JP2001098426A - Highly orientated undrawn yarn of polyester and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a highly orientated undrawn yarn of polyester capable of controlling orientation in spinning and actualizing improvement in productivity, to provide a method for stably producing the highly orientated undrawn yarn of polyester without a problem in terms of process and to obtain the highly orientated undrawn yarn of polyester having excellent drawability and drawing false twisting processability. SOLUTION: This highly orientated undrawn yarn of polyester has >=25×10-3 and <=70×10-3 double refractive index and characteristics which 1 shows a sea-island structure comprising a polyester as a sea component and a polymer having incompatibility with the polyester and a higher elongation viscosity at 100 deg.C than that of the polyester as an island component in the cross section of the highly orientated undrawn yarn, 2 has the total area of the island component of >=0.5% and <=5% the whole cross-sectional area of the yarn and 3 has >=0.95 n when a cumulative frequency R of area of individual island component shown by a Rosin-Rammler distribution function (R is cumulative frequency; x is area of individual island of incompatible polymer) of formula (1): R=100 exp(-kxn).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a highly oriented undrawn polyester yarn and a method for producing the same. More specifically, the present invention relates to a method for producing a highly oriented polyester non-oriented yarn having excellent yarn-making properties and productivity, and a highly oriented polyester non-oriented yarn having excellent stretchability, processability, and processability.

[0002]

2. Description of the Related Art Polyester fibers such as polyethylene terephthalate are used in large quantities and in a wide range of fields because of their excellent properties. Above all, a highly oriented undrawn yarn (hereinafter abbreviated as POY) with a take-up speed of 2000 to 4000 m / min has an advantage that it can be used not only for drawing but also for draw false twisting as it is. Therefore, it occupies an important industrial position.
On the other hand, with regard to false twisted yarns, by adopting the draw false twisting process in which drawing and false twisting are simultaneously performed using this POY, the productivity is greatly improved compared to the conventional method of false twisting drawn yarns. Was achieved.

In recent years, there has been an increasing demand for further improvement in productivity, and attempts have been made to increase productivity per unit time by increasing the spinning speed of undrawn yarn. In the case of a fiber, there is a problem that oriented crystallization proceeds with an increase in spinning speed, and the mechanical properties of the fiber change. For the purpose of solving this problem and obtaining fibers having the same characteristics even when the spinning speed is increased, many means have been studied to suppress the molecular orientation of polyester which increases as the spinning speed increases. Among them, a method of including another polymer in polyester is known.

For example, JP-A-56-91013 discloses a method for improving the residual elongation by using a polyester containing a styrene-based polymer.
No. 47912 discloses a technique for improving the residual elongation by containing a polymer represented by the following formula.

-{CH ₂ C (R1) (R2)} _n- (R1 and R2 are substituents by a combination of arbitrary atoms selected from C, H, N, O, S and P. And R
The molecular weight of 1 + R2 is 40 or more. n is a positive integer. ) In these techniques, although the effect of improving the residual elongation, that is, the effect of suppressing the orientation during spinning, is recognized, the kneaded polymer must be sufficiently kneaded to be dispersed and mixed in the polyester on a molecular order, so that a sea-island shape is obtained. When kneading such as mixing is insufficient, the effect of residual elongation is not recognized, and an undesirable phenomenon of fibrillation appears. Further, as the degree of polymerization increases, an improvement in the residual elongation is observed, but the spinning condition deteriorates.

[0006] As described above, a technique for improving residual elongation by adding another polymer to polyester is known, but its disadvantages are poor spinnability and unevenness of yarn. Several techniques for modifying the blend polymer have been disclosed.

In Japanese Patent Application Laid-Open No. Hei 7-504717, 50
The polymethacrylic acid-methyl ester, in which ~ 90% is imidized, is added to the high polymerization degree polyethylene terephthalate in 0.1%.
A technique has been disclosed in which about 5% by weight is added to increase the high-speed spinnability and increase the residual elongation at the same spinning speed.

[0008] Japanese Patent Application Laid-Open No. 11-61568 discloses that
A vinyl-based polymer (preferably a styrene-maleic anhydride-based copolymer) having an average molecular weight of 500 or more and an average copolymerization amount of maleic anhydride of 2 to 20 mol per 1 mol of the polymer is added to the polyester in an amount of 0. There is disclosed a technique of suppressing the molecular orientation by blending in an amount of from 0.01 to 10% by weight.

All of these techniques are techniques for increasing the compatibility by the interaction between the added polymer and the polyester, finely dispersing the added polymer, and improving the spinning property. However, when the added polymer reacts with the polyester, it acts as a kind of cross-linking agent, causing gelation in the polyester. Production becomes difficult.

As described above, in the prior art in which the polyester contains a polymer that is incompatible with the polyester, the effect of suppressing the orientation is recognized, but the yarn-forming property is poor, so that stable production becomes difficult, and improvement in productivity can be expected. There was a problem that there was not. The resulting highly oriented undrawn yarn also has drawbacks in drawability, processability, and process passability, such as generation of fluff during processing.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polyester highly oriented undrawn yarn which solves the above-mentioned problems of the prior art, suppresses the orientation during spinning, and has excellent spinnability. To provide a method for producing a polyester highly oriented undrawn yarn stably and efficiently without any process problems, and to provide a polyester highly oriented undrawn yarn excellent in stretchability and draw false twisting property. is there.

[0012]

Means for Solving the Problems The present inventors have suppressed the molecular orientation which increases with an increase in the spinning speed, and have a spinning property,
Intensive studies have been made to obtain a highly oriented undrawn polyester yarn having good drawability and draw-twistability. Among these, when dispersing an incompatible polymer that is added to polyester and has an effect of suppressing molecular orientation in polyester melt, the disadvantage of the conventional technology is solved by setting the dispersion distribution state to a specific range. They have found what they can do and have reached the present invention.

That is, according to the present invention, the birefringence is 25 × 10
^-3 or more and 70 × 10 ⁻³ or less, and a highly oriented undrawn polyester yarn having the following features 1 to 3. 1. The cross section of the highly oriented undrawn yarn shows a sea-island structure in which polyester is used as a sea component and a polymer that is incompatible with the polyester and has an extensional viscosity at 100 ° C. higher than the polyester is used as an island component. 2. The total area of the island components is 0.5% of the total cross-sectional area of the fiber
Not less than 5%. 3. The cumulative frequency R of the area of each island component is calculated by the following equation (1) Ro
n expressed by a sin-Rammler distribution function is 0.95
That is all.

R = 100 exp (−kx ⁿ ) (1) where R: cumulative frequency x: area of each island of the incompatible polymer

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The polyester referred to in the present invention is
It is a polymer formed from an ester bond between a dicarboxylic acid compound and a diol compound, preferably polyethylene terephthalate, polypropylene terephthalate, or polybutylene terephthalate, and more preferably polyethylene terephthalate.

The polyester used in the present invention may have another third component copolymerized within a range not to impair the gist of the invention. Examples of the dicarboxylic acid compound include terephthalic acid, isophthalic acid, 2,6 Aromatic, aliphatic and alicyclic dicarboxylic acids such as naphthalenedicarboxylic acid, diphenyldicarboxylic acid, adipic acid, sebacic acid, 1,4-cyclohexanedicarboxylic acid, 5-sodium sulfoisophthalic acid and 5-tetrabutylphosphonium isophthalic acid And their derivatives. Examples of the diol compound include aromatic and aliphatic compounds such as ethylene glycol, propylene glycol, butylene glycol, tetramethylene glycol, 1,4-cyclohexanedimethanol, diethylene glycol, neopentyl glycol, polyalkylene glycol, bisphenol A and bisphenol S. And alicyclic diol compounds. Further, the polyester of the present invention may contain a small amount of additives such as a matting agent, a flame retardant, and a lubricant.

Intrinsic viscosity (IV) of the polyester of the present invention
Is preferably 0.55 or more. Although there is no particular upper limit for the IV, it is economical to use an IV of 0.8 or less obtained by liquid phase polymerization when used for clothing fibers.

The highly oriented undrawn polyester yarn of the present invention comprises
Birefringence, which is an index indicating the degree of molecular orientation, is 0.025 to
0.070. Birefringence is 0.025 to 0.070
With this, an appropriate heating temperature and stretching ratio can be obtained in the stretch false twisting process, and stable processing can be performed.

The highly oriented undrawn polyester yarn of the present invention has a sea-island structure, and a polymer which is incompatible with polyester as an island component needs to have a higher elongational viscosity at 100 ° C. than that of polyester. It is known that the molecular orientation in polyester melt spinning is proportional to the spinning tension at the end of thinning of the melt. Therefore, in order to obtain a fiber in which the molecular orientation is suppressed even when the spinning speed is increased, it is important that the incompatible polymer contained in the polyester exhibits a high elongational viscosity during large deformation during the spinning process. it is conceivable that. It is considered that the immiscible polymer has a higher elongational viscosity than the polyester, so that the tension during spinning is concentrated on the polymer, and conversely, the spinning tension of the polyester is reduced, so that the molecular orientation is suppressed.

As described above, the elongational viscosity of the polymer incompatible with the polyester in the present invention needs to be higher than that of the polyester, but the measurement temperature is preferably close to the deformation temperature of the polymer in the spinning process. It is sufficient to measure at 100 ° C. to know the effect. Further, various devices for measuring the extensional viscosity can be selected, but a Meissner-type extensional viscometer is most common.

The strain rate at the time of measuring the extensional viscosity is not particularly limited as long as the conditions are the same for the polyester to be compared and the polymer incompatible with the polyester, and may be within a range that can be measured with a Meissner-type extensional viscometer. I just need. However, the elongation strain applied to the polymer during the spinning process is very large, and it is preferable that the elongation strain is measured at an elongation strain rate of 0.1 s ⁻¹ or more.

The polymer incompatible with the polyester in the present invention includes, for example, a polystyrene-based polymer, a polymethyl methacrylate-based polymer, a poly (4-methyl-1-pentene) -based polymer and a polybutene-based polymer. Is particularly preferable from the viewpoints of high alignment suppressing effect, heat resistance and economy.

The polymer incompatible with the polyester in the present invention may be a copolymer of a plurality of constituent monomers as long as the gist of the present invention is not impaired. Other than styrene, side-chain alkyl-substituted styrenes such as α-methylstyrene and α-ethylstyrene, and nuclear alkyl-substituted styrenes such as vinyltoluene, vinylxylene, ot-butylstyrene, p-methylstyrene and divinylbenzene Chlorostyrene, halogenated styrenes such as dichlorostyrene, etc., and methyl methacrylate, 4-methyl-1-pentene, maleic anhydride, butadiene, etc., but the alignment suppressing effect, thermal stability, price, etc. Considering that 95
It is preferable to use a polymer whose% or more is composed of a single monomer.

The content of the polymer incompatible with the polyester in the present invention is such that the total area of the island components formed by the incompatible polymer in the fiber cross section is 0.5% or more with respect to the total cross sectional area of the fiber. 5% or less. If it is less than 0.5%,
A sufficient orientation suppression effect intended by the present invention cannot be obtained.
On the other hand, if it exceeds 5%, the incompatibility polymer appearing on the surface of the fiber is unfavorable because it impairs the processability such as falling off or fusing in the higher processing step.

When the cross section of the highly oriented undrawn yarn of the present invention is photographed by, for example, a transmission electron microscope (TEM), the polyester forms a sea component and the polymer incompatible with the polyester forms an island component. It can be observed that the fine polymer is finely dispersed. When the cumulative frequency R relating to the area of each island component formed by the incompatible polymer is expressed by the following equation (1), Rosin-Rammler distribution function, n is 0.95 or more.

R = 100 exp (−kx ⁿ ) (1) where R: cumulative frequency x: area of each island of the incompatible polymer The polymer incompatible with the polyester contained in the polyester is a highly oriented undrawn yarn Can be observed by photographing the cross section of the sample with, for example, a transmission electron microscope (TEM). The observation is performed at a sufficiently high magnification, and the magnification is such that the size of the incompatible polymer finely dispersed in the polyester can be observed, but a magnification of about 7000 times is sufficient. In addition, in order to give a contrast and facilitate observation when taking a photograph, it is preferable to perform staining with, for example, ruthenium tetroxide.

In the present invention, for example, the area of one island of an incompatible polymer dispersed in polyester, which is observed from an image taken by the TEM, is measured using, for example, an imaging analyzer, and the equation (1) is obtained. X inside
Expressed by Next, the distribution state of x is represented by a histogram, and the cumulative frequency of x is represented by R. The number of observations of x must be a statistical number, and is a sample number of 1000 or more, preferably 3000 or more. More preferably, sampling is performed not only from one cross-sectional photograph but also from a plurality of cross-sectional photographs.

In the present invention, the relationship between R and x is expressed by the following equation (1).
It is represented by a distribution function represented by This distribution function is Ro
It is called a sin-Rammler distribution function, which is widely used as a distribution function representing the distribution of crushed particles and the like. For example, "Theory and Calculation of Chemical Machines" (Saburo Kamei, Sangyo Tosho, published in 1949) ) P401. Here, k is the size of the island of the incompatible polymer, and n is a constant representing the sharpness of the distribution of x. n becomes larger as the distribution of x becomes sharper, and approaches 1 in an ideal distribution state.

In the present invention, it is preferable to adopt a portion where the above-mentioned cumulative frequency is 10% or more and 90% or less. 10
% Or more than 90% may be excluded because they may contain information other than the incompatibility of the immiscible polymer intended for the present invention, such as errors during imaging processing and foreign substances. Is preferred. In order to achieve the object of the present invention, it is sufficient to employ a cumulative frequency portion of 10% or more and 90% or less.

In the present invention, k and n have a linear relationship when log (2-logR) transformed by taking the common logarithm of both sides of equation (1) is plotted on the ordinate and log (x) is plotted on the abscissa. ,
The slope can be obtained as n and the intercept of the vertical axis as k. The method of obtaining the approximate straight line may be a method of obtaining by the least square method.

In the present invention, the value of n in the equation (1) is 0.9.
5 or more. If it is less than 0.95, the unevenness of the yarn is large, so that the dyeing unevenness and the physical property unevenness are apt to occur, and the yarn forming property is poor. In order to obtain a fiber which has a sufficient orientation suppressing effect and has a small yarn unevenness and a good yarn-making property as an object of the present invention, it is necessary that n is 0.95 or more.

Now, when producing a fiber by blending a polymer incompatible with polyester, in order to obtain a fiber having small yarn spots and good yarn-making properties, the dispersion diameter of the incompatible polymer has been conventionally determined. It is a well-known technique so far that it is sufficient to make it fine. For example, JP-A-60-209515 discloses that a high-viscosity polyethylene terephthalate melt is mixed with an immiscible polymer in an amount of 0.1 to 10% by weight to have an average particle diameter of 3 μm or less immediately before spinning. Thus, a technique for achieving an improvement in productivity by melt spinning is described. However, as a result of a detailed study of the correlation between the dispersion state of the incompatible polymer and the yarn spots / spinning properties, the average particle size of the incompatible polymer dispersed in the fiber was determined to be It was found that the distribution of the particle size hardly correlated with the properties, but rather had a significant effect. In other words, even if the average particle size is large, if the distribution is narrow, it is possible to reduce the yarn spots and improve the spinning property, but even if the average particle diameter is small, if the distribution is large, the yarn spots will also be reduced. The yarn formability cannot be improved.

This fact is important because it also indicates that reducing the amount of incompatible polymer having a certain dispersion diameter or more does not necessarily mean that the yarn spots and the spinnability are improved. European Patent EP 0 860 534 describes a technique for producing yarn by blending a copolymer composed of two or more of acrylic acid or methacrylic acid, maleic acid or maleic anhydride, and styrene with PET. Among them, the immiscible polymer has an average particle diameter of 400 nm or less immediately after spinning, and 1000 nm or less.
It is stated that the best condition is obtained when the ratio of the above particle diameter is 1% or less. However, as a result of intensive studies, we have found that even if the ratio of the particle size of 1000 nm or more exceeds 1%, it is possible to obtain good yarn-making properties if the particle size distribution is sufficiently narrow. . Furthermore, even if the average particle diameter is sufficiently small and the ratio of the particle diameters having a particle diameter of 1000 nm or more is 1% or less, it is found that if the distribution of the particle diameters is wide, sufficient spinnability cannot be obtained. did.

As described above, the particle size distribution is a very important factor in improving the yarn spots and the spinnability, and the Rosin-Rammler function is applied as the distribution function, and the sharpness of the distribution is expressed by the equation (1). The present invention has been found to be able to quantitatively express the correlation with the thread spots and the spinnability by expressing the number n.

The weight average molecular weight of the incompatible polymer of the formula (1) in the present invention is preferably 200,000 or more. When the weight average molecular weight is 200,000 or more, the effect of suppressing molecular orientation, which is the object of the present invention, is sufficiently exhibited. Although there is no particular upper limit of the weight average molecular weight, those having an excessively high molecular weight have a very high melt shear viscosity and are less likely to flow in a spinning machine, so the weight average molecular weight is preferably 800,000 or less, Preferably, the weight average molecular weight is 500,000 or less. The weight average molecular weight may be one which is simply measured, and examples include gel permeation chromatography (GPC).

The polyester highly oriented undrawn yarn of the present invention has 3
It is preferable to perform melt spinning at a take-up speed of 500 to 7000 m / min. The purpose of adding the incompatible polymer is to utilize the difference in elongational viscosity between the polymer and the polyester, and the difference in elongational viscosity increases as the spinning speed increases. Therefore, in order to achieve the sufficient effect of suppressing the molecular orientation aimed at by the present invention, the spinning speed must be 3500.
It is preferably at least m / min. Such a spinning speed is higher than a widely used spinning speed in producing POY, and by producing a yarn at such a high spinning speed, the object of the present invention is to improve the productivity of highly oriented undrawn yarn. Can be achieved.

When the spinning speed is increased, when the spinning speed exceeds 7000 m / min, the yarn quality changes from a highly oriented undrawn yarn to a yarn quality close to that of a drawn yarn.
m / min or less.

The distribution of the immiscible polymer of the present invention is expressed by the following formula (1).
There is no particular limitation on the means for making the mixture, but, for example, a polyester and an immiscible polymer mixed in a pellet state were melted and kneaded by a single-screw extruder or a twin-screw extruder of a Maddock or Dharmage type. Thereafter, the mixture is kneaded using a stationary kneader in a pipe or a pack, filtered by a pack member provided with a sand layer and a filter according to a standard method, discharged from a die, and taken up at a desired spinning speed. Alternatively, the polyester and the immiscible polymer may be melted by separate extruders, kneaded by a static or dynamic kneader, and then thread-formed according to a standard method.

It is preferable to use a stationary kneader used in this case, which is divided into ten or more passages.

As described above, in the present invention, the polyester is made to contain a polymer that is incompatible with the polyester and has a higher elongational viscosity than the polyester, and the dispersion distribution is represented by the formula (1).
Melt spinning, which has a large orientation suppression effect and is excellent in spinnability, in particular, melt spinning of POY becomes possible, and an improvement in productivity can be achieved. Further, such POY can be obtained without requiring special kneading / dispersion, and the POY obtained by this method can improve the processability during stretching and draw false twisting, and can be used as a processed yarn. It has favorable properties, such as higher crimp properties, and is considered to be very significant from an industrial point of view.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples. The physical properties in the examples were measured by the following methods.

[0042]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Intrinsic viscosity IV Measured in orthochlorophenol at 25 ° C. B. Elongational Viscosity (ηE) The elongational viscosity was measured with a Meissner-type elongational rheometer at a constant strain rate (0.1 s ⁻¹ ) and at 100 ° C. As the measured value, the value of the extensional viscosity 10 seconds after the start of the measurement was adopted. C. Strength / elongation Measured using an Orientec Tensilon tensile tester at an initial sample length of 50 mm and a tensile speed of 400 mm / min. D. Birefringence (Δn) Using a BH-2 polarizing microscope compensator manufactured by OLYMPUS, the birefringence was determined from the retardation and the fiber diameter by an ordinary interference fringe method. E. FIG. Rosin-Rammler
Observation of the cross section of the distribution function fiber was performed using a transmission electron microscope (TE
M), and the measurement was performed using an H-7100FA model manufactured by Hitachi, Ltd. under the conditions of an acceleration voltage of 100 kV. In addition, the sample section was sliced to about 1200 angstroms, and R
Staining was performed with uO ₄ .

Next, the islands of the incompatible polymer taken in the TEM photograph were copied on a transparent plastic sheet and processed by an imaging analyzer. A histogram was prepared for the area x of each island of the obtained incompatible polymer, and k of the Rosin-Rammler distribution function shown below was obtained by the method described in the text.
And n were obtained.

R = 100 exp (−kx ⁿ ) (1) Weight average molecular weight (Mw) The polymer sample was dissolved in a solvent so that the concentration of the dried polymer sample became 0.5 mg / ml, and the solution was filtered and then measured by gel permeation chromatography (GPC). Here, this GPC is provided with a differential refractometer as a detector. G. FIG. Crimp characteristics (CR) of the processed yarn The fiber is wrapped in a 10-turn scallop shape, 90 ° C, 20
Perform warm water treatment for 1 minute. After air drying overnight, apply an initial load of 0.04 times the denier of the fiber and an actual load of 2.0 times the denier of the fiber in water at 20 ° C, and measure the length of the case after 2 minutes. (L1). Immediately remove the actual load 2
After a minute, the length is measured again (L2). Based on L1 and L2 obtained in this manner, {(L1-L2) / L1} ×
100 was taken as the CR value. H. Using a fly counter manufactured by Toray Co., Ltd.
Under the conditions of 0 m / min and measurement sensitivity of 0.1, measurement for 50 minutes was 1
Performed 0 times, the average value of the counted fluff number 10 ⁴
The number of fluff per m was used. I. We make knitted fabric with false twist processing thread and dye with blue disperse dye,
It was determined visually.

Hereinafter, examples and comparative examples will be shown, but the present invention is not limited to the examples. Details are shown in Table 1. Example 1 Polystyrene having a weight average molecular weight of about 330,000 (polystyrene having a weight average molecular weight of about 330,000 by A & M Co., Ltd.) was obtained by a chip blender with respect to polyethylene terephthalate having an IV of 0.65 obtained by a general polycondensation reaction using terephthalic acid and ethylene glycol. 685) was mixed at 2 wt%, melt-kneaded with a single-screw extruder having a kneading function of a Maddock type, and further discharged through a static kneader “High Mixer” manufactured by Toray Engineering Co., Ltd. to obtain a polyester composition. Was. The high mixer used had a 15-stage channel dividing function. In addition, the extensional viscosity of polystyrene was higher than that of polyethylene terephthalate as shown in Table 1.

Using a spinning machine of a pressure melter type, the spinning temperature was 295 ° C., the pore diameter was 0.23 mmφ, and the number of holes was 3
62.5 g / min, 5000 m / min.
At a spinning speed of 10 minutes to obtain a polyester POY.
No yarn breakage occurred during spinning, and the spinning properties were excellent. Table 1 shows the fineness, elongation, and Δn of this POY. Δn is smaller than POY (Comparative Example 1) obtained at the same spinning speed, and it can be seen that the orientation during spinning is suppressed.

The Rosin-Rammler distribution function n indicating the dispersion state of the immiscible polymer observed from the cross-sectional area of the yarn was 0.95 or more, and the yarn production was good.

The POY was processed at a processing speed of 800 m / min and a processing temperature of 2 using a friction disk type draw false twisting machine.
Stretching false twisting (hereinafter referred to as DTY processing) was performed at 10 ° C. No thread breakage during processing, excellent workability,
There was also very little fluff. The fineness of this processed yarn,
The CR is shown in Table 1. It can be seen that CR has excellent crimp characteristics. In addition, no staining spots were observed.

As can be seen from Table 1, in obtaining a 75 denier textured yarn, a polyester composition containing polystyrene having a weight average molecular weight of about 330,000 was used to obtain a P yarn.
Even if the spinning speed of OY is increased, the orientation is suppressed.
The TY processing magnification can be increased, and POY productivity can be greatly improved (spinning discharge rate can be increased). In addition, the obtained POY has excellent workability and is crimped when processed yarn is used. It can be seen that the material has excellent characteristics. No spots were observed. Example 2 When melt-kneading polyester and polystyrene, a highly oriented undrawn yarn was produced in the same manner as in Example 1, except that the number of stages of the high mixer was changed to 10. Δn is smaller than that of Comparative Example 1 and the orientation is suppressed.
Since n of the mmler distribution function was 0.95 or more,
The yarn formability was good. There were few fluffs during false twisting, good workability and product characteristics were obtained, and improvement in productivity was realized. Examples 3 and 4 Highly oriented undrawn yarns were produced in the same manner as in Example 1, except that the IV of the polyester was changed as shown in Table 1. Δn is smaller than that of Comparative Example 1, the orientation is suppressed, and Rn
Since the osin-Rammler distribution function n was also 0.95 or more, the spinning property was good. There is little fuzz at the time of false twisting, CR is also a sufficiently high value, there is no dyeing spot,
Good workability and product characteristics were obtained, and improvement in productivity was realized. Examples 5 and 6 Highly oriented undrawn yarns were produced in the same manner as in Example 1 except that the spinning speed was changed. Δn was smaller than Comparative Example 1 in any of the examples, the fiber orientation was suppressed, and the n of the Rosin-Rammler distribution function was 0.95 or more, so that the spinnability was good. The fluff during the false twisting process was small, the CR was a sufficiently high value, and the dyeing spots were not in any of the examples. Good processability and product characteristics were obtained, and improvement in productivity could be realized. Examples 7 and 8 Highly oriented undrawn yarns were produced in the same manner as in Example 1 except that the ratio of polystyrene was changed. Δn was smaller than Comparative Example 1 in any of the examples, the fiber orientation was suppressed, and the n of the Rosin-Rammler distribution function was 0.95 or more, so that the spinnability was good. The fluff during the false twisting process was small, the CR was a sufficiently high value, and the dyeing spots were not in any of the examples. Good processability and product characteristics were obtained, and improvement in productivity could be realized. Examples 9 and 10 The weight average molecular weight of polystyrene was 230,000 (A &
M, Inc. Styron 679R), 380,000 (A & M
Example 1 except that Stylon 8259 manufactured by Co., Ltd. was used.
A highly oriented undrawn yarn was produced in the same manner as described above. Δn was smaller than Comparative Example 1 in any of the examples, the fiber orientation was suppressed, and the n of the Rosin-Rammler distribution function was 0.95 or more, so that the spinnability was good. The fluff during the false twisting process was small, the CR was a sufficiently high value, and the dyeing spots were not in any of the examples. Good processability and product characteristics were obtained, and improvement in productivity could be realized. Examples 11 and 12 Polymers incompatible with polyester were respectively polymethyl methacrylate (SUMIPEX M manufactured by Sumitomo Chemical Co., Ltd.).
E), poly 4-methyl 1 pentene (manufactured by Mitsui Chemicals, Inc., T
PX-MX004) to produce a highly oriented undrawn yarn in the same manner as in Example 1. Δn was smaller than Comparative Example 1 in any of the examples, the fiber orientation was suppressed, and the n of the Rosin-Rammler distribution function was 0.95 or more, so that the spinnability was good. The fluff during false twisting was small, the CR was a sufficiently high value, and the spots were not in any of the examples. Good workability and product characteristics were obtained, and improvement in productivity was realized. Comparative Example 1 Polyethylene terephthalate having an IV of 0.65 obtained by a usual polycondensation reaction was spun at a spinning temperature of 295 ° C. and a pore diameter of 0.23 mm using a pressure melter type spinning machine.
82.5 g / min from a spinneret with 36 holes
Polyester PO at a spinning speed of 2,000 m / min
Y was obtained. No yarn breakage occurred during spinning, and although the spinnability was excellent, Δn was large and the improvement in productivity, which was the object of the present invention, could not be realized. Comparative Example 2 A polyester and polystyrene were melt-kneaded in Example 1 except that an extruder having no kneading function such as a mud dock or dalmage was used without using a high mixer.
A highly oriented undrawn yarn was produced in the same manner as described above. Δn was smaller than that of Comparative Example 1, and the orientation was suppressed.
Since n of the in-Ramler distribution function was 0.95 or less, the spinning property was poor. In addition, there were many fluffs at the time of false twisting, dyeing spots were observed, and both processability and product characteristics were poor. Comparative Examples 3 and 4 A highly oriented undrawn yarn was produced in the same manner as in Example 1 except that the ratio of polystyrene was changed.

In Comparative Example 3, since the addition amount of polystyrene was not sufficient, the effect of suppressing the orientation aimed at by the present invention was small and the elongation was low.

On the other hand, in Comparative Example 4, Δn was smaller than in Comparative Example 1, and the orientation was suppressed.
Since the n of the ler distribution function was 0.95 or less, the yarn formability and workability were poor. Comparative Example 5 A highly oriented undrawn yarn was produced in the same manner as in Example 1 except that the weight average molecular weight of polystyrene was changed. Rosi
Although n of the n-Rammler distribution function was 0.95 or more, the spinning property was good, but Δn was larger than that of Comparative Example 1, and the sufficient effect of suppressing the orientation intended for the present invention was not obtained.

[0052]

[Table 1]

[0053]

The highly oriented unstretched yarn of the present invention increases as the spinning speed increases by dispersing an incompatible polymer having a higher elongational viscosity in the polyester than in the polyester and making the dispersion state specific. It is intended to suppress the molecular orientation and to achieve good yarn forming properties, stretchability and stretch false twisting properties. The dispersion state of the polymer incompatible with the polyester is such that n is 0.95 or more when the cumulative frequency R of the island area of each incompatible polymer is represented by the following equation (1) Rosin-Rammler distribution function. is there.

R = 100 exp (−kx ⁿ ) (1) where R: cumulative frequency x: area of each island of the incompatible polymer Further, POY formed from the polyester composition of the present invention is stretched and stretched. It has favorable characteristics such as improved processability during false twisting and higher crimping characteristics when processed yarn is used.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4L041 AA15 AA20 BA16 CA06 CA39 CA47 CA55 DD01 DD04 DD14 EE02

Claims (3)

[Claims] 1. A birefringence of not less than 25 × 10 ^{-3 and not} less than 70 × 10
^-3 or less, a polyester highly oriented undrawn yarn having the following features 1 to 3. 1. The cross section of the highly oriented undrawn yarn shows a sea-island structure in which polyester is used as a sea component and a polymer that is incompatible with the polyester and has an extensional viscosity at 100 ° C. higher than the polyester is used as an island component. 2. The total area of the island components is 0.5% of the total cross-sectional area of the fiber
Not less than 5%. 3. The cumulative frequency R of the area of each island component is calculated by the following equation (1) Ro
When expressed as a sin-Rammler distribution function, n is 0.9.
5 or more. R = 100 exp (−kx ⁿ ) (1) where R: cumulative frequency x: area of each island of the incompatible polymer 2. The highly oriented undrawn polyester yarn according to claim 1, wherein the polymer incompatible with the polyester is a polystyrene-based polymer. 3. The polymer according to claim 1, wherein the weight-average molecular weight of the polymer incompatible with the polyester is 200,000 or more.
Or the polyester highly oriented undrawn yarn according to 2.