KR20030047192A - Modified Cross-section Polytrimethylene Terephthalate Fiber And Method For Producing The Same - Google Patents

Abstract

PURPOSE: Polytrimethylene terephthalate modified cross-section fiber is characterized by having excellent moisture absorption and light scattering effect besides maintaining advantages of PTT. A manufacturing method thereof is characterized by using a spinning base manufactured especially. CONSTITUTION: The spinning base is characterized by having 3-5 spinning nozzles around the center spinning nozzle. The polytrimethylene terephthalate modified cross-section fiber is obtained by melt-spinning at least 80mol% of PTT polymer at 240-290deg.C at 500-8000m/min. of velocity. The PTT polymer has 0.4-1.5dl/g of inherent viscosity.

Description

Modified Cross-section Polytrimethylene Terephthalate Fiber And Method For Producing The Same}

FIELD OF THE INVENTION The present invention relates to polytrimethylene terephthalate (hereinafter referred to as PTT) release cross-section yarns and a method for manufacturing the same, and more particularly, in the form of three to five smaller prisoners around the central hole. The present invention relates to a mold release cross-section yarn made using a mold release cross-section spinneret and a manufacturing method thereof.

PTT was made by condensation polymerization of terephthalic acid and 1,3-propanediol. The polymerization method was reported together with the polyethylene terephthalate polymerization method in 1941, but the price of 1,3-propanediol, the main raw material, was very interesting. Later, in the early 1990s, the US company, Shell, succeeded in developing a technology that lowered the manufacturing cost of 1,3-propanediol, enabling commercial production of PTT, and is currently mainly used in the carpet, engineering plastics, and medical fiber fields. . In particular, when used as a medical yarn is excellent in elasticity and soft to the touch compared to other synthetic fibers, has been spotlighted as the next-generation fiber material.

Since the internal structure of PTT fiber is in a zigzag form, the internal tissues do not easily crystallize, so that the crystallinity is lower and the glass transition temperature (Tg) is lower than that of polyethylene terephthalate fiber. Have. In addition, the elastic recovery rate and chemical resistance to compression has excellent softness and bulky properties, restoring force, drape, silky touch than other fiber materials.

However, since it has a hydrophobic chemical structure, its hygroscopicity is much lower than that of natural fiber, so it does not absorb sweat well in the summer season, and static electricity occurs frequently during the winter season. There is a disadvantage of lack of comfort.

On the other hand, the contents related to the production of PTT shaped cross-section yarn is disclosed in Japanese Patent Laid-Open Nos. 11-189920 and 11-302922, but there is no mention of hygroscopicity, and the cross-sectional shape of the spinneret is also limited to other forms of the present invention.

In the present invention to solve the problems of the prior art as described above, while maintaining the advantages of the PTT as it is, using a specially produced spinneret provides a method for producing a release cross-section yarn having excellent hygroscopicity and light scattering effect The purpose.

That is, the present invention relates to a method for producing a PTT shaped cross-section yarn, characterized in that the molten spinning through the release cross-section spinneret consisting of a spinneret having a shape of three to five smaller holes around the central hole.

1 is an enlarged plan view of one spinneret of a spinneret for producing a cross-section yarn having three protrusions;

Fig. 2 is an enlarged plan view of one spinneret of spinnerets for producing a cross section yarn having four protrusions;

3 is an enlarged plan view of one spinneret of the spinneret for producing a cross section yarn having five protrusions;

Fig. 4 is an enlarged plan view of a hetero sectional yarn having four protrusions.

Hereinafter, the present invention will be described in more detail.

In the present invention, the PTT polymer produced by condensation polymerization of terephthalic acid and 1,3-propanediol is dried and used for melt spinning. At this time, the PTT content in the polymer is 80 mol% or more, and the preferable intrinsic viscosity is 0.4 to 1.5 dl / g, more preferably 0.7 to 1.2 dl / g. When the intrinsic viscosity is less than 0.4 dl / g, the molecular weight of the polymer is so low that the strength is very low, and when the intrinsic viscosity exceeds 1.5 dl / g, problems such as excessive rise in pack pressure and poor radioactivity occur.

The dried polymer is melt-extruded through the spinneret of the release cross-section characteristically used in the present invention. Specifically, the spinneret may be formed of a spinneret having a shape as shown in FIGS. 1 to 3.

Preferable melt spinning temperature is 240 degreeC-290 degreeC, More preferably, it is 250 degreeC-280 degreeC. If the melt spinning temperature is less than 240 ℃ yarn strength is low and the pack pressure is excessively increased, if the melt spinning temperature exceeds 290 ℃ thermal decomposition of the polymer causes problems such as yarn elongation and dyeing.

Preferred spinning speeds are 500 to 8,000 m / min and more preferably 800 to 5,000 m / min based on the roller speed. If the spinning speed is less than 500m / min, the productivity is greatly reduced, if the spinning speed exceeds 8,000m / min there is a problem that the crystal region of the fiber is destroyed and the physical properties of the yarn is not properly expressed.

Next, the unstretched yarn spun by the above-described method is stretched or flammable. At this time, the stretching ratio is 1.2 to 4.0, and preferably 1.3 to 3.5. If the height ratio is less than 1.2, the strength is very low because it is unoriented, and if the height ratio is higher than 4.0, frequent trimming occurs and operation is impossible.

The degree of deviation of the cross section of the yarn manufactured as described above can be evaluated using the degree of release. In the present invention, this is defined as the ratio of the circumscribed circle and the inscribed circle area of the yarn, as shown in FIG.

Preferable release degree is 30 to 80%, More preferably, it is 40 to 70%. If the degree of release is less than 30%, the circular cross section is close to the hygroscopicity improvement effect. If the degree of release exceeds 80%, the cross section becomes uneven, and in severe cases, the spinning operation becomes impossible.

The PTT fiber produced by the above method exhibits strength of 2.5-6.0 g / d, elongation 20-70%, non-shrinkage 5-25%, birefringence 40-70, and the absorption rate of cotton fabric is 78mm / min. At the same time, it has excellent hygroscopicity and light scattering effect of 35 mm / min or more.

The present invention will be described in detail through the following examples. However, these examples are for illustrative purposes and should not be construed as limiting the scope of protection of the present invention.

<Example 1>

After drying the PTT having an intrinsic viscosity of 0.9 cm 3 / g well, it was melt-extruded under the condition of spinning temperature of 260 ° C. and spinning speed of 3800 m / min using spinnerets composed of 36 spinnerettes as shown in FIG. 2. PTT fiber was obtained by stretching after winding through a first roller (temperature 60 ° C., speed 2000 m / min) and a second roller (temperature 130 ° C., speed 3800 m / min) through a 0.5 kPa cooling wind. The degree of release of the obtained yarn cross section was 35% and the physical properties of the yarn are shown in Table 1.

<Example 2>

Except for using the spinneret formed so that the degree of release of the yarn cross-section 40% was carried out in the same manner as in Example 1. The physical properties of the yarns are shown in Table 1.

<Example 3>

The same procedure as in Example 1 was conducted except that spinnerets formed such that the degree of release of the yarn cross section was 60% were used. The physical properties of the yarns are shown in Table 1.

Comparative Example 1

The same procedure as in Example 1 was conducted except that spinnerets formed such that the degree of release of the yarn cross section was 25% were used. The physical properties of the yarns are shown in Table 1.

Comparative Example 2

The same procedure as in Example 1 was conducted except that spinnerets formed such that the degree of release of the yarn cross section was 85% were used. The physical properties of the yarns are shown in Table 1.

Comparative Example 3

The same procedure as in Example 1 was conducted except that a spinneret consisting of a spinneret having a circular cross section was used. The physical properties of the yarns are shown in Table 1.

<Comparative Example 4>

The same procedure as in Example 1 was conducted except that a spinneret consisting of a spinneret having a Y-shaped cross section was used. The physical properties of the yarns are shown in Table 1.

* ◎: Excellent, ○: Good, ×: Poor

<Property evaluation method>

Radiation workability was evaluated as 'excellent' for unsalted trimming, 'good' if trimming frequency was 1-5 times, and 'bad' if exceeded 5 times, and hygroscopicity was JIS L 1096 6.26.1 ( Method B) was used to measure light scattering by sensory evaluation.

As described above, the PTT release cross-section yarn produced by the method of the present invention has excellent hygroscopicity and light scattering effect.

Claims (4)

A method of manufacturing a PTT shaped cross-section yarn, characterized in that the melt spinning through a mold release spinneret consisting of a spinneret having a shape of three to five smaller holes around the central hole. The method according to claim 1, wherein the melt spinning is performed at a speed of 500 to 8,000 m / min at a temperature of 240 to 290 ° C. The method according to claim 1, wherein the PTT content of the PTT polymer used for melt spinning is 80 mol% or more and the intrinsic viscosity is 0.4 to 1.5 dl / g. PTT release cross-section yarn prepared by the method of claim 1, the degree of release is 30% to 80%, the absorption rate is 35mm / min or more.