JP3260685B2 - Method for producing polyester filament yarn - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for efficiently producing a polyester filament yarn having a high uniformity, which is capable of obtaining a fabric having a high shrinkage and a supple feel, and which is less likely to cause spots. It is about the method.

[0002]

2. Description of the Related Art Conventionally, low-crystalline polyester yarns are characterized by a high shrinkage and a supple feel.
In melt-spinning a low-crystalline polyester, spinning conditions for suppressing crystallization are employed in order to make the most of such features. For example, melt spinning at low speed,
Then, a method of stretching at a low temperature is employed.
However, not only has the drawback that the productivity is low due to the low spinning speed, but also when the yarn spun at a low speed is drawn, the drawing mode becomes neck drawing. If not, stretch spots are likely to occur,
Even if the stretching temperature is lowered, there is naturally its limit,
The performance of the obtained filament yarn was limited. On the other hand, the yarn spun at a high speed can be drawn even at a relatively low temperature and the productivity is improved.However, when the low-crystalline polyester is continuously drawn after high-speed spinning, the undrawn yarn is heated with a heating roller. In addition to the problem that the yarn is liable to be stably spun due to a large sway during preheating, the crystallization proceeds on the preheating roller to obtain a filament yarn having an intended performance. There was a problem that can not be.

[0003]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, provides a fabric having a high shrinkage and a supple feel, and achieves uniformity in which spots and the like are hardly generated. An object of the present invention is to provide a method capable of efficiently producing an excellent polyester filament yarn.

[0004]

According to the study of the present inventor, the above-mentioned object is achieved when the third component is 8 to 8% based on the total acid component.
A 40 mol% copolymerized polyethylene terephthalate-based polyester is melt-discharged from a spinneret, and the discharged yarn is cooled and solidified to a temperature equal to or lower than the glass transition temperature (Tg + 10 ° C.) of the polyester, and then ambient temperature (T ₁ ) Is passed through a heating zone satisfying the following formula in a non-contact state, and then is taken up at a speed of 3500 to 4500 m / min by a heating take-off roller having a temperature (T ₂ ) satisfying the following formula. It has been found that it can be achieved by a method for producing a polyester filament yarn excellent in uniformity and feeling, characterized in that it is stretched at a draw ratio of 1.1 to 2.0 times continuously without winding the strip continuously. Was. Tg + 20 ° C ≦ T ₁ ≦ Tg + 80 ° C. Tg ≦ T ₂ ≦ Tg + 30 ° C.

[0005]

DETAILED DESCRIPTION OF THE INVENTION The polyester used in the present invention is a polyethylene terephthalate polyester obtained by copolymerizing a third component with 8 to 40 mol%, preferably 10 to 20 mol%, based on the total acid components. Examples of preferably used copolymerization components include, for example, isophthalic acid, bisphenol A, bisphenol A ethylene oxide adduct, diethylene glycol, neopentyl glycol, and the like, and isophthalic acid is particularly preferable.
The intrinsic viscosity IV of the polyester (measured at a temperature of 30 ° C. in an orthochlorophenol solvent) is not particularly limited and may be appropriately selected depending on the use of the obtained filament yarn. Especially 0.6 ~
About 1.2 are used.

In the present invention, first, the copolymerized polyester is melted and discharged from a spinneret, and a cooling air is blown onto the melted and discharged yarn once to lower the glass transition temperature (Tg + 10 ° C.) of the polyester. After cooling and solidifying to a temperature, preferably a temperature of (Tg-20 ° C) or more and (Tg + 10 ° C) or less, the air is passed through the heating zone in a substantially non-contact state, and the air loaded on the yarn during the passage is heated. The first stretching is performed by the effect of resistance and heat.

Here, the discharge yarn is once (Tg + 10 ° C.)
If not cooled to the following temperature, since the drawing in the heating zone is flow drawing, the yarn is simply thinned and yarn spots are easily generated, and the heating roller which is the next step At the time of take-off, the swing of the yarn becomes large and not only cannot be stably spun, but also the yarn is apt to break, which is not preferable. If the temperature of the discharged yarn is excessively low and the temperature of the discharged yarn is too low, it is difficult to perform uniform and sufficient stretching in the zone unless the length of the next heating zone is increased, resulting in insufficient yarn physical properties. It is desirable that the yarn temperature be (Tg-20 ° C.) or more, since it is liable to occur.

Next, the ambient temperature (T ₁ ) in the heating zone
Is important in the range of (Tg + 20 ° C.) to (Tg + 80 ° C.), preferably (Tg + 20 ° C.) to (Tg + 40 ° C.). When the ambient temperature is lower than (Tg + 20 ° C.), In the same way as high-speed take-off with a conventional heating roller,
Not only is it difficult to stably spin, but the feel becomes hard, which is not preferable. On the other hand, if the ambient temperature exceeds (Tg + 80 ° C.), the crystallization of the yarn proceeds and not only the shrinkage property decreases, but also the feeling becomes hard, which is not preferable.

The heating zone may have any shape as long as the yarn is of a non-contact type, but usually a cylindrical shape is used. Also, any heating method such as a far-infrared heater, a heater heating type using a heat medium sealed therein, and the like can be used. The length of the heating zone is about 50-300 cm, especially 8
It is preferably about 0 to 150 cm.

[0010] The yarn passed through the heating zone is taken up by a heating take-up roller after applying an oil agent as required. This take-up speed must be in the range of 3500-4500 m / min. If it is less than 3500 m / min, the air resistance applied to the yarn in the heating zone becomes insufficient and the yarn is stretched. Since this does not occur sufficiently, the yarn sways frequently, and it becomes impossible to spin stably. On the other hand, if the take-up speed exceeds 4500 m / min, the orientation crystallization by high-speed spinning proceeds too much, and the feeling becomes too hard, which is not preferable.

The drawn undrawn yarn must be continuously drawn without being once wound. In the present invention, the above-mentioned drawing roller is used as a heating roller to preheat the yarn at the same time that the drawn yarn is drawn. Stretch between rollers. Therefore, the temperature (T ₂ ) of the heating take-off roller must be equal to or higher than the glass transition temperature (Tg) and equal to or lower than (Tg + 30 ° C.), preferably (Tg + 10 ° C.) to (Tg + 20 ° C.). When the temperature is lower than Tg, the preheating of the yarn becomes insufficient and the unevenness in drawing tends to occur, which is not preferable.
If the temperature exceeds (Tg + 30 ° C.), crystallization is excessively advanced during stretching, and the high shrinkage properties aimed at by the present invention cannot be obtained, and a supple hand cannot be achieved.

The stretching ratio (DR) at this time is as follows.
It is necessary to make it 1 to 2.0 times, preferably 1.2 to 1.5 times. When the draw ratio is less than 1.1 times, the orientation of the obtained yarn becomes insufficient, the hand tends to be hardened, and the strength becomes insufficient. On the other hand, when the ratio exceeds 2.0 times, fluff due to breakage of single yarn during stretching increases, and crystallization proceeds too much, so that the feeling becomes inferior.

The thus drawn yarn can be used as it is, but the obtained yarn has a birefringence Δn of 0.3.
The heat treatment is preferably performed at a temperature in a range of 13 or more and a density satisfying 1.365 g / cm ³ or less. For this purpose, the stretching roller may be a heating roller or another heating roller may be provided, but the former is more preferable because it is simpler. Heat stretching roller temperature is 110
It is desirable that the temperature be higher than the temperature of the take-off roller at about 150 ° C. The birefringence Δn of the heat-treated yarn is 0.1
If the density is less than 3 or the density exceeds 1.365 g / cm ³ , the texture of a woven or knitted fabric tends to be hard.

[0014]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Examples 1 to 5 and Comparative Examples 1 to 8 A polyethylene terephthalate copolymer polyester (Tg) having an intrinsic viscosity of 0.64 and a copolymer of 10% by mole of isophthalic acid.
= 70 ° C), extruded from a spinneret having a diameter of 0.3 mm and a discharge hole with 12 holes, and blown with cooling air to the discharge yarn to once cool and solidify to the temperature shown in Table 1. , Passed through the heating zone shown in Table 1 in a non-contact state, and then taken up with the heating take-up roller shown in Table 1 at the speed shown in Table 1, and the drawn undrawn yarn was shown with a drawing roller heated to 120 ° C. A drawing heat treatment was performed at the magnification described in Example 1 to obtain a filament yarn of 50 denier / 12 filaments. Table 1 shows the evaluation results of the obtained yarns.

In addition, feeling (hardness, flexibility, swelling)
Converts the obtained filament yarn into partially oriented yarn (POY) 8
0 denier / 36 filaments and mixed fiber (5 entanglements /
m), and the obtained mixed yarn is subjected to a trichotin structure (warp density 1).
55 threads / 37.9 mm, weft density 240 threads / 37.9 m
m), and the obtained raw fabric is then woven at 96 ° C for 3 hours.
After applying a shrinkage heat treatment at 130 ° C. for 10 minutes and at 195 ° C. for 45 seconds for 10 seconds at 135 ° C. for 20 minutes using a disperse dye.
Stained for minutes. The resulting fabric was evaluated for sensory (tactile sensation) by five panelists, and represented by the following criteria. Hardness: Feeling when squeezed by hand ○: Soft ×: Hard Suppleness: Clinging to finger when squeezed by hand (followability) ○: Good responsiveness to finger ×: Poor responsiveness to finger Swelling: Raw fabric width shrinkage ratio after shrinkage heat treatment ○: 16% or more ×: less than 16%

The process condition was represented by the number of times of yarn breakage per day when the spinning machine with 6 spindles was operated for 3 days. Stretch unevenness is obtained by knitting the obtained filament yarn at 100 ° C. under normal pressure.
Judgment was made based on the degree of stained spots (striated spots) when stained with. ：: good △: spots slightly observed, but acceptable
×: Not possible Further, the dry heat shrinkage was measured by treating in an air thermostat at 150 ° C. for 30 minutes.

[0018]

[Table 1]

[0019]

[Table 2]

[0020]

According to the method of the present invention, a low-crystallinity polyethylene terephthalate-based copolymerized polyester is taken at a high speed and then continuously stretched in a non-contact zone heated to a specific temperature in advance. Since the yarn is passed in the state, the yarn sway at the time of take-up is suppressed, so that the yarn can be stably spun and the subsequent stretching can be made uniform. As a result, the filament yarn obtained by the present invention has a high shrinkage property, is free of unevenness in drawing, is excellent in uniformity, and can be obtained as a fabric having a supple hand, and its industrial value is extremely large. There is.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-2-139409 (JP, A) JP-A-59-112025 (JP, A) JP-A-9-49119 (JP, A) JP-A-51- 99112 (JP, A) JP-A-51-82020 (JP, A) JP-A-62-85020 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) D01F 6/62 301- 308 D01F 6/82 301-6/86 307 D01F 6/92 301-309

Claims (2)

(57) [Claims] The third component is 8 to 4 based on the total acid component.
A 0 mol% copolymerized polyethylene terephthalate-based polyester is melt-discharged from a spinneret, and the discharged yarn is cooled and solidified to a temperature not higher than the glass transition temperature (Tg + 10 ° C.) of the polyester, and then ambient temperature (T ₁ ) Is passed through a heating zone satisfying the following formula in a non-contact state, and then is taken up at a speed of 3500 to 4500 m / min by a heating take-off roller having a temperature (T ₂ ) satisfying the following formula. A method for producing a polyester filament yarn having excellent uniformity and texture, wherein the filament is continuously stretched without being wound once and stretched at a stretch ratio of 1.1 to 2.0 times. Tg + 20 ° C ≦ T ₁ ≦ Tg + 80 ° C. Tg ≦ T ₂ ≦ Tg + 30 ° C. 2. The discharge yarn (Tg−20 ° C.) or more (Tg
The method for producing a polyester filament yarn excellent in uniformity and feeling according to claim 1, wherein the polyester filament yarn is passed through a heating zone after being cooled and solidified to a temperature of + 10 ° C or lower.