / liter of a 10% acetic acid solution and 10% of Disper VG
% Solution at a rate of 5 cc / liter of about 100
The mixture is placed in a dyeing container containing water by weight, and heating is started while stirring, and the water temperature is gradually raised to a boiling point. Stirring is continued for about 40 minutes after boiling, then the temperature is lowered to 80 ° C., and bisnol is added at a rate of 2 g / liter, followed by stirring for about 20 minutes. The obtained tube net sample is sufficiently washed with water and air-dried. The dyeability of the tube net sample after dyeing was L * ≦ 40.0 and the tube net sample before and after dyeing was ΔE ≧ 55.0.

(6) Measurement of Thermal Stress The thermal stress was measured using KE-2 manufactured by Kanebo Engineering Co., Ltd. at an initial load of 0.0442 cN / dtex (0.05 g / d) and a heating rate of 100 ° C./min. The value of the maximum point of the thermal stress was defined as the maximum thermal stress, and the temperature at that time was defined as the thermal stress peak temperature.

(7) Evaluation of woven fabric Sensory evaluation of stretchability and hand was performed by ten persons who were arbitrarily selected.

Example 1 Polytrimethylene terephthalate (A) having an intrinsic viscosity of 1.05 and an intrinsic viscosity of 0.4
And polyethylene terephthalate (B) of No. 3 were respectively supplied to a composite spinning machine, and the composite weight ratio was 1: 1, and the spinning temperature was 27.
At 0 ° C., the composite melt is discharged into a side-by-side mold, and after cooling and solidifying, an oil is applied and taken up via a first roller at a temperature of 80 ° C. and a speed of 1500 m / min.
78 dt after stretching with a second roller at a speed of 4000 m / min
An ex / 24fil (70d / 24fil) composite fiber was obtained. Table 1 shows the physical properties of the obtained fibers and the evaluation results of the fabric.

[Example 2] Polytrimethylene terephthalate (A) having an intrinsic viscosity of 1.05 and an intrinsic viscosity of 0.5
8 of polyethylene terephthalate (B) were supplied to a composite spinning machine, and the composite weight ratio was 1: 1 and the spinning temperature was 27.
At 0 ° C., the composite melt is discharged in a side-by-side mold, and after cooling and solidifying, an oil is applied and taken up via a first roller at a temperature of 80 ° C. and a speed of 1500 m / min.
78 dt after stretching with a second roller at a speed of 4000 m / min
An ex / 24fil (70d / 24fil) composite fiber was obtained. Table 1 shows the physical properties of the obtained fibers and the evaluation results of the fabric.

[Comparative Example 1] Polytrimethylene terephthalate (A) having an intrinsic viscosity of 1.05 and an intrinsic viscosity of 0.4
And polyethylene terephthalate (B) of No. 3 were respectively supplied to a composite spinning machine, and the composite weight ratio was 1: 1, and the spinning temperature was 27.
At 0 ° C., a composite melt was discharged in a side-by-side mold, and after cooling and solidifying, an oil agent was applied, and the oil was taken up through a take-up roller at a speed of 3000 m / min, and 190 dtex / 24 fill (1
70d / 24fil) was obtained. The obtained undrawn fiber is subjected to a preheating temperature of 80 ° C. and a set temperature of 140 ° C.
To obtain a composite fiber. Table 1 shows the physical properties of the obtained fibers and the evaluation results of the fabric.

[Comparative Examples 2 and 3] Instead of polyethylene terephthalate having an intrinsic viscosity of 0.43, the intrinsic viscosity was 0.64.
Example 1 was repeated except that the polyethylene terephthalate (Comparative Example 2) or 0.30 (Comparative Example 3) was used. Table 1 shows the physical properties of the obtained fibers and the evaluation results of the fabric.
In Comparative Example 3, the spinning condition was extremely poor, and the evaluation of fibers and woven fabric was not performed.

[0031]

[Table 1]

[0032]

According to the production method of the present invention, it is possible to easily obtain a polyester composite fiber having high crimpability and good dyeability. By using the fibers, it is possible to provide a fabric that exhibits excellent stretchability and a soft feeling with swelling, and that has good dyeability and can be dyed in a dark color.

 ──────────────────────────────────────────────────の Continued on the front page F term (reference) 4L041 AA08 AA10 AA20 BA02 BA05 BA09 BA22 BA59 BC05 BC20 CA08 DD01 DD04 4L048 AA21 AA22 AA28 AA30 AA44 AA48 AA49 AA50 AA55 AB07 AC07 AC09 AC10 AC11 CA00 CA04 CA12 CA13

Claims (2)

[Claims] 1. A side-by-side type of polytrimethylene terephthalate-based polyester A having an intrinsic viscosity of 0.9 to 1.3 and polyethylene terephthalate-based polyester B having an intrinsic viscosity of 0.4 to 0.6 The melt is discharged in a composite form into an eccentric core-sheath type, and the discharged yarn is cooled and solidified.
Withdrawing at a speed of ３3500 m / min and then continuously without winding once, the elongation of the obtained fiber is 20 to 50%
A method for producing a polyester composite fiber, characterized in that the polyester composite fiber is drawn at a ratio of: 2. A side-by-side type or eccentric type of a polytrimethylene terephthalate-based polyester A having an intrinsic viscosity of 0.9 to 1.3 and a polyethylene terephthalate-based polyester B having an intrinsic viscosity of 0.4 to 0.6. In the composite fiber joined in a core-sheath type, the composite fiber has a speed of 500 to
It is a fiber that is drawn at 3500 m / min and then drawn continuously without being once wound, and has the following (a)
Polyester composite fibers satisfying the characteristics of (f) to (f) at the same time. (A) Elongation: 20 to 50% (b) Strength: 2.7 to 4.5 cN / dtex (c) Boiling water shrinkage: 5 to 10% (d) Total crimp: 15 to 55% (0. 0018cN /
dtex load) (e) Maximum thermal stress: 0.09 to 0.27 cN / dte
x (f) Thermal stress peak temperature: 180 to 220 ° C