JPH08109517A - Production of crimpable conjugated polyester fiber - Google Patents

Abstract

PURPOSE: To suppress the yarn breakage and stably produce bimetallic conjugated fibers capable of well manifesting crimps in producing the fibers according to a high-speed spinning method. CONSTITUTION: Two kinds of polyesters A and B having 5.0-15.0mol% difference in copolymerization ratio between the components (A) and (B), >=0.6 intrinsic viscosity and <=0.1 difference in intrinsic viscosity are discharged from a side-by- side conjugated spinneret and the cooled spun yarns are passed through a heating zone during an interval to the take-off roller, thereby drawn and subsequently taken off at >=4000m/min with the take-off roller, in producing polyester fibers in which the polyesters A and B are compounded into a side-by-side state.

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 composite polyester fiber, more specifically 2
The present invention relates to a method for producing a crimpable composite polyester fiber in which various kinds of polyesters are composited side-by-side at a low cost with good spinnability.

[0002]

2. Description of the Related Art In recent years, a high-speed spinning method has been developed for producing polyester at a high spinning speed of 4000 m / min or more. The high-speed spinning method has the advantages that it can improve productivity and reduce costs, and that it has different fiber internal structure from conventional polyester fibers, so that dyeability is improved and the texture is softened.

On the other hand, 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, as a combination of two kinds of polyesters, polyesters having different copolymerization ratios and melt viscosities are generally used. JP-A-48-24026 and JP-A-51-15020 propose a method for high-speed spinning of side-by-side type polyester composite fibers having different copolymerization ratios. In addition, JP-A-48-
Japanese Patent No. 48718 proposes a method for producing side-by-side type polyester conjugate fibers having different melt viscosities by high-speed spinning. When the crimpable conjugate fiber is produced by these methods, there is a problem that frequent yarn breakage occurs and stable yarn production becomes difficult.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been earnestly studied for the purpose of suppressing yarn breakage and stably producing a bimetal composite fiber when crimping is exhibited by a high speed spinning method. As a result, it was obtained.

[0005]

The above-mentioned object of the present invention is to produce a polyester fiber in which two kinds of polyesters A and B are side-by-side composited so that the difference in the copolymerization ratio between the A and B components is 5. Two kinds of polyesters A and B having an intrinsic viscosity of 0 to 15.0 (mol%), an intrinsic viscosity of 0.6 or more, and an intrinsic viscosity difference of 0.1 or less are discharged from a side-by-side composite spinneret and cooled. Can be achieved by passing through a heating zone up to the take-up roller, and then drawn at 4000 m / min or more by the take-up roller. .

The present invention will be described in detail below. The polyesters A and B used in the present invention are required to have a difference in the copolymerization rate of the respective components A and B from 5.0 mol% to 15.0 mol%. When the difference in the copolymerization rate is less than 5.0 mol%, the crimp expression level decreases, and conversely 1
When it exceeds 5.0 mol%, the heat resistance is lowered and the yarn breaks frequently during high-speed spinning. The preferred difference in the copolymerization rate is 8.0 mol% or more and 13.0 mol% or less.

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. 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 6000, cyclohexanediol, an ethylene oxide adduct of bisphenol A, an ethylene oxide adduct of bisphenol sulfone and the like can be preferably used. As the copolymerization rate in the present invention, the total copolymerization rate is used when a plurality of components are copolymerized.

Next, the above-mentioned polyester A of the present invention,
The intrinsic viscosity of B must be 0.6 or more. Further, it is necessary that the difference in intrinsic viscosity between the A and B components is 0.1 or less. When each intrinsic viscosity is less than 0.6 and when the difference between the intrinsic viscosities of the A and B components is more than 0.1, the spinneret surface used for the bimetal composite spinning becomes severely soiled or discharged from the die. The resulting composite polymer stream is likely to bend immediately after discharge, which adversely affects the yarn-forming stability. Intrinsic viscosity is measured at orthochlorophenol at 25 ° C. The upper limit of the intrinsic viscosity is preferably 0.8 or less, and more preferably 0.7 or less for the polyesters of the components A and B, because good crimps are expressed even at high speed spinning.

The present invention requires that the discharged composite polymer stream be cooled and then stretched by passing it through a heating zone between the take-up rollers. If it does not pass through the heating zone, yarn breakage will occur frequently and 4000m /
It is difficult to make stable yarn for more than a minute.

The yarn is cooled until the temperature is lower than the lower one of the glass transition temperatures of the A and B components. If the cooling is insufficient, it becomes difficult to stably perform stretching in the heating zone, and the resulting fiber has uneven thickness and uneven dyeing. Usually, this problem can be avoided by installing a cooling device between the spinneret and the inlet of the heating zone to set the cooling distance to 0.5 m or more and the cooling wind speed to 15 m / min or more.

In the heating zone, it is necessary to heat the yarn to a temperature higher than the higher glass transition temperature of the A and B components. When the temperature is lower than this temperature, drawing does not occur in the heating zone, so that the yarn speed at the end of cooling becomes extremely high, which is the same as the speed of the take-up roller, and the flow of the bimetal composite polymer is stably spun and cooled. Becomes difficult. In the present invention, since the yarn is drawn in the heating zone, the yarn speed at the end of cooling is sufficiently lower than the take-up roller speed, stable spinning and cooling can be achieved, and the occurrence of yarn breakage is significantly reduced. Frequent yarn breakage.

In the heating zone, it is preferable to heat the yarn at the same time as drawing the yarn. By the heat treatment, the shrinkage characteristics of the obtained fiber can be controlled within a range that causes no problem in the post-processing step. The fiber obtained in the present invention develops crimp at the same time as shrinkage of the fiber itself when subjected to boiling water treatment,
The fiber shrinkage is 35% or less, preferably 25% or less, and the crimp shrinkage is preferably 25% or more,
It is important to control the temperature inside the heating zone so that it is more preferably 30% or more. For this purpose, the inner wall temperature of the heating zone is preferably 110 to 200 ° C, more preferably 130 to 170 ° C. The temperature of the inner wall of the heating zone may be the highest temperature in the inner wall, and the ambient temperature at the bottom of the heating zone may be used instead. In order to raise the temperature of the yarn in the heating zone to perform the desired heat treatment, the minimum treatment length is necessary, and the length is preferably about 1.0 m.

The crimpable conjugate polyester fiber obtained by this method exhibits a higher shrinkage force during crimping treatment, as compared with the fiber obtained by high speed spinning without a heating zone,
It is advantageous for the crimp development in the woven or knitted fabric under the restraining force. When the heat shrinkage stress value is compared as the fiber property, the normal high speed spinning fiber is 0.1 to 0.15 g / d, and the fiber of the present invention is 0.2 to
It is 0.5 g / d. Further, the value of the crimp extension ratio showing the stretch back property after the crimp development is also high, which is 40% or more.

Next, according to the present invention, a take-up roller 40 is used.
It is necessary to collect at 00 m / min or more. 4000m
If it is less than 1 / min, not only the advantage of improving the productivity of high-speed spinning cannot be utilized, but also the obtained fiber has a high elongation at break and only a fiber that is difficult to handle in a processing step having a low elastic modulus can be obtained. This is because the production method of the present invention employs a method of stretching the yarn in the heating zone between the cooling of the spun yarn and the take-up roller. This is because the stress becomes low and the polyester molecular chains cannot be fully oriented.

In the present invention, it is preferable that each of the A and B components contains 0.05 volume% or more of particles having an average particle diameter of 1.5 μm or less. If the average particle diameter exceeds 1.5 μm, yarn breakage tends to increase. The amount of particles added is 0.0
If it is less than 5% by volume, stains are likely to occur when the obtained fiber is dyed as a woven or knitted material. Examples of the added particles include titanium oxide, silicon oxide, calcium carbonate, alumina, silicates such as aluminum silicate, and crosslinkable polymers. By adding silicon oxide particles or calcium carbonate particles, a highly transparent crimpable polyester composite fiber can be obtained, which is preferably used.

The fiber of the present invention may contain an antistatic agent, a flame retardant, a lightproofing agent, a hygroscopic agent, a color former, etc., if necessary, in order to impart functionality.

[0017]

EXAMPLES Each characteristic value in the examples was determined according to the following method.

(A) Intrinsic viscosity Orthochlorophenol was measured at 25 ° C.

(B) Crimping extension ratio, fiber contraction ratio, crimp contraction ratio A sample having a circumference of about 100 cm is used as a sample, and 0.2 mg /
Measure the length L0 under load d. Next, 0.2 mg /
d under load of 98 ° C in boiling water for 15 minutes, air-dried, and then load L0.2 under load of 0.2 mg / d on the sample.
To measure. Further, the sample length L2 is measured with a load of 200 mg / d, and the crimp stretch ratio (%), the fiber shrinkage ratio (%), and the crimp shrinkage ratio (%) are determined by the following formulas. Crimping extension rate = (L2-L1) / L1 x 100 Fiber shrinkage rate = (L0 -L2) / L0 x 100 Crimping shrinkage rate = (L2-L1) / L0 x 100 (c) Spinnability 5 kg Continuous winding Then, the number of yarn breakages when 10 samples were wound was used as a measure of the spinnability.

(D) Elongation at break, elastic modulus N was measured using a Tensilon tensile tester manufactured by Orientec Co., Ltd. under the conditions of a test length of 200 mm and a pulling speed of 200 mm / min.
= 5, the elongation at break and the initial elastic modulus were measured.

(E) Dyeing unevenness The sample was woven as a weft thread, and as a dye, Diaceritone Fast Ruby 3B was put in boiling water at 95 ° C.
g, and the sample fabric was dipped for 15 minutes and dyed with stirring. After washing with water and drying, stains were evaluated according to the following criteria. It should be noted that the deep-dyeing portion was made by observing the presence of the deep-dyeing single yarn with a magnifying glass after visual observation. Number of densely dyed parts (co / 380 cm ² ) Judgment 0 ○ 1 or more × Examples 1 to 3, Comparative Examples 1 and 2 Esterification reaction was carried out using terephthalic acid / ethylene glycol and isophthalic acid / ethylene glycol slurries. Then, an ethylene glycol solution of an ethylene oxide adduct of bisphenol A (BPA-EO) and an aggregating silicon oxide particle having an average particle diameter of 0.20 μm were added to 0.1.
Isophthalic acid (IPA) is added to the total acid component of the copolyester by adding it in a volume% and polymerizing by a conventional method.
Was changed and the mole fraction of the ethylene oxide adduct of bisphenol A with respect to the total glycol component of the copolyester was changed to obtain a polyester chip of A component having an intrinsic viscosity of 0.67.

Further, the intrinsic viscosity is 0.65 and the average particle size is 0.
Polyethylene terephthalate added with 0.15% by volume of titanium oxide particle size of 47 μm was used as the B component polyester.

With a spinning temperature of 290 ° C. and a discharge ratio of 1: 1 from a composite spinneret having 36 holes in which the A and B components are face-symmetrically merged on the upstream side of the spinning discharge holes, A:
A side-by-side composite flow of B component was discharged. Under the base 2
After passing through the 0 cm insulation area, the wind speed is 20 m / min, the air temperature is 25
After cooling in a uniflow chimney with a temperature of 0.6m and a length of 0.6m, the inlet has a length of 1.5m and an inner diameter of 3 with a distance of 1.5m from the die.
Stretching heat treatment is carried out by a heating cylinder of 5 mm and an inner wall temperature of 140 ° C., and an oil agent and entanglement are sequentially applied to give a peripheral speed of 5200 m /
After passing through the first and second take-up rolls for 10 minutes, the tension is 0.25 g / d.
Then, a crimpable composite polyester fiber of 50 denier 36 filaments was wound up.

Table 1 shows the crimp extension ratio and the spinnability of the obtained fiber.
Shown in

[0025]

[Table 1] Comparative Examples 3 to 5 A crimpable composite polyester fiber of 50 denier 36 filaments was wound in the same manner as in Example 1 except that the intrinsic viscosity of each of the components A and B was changed.

Table 2 shows the spinnability of the obtained fiber.

[0027]

[Table 2] Examples 4, 5 and Comparative Example 6 50 was carried out in the same manner as in Example 1 except that the take-up speed was changed.
A denier 36 filament crimpable composite polyester fiber was wound up.

Table 3 shows the breaking elongation and elastic modulus of the obtained fiber.

[0029]

[Table 3] Examples 6, 7 and Comparative Example 7 A crimpable composite polyester fiber of 50 denier 36 filaments was wound in the same manner as in Example 1 except that the inner wall temperature of the heating zone was changed.

Table 4 shows the crimp expansion ratio, the fiber contraction ratio, the crimp contraction ratio, and the spinnability of the obtained fiber.

[0031]

[Table 4] Examples 8 and 9 Comparative Examples 8 and 9 A crimpable composite polyester fiber having 50 denier and 36 filaments was wound in the same manner as in Example 1 except that the average particle diameter and the addition amount of the component A were changed. .

Table 5 shows the spinnability and dyeing unevenness of the obtained fiber.

[0033]

[Table 5]

[0034]

INDUSTRIAL APPLICABILITY The present invention makes it possible to suppress yarn breakage and to stably produce a bimetal composite fiber when crimping is exhibited by a high-speed spinning method.

Claims (2)

[Claims] 1. When producing a polyester fiber in which two kinds of polyesters A and B are composited side by side, the difference in the copolymerization rate between the A and B components is 5.0 to 15.0 (mol%), and the intrinsic viscosity is 1. Is 0.6 or more and the difference in intrinsic viscosity is 0.
Two kinds of polyesters A and B which are 1 or less are discharged from the side-by-side composite spinneret and then drawn by passing through a heating zone between the cooling roller and the take-up roller, and then 4000 m / A method for producing a crimpable composite polyester fiber, wherein the crimpable composite polyester fiber is collected in a minute or more. 2. The method for producing a crimpable composite polyester fiber according to claim 1, wherein the polyesters of A and B types contain 0.05% by volume or more of particles having an average particle diameter of 1.5 μm or less. .