JP2002061038A - Polytrimethylene terephthalate fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a PTT(polytrimethylene terephthalate)-POY(pre-oriented yarn) capable of being industrially produced without causing tightening of wound yarns and occurring buldge, and enabling a stable draw-false twisting at a high speed, and further to provide a false twisted yarn with an excellent quality. SOLUTION: This PTT-POY having an intrinsic viscosity, an orientation, an elongation and a shrinkage within specific ranges is produced by using a PTT polymer having a high polymerization degree, and using a special spinning method of extruding the PTT polymer at a surface temperature of a spinneret within a specified range to reduce the rapid cooling of the molten yarn, and winding the cooled yarn by an extremely low tension. The false-twisted yarn of the yarn, and the method for producing them are also provided. As a result, the PTT-POY can be produced without causing the tightening of the wound yarn and the bulge, draw-false twisting processability at the high speed is extremely improved, and the false twisted yarn in high quality can be obtained in good productivity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to partially trimmed polytrimethylene terephthalate fiber suitable for high-speed draw false twisting, a cheese-like package thereof, and a false twisted yarn. More specifically, the present invention relates to a partially trimmed polytrimethylene terephthalate fiber, a cheese-like package, and a method for high-speed drawing false twisting, which can be industrially manufactured and can be subjected to stable high-speed drawing false twisting.

[0002]

2. Description of the Related Art Fibers using polytrimethylene terephthalate (hereinafter abbreviated as "PTT") have properties similar to polyamide such as low elastic modulus (soft texture), excellent elastic recovery and easy dyeing, and light resistance. It is an epoch-making fiber having properties similar to polyethylene terephthalate (hereinafter abbreviated as “PET”) fiber such as heat resistance, heat setting property, dimensional stability and low water absorption. One of the fiber forms that can make the most of the properties of the PTT fiber is a false twisted yarn. As disclosed in Japanese Patent Application Laid-Open Nos. 9-78373 and 11-093026, false twisted yarn of PTT fiber is used.
Compared to polyester fibers such as ET fibers, the fibers are excellent in elastic recovery and softness, and thus are extremely excellent as raw yarns for stretching.

[0003] It is very important to increase the productivity and reduce the production cost when utilizing the characteristics of the PTT false twisted yarn in a wide range of fields where PET and polyamide fibers are used. Become. However, in the above publications and the like, a stretched fiber produced by a two-stage process such as spinning and drawing with low productivity is used as a raw yarn for false twisting, so that the fiber production cost increases.
Further, since the supplied raw yarn is a drawn yarn, it is not possible to perform a draw false twisting process at high speed with high productivity.

In order to increase the productivity and reduce the production cost, it is desired to perform high-speed draw false twisting using a fiber produced in a single step, like PET or polyamide fiber. . As a technique for performing high-speed draw false twisting using PTT fiber manufactured in a one-step process,
"Chemical Fibers Internet
ionical, Vol. 47, published February 1997, 72-74
The page shows a technique of performing draw false twisting using partially oriented fibers of PTT (hereinafter abbreviated as “POY”). Here, the PTT polymer having an intrinsic viscosity [η] of 0.9 is 250 to 2
After being extruded at 75 ° C. and solidified by cooling, a finish is applied,
Without using a godet roll or after passing through a cold godet roll, P wound up at 600 to 3200 m / min.
A technique for false twisting TT-POY fibers at a processing speed of 450 to 1100 m / min is described.

[0005] Also, "Chemical Fibers"
International ", vol. 50, published in February 2000, p. 53-56 describes PTT polymer as 245-26.
PTT-PO rolled at 600 to 3000 m / min after extruding at 5 ° C., cooling and solidifying, applying a finishing agent, without using a godet roll, or after passing through a godet roll
A technique of false twisting a Y fiber at a processing speed of 500 to 700 m / min at a temperature of 230 ° C. for a non-contact type heater and 160 ° C. for a contact type is described. However, according to the study of the present inventors, even if an attempt was made to perform a draw false twisting process at a high speed of 500 m / min or more by the technology described in the above-mentioned document, a PET false twisted yarn or a two-stage yarn was produced. Compared to a PTT false twisted yarn obtained by false twisting a drawn yarn at a low speed, sufficient crimp cannot be imparted, and the number of crimps, expansion and contraction, and elasticity are low, and softness and stretchability are low. Only a false twisted yarn of poor quality can be obtained. Further, even if this processed yarn is used, since the number of crimps is small, it is only possible to obtain a coarse and low-quality cloth having a rough surface.

The reason why a false twisted yarn excellent in crimping properties cannot be obtained by high-speed draw false twisting as described above is considered as follows. Since the PTT molecule has a coiled shape, the bonding force between adjacent molecules is weak, and partial melting occurs at a temperature at which the molecules move actively. For this reason, unlike PET fibers and polyamide fibers, PTT fibers have reduced strength and elongation at temperatures exceeding 160 ° C., such as during false twisting. As a result, fluffing and thread breakage occur in false twisting at high speed where the tension at the time of processing increases. By lowering the number of twists or lowering the processing temperature, fluff and yarn breakage can be suppressed, but only low-quality false twisted yarns with low crimp number, elastic elongation and elasticity, and inferior softness and stretchability. You won't get it.

[0007] As a technique for improving false twisting workability, Korean Patent Publication No. 98049300 discloses a technique of limiting the intrinsic viscosity to 0.1.
With a PTT polymer of 75-1.1, 2500-5
Method for producing PTT-POY spinning at a spinning speed of 500 m / min, and processing temperature of 150 to 160 using said POY
A technique for performing false twisting at a temperature of 400 ° C. and a processing speed of 400 m / min is disclosed. In this publication, in order to improve false twisting workability,
Using a polymer with high intrinsic viscosity [η] such as 1.0,
The spinning speed is increased as much as possible to improve the strength and heat resistance of PTT-POY. Also, Japanese Patent Application Laid-Open No. 57-19353
No. 4 discloses a P spinning at a spinning speed of 2500 to 3000 m / min using a polymer having an intrinsic viscosity [η] of 0.97.
TT-POY is disclosed.

However, according to the study by the present inventors, even when a polymer having a high intrinsic viscosity as described in the above-mentioned patent document is used, the strength at high temperatures cannot be sufficiently increased, and the high-speed stretching False twisted yarn of excellent quality cannot be obtained by twisting. Further, when a polymer having a high intrinsic viscosity is used, the melt pressure is high, so that the extrusion pressure is high and uniform extrusion is difficult, and the spinning tension is high, and yarn breakage is likely to occur. Furthermore, when a polymer having a high intrinsic viscosity is used, the resulting fiber has a high boiling water shrinkage and a peak value of thermal stress, so that the yarn largely shrinks on the yarn tube and the yarn tube is tightened. For this reason, when winding the amount of yarn that is usually produced industrially, the yarn tube is deformed, and it becomes difficult to remove the cheese-like package around which the yarn is wound from the spindle of the winder. The following two reasons are considered as the reasons for the fiber shrinking as described above.

1) Unlike PET, PTT has a zigzag molecular structure, and therefore has a glass transition point (hereinafter referred to as "T
g "), which is as low as 30 to 50 ° C, and the molecules move and contract even at room temperature. 2) Unlike PET, PTT has a high elastic recovery, so that the stress at the time of winding remains without being relaxed, and shrinks after winding. When the molecular weight is high, the stress is hardly relieved, and the resin shrinks with a strong force. In such a situation, even if the deformation of the yarn tube is suppressed by using a high-strength yarn tube, a phenomenon called a bulge may occur on the package side surface, or the yarn may be tightly tightened by the inner layer of cheese. For this reason, the tension at the time of unwinding the yarn is increased, and the fluctuation of the tension is also increased, so that fluff and breakage of the yarn frequently occur at the time of false twisting, and uneven crimping and uneven dyeing occur.

When a polymer having a high intrinsic viscosity is used, the strength and elongation recovery of the obtained processed yarn are reduced. The cause is considered as follows. That is, in the case of a polymer having a high intrinsic viscosity, the entanglement of molecules cannot be sufficiently loosened by melting. Therefore, the molecules cannot be sufficiently oriented by the stretching, and the strength and the elongation recovery rate decrease. With such a fiber, yarn breakage or fluff occurs frequently in false twisting.
Even if the melting temperature is increased, not only can the entanglement be sufficiently loosened, but also the degree of polymerization decreases due to thermal decomposition, and the strength and elongation recovery rate decrease. The prior art discloses a PTT fiber capable of industrially producing a high-quality false-twisted yarn by high-speed draw false twist with high productivity without causing any tightening or bulge, and without causing fluff or yarn breakage. Not at all.

[0011]

As a result of studies by the present inventors, PTT-POY suitable for high-speed stretch false twisting and produced in a one-step process and a method for producing PTT-POY have the following problems in the prior art. It turned out that there was. (1) In high-speed draw false twisting, fluff and yarn breakage frequently occur, and stable false twisting cannot be performed. If the number of twists and the processing temperature are reduced to suppress fluff and yarn breakage, the crimp number, stretch extension and elastic modulus are low, and only low quality false twisted yarn with poor softness and stretchability can be obtained. I will. (2) Even if a polymer having a high degree of polymerization is used to suppress fluff and yarn breakage during high-speed drawing false twisting, a sufficient effect cannot be obtained, and the tension during spinning increases, resulting in yarn breakage and fluff. Due to frequent occurrences, tightening or bulging, it is not possible to wind a cheese-like package having a yarn amount equivalent to that of PET manufactured industrially.

An object of the present invention is to provide a PTT fiber, a cheese-like package and a high quality false twisted yarn which can be industrially manufactured and can be drawn and twisted stably at a high speed. The problem to be solved in order to achieve the object of the present invention is that, in order to cope with the above-mentioned problem (1), in order to enable industrial high-speed stretch false twisting, the high elongation at high temperature is high, Another object of the present invention is to provide a PTT-POY having good stretchability and to suppress the occurrence of thread breakage, tight tightening and bulge in order to enable industrial production in response to the problem (2).

[0013]

Means for Solving the Problems As a result of intensive studies, the present inventors have surprisingly found that using a PTT polymer having a high degree of polymerization, a specific range of the spouting surface in order to suppress rapid cooling of the molten fiber. Extrusion at a temperature and a fiber with intrinsic viscosity, orientation, elongation and shrinkage within a specific range, manufactured using a special spinning method that winds at an extremely low tension. The present invention was found to be excellent and could significantly improve draw false twisting at high speed, and completed the present invention. That is, the present invention is as follows. 1. PTT fiber (I) A PTT fiber comprising 90% by mole or more of polytrimethylene terephthalate composed of trimethylene terephthalate repeating units and satisfying the following requirements (A) to (D). (A) Intrinsic viscosity: 1.0 to 1.6 (B) Birefringence: 0.03 to 0.07 (C) Elongation at break: 40 to 140% (D) Peak value of thermal stress: 0.01 ~ 0.10cN / dtex

(II) A PTT fiber, wherein the toughness calculated from the following formula using the strength and elongation at 160 ° C. in (I) is 9 or more. Toughness = strength (cN / dtex) × √elongation (%) (III) In (I) or (II), the following (E)
PTT fiber satisfying (F). (E) Density: 1.320 to 1.340 g / cm ³ (F) Boiling water shrinkage: 3 to 40% (IV) Wide-angle X-ray diffraction in the direction perpendicular to the fiber axis in (I) to (III) A PTT fiber having a strength satisfying the following expression. I ₁ / I ₂ ≧ 1.0 where I ₁ : 2θ = 15.5-16.5 ° maximum diffraction intensity I ₂ : 2θ = 18-19 ° average diffraction intensity

2. Cheese-like package (I) A cheese-like package in which any one of the PTT fibers (I) to (IV) of the present invention is wound and the bulge ratio is 20% or less. 3. Method for producing PTT fiber (I) A method for melt-spinning polytrimethylene terephthalate having an intrinsic viscosity of 1.0 to 1.6, in which 90 mol% or more is composed of trimethylene terephthalate recurring units, comprising: Is changed to a solid multifilament by cooling the molten multifilament extruded from the spinneret to 255 to 290 ° C, and then 0.02 to 0.20 cN / dt.
A method for producing a PTT fiber, comprising winding at a speed of 2000 to 4000 m / min with a winding tension of ex. (II) A method for producing a PTT fiber according to (I), wherein the molten multifilament extruded from the spinneret is cooled and changed into a solid multifilament, and then heat-treated at 50 to 170 ° C.

4. False twisting yarn (I) A false twisting process characterized by comprising 90% by mole or more of polytrimethylene terephthalate composed of trimethylene terephthalate repeating units and satisfying the following requirements (G) to (J): yarn. (G) Intrinsic viscosity: 1.0 to 1.6 (H) Stretching elongation: 180 to 300% (I) Stretching elasticity: 80 to 100% (J) Number of crimps: 4 to 30 pieces / cm Method for producing false twisted yarn (I) PTT according to any of (I) to (IV) above
Using fiber, false twist processing speed 500-1200 m / min,
A method for producing a false twisted yarn, comprising performing draw false twisting at a processing temperature of 165 to 210 ° C.

Hereinafter, the present invention will be described in detail. (1) Raw Material of Polymer The polymer used in the present invention is polytrimethylene terephthalate (PTT) in which 90 mol% or more is composed of trimethylene terephthalate repeating units. Where PT
T is a polyester containing terephthalic acid as an acid component and trimethylene glycol (also referred to as 1,3-propanediol) as a diol component. The PTT may contain other copolymer components at less than 10 mol%. Examples of such a copolymerization component include 5-sodium sulfoisophthalic acid, 5-potassium sulfoisophthalic acid, 3,5-dicarboxylic acid benzenesulfonic acid tetrabutylphosphonium salt, and 3,5-dicarboxylic acid benzenesulfonic acid tributylmethylphosphonium salt. 1,4-butanediol, neopentyl glycol, 1,6-hexamethylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, adipic acid, dodecanedioic acid,
Ester-forming monomers such as 1,4-cyclohexanedicarboxylic acid.

The polymer used in the present invention may contain, if necessary, various additives such as a matting agent, a heat stabilizer, a defoaming agent, a coloring agent, a flame retardant, an antioxidant, an ultraviolet absorber, An infrared absorber, a crystal nucleating agent, a fluorescent whitening agent, a matting agent other than titanium oxide, and the like may be copolymerized or mixed. In particular,
In order to suppress fluff and yarn breakage during spinning and post-processing, it is preferable to contain 0.01 to 3% by weight of titanium oxide having an average particle size of 0.01 to 2 µm. The intrinsic viscosity [η] of the polymer used in the present invention needs to be 1.0 to 1.6.
More preferably, 1.1 to 1.5, particularly preferably 1.2.
~ 1.4. The use of a polymer in this range can increase the toughness at a high temperature for the first time, and PTT-P which is an object of the present invention and is excellent in high-speed draw false twisting workability.
OY can be obtained. When the intrinsic viscosity [η] is less than 1.0, it is difficult to develop strength at a high temperature required for high-speed stretch false twisting. On the other hand, when the intrinsic viscosity is more than 1.6, the melt viscosity is too high, and melt fracture or poor spinning occurs during spinning, which is not preferable.

The intrinsic viscosity [η] of the polymer in the present invention is determined using an Ostwald viscometer at 35 ° C. in o-chlorophenol at a specific viscosity ηsp and a concentration C (g / 10 g).
0 ml) and extrapolating the ratio ηsp / C to zero concentration,
This is a value obtained according to the following equation. [Η] = lim (ηsp / C) C → 0 As a method for producing the polymer used in the present invention, a known method can be used as it is.

For example, starting from terephthalic acid or dimethyl terephthalate and trimethylene glycol, one or more metal salts such as titanium tetrabutoxide, calcium acetate, magnesium acetate, cobalt acetate, manganese acetate, and a mixture of titanium dioxide and silicon dioxide. Two or more of them are added and subjected to an esterification reaction or a transesterification reaction under normal pressure or under pressure, and then a catalyst such as titanium tetrabutoxide, antimony trioxide, antimony acetate is added, and the polycondensation reaction is carried out under reduced pressure at 250 to 270 ° C. Let it. Also, at any stage of the polymerization, it is preferable to add a stabilizer prior to the polycondensation reaction to improve whiteness, improve melt stability, and reduce the molecular weight of organic substances such as PTT oligomers, acrolein, and allyl alcohol having a molecular weight of 300 or less. This is preferable from the viewpoint of controlling generation. In order to increase the degree of polymerization of the polymer, it is preferable to perform solid-state polymerization under nitrogen or under reduced pressure after performing the above-described melt polymerization. The temperature at which the solid phase polymerization is performed is preferably in the range of 200 to 220 ° C. from the viewpoint of suppressing the polymerization rate, the coloring of the polymer, and the fusion.

(2) PTT fiber (I) The PTT fiber of the present invention includes the following (A)
It is necessary to satisfy the requirement of (D). (A) Intrinsic viscosity: 1.0 to 1.5 (B) Birefringence: 0.03 to 0.07 (C) Elongation at break: 40 to 140% (D) Peak value of thermal stress: 0.01 -0.10 cN / dtex In order to enable stable and high-speed draw false twist processing without generation of fluff and yarn breakage, which is the first object of the present invention, in order to increase toughness at high temperatures, the It is necessary to increase the degree of polymerization and to entangle the degree of orientation and molecules in a specific range. Further, in order to eliminate the tightening of the fiber, which is the second problem of the present invention, it is necessary that the molecules are not excessively oriented and in a state of tension so that the yarn does not significantly shrink on the yarn tube. is important. For this purpose, the fibers need to be in a specific range of orientation and tension.

As an index of the degree of polymerization, intrinsic viscosity is suitable. As an index of the orientation, the birefringence of the fiber is suitable. Elongation at break is suitable as an index of entanglement and orientation of molecules. Further, a peak of the thermal stress is suitable as an index indicating the tension state of the fiber. Therefore, the intrinsic viscosity of the fiber, the birefringence, the elongation at break, and the peak value of the thermal stress satisfy the above-mentioned ranges. PTT-POY which can be industrially manufactured without generation of bulge or bulge.

(I) Intrinsic viscosity (A) The intrinsic viscosity [η] of the fiber needs to be 1.0 to 1.6. Only when the intrinsic viscosity of the fiber is in this range, the toughness at a high temperature can be increased, and the PTT-POY excellent in the high-speed draw false twisting property aimed at by the present invention is obtained. When the intrinsic viscosity [η] is less than 1.0, it is difficult to develop toughness at a high temperature required for high-speed stretch false twisting. On the other hand, when the intrinsic viscosity exceeds 1.6, the melt viscosity is too high, so that melt fracture or poor spinning occurs at the time of spinning, so that only non-uniform fibers can be obtained. In some cases, the peak value of the thermal stress in the tension state is large, and only a fiber that is easily wound can be obtained. The intrinsic viscosity of the fibers is preferably from 1.1 to 1.5, particularly preferably from 1.2 to 1.4.

(Ii) Birefringence (B) The birefringence of the fiber must be 0.03-0.07. If the birefringence of the fiber exceeds 0.07, the degree of orientation of the fiber becomes high, so that the elongation becomes low, so that high-speed draw false twisting cannot be performed. In addition, since the contracting force is increased, tight winding occurs. When the birefringence of the fiber is less than 0.03, physical properties such as boiling water shrinkage change over time or the fiber becomes brittle even when stored at room temperature because of low orientation, and the fiber becomes brittle, resulting in high speed. Cannot be industrially performed. The birefringence of the fiber is preferably 0.035 to 0.065, more preferably 0.1 to 0.065.
040 to 0.060.

(Iii) Elongation at break (C) Elongation at break must be 40 to 140%. If the elongation at break is less than 40%, the elongation is too low, so that fluff or yarn breakage occurs during spinning or false twisting. Elongation at break of 1
If it exceeds 40%, physical properties such as boiling water shrinkage may change over time or the fibers may become brittle even when stored at room temperature. Can not be done. The preferred range of the elongation at break is 50
To 120%, and more preferably 60 to 100%.

(Iv) Thermal stress peak value (D) The thermal stress peak value of the fiber is 0.01 to 0.10 cN / d.
must be tex. When the peak value of the thermal stress of the fiber exceeds 0.10 cN / dtex, the fiber is in an excessively tensioned state, has a strong contracting force, and largely contracts after being wound to cause tightness. I will. If the peak value of the thermal stress of the fiber is less than 0.01, the contracting force is too weak, the fiber collapses during winding, or the boiling water shrinkage ratio even when stored at room temperature due to low orientation. The physical properties change with time, the fibers become brittle, and the high-speed draw false twisting cannot be performed industrially. The peak value of the thermal stress of the fiber is preferably 0.015 to 0.08 cN / dtex, and more preferably 0.02 to 0.06 cN / dtex.

(II) Physical Properties of PTT Fiber (i) Physical Properties of Fiber at High Temperature It is preferable that the toughness calculated from the following equation using the strength and elongation at 160 ° C. is 9 or more. Toughness = strength (cN / dtex) × √elongation (%) In order to suppress fluff and yarn breakage during false twisting of PTT, it is important that fibers are not easily cut at the processing temperature. The hardness of cutting is preferably expressed simply by the product of the strength and the square root of elongation in the above equation, which is generally referred to as toughness, which simply indicates the energy when the fiber is cut. If the toughness is less than 9, yarn breakage is likely to occur at high temperatures, and high-speed draw false twisting cannot be performed industrially. The toughness is preferably 10 or more, and more preferably 11 or more. The upper limit of toughness is not particularly limited, and the higher the better, the better.

(Ii) Density (E) The density of the fibers is preferably from 1.320 to 1.340 g / cm ³ . If the density exceeds 1.340 g / cm ³ , roll collapse will occur. Although the reason is not clear, a fiber having a high density has high crystallinity, and the fiber itself and the surface of the fiber become hard. As a result, it is considered that the area when the yarn is brought into contact with the yarn is reduced, and the coefficient of static friction between the yarn and the yarn is reduced. Moreover, fluff and yarn breakage are likely to occur during the false twisting, and it becomes impossible to perform the industrially stable false twisting. On the other hand, the density is 1.320
If the molecular weight is less than g / cm ³ , the molecules are not fixed, and the fibers shrink and cause tightness, and the physical properties of the fibers change over time. In some cases, the yarn cannot be obtained. The density is preferably 1.322 to 1.336 g / cm ³ , more preferably 1.326 to 1.334 g / cm ³ .

(Iii) Shrinkage of boiling water (F) The shrinkage of boiling water of the fiber is preferably 3 to 40%.
When the boiling water shrinkage exceeds 40%, the molecules are in a state of tension, which causes tightness in the winding, and changes in physical properties such as the boiling water shrinkage and the peak value of thermal stress even when stored at room temperature. This makes it impossible to perform high-speed stretch false twisting stably over a long period of time. On the other hand, if it is less than 3%, the fibers become brittle and fluff and yarn breakage occur frequently, so that false twisting may be difficult. The boiling water shrinkage ratio is preferably 4 to 20%, and more preferably 5 to 15%.

(Iv) Observation of diffraction peaks derived from crystals by wide-angle X-ray diffraction In the present invention, the fact that fibers are crystallized and the structure is fixed, that is, diffraction peaks derived from crystals are observed by wide-angle X-ray diffraction. Is preferably performed. Hereinafter, wide-angle X-ray diffraction will be described in detail with reference to the drawings. As a typical example of a diffraction pattern in a direction perpendicular to the fiber axis when X-rays are irradiated from a direction perpendicular to the fiber, FIG. 1- (A) shows a case where a diffraction peak derived from a crystal is observed. Figure 1
The pattern in the case where no diffraction peak derived from the crystal is observed is shown in (b). Here, X-rays use CuKα rays. It is known that PTT takes a crystal form belonging to a triclinic form, (Polym. Prepr. Jpn., V
ol. 26, p427 (1997)) When the fiber is crystallized, 2θ in the direction perpendicular to the fiber axis is
A diffraction peak derived from the (010) plane is observed around 15.5 °.

In the present invention, as shown in FIG. 1- (A), a diffraction image was observed depending on whether the wide-angle X-ray diffraction intensity in the direction perpendicular to the fiber axis satisfies the following expression. It was determined whether or not. I ₁ / I ₂ ≧ 1.0 where I ₁ : 2θ = 15.5-16.5 ° maximum diffraction intensity I ₂ : 2θ = 18-19 ° average diffraction intensity On the other hand, in FIG. Only the broad diffraction originating from the amorphous phase is observed, but the peak originating from the crystal as shown in FIG. 1- (a) is not observed. In this case, the above expression is not satisfied. Observation of a diffraction peak derived from the crystal by wide-angle X-ray diffraction indicates that the fiber is clearly crystallized and the structure is fixed. When no diffraction image derived from the crystals is observed, the fibers are not crystallized. Therefore, since the molecule is not fixed, the fiber shrinks to cause tightness, and the physical properties of the fiber change with time, so that the false twisting cannot be stably performed over a long period of time. I ₁ / I
The value of ₂ is preferably 1.1 or more, more preferably 1.2.
That is all.

(V) Strength The strength of the PTT fiber of the present invention is preferably at least 1.3 cN / dtex. If the strength is less than 1.3 cN / dtex, the strength is low, so that when the yarn is unwound or false twisting is performed, fluff and breakage of the yarn frequently occur. Preferably, 1.5
cN / dtex or more, more preferably 1.7 cN / dt
ex or more.

(Vi) U% The U% of the fiber is preferably 0 to 2%. U%
USTER TEST manufactured by Zellbeger Worcester Co., Ltd.
This is a value obtained from the variation of the mass of the fiber sample by ER3. In this apparatus, a change in mass can be measured by a change in dielectric constant when a fiber sample is passed between electrodes. When passing through the apparatus at a constant speed, an uneven curve as shown in FIG. 2 is obtained. From this result, U% can be obtained according to equation (1) in FIG. When U% exceeds 2%, fluff and yarn breakage occur frequently during false twisting, and only false twisted yarn having large dyeing unevenness and crimp unevenness can be obtained. U
% Is preferably 1.5% or less, more preferably 1.0% or less. Of course, the lower the U%, the better.

(Vii) Fiber Form The PTT fiber of the present invention is preferably a multifilament. Although the total fineness is not particularly limited, it is usually 5 to 400 d.
tex, preferably 10 to 300 dtex, and the single yarn fineness is not particularly limited, but is 0.1 to 20 dtex, preferably 0.5 to 10 dtex, and more preferably 1 to 5 dte.
x. The cross-sectional shape of the fiber is not limited, such as round, triangular, other polygonal, flat, L-shaped, W-shaped, cross-shaped, well-shaped, dogbone-shaped, etc. Is also good.

(3) Cheese-like Package The fiber of the present invention is preferably wound around a cheese-like package. In order to follow modernization and rationalization of the false twisting process in recent years, it is preferable that the package is large-sized, that is, wound in a cheese-like package that can be wound in large quantities. In addition, when the yarn is unwound during false twisting by using a cheese-like package, fluctuations in unwinding tension are reduced, and stable processing can be performed.

(I) Bulge Ratio The cheese-like package in which the fiber of the present invention is wound preferably has a bulge ratio of 20% or less. FIG. 3A shows a cheese-like package (10) in which the yarn is wound into a desired shape.
0). The yarn is wound on a cylindrical yarn layer (104) having a flat end surface (102) formed on a winding core (103) such as a yarn tube. The bulge is a bulging end face (102a) of the cheese-like package (100) which is generated when the winding thread slides due to a strong tightening force due to the contraction of the winding thread as shown in FIG.

The bulge ratio is defined as shown in FIG.
It is a value calculated by using the following formula by measuring the winding width Q of the innermost layer and the winding width R of the bulging portion shown in (b). Bulge rate = {(R−Q) / Q} × 100% If the bulge rate of a cheese-like package exceeds 20%, the wound yarn will be broken during transportation, making it impossible to unwind, yarn breakage due to uneven unwinding tension, and fluff. , Stain spots and the like are likely to occur. In the worst case, the end face protrudes from the thread tube, so that it cannot be transported. Further, the tightening of the winding is large, and it often does not come off the spindle of the winding machine. Preferably, the bulge ratio is at most 15%, more preferably at most 10%. Of course, 0% is most preferable.

(Ii) Cheese-like Package Shape For industrial production, it is extremely important to reduce the frequency of replacing the yarn tube at the time of spinning from the viewpoint of improving working efficiency and reducing costs. In addition, in the false twisting process, after using a cheese-like package, it is used by connecting it to the next cheese-like package, but reducing the frequency of this connection is also extremely important from the viewpoint of improving work efficiency and reducing costs. It is. Therefore, the cheese-like package contains 1
Preferably, at least 2 kg of the fiber of the present invention is wound, more preferably at least 2 kg, more preferably at least 4 kg.
That is all. If the weight is less than 1 kg, the frequency of the exchange of the tube and the frequency of the splicing are too high, and it is difficult to industrially manufacture.

Further, when performing the draw false twist at a high speed, it is preferable to reduce the tension at the time of releasing the fiber from the yarn tube and to suppress the fluctuation of the tension. Since the PTT fiber has a higher coefficient of friction than PET or the like, when the fiber is unwound from the yarn tube at a high speed, yarn breakage or fluff is likely to occur. Further, the tension tends to fluctuate, and it is not easy to obtain a uniform false twisted yarn. For this purpose, the winding width Q of the fiber on the yarn tube is preferably set to 40 to 300 mm. If the winding width exceeds 300 mm, the tension at the time of release is increased, and the tension fluctuation is increased. If the winding width is less than 40 mm, the tension will be low, but the end of the wound yarn will be easily broken during unwinding.
The winding width is more preferably 60 to 200 mm, and 70 to 150 mm.
mm is more preferred. The yarn tube preferably has a diameter of 50 to 250 mm, more preferably 80 to 150 mm.
It is. The yarn tube used in the present invention may be formed of any of resin such as phenolic resin, metal, and paper. In the case of paper, the thickness is preferably 5 mm or more.

(4) Method for Producing PTT Fiber Next, a method for obtaining the PTT fiber and the cheese-like package of the present invention will be described. The PTT fiber of the present invention is basically formed by using a PTT polymer having an intrinsic viscosity of 1.0 to 1.6, and cooling a molten multifilament extruded from a spinneret at a spinneret surface temperature of 255 to 290 ° C. After changing to a solid multifilament, 0.02 to 0.20 cN / dt
It is obtained by winding at a speed of 2000 to 4000 m / min with a winding tension of ex.

Hereinafter, a preferred method for producing the PTT fiber of the present invention will be described in detail with reference to FIGS. 1) First, PTT pellets dried to a moisture content of 100 ppm or less in the dryer 1 are supplied to the extruder 2 set at 250 to 290 ° C and melted. 265-2 for molten PTT
The liquid is sent to the spin head 4 set at 95 ° C. and measured by a gear pump. Thereafter, the melted multifilament is extruded into a spinning chamber 14 through a spinneret 6 having a plurality of holes mounted on a spinneret pack 5. The water content of the PTT pellet supplied to the extruder is preferably 50 ppm or less, more preferably 30 ppm or less, from the viewpoint of suppressing a decrease in the polymerization degree of the polymer. The temperature of the extruder is preferably selected from the above range depending on the capacity of the extruder and the intrinsic viscosity and shape of the PTT pellet. The temperature of the extruder is more preferably in the range of 255 to 280 ° C. The polymer melted by the extruder is then sent to a spin head 4, measured by a gear pump, and extruded from a spinneret 6.

In the present invention, the spinning surface temperature is set to 255.
It is one of the important points that the temperature is set to ２290 ° C. Since a polymer having a high intrinsic viscosity, that is, a polymer having a high degree of polymerization has a high melt viscosity and an extensional viscosity, the following problems occur when spinning at a high speed such as POY.・ The spinning tension is too high and yarn breakage occurs frequently. -Yarn unevenness occurs. For this reason, yarn breakage and fluff frequently occur during the stretch false twisting process.・ To forcibly stretch polymers with high elongational viscosity,
The molecules become excessively strained, and the boiling water shrinkage and the peak value of the thermal stress increase. As a result, winding tightening occurs.・ Entanglement of molecules cannot be sufficiently disentangled to forcibly stretch a polymer with high elongational viscosity.If stretching is performed by stretch false twisting, the tension will increase and fluff and yarn breakage will occur frequently. Since they cannot be sufficiently aligned, the strength and elastic modulus of the obtained processed yarn are reduced.

If the spin head temperature is increased to lower the melt viscosity or elongational viscosity, the resulting fiber becomes so thermally decomposed that the obtained fiber is colored or the degree of polymerization is reduced, so that the fiber does not exhibit satisfactory strength. Or stretch false twisting becomes impossible. In order to solve such a problem, it is necessary to keep the spinning surface temperature within the range of the present invention.
If the spinning surface temperature is less than 255 ° C., the above-described problems such as yarn breakage, frequent fluffing, and yarn unevenness occur. On the other hand, when the spinning surface temperature exceeds 290 ° C., thermal decomposition becomes severe, and the obtained yarn is colored and does not show satisfactory strength.
High-speed stretch false twisting cannot be performed. The spinning surface temperature is preferably from 260 to 285C, more preferably from 265 to 280C.

To achieve such a spinning surface temperature,
It is preferable to set the temperature of the spin head appropriately and to install a heating cylinder immediately below the spinneret. Spin head temperature is 2
65-295 ° C., preferably 270-290 ° C.
° C, more preferably 275-285 ° C. The heating cylinder temperature is 100-350
C., preferably 150 to 300 C., more preferably 20 to 300.degree.
0-250 ° C is particularly preferred. The length of the heating cylinder is preferably from 50 to 300 mm, more preferably from 100 to 250 mm, from the viewpoint of the effect of loosening the entanglement of the polymer and the workability of spinning.

In the present invention, in order to prevent the extruded polymer from being excessively stretched, the draft at the time of spinning is set at 10 times.
It is preferable to be in the range of 0 to 1000. Here, the spinning draft is a value represented by the following equation. Spinning draft = V ₂ / V _1, however, V _1: the linear velocity of the polymer when extruded from the spinning nozzle (m / min) V _2: first roll speed (m / min) (without the first roll If the draft is less than 100, the spinning diameter becomes too small and the extrusion pressure becomes high, so that the melt fracture occurs and the property unevenness such as elongation increases, or the winding speed is too slow. The PTT-POY of the present invention has a degree of orientation and elongation.
Out of range. Draft is 1000
If the ratio exceeds, the polymer is forcibly stretched, so that the above-mentioned various problems are likely to occur. Spinning draft is 15
0 to 800 are preferable, and 200 to 600 are more preferable.

The spinneret preferably has a diameter of 0.25 to 0.7 mm and a ratio of diameter to length of 1: 0.25 to 1: 3. If the diameter is less than 0.25 mm or the ratio of the diameter to the length exceeds 3, the extrusion pressure becomes too high, which makes it difficult to extrude or that the fiber becomes uneven. On the other hand, when the diameter exceeds 0.7 mm, the fiber unevenness becomes large. If the ratio of the diameter to the length is less than 0.25, the spinning may be deformed or chipped over a long period of time.

2) Next, the molten multifilament extruded from the spinneret is cooled and changed into a solid multifilament. Cooling is preferably performed by blowing cold air of 0 to 40 ° C. onto the molten multifilament. By the time the solid multifilament is wound up, the finishing agent applying device 10
Preferably, a finish is provided by the By adding a finishing agent, the sizing, antistatic and slip properties of the fiber are improved, and the generation of fluff and yarn breakage during winding or false twisting is suppressed, or the wound cheese-like The form of the package can be kept good.

The finishing agent is a water emulsion obtained by emulsifying an oil using an emulsifier, a solution obtained by dissolving the oil in a solvent, or the oil itself, which improves the fiber convergence, antistatic properties, slipperiness, etc. It is to let. Here, the oil agent is an aliphatic ester, a mineral oil, a molecular weight of 1,000 to 200.
A mixture containing at least one of the polyethers of No. 00 and having a sum of 40 to 90% by weight is preferable, and the components are preferably selected as necessary.

In the present invention, the oil agent is preferably applied to the fiber as a water emulsion having a concentration of 1 to 20% by weight. By using a water emulsion liquid, it becomes easy to suppress uneven adhesion of the oil agent and to improve the form of the wound yarn. The concentration of the water emulsion is more preferably 2 to 10% by weight, and particularly preferably 3 to 7% by weight. When the concentration of the oil agent is low, it is necessary to apply a large amount of finish to the fiber in order to attach a preferable amount of the oil agent to the fiber. When the concentration is less than 1% by weight, the amount of the finish is too large, and it is difficult to give the finish to the fiber. On the other hand, the concentration is 20% by weight.
If the ratio exceeds the above range, the viscosity of the finishing agent is high, and the amount of the finishing agent is reduced when a certain amount of the oiling agent is to be adhered to the fiber, so that it is difficult to uniformly apply the oiling agent to the fiber.

It is preferable that the oil agent is applied in an amount of 0.2 to 3% by weight based on the weight of the fiber. If it is less than 0.2% by weight,
The effect of the oil agent is small, and the yarn breaks down due to static electricity, and the yarn breaks or fuzzes due to friction. 3% by weight
If the ratio exceeds the above range, the resistance of the fibers during running becomes too large, and the oil agent adheres to the rolls, hot plates, guides, etc., and contaminates them. Oil agent is 0.25 to fiber weight
It is preferable to attach 1.0% by weight, particularly preferably 0.3 to 0.7% by weight. Of course, a part of the oil agent may permeate into the fiber.

As a method for applying the finishing agent, a known method using an oiling roll or a method described in, for example, JP-A-59-1
Although a method using a guide nozzle disclosed in Japanese Patent No. 16404 or the like can be used, a method using a guide nozzle is preferable in order to suppress the occurrence of yarn breakage and fluff due to friction of the finish applying device itself. The location at which the finish is applied to the fibers may be in the chamber 14, in the zone 15 where the fibers are heat treated, before the first roll 11, and anywhere between these zones. The position closest to the spinneret immediately after being cooled to room temperature by 9 and converted into the solid multifilament 8 is preferable. This is because the fibers are bundled at the same time as the finish is applied, so that the closer this position is to the spinneret, the lower the air resistance, and the more the occurrence of yarn breakage and fluff can be suppressed.

3) The solid multifilament 8 provided with the oil agent may be wound directly by a winder, but once wound around a rotating roll such as the first roll 11,
It is preferable to take up with a winder. This is because adjusting the speed of the roll and the winder makes it easier to control the winding tension. Here, reference numeral 12 denotes a free roll that is not driven by itself. The solid multifilament 8 is preferably subjected to a heat treatment before winding. By performing the heat treatment, the fiber can be crystallized and the structure can be fixed, and the tightness of the winding and the temporal change of the physical properties of the fiber during storage can be suppressed.

As a heat treatment method of the fiber, in addition to the heat treatment method using the first roll 11 in FIG. 4, a heat treatment method using the first roll 11 and / or the second roll 16 in FIG. (B) a method of heat-treating with one or more of the first Nelson roll 17 to the second Nelson roll 18 by the first heater 19 and / or the second heater 20 of FIG. A method of performing heat treatment, a method of performing heat treatment using the first heater 19 in FIG. In the case of FIGS. 5- (C) and (D), the heat treatment may be performed by a roll in addition to the heat treatment by the heater.

As the heater used for the heat treatment, either a contact type heater or a non-contact type heater may be used. Alternatively, a method using a heated gas may be used. Among them, a method using a heating roll is most preferable because the above-described speed adjustment of the roll and the winder and the heat treatment can be performed simultaneously. In the present invention, the expression “heat treatment with a roll” means that the heat treatment is performed with a self-driven roll and that the heat treatment is not performed with a free roll. However, the heat treatment may be performed with a free roll.

The temperature of the heat treatment is preferably from 50 to 170 ° C. If the temperature is lower than 50 ° C., the fiber cannot be sufficiently crystallized to fix the structure, so that the fiber is tightly wound or the physical properties change with time, so that it becomes difficult to perform the false twisting industrially. On the other hand, if the temperature exceeds 170 ° C., yarn breakage or fluff may occur during the heat treatment, or crystallization may proceed excessively, resulting in fiber-
The coefficient of static friction between the fibers becomes small and the bulge ratio becomes large, or false twisting becomes difficult. The temperature of the heat treatment is preferably 60 to 150 ° C, more preferably 80 to 150 ° C.
130 ° C.

The heat treatment time is preferably 0.001 to 0.1 second. The term “heat treatment time” as used herein refers to the total time when heat treatment is performed with a plurality of rolls or heaters. If the heat treatment time is less than 0.001 second, the heat treatment time is so short that sufficient crystallization cannot be promoted, so that tightening and bulge are liable to occur and change over time is liable to occur. On the other hand, if the heat treatment time exceeds 0.1 seconds, crystallization proceeds too much, the coefficient of static friction between fibers becomes too small, and the resulting cheese-like package tends to have a large bulge. In the present invention, the crystallinity increases even when the heat treatment temperature is increased, the heat treatment time is increased, or the winding speed is increased. Therefore, it is more preferable to select a heat treatment time according to the heat treatment temperature and the winding speed.

4) Next, the solid multifilament is wound by using the winder 13. Winding speed is 2000-4
000 m / min. Winding speed is 20
If it is less than 00 m / min, the physical properties change over time during storage or the fibers become brittle because the orientation of the fibers is low, making it difficult to handle and false twist the fibers. Also, 4000m /
If the length exceeds the above range, the orientation and crystallization of the fiber are excessively advanced, and the tension at the time of winding cannot be reduced, so that the fiber largely shrinks on the yarn tube and tightness of the winding occurs. Preferably, 2
200 to 3800 m / min, more preferably 250
0 to 3600 m / min. In the present invention, the tension at the time of winding needs to be 0.02 to 0.20 cN / dtex.

If a conventional melt spinning of PET or nylon is used to wind the yarn at such a low tension, the running of the yarn becomes unstable, and the yarn may come off from the traverse of the winder, causing yarn breakage. Or a switching error occurs when the winding yarn is automatically switched to the next yarn tube. However,
Surprisingly, PTT fiber does not cause such a problem even if it is wound with an extremely low tension as in the present invention, and a cheese-like package having a good winding shape is obtained for the first time with a low tension because the tension is low. be able to. It is considered that the reason why the winding can be performed stably even at such a low tension is due to the low elastic modulus and the high elastic recovery rate which are the characteristics of the PTT fiber.

When the tension is less than 0.02 cN / dtex, the tension is too weak, so that the traverse with the traverse guide of the winding machine cannot be made good, and the winding form becomes poor, the yarn comes off from the traverse, and the yarn is removed. Cutting may occur. On the other hand, when it exceeds 0.20 cN / dtex, even if the fiber is heat-treated and wound up, tight tightening occurs. The tension at the time of winding is preferably 0.025.
0.15 cN / dtex, more preferably 0.03 to
0.10 cN / dtex. It is preferable to adjust the peripheral speed of the roll when installing the roll before the winder so that the winding tension is within the above range. The roll speed is preferably 0.80 to 1.1 times the normal winding speed.

In the present invention, a confounding treatment may be performed as necessary in the spinning process. The confounding process is performed before the finish is applied.
It may be performed before heat treatment or before winding, or at a plurality of places. The winding machine used in the present invention may be any of a spindle driving system, a touch roll driving system, and a system in which both the spindle and the touch roll are driven, but both the spindle and the touch roll are driven. This type of winder is preferable for winding a large amount of yarn.

When only one of the touch roll and the spindle is driven, the other is rotated by friction from the drive shaft, so that the surface speed differs between the thread tube attached to the spindle and the touch roll due to slippage. . For this reason, when the thread is wound from the touch roll to the spindle, the thread is stretched or loosened, the tension is changed, the winding appearance is deteriorated, or the thread is easily rubbed and damaged. By driving both the spindle and the touch roll, it is possible to control the difference between the surface speeds of the touch roll and the thread tube, reduce slippage, and improve the yarn quality and winding appearance. it can.

The winding angle when winding the fiber is preferably 3.5 to 8 °. If the angle is less than 3.5 °, the yarns do not intersect with each other so much that the yarns are slippery. On the other hand, when the angle exceeds 8 °, the diameter of the end portion becomes larger than that of the central portion because the amount of yarn wound around the end portion of the yarn tube increases. For this reason, when winding, only the end comes into contact with the touch roll and the yarn quality deteriorates, and the tension fluctuation when unwinding the wound yarn increases, causing fluff and yarn breakage. It is easy to occur frequently.
The twill angle is more preferably 4 to 7 °, particularly preferably 5 to 7 °.
6.5 °.

5) The PTT-POY of the present invention can be made into a false twisted yarn having very soft and good stretchability and durability by performing stretch false twisting. The false twisted yarn of the present invention has an intrinsic viscosity of 1.0-1.
Must be 6. By setting the intrinsic viscosity in this range, the high-speed stretch false twisting process, which is the object of the present invention, becomes possible. The false twisted yarn of the present invention has a stretch ratio of 180 to 3;
00%, elastic modulus is 80 ~ 100%, crimp number is 4 ~
It needs to be 30 pieces / cm. By satisfying these, it is possible to obtain a high-quality fabric having very soft and good stretchability and its durability, excellent in processability such as weaving and knitting, and smooth surface. Become.

The expansion and contraction rate is less than 180%, the expansion and contraction modulus is less than 80%, and the number of crimps is 4 / c.
If it is less than m, the processed yarn will be inferior in softness and elastic recovery, or will have insufficient bulky properties, and will be a filament-touched yarn with insufficient swelling. On the other hand, when the stretch ratio exceeds 300% or the number of crimps exceeds 30 pieces / cm, the processability of weaving and the like deteriorates, and the resulting fabric has a large feeling of roughness and flutter. However, the fabric does not fully utilize the soft texture of PTT. The higher the elastic modulus, the better, the upper limit being 100%. The stretch ratio is preferably 200 to 280%, more preferably 220 to 2%.
60%, and the elastic modulus is preferably 85-100.
%, More preferably 90-100%, and the crimp number is preferably 6-28 / cm, more preferably 8-25 / c.
m.

The false twisted yarn of the present invention has a strength of 2.5
It is preferably at least cN / dtex. By setting the strength in this range, yarn breakage in the process of forming a fabric can be reduced, and the strength of the obtained fabric can be increased. The strength is more preferably 3.0 cN / dtex or more, and 3.2.
cN / dtex or more is more preferable. The higher the strength, the better, but it is usually difficult to produce a processed yarn of 5 cN / dtex or more. Such a false twisted yarn is the PT yarn of the present invention.
It can be obtained only by using T-POY and cheese-like package. The intrinsic viscosity of the fiber is high and it has a specific structure, so it has excellent physical properties at high temperatures.The unwinding tension from the cheese-like package is low and the tension unevenness is small. Ratio, disk speed /
This is because the yarn speed ratio can be selected.

As a method of the stretch false twisting, a friction type, a nip belt type, an air twisting type or the like which can perform a stretch false twisting at a high speed is preferable. The processing speed is preferably 500 m / min or more from the viewpoint of productivity.
0 m / min or more is more preferable, and 800 m / min or more is particularly preferable. The processing temperature is 165 to 165 for contact type heater.
It must be 210 ° C. If the processing temperature is lower than 165 ° C., sufficient crimp cannot be provided. Also, 21
If the temperature exceeds 0 ° C., fluff and thread breakage occur frequently. In a non-contact type heater, the preferable temperature varies depending on the distance between the heater and the fiber.
Corresponds to 00 ° C. Temperature of contact type heater is 170 ~
200 ° C. is more preferred, and even more preferably 175-1.
90 ° C.

The draw ratio (drawing ratio) at the time of false twisting is preferably adjusted so that the elongation of the false twisted yarn is 40 to 50%. In this case, the stretching ratio is usually 1.05 to
2.0 times. In the case of a disk-type false twisting machine, it is preferable to use ceramic, urethane, or the like as the twisted disk, and the disk speed / yarn speed ratio (D / Y ratio) is 1.7 to 1.0.
It is preferably 3. With this range, the number of crimps within the range of the present invention can be easily obtained.

[0068]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below using examples and the like. Needless to say, the present invention is not limited by the examples and the like. The main measured values in the examples were measured by the following methods. (1) Intrinsic viscosity The intrinsic viscosity [η] was measured using an Ostwald viscometer, 35
° C, specific viscosity ηsp in o-chlorophenol and concentration C
The ratio ηsp / C of (g / 100 ml) was extrapolated to zero concentration and determined according to the following equation. [Η] = lim (ηsp / C) C → 0

(2) Birefringence Fiber Handbook-Raw Material Edition, p. 969 (5th printing, Maruzen Co., Ltd., 1978), using an optical microscope and a compensator, from the retardation of polarized light observed on the fiber surface. (3) Strength (rupture strength), elongation (elongation at break) Using Tensilon manufactured by Orientec Co., Ltd., which is a constant-speed elongation type tensile tester based on JIS-L-1013,
The measurement was performed at a grip interval of 20 cm and a tensile speed of 20 cm / min. The strength and elongation at 160 ° C.
The measurement was performed with the sample placed in a high-temperature bath at 160 ° C.

(4) Peak value of thermal stress KE-2 manufactured by Kanebo Engineering Co., Ltd. was used. The measurement was carried out at an initial load of 0.044 cN / dtex and a heating rate of 100 ° C./min. The obtained data is plotted with temperature on the horizontal axis and thermal stress on the vertical axis to draw a temperature-thermal stress curve. The value of the maximum point of the thermal stress was defined as the peak value of the thermal stress. (5) Density Based on JIS-L-1013, carbon tetrachloride and n-
The measurement was performed by a density gradient tube method using a density gradient tube prepared with heptane. (6) Shrinkage rate of boiling water Based on JIS-L-1013, it was determined as a skein shrinkage rate.

(7) Wide Angle X-Ray Diffraction (Counter Method) Observation was carried out under the following conditions using a wide angle X-ray diffractometer Rotaflex RU-200 manufactured by Rigaku Corporation (currently Rigaku Corporation). X-ray type: CuKa line Output: 40 KV 120 mA Goniometer: manufactured by Rigaku Corporation (currently Rigaku Corporation) Detector: scintillation counter Count recorder: RINT2000, online data processing system Scanning range: 2θ = 5 to 40 ° sampling interval : 0.03 ° Integration time: 1 second The diffraction intensity used was the true diffraction intensity obtained from the diffraction intensity obtained by measuring the sample and the air scattering intensity according to the following formula. True diffraction intensity = sample diffraction intensity-air scattering intensity

(8) U% U% is USTER · T manufactured by Zellbeger Worcester Co., Ltd.
It was determined by measuring with ESTER3 under the following conditions. Measurement speed: 100m / min Measurement time: 1 minute Measurement times: 2 Twist type: S twist

(9) Adhesion rate of oil agent Based on JIS-L-1013, the fiber was washed with diethyl ether, diethyl ether was distilled off, and the amount obtained by dividing the amount of pure oil agent adhering to the fiber surface by the fiber weight was calculated. The oil agent adhesion rate was used. (10) Bulge ratio Yarn layer (104) shown in FIG. 3- (A) or FIG. 3- (B)
Of the innermost layer and the winding width R of the bulging portion
Was measured and calculated according to the following equation. Bulge rate = {(RQ) / Q} x 100%

(11) Crimp Number of False Twisted Yarn According to JIS-L-1015, five false twisted yarns are treated in air at 90 ° C. for 15 minutes, and then the false twisted yarn per 25 mm is cut. The number of crimps was counted and the average was determined.
The value obtained by converting the result to the number of crimps per cm was used. (12) Stretching and elongation rate of false twisted yarn Based on JIS-L-1090, 15
After the treatment for 5 minutes, the stretch and elongation (%) of the false twisted yarn was determined by the stretch A method. (13) Elastic elastic modulus of false twisted yarn Based on JIS-L-1090, it is 15 in air at 90 ° C.
After treating for 1 minute, the elastic modulus (%) of the false twisted yarn was determined by the elasticity A method.

[0075]

Examples 1 to 4 Dimethyl terephthalate and 1,3-propanediol were charged at a molar ratio of 1: 2, and titanium tetrabutoxide corresponding to 0.1% by weight of dimethyl terephthalate was added. The transesterification reaction was completed at ℃. Next, titanium tetrabutoxide was further added at 0.1% by weight based on the theoretical polymer amount, and titanium dioxide was added at 0.05% by weight based on the theoretical polymer amount, and reacted at 270 ° C. for 3 hours. The obtained polymer was further reduced under reduced pressure at 210 ° C.
To obtain a polymer having the intrinsic viscosity shown in Table 1. The obtained polymer was dried by an ordinary method using the apparatus shown in FIG.
After being melted by the extruder set in, the liquid was sent to the spin head at the temperature shown in Table 1, and from a single-array spinneret having 36 holes of 0.35 mm in diameter and 0.35 mm in length opened. Extruded. Under the spinneret, a length of 10 at the temperature shown in Table 1
A 0 mm heating cylinder was installed. The spinning surface temperature at this time is shown in Table 1.

Next, a cool air having a temperature of 20 ° C. was blown at a wind speed of 0.4 m /
After cooling to a solid multifilament by applying to the molten multifilament in minutes, using a guide nozzle, it contained 60% by weight of octyl stearylate, 15% by weight of polyoxyethylene alkyl ether, and 3% by weight of potassium phosphate. The oil agent was applied as a water emulsion finish having a concentration of 5% by weight so that the oil agent adhesion rate to the fiber was 0.5% by weight. The solid multifilament to which the oil agent has been applied is wound on the first roll at the temperature and speed shown in Table 1 six times, and then shown in Table 1 using a winding machine that drives both the spindle and the touch roll. At a winding speed and a winding tension, 4 kg are wound at a winding width of 90 mm on a paper yarn tube having a diameter of 124 mm and a thickness of 7 mm with a winding angle of 5 ° and a winding width of 90 mm and 100 dt.
A cheese-like package wrapped with ex / 36f fibers was obtained. The wound cheese-like package was easily removed from the spindle of the winder, and the bulge ratio was in a good range. The physical properties of the obtained fibers are shown in Table 2. All of the obtained fibers corresponded to the scope of the present invention, and no yarn breakage or fluff was observed during the spinning process.

[0077]

Comparative Examples 1 to 5 Fibers were obtained in the same manner as in Example 1 under the conditions shown in Table 1. The physical properties of the obtained fibers are shown in Table 2. In Comparative Examples 1 and 2, the intrinsic viscosity of the fiber was out of the range of the present invention because the intrinsic viscosity of the polymer used was low.
The toughness at 60 ° C. was also low. Comparative Example 3
Since the intrinsic viscosity of the polymer used was too high, yarn breakage frequently occurred during spinning, and fibers could not be obtained. In Comparative Example 4, the surface temperature of the spinneret was low because the heating cylinder was not provided, and the cheese-like package could not be taken out from the spindle of the winder even if 1 kg was wound up due to tight winding. When the physical properties of the fiber were measured by winding up about 200 g of the fiber, the peak value of the thermal stress was high, the yarn unevenness was large, and the U% was high. In Comparative Example 5, since the winding speed was low, the birefringence and the elongation were out of the range of the present invention, and the density was low and the boiling water shrinkage was large.

[0078]

[Table 1]

[0079]

[Table 2]

[0080]

Examples 5 and 6 Using the fibers shown in Table 3, using a ceramic twisted disk with an FK-6 false twisting machine manufactured by Ishikawa Seisakusho, using a ratio of disk speed / yarn speed (7) D / Y
At a ratio of 2.3, high-speed draw false twisting was performed under the conditions shown in Table 3. No fuzz or yarn breakage during false twisting, excellent twisted yarn with physical properties within the scope of the present invention, crimped form similar to PET, softness unique to PTT, elastic recovery properties Could be obtained. The obtained processed yarn had very good weaving and knitting properties. Even after three months, there was almost no change in physical properties with time, and when stretched false twisting was performed, a false twisted yarn of the same quality could be obtained under the same conditions as described above.

[0081]

Comparative Examples 6 to 9 High-speed draw false twisting was performed in the same manner as in Example 7 using the fibers shown in Table 3. In Comparative Example 6, since the false twist temperature was too low even when the PTT-POY of the present invention was used, the stretch ratio, the stretch elastic modulus, etc. were out of the range of the present invention, and the crimped form, the elastic recovery property, etc. were poor. Only twisted yarn could be obtained. In Comparative Examples 7 and 9, since PTT-POY out of the range of the present invention was used, yarn breakage occurred frequently and a false twisted yarn could not be obtained.
In Comparative Example 8, PTT-POY out of the range of the present invention was used.
In the case of using, although the yarn breakage could be suppressed by lowering the false twisting temperature from the range of the present invention, the stretching elongation, the stretching elasticity, etc. are out of the range of the present invention, and the crimping form, elastic recovery, etc. are inferior. Only the false twisted yarn was obtained.

[0082]

[Table 3]

[0083]

The PTT fiber of the present invention has a high degree of polymerization of PT.
Extrusion at a specific range of spinning surface temperature to suppress rapid cooling of molten fiber using T-polymer, and manufactured using a special spinning method of winding at extremely low tension. PTT-POY, which has high orientation, elongation and shrinkage, and can be produced industrially stably in a single-stage spinning process with high productivity. Therefore, high-quality false twisted yarn can be stably obtained by high-speed drawing false twisting with high productivity. The false twisted yarn produced using the PTT fiber of the present invention has a soft texture and a high crimp ratio,
A very twisted yarn suitable as a stretch material, having an extremely excellent elasticity and elasticity. For this reason, it is useful for so-called zokki or knitting type pantyhose, tights, socks (backing yarn, rubber cuff), jersey, covering yarn of elastic yarn, and companion yarn of knitting products such as knitting pantyhose.

[Brief description of the drawings]

FIG. 1 is a wide-angle X-ray diffraction chart in which peaks derived from crystallinity are observed. Figure 1- (b)
Is a wide-angle X-ray diffraction chart in which no peak derived from crystallinity is observed.

FIG. 2 is a non-uniformity curve (change in fiber mass) when the fiber is passed through USTER TESTER3.

FIG. 3 is a schematic view showing a cheese-like package in which the PTT fiber of the present invention is wound around a yarn tube. Figure 3- (a)
FIG. 2 is a schematic view of a desirable cheese-like package. FIG.
(B) is a schematic diagram of a cheese-like package with a bulge.

FIG. 4 is a schematic view showing an outline of a spinning machine for carrying out the present invention.

FIG. 5 is a schematic view schematically showing another embodiment of a zone for heat treating fibers of a spinning machine embodying the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dryer 2 Extruder 3 Bend 4 Spin head 5 Spinner pack 6 Spinner 7 Heating cylinder 8 Multifilament 9 Cooling air 10 Finishing agent application device 11 1st roll 12 Free roll 13 Winding machine, package 13a spindle, package 13b Touch roll 14 Spinning chamber 15 Zone for heat-treating fiber 16 Second roll 17 First Nelson roll 18 Second Nelson roll 19 First heater 20 Second heater

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4L035 BB33 DD20 EE02 EE20 FF08 HH10 4L036 MA05 MA26 MA33 PA14 PA49 RA04 UA01 UA16

Claims (9)

[Claims] 1. A polytrimethylene terephthalate fiber comprising at least 90 mol% of polytrimethylene terephthalate composed of trimethylene terephthalate repeating units and satisfying the following requirements (A) to (D): . (A) Intrinsic viscosity: 1.0 to 1.6 (B) Birefringence: 0.03 to 0.07 (C) Elongation at break: 40 to 140% (D) Peak value of thermal stress: 0.01 ~ 0.10cN / dtex 2. The polytrimethylene terephthalate fiber according to claim 1, wherein the toughness calculated from the following formula using the strength and elongation at 160 ° C. is 9 or more. Toughness = strength (cN / dtex) x √ elongation (%) 3. The polytrimethylene terephthalate fiber according to claim 1, which satisfies the following (E) to (F). (E) Density: 1.320 to 1.340 g / cm ³ (F) Boiling water shrinkage: 3 to 40% 4. The wide-angle X-ray diffraction intensity in a direction perpendicular to the fiber axis satisfies the following expression.
The polytrimethylene terephthalate fiber according to any one of the above. I ₁ / I ₂ ≧ 1.0 where I ₁ : 2θ = 15.5-16.5 ° maximum diffraction intensity I ₂ : 2θ = 18-19 ° average diffraction intensity 5. A cheese-like package wound with the polytrimethylene terephthalate fiber according to claim 1, and having a bulge ratio of 20% or less. 6. An intrinsic viscosity comprising at least 90 mol% of trimethylene terephthalate repeating units having an intrinsic viscosity of 1.0 to 1.
6. A method of melt-spinning polytrimethylene terephthalate of No. 6 wherein the molten multifilament extruded from the spinning nozzle is cooled to a solid multifilament by setting the surface temperature of the spinning nozzle to 255 to 290 ° C. .20c
A method for producing polytrimethylene terephthalate fiber, comprising winding at a speed of 2000 to 4000 m / min with a winding tension of N / dtex. 7. The molten multifilament extruded from the spinneret is cooled and changed into a solid multifilament,
7. The heat treatment is performed at 0 to 170 [deg.] C.
A method for producing the polytrimethylene terephthalate fiber according to the above. 8. A false twisted yarn comprising 90% by mole or more of polytrimethylene terephthalate composed of trimethylene terephthalate repeating units and satisfying the following requirements (G) to (J). (G) Intrinsic viscosity: 1.0-1.6 (H) Stretching elongation: 180-300% (I) Stretching elasticity: 80-100% (J) Crimp number: 4-30 / cm 9. A method of performing a false twisting process using the polytrimethylene terephthalate fiber according to claim 1 at a false twisting speed of 500 to 1200 m / min and a processing temperature of 165 to 210 ° C. A method for producing a false twisted yarn.