JP2002212839A - Polyester fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that, when the uniformity of the quantity of an oil adhered to a fiber in the longitudinal direction is not considered as before, a stable weaving or knitting process or a stable false-twisting process can not be provided, since the changes of a tensile force and the failures of unwinding are frequently caused in the knitting process or the false-twisting process. SOLUTION: This polyester fiber satisfies a birefringence of 0.04 to 0.12, an adhered oil quantity f0 (wt.%) of 0.3 to 1.5 wt.% measured by a methanol extraction method, and a uniform adhesion parameter F≡(fmax-fmin)/f0<=0.15, wherein fmax and fmin are the maximum value and minimum value, respectively, among values f1 to f10 obtained by measuring the adhered oil quantities of a 1,000 m fiber ten times.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester fiber which contributes to stabilizing the process of melt spinning, improving the quality of the obtained drum, and stabilizing the passability of the subsequent process.

[0002]

2. Description of the Related Art Polyester fibers are widely used for apparel and industrial materials because they have many excellent properties including mechanical properties. Among them, polyethylene terephthalate is the most widely used polyester.

[0003] In apparel applications, including a two-step method of once winding at a winding speed of 3500 m / min or less and stretching it,
A recently developed one-step method for obtaining a drawn yarn in one step at a winding speed of 3500 m / min or more is used. Yarns obtained by any of the methods may be used as they are for woven or knitted fabrics, or may be used for processing such as false twisting. Is usually the case. JP-A-50-126919 or JP-A-59-126919
No. 125933 discloses a technique for stabilizing the processability by defining the amount of the oil agent, but there is no reference to the necessity of applying the oil agent uniformly in the longitudinal direction of the yarn and the technology. Not.

[0004] As the winding speed increases, the spinning speed also increases, and the spinning tension increases dramatically due to the increase in air resistance. In order to reduce the spinning tension, it is necessary to shorten the distance from when the polymer is discharged to when the polymer is bundled, and an oiling nozzle is generally used as a method for applying an oil agent to the bundled yarn. However, when the oil agent is applied, the resistance when the yarn comes into contact with the oiling nozzle is extremely large, and the yarn tension on the oiling nozzle fluctuates due to the fluctuation of the yarn due to interference of the accompanying airflow of the yarn. Fluctuations in the amount of oil agent adhesion in the longitudinal direction increase. Also, in order to reduce the resistance on the oiling nozzle, a larger amount of oil is generally applied as compared with the two-step method, but this also increases the unevenness of the oil applied amount in the longitudinal direction of the yarn.

[0005] When such a polyester fiber having a large variation in the adhesion amount of the oil agent is subjected to a post-process such as weaving or false twisting, particularly in the false twisting process, there is a problem such as twisting-out or yarn breakage due to twisting tension fluctuation. May occur.

[0006]

SUMMARY OF THE INVENTION In order to solve the problems of the prior art, when obtaining a drawn fiber in one step, the amount of oil applied is suppressed to a minimum level required in a subsequent step, and the oil is applied to the yarn. As a result of earnestly studying a technique for stabilizing the post-process by imparting it uniformly in the longitudinal direction, the present invention has been achieved.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a polyester
In the fiber, the birefringence is 0.04 to 0.12, and methanol
Oil adhesion amount f measured by extraction₀(% By weight) 0.3 to
Measure the weight of oil agent with 1.5% by weight and length of 1000m 10 times
Obtained value f₁~ F_Ten(% By weight) _max,
The smallest one f_minAs the uniform adhesion parameters
TA F≡ (f_max-f_min) / f₀Satisfies ≦ 0.15
Can be achieved by polyester fibers.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

The polyester in the present invention includes polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene naphthalate and the like, and is particularly effective for polyethylene terephthalate. The polyester may be one in which a part of the dicarboxylic acid component and a part of the diol component are each substituted with another copolymerizable component in a range of 10 mol% or less. They may also contain additives such as matting agents, antistatic agents, pigments and the like.

In the present invention, the birefringence (Δn) is set to 0.04 to 0.12
And particularly preferably 0.07 to 0.10. If Δn is less than 0.04, the obtained fiber will not be a fiber that can withstand practical use as it is in the subsequent step. In addition, when subjected to the false twisting step, it is necessary to reduce the twisting tension in order to obtain the desired physical properties. Particularly, in high-speed processing, the tension is low, and thus the processed yarn may be frequently broken, which is not preferable. On the other hand, when Δn exceeds 0.12, the twisting tension becomes too high, and the processing thread is frequently broken, and the disc, belt, thread guide, and the like become excessively worn.

In the present invention, the amount of oil agent adhered to the polyester fiber
f ₀ must be 0.3-1.5% by weight, and further 0.3-0.8%
% By weight. If the amount is less than 0.3% by weight, the amount of the oil agent is too small, so that the resistance on the yarn path guide and the heater is increased in the subsequent step, and the fluctuation of the yarn tension frequently increases, which is not preferable. Further, when the content is 1.5% by weight or less, it is possible to reduce stains in a subsequent step and to obtain a stable passage property.

[0012] uniformly in the present invention attached parameters F≡ (f _max -
f _min ) / f ₀ needs to be 0.15 or less. If it exceeds 0.15, the uniformity in the longitudinal direction of the oil agent adhering to the yarn is poor, so that the unwinding property is poor in the process of forming a woven or knitted fabric as it is, or the unraveling when subjected to the false twisting process is performed. Insufficiency of the winding property and fluctuation of twisting tension frequently occur, which often causes yarn breakage, which is not preferable.

In the present invention, the tension T ₂ when the polyester fiber is run while being brought into contact with the specular friction member is in the range of T _2a × 0.75 to T _2a × 1.25 with respect to the average value T _{2a of the} tension,
And it is preferable tension variation T _s between the yarn length 5cm is T _2a × 0.3 or less. Thereby, it is possible to suppress a fluctuation in tension and the like in a later step such as a weaving step or a false twisting step, and to make the step more stable.

Next, the effects of the present invention will be described using embodiments.
This example is one of the embodiments of the present invention, and the present invention is not limited thereto.

[0015]

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

A. Birefringence (Δn) The birefringence was calculated by measuring the retardation and optical path length of a single yarn with an OLYMPUS BH-2 polarizing microscope.

B. Amount of oil agent (f ₀ ) The yarn is measured for 10,000 m and its weight is measured. Next, this was left standing in refluxing methanol for 3 hours, and then the yarn was taken out.
The remaining methanol was evaporated to dryness, the weight was measured, and the weight% was calculated.

C. Attached amount of oil agent (f _{1 to} f ₁₀ ) Yarns are weighed at random every 1000 m and their weight is measured. Next, this was allowed to stand in refluxing methanol for 3 hours, and then the yarn was taken out. The remaining methanol was evaporated to dryness, the weight was measured, and the weight% was calculated.

[0019] D. Tension of yarn is traveling in contact with the mirror surface friction body _{(T 2a, T 2max, T} 2min, T s) having a diameter of 35mm cylindrical, surface roughness arithmetic average R _a is 0.14μ
27.5 mm of thread on the side of the mirror-like frictional body, converted to an angle of 90 °
Contact, control the tension on the entry side to 10 cN / dtex and measure the tension on the exit side when measured at a yarn speed of 2.5 m / min for 1 minute,
The average value T _{2 a,} the maximum value T _2max, the minimum value was T _2min, and. The fluctuation width when the tension variation between the yarn to 5cm travel is maximized and the T _s.

E. Yarn-forming properties The number of tension fluctuations exceeding an average of ± 5% of the untwisting tension per 24 hours of processing time, the number of broken yarns per 24 hours of processing time, and the number of fluffs obtained per 2,000 m of processed yarn Is measured, and those with one or more breaks in the processed yarn are evaluated as x, and those with 0 breaks are performed according to the criteria in Table 1, and
△ and △ were accepted.

[0021]

[Table 1] Example 1 100 parts of terephthalic acid and 50 parts of ethylene glycol were subjected to an esterification reaction according to a conventional method, and after the reaction, antimony trioxide was obtained.
0.03 part, 0.01 part of cobalt acetate and phosphoric acid were added so that the content of phosphorus atoms in the polymer finally obtained was 100 ppm, and the polycondensation reaction was completed. The obtained polyethylene terephthalate was treated at 25 ° C with orthochloropheno-
The intrinsic viscosity measured in the reactor was 0.67. After drying the obtained chip, spinning at a spinning temperature of 290 ° C. according to a conventional method, and cooling and solidifying, using an oiling nozzle having a yarn length of 7 mm at a position where the yarn temperature becomes 50 ° C. or less, the portion where the yarn enters the oiling nozzle With a clearance angle of 3.5 ° and a clearance angle of 6 ° at the outgoing part, 5
An oil solution having a concentration of% by weight was applied, and at a position 3 m from the cooling and solidification point, the interlaced nozzle was interlaced at a pressure of 2 MPa. The birefringence of this fiber, oil adhesion f ₀ , uniform adhesion parameter F
Are shown in Table 2. Using the obtained fiber as a raw yarn, a draw false twisting was performed at a processing speed of 1000 m / min, a processing magnification of 1.9 times, and a processing temperature of 220 ° C., to obtain a polyester processed yarn of 84 dtex-36 filament. Table 2 shows the results and the determination based on the determination criteria shown in Table 1. No fluff and yarn breakage occurred in the yarn making process, and there was no particular problem during false twisting, and there was no problem with the quality of the obtained processed yarn.

Examples 2, 3, 4, and 5 Interlaced air pressure, winding speed, and processing magnification were 2.7 MP.
a, 4100 m / min, 1.55 times (Example 2), 3.3 MPa, 5000 m / min, 1.
25 times (Example 3), 3.6 MPa, 5300 m / min, 1.20 times (Example 4),
Example 1 except that 4 MPa, 6500 m / min, and 1.05 times (Example 5)
Tables 2 and 3 show the results of spinning and drawing false twisting performed in accordance with the above. There was no fluff or yarn breakage in the yarn making process, and there was no particular problem during false twisting, and there was no problem with the quality of the processed yarn obtained.

Examples 6, 7, 8 and 9 The amount of the oil applied was 0.31% by weight (Example 6), 0.36% by weight (Example
Tables 3 and 4 show the results of spinning and drawing false twisting according to Example 2 except that 7), 0.80% by weight (Example 8) and 1.50% by weight (Example 9) were used. There was no fluff or yarn breakage in the yarn making process, and there was no particular problem during false twisting, and there was no problem with the quality of the processed yarn obtained.

Example 10 The results of spinning and drawing false twisting in accordance with Example 2 except that the concentration of the oil agent was 7.5% by weight are shown in Table 4. There was no fluff or yarn breakage in the yarn making process, and there was no particular problem during false twisting, and there was no problem with the quality of the processed yarn obtained.

Examples 11, 12, 13, 14 and 15 The yarn lengths of the oiling nozzles were 8.5 mm (Example 10), 10 mm (Example 12), 5.5 mm (Example 13) and 4.0 mm (Example 14). ), 2.0mm
Tables 4 and 5 show the results of spinning and drawing false twisting performed in the same manner as in Example 2 except that Example 15 was used. There was no fluff or yarn breakage in the yarn making process, and there was no particular problem during false twisting, and there was no problem with the quality of the processed yarn obtained.

Example 16 The relief angle of the portion where the yarn emerges from the oiling nozzle is 7.5
Table 5 shows the results of spinning and drawing false twisting performed in the same manner as in Example 2 except that the temperature was changed to °. There was no fluff or yarn breakage in the yarn making process, and there was no particular problem during false twisting, and there was no problem with the quality of the processed yarn obtained.

Comparative Examples 1 and 2 Interlace pressure / air pressure / winding speed / working magnification was 1.5 MPa / 2
600m / min / 2.2 times (Comparative Example 1), 5.5MPa / 7500m / min / 1.02 times (Comparative Example 2) and birefringence of 0.03 (Comparative Example 1), 0.14 (Comparative Example 2)
Table 6 shows the results of spinning and drawing false twisting performed in the same manner as in Example 1, except that Fluff in the yarn-making process,
No yarn breakage occurred, but twisting tension fluctuation, yarn breakage, and fluff of the processed yarn occurred frequently during false twisting.

Comparative Examples 3 and 4 0.25% by weight (Comparative Example 3), 1.60% by weight (Comparative Example 4)
Table 6 shows the results of spinning and drawing false twisting performed in the same manner as in Example 2 except that Fluff in the yarn-making process,
No yarn breakage occurred, but twisting tension fluctuation, yarn breakage, and fluff of the processed yarn occurred frequently during false twisting.

Comparative Examples 5 and 6 The results of spinning and drawing false twisting according to Example 2 except that the oil agent concentration was 15% by weight (Comparative Example 5) and 20% by weight (Comparative Example 6) are shown in the table. See Figure 7. No fluff and yarn breakage occurred in the yarn making process, but during false twisting, fluctuations in twisting tension, yarn breakage and fluffing of the processed yarn occurred frequently.

Tables 2 to 7 show Examples 1 to 16 and Comparative Examples 1 to 6.
The birefringence of the fiber obtained in the above, the oil adhering amount f ₀ , the uniform adhering parameter F, the average value T _2a , the maximum value T _2max , and the minimum value of the tension when the fiber is caused to travel in contact with the mirror frictional body
T _2min , the maximum value T _s of the instantaneous tension fluctuation during traveling 5 cm, the number of times of twisting tension when performing draw false twisting using the obtained fiber, the number of times of processing yarn breakage, the obtained processing Thread 2000
The number of fluffs in m and the pass / fail judgment are shown.

[0031]

[Table 2]

[0032]

[Table 3]

[0033]

[Table 4]

[0034]

[Table 5]

[0035]

[Table 6]

[0036]

[Table 7]

[0037]

According to the present invention, the uniformity of the amount of the oil agent adhered to the longitudinal direction of the yarn is defined, and the variation in the entirety and the local variation is suppressed, whereby the tension fluctuation and the drum in the weaving or false twisting process are suppressed. It is possible to suppress unwinding failure during unwinding, to provide stable weaving or false twisting without breakage of processed yarn, and also to suppress deterioration in quality of the obtained processed yarn such as fluff. Becomes possible.

Claims (3)

[Claims] 1. A polyester fiber having a birefringence of 0.1.
04-0.12, oil agent measured by methanol extraction
Adhesion amount f₀(Weight%) 0.3-1.5% by weight and 1000m long oil
Value obtained by measuring the amount of agent adhesion 10 times f₁~ F_Ten(% By weight)
The largest one is f _maxF the smallest one_minAs this
These are the uniform adhesion parameters F≡ (f_max-f_min) / f₀≤0.15
Polyester fiber characterized by satisfying. 2. The polyester fiber according to claim 1, wherein the amount of the oil agent is 0.3 to 0.8% by weight. 3. In a polyester fiber, when the fiber is run in contact with a mirror-like frictional body having an arithmetic average surface roughness _Ra of 0.14 μ, the tension T ₂ satisfies the formula 1, and the yarn length is 5 cm. polyester fibers according to claim 1 or 2, wherein the tension variation T _s is to satisfy the equation 2 in. 0.75 × T _2a ≦ T ₂ ≦ 1.25 × T _2a・ ・ ・ (Equation 1) (where T _2a is the average value of T ₂ ) T _s ≦ T _2a × 0.3 ・ ・ ・ ・ ・ ・ ・ ・ (Equation 2)