JP3358404B2 - Method for producing crimpable composite polyester fiber - Google Patents

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 crimpable conjugated polyester fiber, and more particularly, to a method for producing a crimped conjugated polyester fiber obtained by compounding two kinds of polyesters side-by-side with good thread-forming properties. At a low cost and imparting sufficient crimp development characteristics.

[0002]

2. Description of the Related Art As a method for producing a crimpable composite polyester fiber by high-speed spinning, a method of composite spinning two kinds of polyester side by side is known. At that time, it is common practice to use a polyester having a difference in copolymerization ratio and intrinsic viscosity as a combination of two kinds of polyesters. JP-A-48-24026,
JP-A-51-15020 proposes a method of high-speed spinning a side-by-side type polyester composite fiber having a difference in copolymerization ratio. Also, Japanese Patent Application Laid-Open No. 48-48
No. 718 proposes a method of producing a side-by-side type polyester composite fiber having a difference in melt viscosity by high-speed spinning. When crimping conjugate fibers are produced by these methods, there is a cost advantage that the fibers can be obtained in one spinning step, but there is a problem that frequent yarn breakage occurs and stable yarn production becomes difficult. In addition, the crimpable conjugate fiber produced by such high-speed spinning has a low shrinkage stress, and there is a problem that crimping cannot be sufficiently developed under the constraint of the fabric.

[0003]

DISCLOSURE OF THE INVENTION The present invention has been intensively studied for the purpose of suppressing yarn breakage and stably producing a bimetal conjugate fiber exhibiting excellent crimp in a single spinning step. The result was obtained.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to produce a polyester fiber in which two types of polyesters A and B are combined side by side, and the difference in the copolymerization ratio of the components A and B is 5.0. (Mol%) or more of the A and B components
Each of the intrinsic viscosities is 0.6 or more, and the difference between the intrinsic viscosities is 0.
The polyester which is 1 or less is discharged at a discharge amount ratio of 8: 2 to 2: 8.
After the spun yarn discharged from the side-by-side composite spinneret is cooled to a temperature below the glass transition point, it is stretched between the second godet roller while being taken up by the first godet roller, and then heat-treated at a stretch ratio of 0.5% or more. 4,000
It can be achieved by a method for producing a crimpable composite polyester fiber, characterized in that it is wound at a speed of at least m / min.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The polyesters A and B used in the present invention have a copolymerization ratio of 5.
It is necessary to have a difference of 0 mol% or more. If the difference in the copolymerization ratio is less than 5.0 mol%, the crimp expression level will decrease. The upper limit of the difference in the copolymerization ratio is preferably 15.0 mol% in order to keep the heat resistance and make the spinning more stable.

As the copolymerization component of the present invention, aromatic dicarboxylic acids, aliphatic dicarboxylic acids, aliphatic diols, alicyclic diols, aromatic diols or diols obtained by adding ethylene oxide or the like to these are used. And specifically, isophthalic acid, naphthalene-2,6-dicarboxylic acid, adipic acid, sebacic acid,
1,4-butanediol, diethylene glycol, trimethylene glycol, polyethylene glycol having a molecular weight of about 600 to 6,000, cyclohexanediol, an ethylene oxide adduct of bisphenol A, an ethylene oxide adduct of bisphenol sulfone, and the like can be preferably used.

In the present invention, when a plurality of components are copolymerized, the total copolymerization ratio is used.

Next, the polyester A of the present invention described above,
It is necessary that the intrinsic viscosity difference of B be 0.1 or less.
If the intrinsic viscosity difference exceeds 0.1, the generation of stains on the spinneret surface used for bimetal composite spinning becomes severe,
The flow of the composite polymer discharged from the die is likely to bend immediately after the discharge, which adversely affects the yarn production stability. Intrinsic viscosity is measured at 25 ° C. in orthochlorophenol. Also,
The respective intrinsic viscosities of A and B need to be 0.6 or more in order to further reduce the stain on the die and achieve stable spinning.
It is important .

As the side-by-side composite spinneret of the present invention, a known spinneret can be used, but from the viewpoint of the spinning property in high-speed spinning, it is preferable to use the one in which each component merges in a plane-symmetric manner at the upstream of the spinneret discharge hole. The cross section of the obtained fiber is shown in FIG. 1 (a), the eccentric core-sheath type shown in FIG. 1 (b), the cross section containing the C component shown in FIG. 1 (c), etc. , B component is not positioned centrally symmetrically, and a crimp occurs in a spiral shape by heat treatment. Further, as the cross-sectional shape of the discharge hole of the composite mouthpiece, in addition to a circle, 3 to 8 leaves, hollow, flat, C type, or the like can be adopted.

The discharge ratio of each of the components A and B of the present invention is 8:
It is necessary to set the range of 2-2: 8. If the content is outside this range, the components on the high shrinkage side or the low shrinkage side will be reduced, and the spiral crimp will be insufficiently developed, resulting in poor crimp development characteristics.

In the present invention, the discharged composite stream is cooled,
It is necessary to stretch with the second godet roller while taking up with the first godet roller. In the case where the stretching is not performed between the god rollers, thread breakage frequently occurs, and it is difficult to perform stable spinning at 4000 m / min or more. At the time of stretching, heat stretching is preferred. At this time, the first godet roller is used as a hot roller, a method of passing a heating body such as a steaming process, a heating plate, a heating pin between the first godet roller and the second godet roller, and the like, but the godet roller is not heated,
It is preferable from the viewpoint of cost merit that the film is thermally stretched by using a normal pressure steam of 95 ° C. or more.

After stretching, stretch 0.5% or more
It is necessary to heat-treat at a specific rate. Stretch rate is 0.
5%Less thanIs sufficient for the composite polyester fiber
It is not possible to apply a large shrinkage stress. As fiber properties
When compared with the heat shrinkage stress value, the ordinary high-speed spun fiber has 0.1%.
1 to 0.15 g / d, the fiber of the present invention is 0.2 to 0.5 g
/ D. Heat treatment temperature at this time promotes crystallization of yarn
105 ° C. or higher to achieve a practically usable shrinkage
So as not to kill the difference in contraction between the A and B components.
The temperature is preferably set to 140 ° C. or lower. Also means of heat treatment
Then, a hot roller, a heating plate, or the like can be used.
However, so that the yarn can be mildly and uniformly heated,
It is preferred to use pressurized steam.

The winding speed needs to be 4000 m / min or more. When the speed is less than 4000 m / min, the productivity is reduced and cost merit cannot be utilized.

The present invention will be described in more detail with reference to FIG. After the polymer discharged from the composite mouthpiece 1 passes through the heat retaining area 2, the polymer is cooled by the chimney 3 and refueled by the refueling device 4, and the unheated first
The second godet roller 6 which is picked up by the godet roller 5 and is not heated
And heat-stretched by passing through a normal-pressure steam processing device 7. Further, the yarn that has passed through the second godet roller 6 is heat-set by the pressurized steam processing device 8, passed through the unheated third godet roller 9, the entanglement applying device 10, and the unheated fourth godet roller 11, and wound up by the winder 12. Thereby, a crimpable composite polyester fiber is obtained.

[0015]

EXAMPLES Each characteristic value in the examples was determined according to the following method. (A) Intrinsic viscosity Orthochlorophenol was measured at 25 ° C.

(B) Crimp elongation rate, fiber shrinkage rate, crimp shrinkage rate
The length L0 is measured under a load of d. Next, 0.2 mg /
The sample was treated in boiling water at 98 ° C. for 15 minutes under a load of d and air-dried.
Is measured. Further, the sample length L2 is measured at a load of 200 mg / d, and the crimp elongation (%), fiber shrinkage (%), and crimp shrinkage (%) are determined by the following equations. Crimp elongation = (L2-L1) / L1 * 100 Fiber shrinkage = (L0-L2) / L0 * 100 Crimp shrinkage = (L2-L1) / L0 * 100

(C) Yarn-producing property The number of times of thread breakage when 10 samples were wound continuously for 5 kg winding was used as a measure of the thread-producing property.

(D) Elongation at break, modulus of elasticity Using a Tensilon tensile tester manufactured by Orientec Co., Ltd., measurement conditions (N: 200 mm, tensile speed: 200 mm / min) (N
= 5), the breaking elongation at break and the initial elastic modulus were measured.

(E) Thermal Shrinkage Stress Using a thermal stress meter KE-2 manufactured by Kanebo Engineering, loop a 20 cm sample into 10 cm, and apply an initial load of denier of the raw yarn to be measured x 1/15 (g). After adjusting the temperature, the temperature is increased at a temperature increasing rate of 150 ° C./min to determine a heat shrinkage stress curve. From this curve, the stress (g / d) at the peak position is read. The recorder was made by Yokokawa Electric X-
YRecorderType 3083 was used.

Example 1 An esterification reaction was carried out using terephthalic acid / ethylene glycol and isophthalic acid / ethylene glycol slurries, and then an ethylene glycol solution of an ethylene oxide adduct of bisphenol A (BPA-EO) was added. Polymerization was performed by the method. The molar fraction of isophthalic acid (IPA) is 7 mol% with respect to all acid components of the copolymerized polyester, the molar fraction of ethylene oxide adduct of bisphenol A is 4 mol% with respect to all glycol components of the copolymerized polyester, and the intrinsic viscosity is 0. A polyester chip of component A was obtained.

Further, polyethylene terephthalate having an intrinsic viscosity of 0.65 was used as the B component polyester.

At a spinning temperature of 290 ° C., a composite spinneret having 36 holes at the upstream side of the spinning discharge holes where the components A and B merge in plane symmetry, A:
A bimetal composite stream of component B was discharged. Next, as shown in FIG. 2, after passing through a heat retaining area 2 20 cm below the base 1, the wind speed 2
After cooling with a uniflow chimney 3 of 0 m / min, air temperature of 25 ° C. and length of 110 cm, refueling was carried out by a refueling device 4 installed 2.5 m below the base, and a non-heating first speed of 3000 m / min.
It was taken up by a godet roller 5 and passed through a normal-pressure steam processing device 7 between the unheated second godet roller 6 at a peripheral speed of 4854 m / min and thermally stretched. Furthermore, the second god roller 6
The yarn passed through is 50 cm long and the pressure is 1.0 kg / c.
Heat set at a stretch rate of 3% by a pressurized steam processing device 8 at m ² and 120 ° C., a third god roller 9 with a peripheral speed of 5000 m / min, a non-heated entanglement imparting device 10, and a non-heated peripheral speed of 5000 m / min. After winding through a fourth wind roller 11 and a winder 12, a crimpable composite polyester fiber having 75 denier and 36 filaments was obtained.

Table 1 shows the spinning conditions, spinnability, mechanical properties of the obtained fibers, shrinkage stress and crimp elongation.

Example 2, Comparative Example 1 A crimpable composite polyester fiber of 75 denier and 36 filaments was wound in the same manner as in Example 1 except that the copolymerization ratio of the component A was changed.

As shown in Table 1, when the difference in the copolymerization ratio between the two components is small, the crimp elongation ratio is low.

[0026] The ratio Comparative Examples 2,3 A, except for changing the intrinsic viscosity of the B components in the same manner as in Example 1, was wound with 75 denier 36 crimpable conjugate polyester fibers of filaments.

As shown in Table 1, if the difference between the intrinsic viscosities of the two components is too large, thread breakage frequently occurs.

Examples 3 and 4 and Comparative Examples 4 and 5 A crimpable conjugate polyester fiber of 75 denier and 36 filaments was wound in the same manner as in Example 1 except that the discharge ratios of the components A and B were changed. .

As shown in Table 1, the discharge amount ratio is 8: 2 to
When the ratio is out of the range of 2: 8, the crimp elongation becomes low.

Comparative Example 6 The yarn discharged in the same manner as in Example 1 was cooled with a chimney, and then refueled with a lubricating device installed 2.5 m below the base. It was taken up by a god roller, wound up by a winder without applying heat stretching and heat treatment, and a crimpable composite polyester fiber of 75 denier and 36 filaments was wound up.

As shown in Table 1, when stretching and heat treatment are not performed, thread breakage occurs frequently and shrinkage stress is low.

Example 5 and Comparative Example 7 A crimpable composite polyester fiber of 75 denier and 36 filaments was wound in the same manner as in Example 1 except that the speed of the second god roller was changed to change the stretch rate during the heat treatment. Was.

As shown in Table 1, when the stretch ratio is low, the shrinkage stress is low.

Examples 6, 7, 8 and 9 In the same manner as in Example 1 except that the temperature of pressurized steam at the time of heat treatment was changed, crimped conjugate polyester fibers of 36 filaments of 75 denier were wound.

As shown in Table 1, the pressurized steam temperature was 1
The temperature is preferably set to 05 ° C. or higher so as not to make the fiber shrinkage rate too large, and it is preferable to set the temperature to 140 ° C. or lower to obtain a sufficient crimp elongation without damaging the difference in shrinkage between the A and B components.

[0036]

[Table 1]

[0037]

According to the method of the present invention, when producing a bimetallic polyester composite fiber having a large shrinkage stress and a good crimpability by a high-speed spinning method, it is possible to produce a stable and low-cost yarn without breakage. Things.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a composite yarn obtained by the method of the present invention.

FIG. 2 is a schematic view of an apparatus for specifically explaining a method for producing a crimpable conjugate polyester fiber of the present invention.

[Explanation of symbols]

 1: Composite mouthpiece 2: Heat retention area 3: Chimney 4: Lubrication device 5: First god roller 6: Second god roller 7: Normal pressure steam processing device 8: Pressurized steam processing device 9: Third god roller 10: Entangling device 11 : 4th God Laura 12: Winder

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) D01F 8/04-8/14 D01D 5/16 D01D 5/22 D01D 5/32 D01D 10/02

Claims (7)

(57) [Claims] When producing a polyester fiber in which two types of polyesters A and B are combined side by side, the difference in the copolymerization ratio of the components A and B is 5.0 (mol%) or more.
A spun yarn discharged from the side-by-side composite die at a discharge amount ratio of 8: 2 to 2: 8 is a polyester in which each of the intrinsic viscosities of the components A and B is 0.6 or more and the difference between the intrinsic viscosities is 0.1 or less. After cooling to a temperature below the glass transition point, the film is stretched between the second godet roller while being taken up by the first godet roller, then heat-treated at a stretch ratio of 0.5% or more, and wound up at 4000 m / min or more. A method for producing a crimpable composite polyester fiber. 2. The difference between the copolymerization ratios of the components A and B is 15.0.
(Mol%) or less. 3. The method for producing a crimpable composite polyester fiber according to claim 1, wherein the side-by-side composite die is such that each component merges in a plane-symmetric manner at an upstream part of the die discharge section. 4. The method for producing a crimpable conjugate polyester fiber according to claim 1, wherein the stretching between the first and second godet rollers is heating stretching. 5. The first and second god rollers are not heated, and
The method for producing a crimpable conjugate polyester fiber according to claim 4, wherein normal pressure steam at 5 ° C or higher is used. 6. The heat treatment temperature after stretching is 105 ° C. or higher.
The method for producing a crimpable composite polyester fiber according to any one of claims 1 to 5, which is at most 0 ° C. 7. The method for producing a crimpable conjugate polyester fiber according to claim 1, wherein the heat treatment means after drawing is pressurized steam.