JP2002030527A - Polyester based conjugated fiber having high durability of stretch properties and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyester based conjugated fiber and a method manufacturing the same having high durability of stretch properties excellent in stretch properties and durability of the stretch properties by forming a side by side type conjugated fiber using PTT(polytetramethylene terephthalate) and PBT (polybutylene terephthalate) and setting the intrinsic viscosity of the both components in a proper relation and elongation rate of crimps, elongation rate of stretching and stretch modulus of elongation in adequate ranges. SOLUTION: This side by side type polyester based conjugated fiber obtained by conjugating polyesters having different viscosities in a conjugating ratio of 65:35-35:65, comprises component A including PTT as main a constituent and component B including PBT as a main constituent, and the intrinsic viscosities of the component A and B satisfies the formula (Y) and the fiber has the following characters; elongation rate of crimp <=20%, elongation rate of stretching >=10%;, stretch modulus of elongation >=90% and Uster irregularity <=2.0%. Formula (Y): 1.5<=Ia/Ib<=2.5 (Ia is the intrinsic viscosity of the component A, Ib is the intrinsic viscosity of the component B).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester conjugate fiber having high elasticity. More specifically, the conjugate fiber comprises a component A mainly composed of polytrimethylene terephthalate and a component B mainly composed of polybutylene terephthalate. The present invention relates to a polyester-based composite fiber having high elasticity and durability and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, polyesters have various excellent properties including mechanical properties, and thus have been widely used not only for clothing. In addition, various methods have been adopted to impart stretchability and crimpability to the polyester yarn by a recent stretch boom.

[0003] For example, there is a method in which a polyester fiber is subjected to false twisting to impart twisting / untwisting torque to impart elasticity. However, there is a problem that when this torque is used for a woven fabric, the surface of the woven fabric is textured, which is likely to be a defect of the woven fabric. On the other hand, composite spinning of polymers having different shrinkage characteristics or melt viscosities into side-by-side type or eccentric core-sheath type,
Various techniques for obtaining crimped yarn have been proposed. For example, JP-B-44-2504 and JP-A-4-308271 disclose a side-by-side composite yarn of polyethylene terephthalate (hereinafter abbreviated as PET) having an intrinsic viscosity difference or an intrinsic viscosity difference. 295634
Publication No. Homo-PET and copolymerized PE with higher shrinkage
A T-by-side composite yarn is described. If such a crimped polyester composite yarn is used, it is possible to obtain a certain degree of elasticity, but the elasticity when used in a woven fabric is insufficient, and it is difficult to obtain a satisfactory elastic woven fabric. was there. The side-by-side type composite yarn as described above has low crimp expression performance during woven fabric restraint,
In addition, crimping is easily caused.

Japanese Patent Application Laid-Open No. Hei 11-189923 proposes a polyester-based composite yarn comprising PET and polytrimethylene terephthalate (hereinafter abbreviated as PTT) having a lower melt viscosity. However, if PTT is PE
When the viscosity is lower than T, for most of the developed crimping forms, the inside of the crimped coil becomes the PET component and the outside becomes the PTT component, so that the obtained crimped yarn has sufficient elasticity and crimp development. In addition, the stretchability, the retention of crimp development becomes very low, and a known crimped yarn is obtained by a side-by-side type composite using PET having substantially different intrinsic viscosity or intrinsic viscosity. There is a problem that it is no different from technology.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art as described above, and to provide a high-stretch and durable polyester composite fiber having stable productivity and excellent stretchability and quality. And a manufacturing method.

[0006]

In order to achieve the above object, the present invention employs the following constitution. That is, (1) Polyesters having different viscosities are used at 65:35 to 35:
In a polyester-based composite fiber composited in a side-by-side type at a composite ratio of 65, an A component mainly composed of polytrimethylene terephthalate and a B component mainly composed of polybutylene terephthalate, and the intrinsic viscosities of the A component and the B component are represented by the following formula ( Polyester composite fiber satisfying (a), having a crimp elongation of 20% or less, a stretch elongation of 10% or more, a stretch elasticity of 90% or more, and a Worcester spot of 2.0% or less. .

1.5 ≦ (Ia / Ib) ≦ 2.5 (I) (where Ia is the intrinsic viscosity of component A, Ib is the intrinsic viscosity of component B (IV) (2) Forming composite fiber The polyester-based conjugate fiber according to the above (1), wherein the amount of COOH terminal groups of the polytrimethylene terephthalate is 20 eq / ton or less.

(3) Polyesters having different viscosities 65:
In a polyester-based composite fiber composited in a side-by-side type at a composite ratio of 35 to 35:65, when performing composite spinning using a high-viscosity component mainly composed of polytrimethylene terephthalate and a low-viscosity component mainly composed of polybutylene terephthalate, High stretch durability characterized in that unstretched yarn spun at a temperature of 260 to 280 ° C, a preheating temperature of 50 to 80 ° C, and a heat setting temperature of 100 to 180 ° C is continuously stretched without being wound once. A method for producing a polyester-based composite fiber.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. In the present invention, the component A is a polyester mainly composed of polytrimethylene terephthalate among the two-component polymers constituting the composite fiber. In the PTT, the methylene chain of the alkylene glycol moiety in the crystal structure is gauche-
Gauche structure (molecular chain bent at 90 degrees),
Furthermore, due to the low binding point density due to the interaction between benzene rings (stacking and paralleling) and high flexibility, it has the unique elasticity that the molecular chain can be easily extended and recovered by the rotation of the methylene group. ing. This P
This is because the elasticity inherent to TT is sufficiently exhibited even in the composite fiber. In the present invention, the composite ratio of the two components constituting the composite fiber is not particularly limited as long as it is a composite ratio generally used for imparting elasticity by a side-by-side composite, and is generally 65:35 by weight. ~ 35:
65, preferably 60:40 to 40:60.
It is.

In the present invention, the component B constituting the composite fiber is polybutylene terephthalate (hereinafter abbreviated as PBT) mainly composed of butylene terephthalate. K. Ta
shiro, Macromolules, 13, 13
According to P.78 (1980), due to stress applied from the outside, PBT reversibly changes between α-from having a short c-axis and β-form having a long c-axis, and has a crystal c-axis length of about 1. It is said that it expands and contracts by about 4 angstroms. This P
The change in the crystal structure caused by the stress inherent to the BT transfers external stress to the elasticity of the fiber structure, and improves the durability of the elasticity.

In the present invention, the intrinsic viscosity of the component A and the intrinsic viscosity of the component B satisfy the following formula (A).

1.5 ≦ (Ia / Ib) ≦ 2.5 (I) where Ia is the intrinsic viscosity of the A component, and Ib is the intrinsic viscosity of the B component.

When the intrinsic viscosity Ia of the component A is lower than Ia = 1.5 × Ib with respect to the intrinsic viscosity Ib of the component B, the PTT component mainly responsible for the elasticity of the conjugate fiber is applied to the inner side of the crimped coil. In addition to this, not only the inherent elasticity of PTT is not sufficiently exhibited, but also it becomes difficult to obtain bulkiness when used in a woven or knitted fabric. Furthermore, it becomes difficult to exhibit the stretching durability due to the change in the crystal structure unique to PBT. On the other hand, when Ia = 2.5 × Ib is exceeded, not only the discharge yarn at the time of conjugate spinning becomes large, it is difficult to obtain a conjugate fiber stably, but also the side surface of the composite interface is largely curved. It becomes a composite fiber of a type or an eccentric core-sheath type, and it cannot be made to be excellent in elasticity.

The conjugate fiber of the present invention has a crimp elongation of 20% or less, and more preferably 15% or less. It exhibits the durability of elasticity when used for a woven or knitted fabric. The stretch ratio is 10% or more. It exhibits extensibility when used for woven or knitted fabric. The elastic modulus of elasticity is 90% or more, more preferably 95% or more. It exhibits shrinkage when used for woven or knitted fabrics. By simultaneously satisfying the properties of the stretch ratio of 10% or more and the stretch modulus of 90% or more, a favorable stretchable polyester-based composite fiber can be obtained.

The conjugate fiber according to the present invention has a Worcester thread spot of 2.0% or less. By setting the worcester thread spots to 2% or less, not only a beautiful cloth surface when used in a woven or knitted fabric can be obtained, but also occurrence of stain spots in dyeing can be avoided. Worcester spots are preferably no more than 1.3%.

In the present invention, the amount of COOH terminal groups of the polytrimethylene terephthalate is preferably 20 eq / ton or less, more preferably 15 eq / ton or less. It is intended to suppress thermal degradation of the polymer during composite spinning and improve continuous spinnability.

Next, an example of a preferred method for producing the conjugate fiber of the present invention will be described.

In the method for producing a conjugate fiber of the present invention, the conjugate fiber is subjected to conjugate spinning at a spinning temperature of 260 to 28.
The composite spun yarn at 0 ° C. is continuously stretched without being wound once, stretched after preheating at 50 to 80 ° C., and stretched at 100 to 18 ° C.
It is preferred to heat set at a temperature of 0 ° C. At this time, P
Since TT and PBT have a lower melting point and lower heat resistance than PET, the spinning temperature is preferably in the range of 260 to 280 ° C. Further, in order to uniformly heat the yarn and to suppress the deterioration of PTT and PBT due to excessive heating,
The preheating temperature at the time of stretching is preferably in the range of 50 to 80 ° C, more preferably in the range of 60 to 80 ° C, so as to make it easier to obtain fibers having a worcester spot of 2.0% or less. Further, the heat setting temperature at the time of stretching is preferably in the range of 100 to 180 ° C., and PTT and PB
This is for facilitating the handling when processing the obtained conjugate fiber into a woven fabric while suppressing the thermal deterioration of T. The stretch ratio is not particularly limited, but is preferably 2.0 to 3.5 times, more preferably 2.5 to 3.3 times,
This is because the side-by-side composite imparts sufficient elasticity and crimp development.

In the present invention, entanglement of the yarn is not a particularly essential condition, and a method of entanglement is not particularly specified. However, in order to improve handling properties such as unwinding property in post-processing. , Using a conventional confounding device.
It is preferable to provide 0 to 5.0 confounds.

[0020]

The present invention will be described in more detail with reference to the following examples. In the text and the examples, the amount of COOH terminal groups, the intrinsic viscosity, the stretching elongation, the stretching elasticity, the crimping elongation,
Worcester spots, the number of confounds, the spinning properties, and the stretch durability are as follows. (1) COOH terminal group content: 0.5 g of polymer was dissolved in 10 ml of o-cresol, cooled to 25 ° C.
Using a MA solution, the value measured by potentiometric titration (eq / to
n). (2) Intrinsic viscosity: orthochlorophenol (hereinafter referred to as OCP)
Dissolve 0.8 g of the sample polymer in 10 ml,
This is a value (IV) obtained by calculating the relative viscosity ηr at 25 ° C. using an Ostwald viscometer by the following equation.

Ηr = η / η ₀ = (t × q) / (t ₀ × q ₀ ) IV = 0.0242ηr + 0.2634 where η: viscosity of polymer solution, η ₀ : viscosity of OCP, t: solution of OCP Fall time (sec), q: density of solution (g /
cm ³ ) t ₀ : OCP falling time (sec), q ₀ : OCP density (g / cm ³ ). (3) Stretching elasticity and elasticity: A 560 mm long scab is made and treated with hot water at 90 ° C. for 20 minutes under a load of 3.53 × 10 ⁻³ cN / dtex. Thereafter, a load (hereinafter abbreviated as M1) of 1.76 × 10 ⁻³ N / dtex was applied to measure the length L0 of the scab after 30 seconds.
After removing the load, a load of 0.09 cN / dtex (hereinafter referred to as M2
), And the length L1 after 30 seconds was measured. Further, after removing M2, the length L2 after 30 seconds was again measured by multiplying M1 again, and the value (%) was obtained by the following equation. (See FIG. 2).

Stretching elongation (%) = {(L1-L0) / L0} × 100 Stretching elasticity (%) = {(L1-L2) / (L1-L)
0)｝ × 100 (4) Crimp elongation: After measuring the bulging length L2 in the measurement of the stretching elongation and the stretching elasticity, M1 was removed, and further,
After repeating the operation of applying M2 for 30 seconds, removing M2 and applying M1 for 30 seconds, 10 times, measuring the length L3 of the cassette 30 minutes after application of M1, the value (%) obtained from the following equation. (See FIG. 2).

Crimping elongation (%) = {(L3-L2) / L2} × 100 (5) Worcester spots: USTE manufactured by Zellweger
Using R TESTER 1 M0delC, 200
The measurement was performed in the normal mode while supplying the yarn at a speed of m / min. (6) Number of confounds: AUTO made by ROTHSCHILD, Switzerland
MATIC ENTERTAINMENT TESTER
Using R2060, measure 30 times at a yarn speed of 4 cm / sec,
This is a value (number / m) obtained from the following equation.

The number of entanglements (pieces / m) = 1000 mm / entanglement distance mm (7) Yarn-producing properties: The following four steps evaluated in order of decreasing the number of yarn breaks during continuous spinning.

○: less than 2.0 times / t ：: less than 2.5 times / t ：: less than 3.0 times / t ×: 3.0 times / t or more (8) Stretching durability: crimp elongation Evaluation was made in the following four steps in ascending order of the rate.

○: less than 10% ：: less than 15% △: less than 20%: not less than 20% (9) Product texture: The sensory evaluation was conducted by five skilled workers for stretchability, bulkiness and surface unevenness. 4 by the judgment of
The evaluation was graded.

○: excellent ：: good Δ: acceptable ×: unacceptable Note that the product herein is a composite yarn obtained by subjecting the composite yarn obtained by the present invention to a twist of 1000 T / m as a weft, and a warp as a weft. This shows a weft-inlaid fabric made of normal PET yarn of 56 decitex and 18 filaments with 1/3 twill, and subjected to crimp development processing and dyeing finish processing by a normal polyester dyeing process.

Example 1 A commercially available direct spinning and drawing machine shown in FIG. 1 was used to prepare a P having an intrinsic viscosity of 1.76 and a COOH end group content of 18.2 eq / ton.
Using TT and PBT having an intrinsic viscosity of 0.80, 56 decitex 24 having a composite ratio of 60:40 at a spinning temperature of 270 ° C.
A side-by-side composite yarn of a filament was obtained. That is, the composite yarn 2 was discharged from the composite spinneret 1, sufficiently cooled by the chimney yarn cooling device 3, and an oil agent was applied by the oiling roller 4. Further, after the oil agent is homogenized by the light entanglement device 5, after preheating by the first hot roller 6,
Stretching was performed at a speed ratio with the second hot roller 7. At this time, it is heat-set at the temperature of the second hot roller 7, entangled with the present entanglement device 8, and further wound around a winder 10 via a god roller 9.

In Example 1, the first hot roller (hereinafter abbreviated as 1 HRV) was taken at 1800 m / min, preheated at a first hot roller temperature (hereinafter abbreviated as 1 HRT) of 65 ° C., and then heated at a second hot roller speed (hereinafter abbreviated as 1 HRT). (Hereinafter 2H
RV) (5040 m / min), stretching at a stretching ratio of 2.8 at the speed ratio of the two rollers, and at the same time heat setting at a second hot roller temperature (hereinafter abbreviated as 2HRT) of 150 ° C., followed by winding with a winder. . The number of thread breaks is 1.8
The composite yarn was stable at the number of turns / t, and the stretchability was 24.4%, the stretch modulus was 95.1%, and the stretchability was good. Further, the crimp elongation rate is 14.3%, which is a good stretch durability, and the worcester spot is 1.0%, and the thickness spot of the thread is small. Those having excellent properties, bulkiness and surface quality were obtained. The results are summarized in Table 1.

Example 2 Intrinsic viscosity 1.36, COOH terminal group content 15.4 eq / t
1 using PTT having an intrinsic viscosity of 0.80 and a spinning temperature of 26 using the apparatus shown in FIG.
A side-by-side type composite yarn of 56 decitex 24 filaments having a composite ratio of 50:50 at 5 ° C. was obtained. At this time, 1 HRV: picked up at 1600 m / min, 1 HRT: 70
After preheating at 2 ° C., 2 HRV: 5000 m / min.
After heat setting at 50 ° C., it was wound up with a winder. The number of times of thread breakage is 2.2 times / t, which is a level that does not cause any problem in actual production.
A composite yarn having an excellent crimp elongation of 9.3% and excellent stretchability and stretch durability was obtained. Worcester spots were as small as 1.2%, and the thread spots were small. The texture of the product using this thread was excellent in stretchability, bulkiness and surface quality. The results are summarized in Table 1.

Example 3 Intrinsic viscosity 1.65, COOH terminal group content 11.6 eq / t
1 using PTT having an intrinsic viscosity of 1.10 and a spinning temperature of 28 using the apparatus shown in FIG.
A side-by-side composite yarn of 56 decitex 24 filaments having a composite ratio of 50:50 at 0 ° C. was obtained. At this time, 1 HRV: picked up at 1500 m / min, 1 HRT: 60
After preheating at 2 ° C., 2HRV was set to 4350 m / min.
After heat setting at 70 ° C., it was wound up with a winder. The thread breakage frequency is 1.3 times / t, showing extremely stable yarn-making properties. The stretchability is 18.3%, the stretch modulus is 96.6%, and the crimp stretch is 9.0%. And a composite yarn having stretch durability was obtained. Worcester spots are 1.8% and the thickness spots of the thread are not problematic. The texture of products using this thread is slightly low in stretchability and bulkiness, but is sufficient as a stretchable material. A product having excellent surface quality was obtained. The results are summarized in Table 1.

Example 4 Intrinsic viscosity 1.44, COOH terminal group amount 10.9 eq / t
using a PTT of on and a PBT with an intrinsic viscosity of 0.80, using the apparatus shown in FIG.
A side-by-side type composite yarn of 56 decitex 24 filaments having a composite ratio of 50:50 at 5 ° C. was obtained. At this time, 1 HRV: picked up at 1000 m / min, 1 HRT: 80
After preheating at 2 ° C., 2 HRV: 3000 m / min.
After heat setting at 60 ° C., it was wound up with a winder. The thread breakage frequency is 0.8 times / t, showing extremely stable yarn-making properties. The stretchability is 27.8%, the stretch modulus is 98.5%, and the crimp stretch is 8.5%. And a composite yarn having stretch durability was obtained. Worcester spots are 0.8% and the thread spots are very small, and the texture of products using this thread is
A material excellent in elasticity, bulkiness and surface quality as an elastic material was obtained. The results are summarized in Table 1.

Example 5 Intrinsic viscosity: 2.00, COOH terminal group content: 13.8 eq / t
1 and a PBT having an intrinsic viscosity of 0.80 using the apparatus shown in FIG.
A side-by-side composite yarn of 56 decitex 24 filaments having a composite ratio of 65:35 at 0 ° C was obtained. At this time, 1 HRV: picked up at 1200 m / min, 1 HRT: 60
After preheating at 2 ° C., 2HRV: 3840 m / min.
After heat setting at 80 ° C., it was wound up with a winder. The number of times of thread breakage is 2.3 times / t, which is a level that does not cause any problem in actual production. The yarn has excellent stretchability of 30.7% of stretch and elongation and 92.3% of stretch elasticity. A composite yarn having an elongation of 18.1% and no problem with stretch durability was obtained. Worcester spots were 1.5%, and there was no problem in thread thickness spots, and the texture of the product using this thread was good in both stretchability, bulkiness and surface quality. The results are summarized in Table 1.

Comparative Example 1 Intrinsic viscosity 0.96, COOH terminal group amount 23.8 eq / t
1 using PTT having an intrinsic viscosity of 0.80 and a spinning temperature of 26 using the apparatus shown in FIG.
A side-by-side composite yarn of 56 decitex 24 filaments having a composite ratio of 50:50 at 0 ° C. was obtained. At this time, 1 HRV: picked up at 1100 m / min, 1 HRT: 60
After preheating at 2 ° C., 2HRV: 3200 m / min.
After heat setting at 50 ° C., it was wound up with a winder. Although the number of times of thread breakage was 1.7 times / t, which was a stable yarn-making property, the stretchability of the obtained yarn was 7.5%, and the stretchability was 62.3.
%, And the crimp elongation was 23.4%, which resulted in poor stretchability and stretch durability. Worcester spots are 3.3% and thread thickness spots are large, and the texture of products using this thread is
It had low elasticity, lacked bulkiness, and had poor surface quality. The results are summarized in Table 1.

Comparative Example 2 Intrinsic viscosity 2.40, COOH terminal group content 11.1 eq / t
1 and a PBT having an intrinsic viscosity of 0.80 using the apparatus shown in FIG.
At 0 ° C., a side-by-side type composite yarn of 56 decitex 24 filaments having a composite ratio of 60:40 was spun. At this time, 1 HRV: picked up at 1200 m / min, 1 HRT:
After preheating at 70 ° C., 2HRV: 3300 m / min, stretching at a stretching ratio of 2.8 times and simultaneously 2HRT:
After heat setting at 160 ° C., an attempt was made to wind up with a winder. However, it was difficult to perform actual spinning due to the fact that the polymer that was severely bent at the spinneret adhered to the surface of the spinneret to perform stable spinning. . With regard to the yarn obtained in a very small amount, the stretching elongation was 6.2%, the stretching elasticity was 52.8%, and the crimping elongation was 3
It could not be as high as 1.9%. The results are summarized in Table 1.

Comparative Example 3 Intrinsic viscosity 1.10, COOH terminal group content 19.6 eq / t
1 using PTT having an intrinsic viscosity of 1.10 and a spinning temperature of 27 using the apparatus shown in FIG.
At 5 ° C., a side-by-side type composite yarn of 56 decitex 24 filaments having a composite ratio of 50:50 was spun. At this time, 1 HRV: picked up at 1300 m / min, 1 HRT:
After preheating at 70 ° C., 2HRV was set to 4700 m / min, and the film was stretched at a draw ratio of 3.6 times and simultaneously 2HRT:
After heat setting at 150 ° C., it was wound up with a winder. The number of times of thread breakage was 2.3 times / t, which was a level that was not a problem in actual production.
The durability is 9.2% and the crimp elongation is 4.2%, which is a high value. The Worcester spots are 1.4% and the thickness spots of the threads are not problematic, but the stretchability is very low. The product used had neither stretchability nor bulkiness, and could not be highly stretchable. The results are summarized in Table 1.

COMPARATIVE EXAMPLE 4 As in Example 5, using PTT having an intrinsic viscosity of 2.00, a COOH terminal group amount of 13.8 eq / ton and PBT having an intrinsic viscosity of 0.80, FIG. Was used to obtain a 56-decitex 24-filament side-by-side composite yarn having a composite ratio of 65:35 at a spinning temperature of 280 ° C. At this time, preheating was performed at a high temperature of 1 HRT: 100 ° C., followed by heat setting at 2 HRT: 180 ° C., followed by winding with a winder. Other spinning conditions are the same as in Example 5. The number of times of yarn breakage is 2.2 times / t, which is a level that does not cause any problem in actual production, and has excellent stretchability of 32.1% of stretch and elongation and 91.5% of stretch elasticity. A composite yarn having an elongation of 20.0% and no problem with stretching durability was obtained, but the wool spot unevenness was 4.1% and the yarn thickness unevenness was extremely large. The texture of the product using this yarn has no problem in stretchability and bulkiness, but the surface quality is very poor, and even in undyed greige fabric, a streak pattern is seen on the fabric surface, and the surface unevenness is very Outstanding, very poor quality. The results are summarized in Table 1.

[0038]

[Table 1]

[0039]

As described above, according to the present invention, PT
In the side-by-side type composite yarn using T and PBT, the intrinsic viscosity of the two components is appropriately set, and the crimp elongation rate,
By setting the stretch ratio and stretch modulus in appropriate ranges, it is possible to obtain high stretch durability polyester composite fiber having excellent stretchability and stretch durability.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating an example of a composite spinning device used in an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a method for measuring a stretch rate, a stretch modulus, and a crimp rate in the present invention. 1: Slipper 2: Discharge yarn 3: Chimney yarn cooling device 4: Oiling roller 5: Entanglement guide 6: First hot roller 7: Second hot roller 8: Entanglement guide 9: Relax roller 10: Winder 11: Package 12 :spindle

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4L041 AA07 AA10 AA18 AA19 AA25 BA02 BA05 BA09 BA59 BC17 BC20 CA08 DD01 DD04 DD15 4L045 BA21 BA60 CA25 DA14 DA23 DA42 DA48

Claims (3)

[Claims] 1. A polyester having a viscosity different from 65:35.
In a polyester composite fiber composited in a side-by-side type at a composite ratio of 35:65, an A component mainly composed of polytrimethylene terephthalate and a B component mainly composed of polybutylene terephthalate, and the intrinsic viscosities of the A component and the B component are as follows. Formula (a) is satisfied, and the crimp elongation is 20% or less,
A polyester-based conjugate fiber having a stretch ratio of 10% or more, a stretch elastic modulus of 90% or more, and a Worcester spot of 2.0% or less. 1.5 ≦ Ia / Ib ≦ 2.5 (I) (where Ia is the intrinsic viscosity of the component A and Ib is the intrinsic viscosity (IV) of the component B) 2. COO of polytrimethylene terephthalate
The polyester-based conjugate fiber according to claim 1, wherein the amount of the H terminal group is 20 eq / ton or less. 3. Polyesters having different viscosities of 65:35 to
In a polyester-based composite fiber composited in a side-by-side type at a composite ratio of 35:65, when a composite spinning is performed using a high viscosity component mainly composed of polytrimethylene terephthalate and a low viscosity component mainly composed of polybutylene terephthalate, a spinning temperature of 260 is used. ~ 280 ° C, preheating temperature 50 ~
A method for producing a polyester-based composite fiber, characterized in that an undrawn yarn that has been composite-spun at 80 ° C and a heat setting temperature of 100 to 180 ° C is continuously drawn without being wound once.