JP2001279528A - Method for producing polyester fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for efficiently producing a polytrimethylene terephthalate having excellent qualities free from unevenness of performances such as dyeability, strength, etc., controlling occurrence of saddle of winding form and burst in a spinning/drawing process. SOLUTION: This method for producing a polyester fiber comprises melting and extruding a polytrimethylene terephthalate-based polyester having 0.4-1.5 intrinsic viscosity from a spinneret, passing the extruded yarn through an air sending zone, cooling and solidifying the yarn, taking off the yarn at 500-4,000 m/minute velocity, then taking up the yarn at 4.5-6.0 degree twill angle of winding under 0.044-0.071 cN/dtex winding tension and a drawing process for hot drawing the obtained undrawn yarn and taking up the yarn under 0.071-0.132 cN/dtex winding tension to give the objective drawn yarn.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polyester fiber made of polytrimethylene terephthalate and having a small amount of stain. More specifically, the production of polytrimethylene terephthalate fiber with excellent performance such as dyeability and strength by suppressing the height and burst of the wound shape during winding in the spinning / drawing process. To possible manufacturing methods.

[0002]

2. Description of the Related Art Polytrimethylene terephthalate has a low elastic modulus, shows a soft feeling, and has properties similar to polyamide such as excellent elastic recovery and dyeing properties, as well as light resistance, heat setting property, dimensional stability, and the like. It has properties similar to polyethylene terephthalate, such as low water absorption, and it has been proposed to utilize these features in many fields such as BCF carpets and brushes (Japanese Patent Application Laid-Open Nos. 9-3724 and 8). No. 173244,
JP-A-5-262882).

[0003] The use of polytrimethylene terephthalate fibers improves the properties of polyamide fibers, such as low light resistance and heat setting properties, while having a low elastic modulus (soft feel) and excellent elastic recovery. It is possible to provide polyamide-like fibers such as properties and ease of dyeing, and therefore, there is a high possibility of being replaced with existing polyamide fibers.

[0004] The process for producing polytrimethylene terephthalate fiber which has been proposed to date is from 300 to 4000.
This is a method in which an undrawn yarn melt-spun at m / min is hot-drawn at one or more stages at a temperature equal to or higher than the glass transition temperature of the undrawn yarn after winding once or continuously without winding. For example, Japanese Patent Application Laid-Open No. 52-5320 discloses a method of stretching a drawn undrawn yarn at a temperature of 20 to 80 ° C. at a ratio of 70 to 99.9% of a maximum drawing ratio at the temperature. 5
In Japanese Patent Application Laid-Open No. 2-8123, the birefringence Δn is 0.0025.
JP-A-58-104216 discloses a method in which the undrawn yarn is once wound or continuously drawn without being wound, and then heat-treated by contacting with a heated solid at 140 to 180 ° C. An undrawn yarn having a birefringence Δn of 0.035 or more melt-spun at 2,000 m / min or more at a temperature of 35 to 80
Stretching method using a heat roller at a temperature of 0 ° C .;
No. 2526 discloses a method in which a melt-discharged yarn is solidified after passing through a heat retaining region to obtain an undrawn yarn, which is subjected to continuous drawing heat treatment without being once wound, and then wound. Have been.

[0005] However, according to the study of the present inventors,
In particular, in the method in which spinning and drawing are performed separately, the resulting polytrimethylene terephthalate fiber has a strong shrinkage force,
For example, it has been found that there is a problem in the process stability that, when wound in a cheese shape, the wound shape tends to have an ear height, and when wound for a long time, a burst is likely to occur.
Furthermore, even if the film could be wound, it is presumed to be due to the poor shape of the film, and there was a problem that periodic dyeing spots were likely to occur when dyeing.

[0006]

SUMMARY OF THE INVENTION The present invention has been made on the background of the above-mentioned prior art, and an object of the present invention is to obtain a good winding appearance stably, and to suppress the occurrence of stain spots even when dyed. ,
Moreover, it is an object of the present invention to provide a method for producing a polytrimethylene terephthalate fiber having good strength.

[0007]

According to the study of the present inventors, the above-mentioned object is achieved by a polytrimethylene terephthalate having an intrinsic viscosity of 0.4 to 1.5, which is substantially composed of trimethylene terephthalate units. The polyester is melt-extruded from a spinneret, and the discharged yarn is cooled and solidified by passing through a blowing area, and then 500 to 4000 m via a roller.
/ Min, then winding tension 0.044 ~
Under 0.071 cN / dtex, winding angle 4.5
A spinning step of winding at 6.0 ° to obtain an undrawn yarn, and drawing the undrawn yarn in one or more stages by hot drawing and then winding at a winding tension of 0.071 to 0.132 cN / dtex to obtain a drawn yarn. A method for producing a polyester fiber comprising a drawing step. It has been found that this can be achieved.

[0008]

Embodiments of the present invention will be described below in detail. The polyester used in the present invention is a polytrimethylene terephthalate-based polyester whose repeating units are substantially composed of trimethylene terephthalate units. The term “substantially” as used herein means that even if it is a polytrimethylene terephthalate homopolyester, it is within a range that does not impair the effects of the present invention, usually 10 mol% or less, preferably 5 mol% based on all acid components. The following ratio indicates that a copolyester having a copolymer component may be used. Examples of the copolymerizable component include acid components such as isophthalic acid, succinic acid, adipic acid, 2,6-naphthalenedicarboxylic acid, 5-sodium sulfoisophthalic acid, and tetrabutylphosphonium 5-sulfoisophthalate, and 1, Examples include glycol components such as 4-butanediol, 1,6-hexanediol, and cyclohexanedimethanol, and hydroxycarboxylic acid components such as ε-caprolactone and 4-hydroxybenzoic acid. Furthermore, in the case of a long-chain glycol component such as polyoxyethylene glycol and polytetramethylene glycol, 10% by weight or less based on the weight of the polyester,
Preferably, it may be copolymerized at a ratio of 5% by weight or less.

If necessary, various additives such as matting agents, heat stabilizers, defoaming agents, tinting agents, flame retardants, antioxidants, ultraviolet absorbers, infrared absorbers, crystal nuclei. An agent, a fluorescent whitening agent and the like may be added during the polymerization of the polyester and copolymerized or mixed, or may be added to the polyester after polymerization and mixed.

The intrinsic viscosity of such a polyester [I
V] is required to be in the range of 0.4 to 1.5, preferably 0.8 to 1.2, from the viewpoint of spinning process stability and mechanical properties of the obtained drawn yarn. If the intrinsic viscosity is less than 0.4, the molecular weight is too low and the strength is reduced, which is not preferable. When the intrinsic viscosity is 0.4 or more and less than 0.8, crystallization proceeds due to aging because the stability of the undrawn yarn wound at a low spinning speed of 1500 m / min or less is insufficient. 0.8 or more is preferable because not only can the drawing be stably performed, but also the quality of the obtained drawn yarn tends to be uneven. On the other hand, if the intrinsic viscosity exceeds 1.5, the melt viscosity becomes too high, and melt fracture or poor spinning occurs during spinning, which is not preferable.

In the present invention, the above-mentioned polytrimethylene terephthalate-based polyester is melt-extruded from a spinneret, and the discharged yarn is cooled and solidified by passing through a blowing area, and then at a speed of 500 to 4000 m / min via a roller. Take over.

[0012] If the melt extrusion temperature (spinning temperature) is too high, coloring and strong elongation degradation due to thermal decomposition of the polymer tend to occur, while if too low, it becomes difficult to obtain a fiber with sufficient strong elongation. The range of 250 to 285 ° C is appropriate,
Particularly, the range of 260 to 280 ° C is preferable.

It is preferable that the melt-discharged yarn is passed through a heat retaining region to suppress rapid cooling before passing through a blowing region to be cooled and solidified. By passing through this heat retaining region, the generation of fine crystals and highly oriented amorphous parts due to rapid cooling of the polymer is suppressed, and an amorphous structure that can be easily stretched in the stretching step described below can be formed, Fibers having physical properties can be obtained stably. In particular, the polytrimethylene terephthalate-based polyester targeted by the present invention has a much faster crystallization rate as compared to polyesters such as polyethylene terephthalate. This is an extremely effective method for suppressing the formation of highly oriented amorphous portions. The ambient temperature is suitably in the range of 80 to 220 ° C, especially 100 to 220 ° C, especially 1 to 220 ° C.
A range from 50 to 200C is suitable. Further, the length of the heat retaining region is suitably in the range of 5 to 80 cm, particularly 10 to 40 cm.

On the other hand, if the air volume in the air blowing region is too small, it is difficult to sufficiently cool the fiber, and there is a tendency that the physical properties of the fiber vary and the yarn spots become severe. It is appropriate to set the range to 0.5 to 2.5 m ³ / min, particularly preferably to 1.0 to 2.0 m ³ / min, since the wrinkles become severe and the spinnability decreases.

The cooled and solidified yarn is passed through a roller at a speed of 500 to 4000 m / min, preferably 1500 to 4000 m / min.
It needs to be picked up at a speed of 3500 m / min. Here, when the take-off speed is less than 500 m / min, the spinning stability is good, but productivity is greatly reduced, which is not preferable. On the other hand, if it exceeds 4000 m / min, the orientation of the amorphous part and the partial crystallization of the obtained undrawn yarn are excessively advanced,
In the stretching step described below, it is difficult to stretch at a sufficient stretching ratio, and it is difficult to obtain a stretched yarn having sufficient strength under stable productivity, which is not preferable. In addition,
The number of rollers at the time of taking off is not particularly limited.
Although a plurality of the above may be used, they are usually taken out via a pair of rollers. At this time, the rotation speed (peripheral speed) of the first roller and the second roller may be different within a range that does not impair spinning stability, but is usually set to the same speed.

Next, the taken-up yarn is taken up by a take-up device.
0.071 cN / dtex range, preferably 0.04
The yarn is once wound as an undrawn yarn in a range of 9 to 0.062 cN / dtex and with a winding angle of 4.5 to 6.0 degrees, preferably 5.0 to 5.8 degrees. When the winding tension is less than 0.044 cN / dtex, it is not preferable because the yarn is easily wound around the take-up roller. On the other hand, if it exceeds 0.071 cN / dtex, the polytrimethylene terephthalate-based polyester has a high elastic recovery performance, which causes tightness in winding and deforms the wound shape, and the drawn yarn obtained therefrom has strength and dyeing properties. This is not preferable because spots are likely to be generated. The method of controlling the winding tension is arbitrary, but can be easily achieved by, for example, setting the speed of the winder lower than the speed of the final roller of the take-up roller group.

On the other hand, if the winding angle is less than 4.5 degrees, the yarn tends to fall off and cannot be stably wound. A large shrinkage force deforms the winding shape, causing variations in the contact area between the winding surface and the touch roller, reducing the contact area with the touch roller, and as a result, the contact pressure tends to concentrate and burst, which is preferable. Absent.

In the above-mentioned spinning step, the yarn may be entangled through a tangling device such as an interlace, if necessary. At that time, the entanglement imparting device may be located before or after the take-up roller, or may be located at an intermediate position when taking up via a plurality of roller groups. Further, the confounding processing may be performed at two or more positions as needed.

In the present invention, the undrawn yarn once wound in the above-mentioned spinning step is subjected to one-stage or multi-stage heat drawing, and then to a winding tension of 0.071 to 0.132 cN / dtex, preferably 0.080 to 0. Wind at 120 cN / dtex.

If the drawing temperature is too low, it is difficult to perform uniform drawing and the fiber performance tends to be uneven, while if it is too high, fusion tends to occur.
A range of 0 ° C is appropriate, and a range of 60 to 80 ° C is particularly preferable. On the other hand, if the draw ratio is too low, the fiber properties become insufficient, while if it is too high, fluff or breakage tends to occur at the time of drawing. Therefore, the maximum draw ratio (DRMAX) of the undrawn yarn at the drawing temperature is high. ) Of 0.6 to 0.95
It is appropriate to stretch the film by a factor of, for example, 0.7 to 0.9.

The drawn yarn has a temperature of 100 to 170 ° C., preferably 120 to 15 ° C. in order to suppress the boiling water shrinkage.
Heat set at 0 ° C. When the heat setting temperature is lower than 100 ° C, the setting effect is insufficient and the boiling water shrinkage tends to increase. On the other hand, when the temperature exceeds 170 ° C, the yarn is fused to the heater and single yarn breakage or breakage occurs. It happens frequently. The heater used in the heat setting is not particularly limited, and a conventionally known heater such as a plate heater, a heating roller, and a non-contact heater can be used.

The heat-set yarn can be adjusted, for example, by setting the overfeed (the ratio of the speed of the winding roller to the speed of the final stretching roller to 3 to 10%) to a winding tension of 0.071 to 0.071%. 0.132cN / dte
x, preferably 0.080 to 0.120 cN / dtex
Need to be wound up. Here, the winding tension is 0.071
If it is less than cN / dtex, it is difficult to wind it stably. Conversely, if it exceeds 0.132 cN / dtex, physical properties of the drawn yarn obtained by drawing between the final roller and the winder It is not preferable because it varies.

The polyester fiber obtained by the production method of the present invention described above can be obtained, for example, when the elongation is adjusted to 10 to 45%, which is a general elongation for clothing.
The strength is 3.0 to 5.0 g / de, the elastic recovery at 10% elongation is 85 to 100%, and the peak value of thermal stress is 0.265.
~ 0.883 cN / dtex, boiling water shrinkage 5-17%
Fibers having a performance in the range of

According to a more detailed study of the inventor,
If the stretching heat setting conditions are appropriately selected so that the peak value of the thermal stress is 0.353 g / dtex or more and the elongation is 35% or less, the elastic recovery performance is improved and the elastic recovery at 10% elongation is improved. And a woven or knitted fabric having excellent stretchability can be obtained.
If it exceeds 706 cN / dtex, the elastic recovery rate is improved, but the shrinkage is too large, so that the obtained fabric tends to be hard even if the woven knitting density is lowered. If the boiling water shrinkage rate is less than 7%, Further, it has been found that even if the peak value of the thermal stress is sufficiently high, the amount of shrinkage becomes too small, so that the obtained fabric tends to be paper-like. Further, the peak temperature of the thermal stress is suitably in the range of 150 to 180 ° C., so that the cloth obtained in this temperature range can be subjected to a sufficient and appropriate shrinkage treatment by heat setting. If the temperature is lower than 150 ° C., it is found that the microstructure change of the fiber is likely to occur when ironing at the time of use.

The polyester fiber according to the present invention is preferably a multifilament yarn for use in clothing. At this time, the total fineness does not need to be particularly limited, but is usually 11 to 11.
The range of 220 dtex, particularly 33 to 110 dtex is appropriate, and the single-fiber fineness need not be particularly limited.
An appropriate range is 1 to 5.6 dtex, particularly 1.1 to 3.3 dtex. 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, dog bone-shaped, etc. There may be.

[0026]

EXAMPLES The present invention will be described below more specifically with reference to examples. In addition, each characteristic value in an Example was measured by the following method.

(1) Intrinsic viscosity The intrinsic viscosity was determined according to a conventional method using orthochlorophenol at a temperature of 35 ° C. as a solvent.

(2) Tension measurement TENSION ANALYZER M manufactured by Toray Industries, Inc.
Using ODELTA-801, the measurement was performed between the final drawing roller and the winding roller in the case of spinning, and between the final drawing roller and the winding roller in the case of stretching.

(3) Breaking strength and elongation Using an autograph tensile tester manufactured by Shimadzu Corporation, breaking strength and elongation were measured for three samples at a sample length of 200 mm and a tensile speed of 200 mm / min, and the average was determined.

(4) Boiling water shrinkage (BWS) A 200 mm skein made by winding a sample 10 times is 0.0
The length L ₀ when a load of 265 cN / dtex (0.03 g / de) was hung was measured, and then immersed in boiling water at a temperature of 100 ° C. for 30 minutes with no load, and then dried sufficiently. measuring the length L ₁ when applying the same load as described above. The boiling water shrinkage (BWS) was calculated from the following equation. BWS (%) = 100 × (L ₀ −L ₁ ) / L ₀

(5) Elastic recovery rate at 10% elongation The sample fiber was attached to a tensile tester at a distance between chucks of 250 mm, stretched at an elongation rate of 10% at a pulling speed of 50 mm / min, and allowed to stand for 1 minute. Then, 50mm /
The sample length was returned to the original length at a speed of one minute, and the moving distance (L'mm) of the chuck under stress was read at this time, and was determined according to the following equation. Elastic recovery rate (%) = [L '/ 25] x 100

(6) Thermal stress KE-2 manufactured by Kanebo Engineering Co., Ltd. was used. It was measured at an initial load of 0.0442 cN / dtex (0.05 g / d) and at a heating rate of 100 ° C./min. The obtained data was plotted with the temperature on the horizontal axis and the thermal stress on the vertical axis. The maximum value of the thermal stress was defined as the peak value of the thermal stress, and the temperature at that time was defined as the peak temperature of the thermal stress.

Example 1 A polytrimethylene terephthalate having an intrinsic viscosity of 1.025 was dried by a conventional method to reduce the water content to 50 ppm, and then melted at 265 ° C. to obtain a diameter of 0.3.
It was extruded through a single-array spinneret having 36 mm discharge holes. The extruded melt discharge yarn has a length of 10c.
m, after passing through a heat-retaining region at a temperature of 180 ° C.
It was quenched and solidified by passing through an air blowing area of 2 m ³ / min. Next, the solidified yarn is taken up via a first roll at a speed of 2525 m / min and a second roll at a speed of 2525 m / min.
Next, the film was wound by a winder at a speed of 2500 m / min. At this time, the tension between the second roll and the take-up roll is 0.056c.
N / dtex (0.064 g / de). The twill angle was set to 5.5 °.

The obtained undrawn yarn was drawn at a temperature of 60 ° C., at a set temperature (plate heater) of 130 ° C., at a draw ratio of 1.
Eight times (0.82 times DRMAX), an overfeed rate of 5.6%, and a winding speed of 500 m / min, the film was drawn in one step to obtain a drawn yarn of 83 dtex / 36fil (75d / 36f). The winding tension at this time is 0.114 cN / dte
x (0.13 g / de). Table 1 shows spinning and drawing conditions and evaluation results of the obtained fibers. No yarn breakage or fluff was observed during the spinning and drawing processes, and the wound appearance was good. In addition, the elastic recovery rate was 90% or more, and no staining was observed in the result of the dyeing by the net screen.

[Examples 2 to 6] In Example 1, Table 1
Example 1 except that the spinning and drawing conditions were changed as described in
83dtex / 36fil (75d / 3
6f) was obtained. Table 1 shows the spinning stretching conditions and the evaluation results of the obtained fibers. In each case, no yarn breakage or fluff was observed during the spinning and drawing steps, and the wound appearance was good. Further, the elastic recovery rate was 85% or more, and no staining was observed in the result of the tube net dyeing.

[0036]

[Table 1]

[Comparative Examples 1 to 6] Using the polymer of Example 1, 83 dtex / 36 fil under the conditions shown in Table 2.
(75d / 36f) fiber was obtained. As shown in Table 2, all of them were out of the range of the present invention, and the wound shape was poor at ear height and the staining spot was severe.

[0038]

[Table 2]

[0039]

According to the method for producing a polyester fiber of the present invention, a high-quality polytrimethylene terephthalate-based polyester fiber which is hardly stained even when dyed and has good strength is stably produced. The industrial value is extremely large.

Claims (4)

[Claims] 1. A polytrimethylene terephthalate polyester substantially consisting of trimethylene terephthalate units and having an intrinsic viscosity of 0.4 to 1.5 is melt-extruded from a spinneret, and the discharged yarn is passed through a blowing region. After cooling and solidifying by means of a roller, it is taken up through a roller at a speed of 500 to 4000 m / min, and then a winding tension of 0.044 to 0.0
A spinning step of winding at a winding angle of 4.5 to 6.0 degrees under 71 cN / dtex to obtain an undrawn yarn, and a winding tension of 0.1 after the undrawn yarn is hot-drawn in one or more stages. 071
A drawing step of winding up to 0.132 cN / dtex to obtain a drawn yarn. 2. A polytrimethylene terephthalate-based polyester is extruded from a spinneret at a spinning temperature of 250 to 285.degree. C., and the discharged yarn is passed through a heat retaining region having an atmospheric temperature of 80 to 220.degree. C. and a length of 5 to 80 cm. The method for producing a polyester fiber according to claim 1, wherein the polyester fiber is passed through a blowing area. 3. The air volume in the air blowing area is 0.5 to 2.5 m ³ /
The method for producing a polyester fiber according to claim 1, wherein 4. Stretching at a stretching temperature of 50 to 90 ° C. to 0.6 to 0.95 times the maximum stretching ratio of the undrawn yarn,
4. Winding after heat setting at 00 to 170C.
The method for producing a polyester fiber according to any one of the above.