KR20000046089A - Polyester industrial yarn by using a heteromorphy spinning base and preperation thereof - Google Patents

Abstract

PURPOSE: Provided is a process for producing a polyester industrial grey yarn which has improved tenacity, modulas and shrinkage. Thereby, it is possible to produce a polyester industrial grey yarn which has excellent tenacity, degree of orientation, modulas, spinning workability and physical property. CONSTITUTION: A polyester industrial grey yarn is comprised of following the steps of: melting solid polymerization polyester chip; spinning it through a shaped spinning nozzle which has slit of not less than two and hollowness of under 10%; passing the filament through a hood which has length of 100-200mm and surrounding temperature of 200-250°C; winding the filament to produce undrawn yarn having degree of orientation being 45-60x10¬-3 by using a godet roller. The solid polymerization polyester chip which has inherent viscosity of 1.0-1.2 and moisture regain of 20-25ppm is prepared by solid-polymerizing polyester raw chip. The polyester industrial grey yarn is characterized by having inherent viscosity of 0.95-1.10, initial elastic coefficient of 110-130g/d, tenacity of 8.5-9.2g/d, elongation of 11.0-12.0%, shrinking percentage of 5.8-7.0% and crystallinity of 48-52%.

Description

Polyester Industrial Yarn Using Deformed Section Spinneret and Its Manufacturing Method

The present invention relates to a polyester industrial yarn used as a reinforcement material for rubber products such as tires, and a method of manufacturing the same. More specifically, the same polymer as that used for general high-strength yarns is formed through the spinneret of the cross-section of the filament surface and the central portion. The same high shear stress is applied to the yarn to make the unstretched yarn with a uniform orientation along the yarn diameter direction, and to be wound at a high speed of 2,500m / min or more, and to perform three-stage stretching using a Godet roller, so that the modulus is high even after the twisting and deepening process. The present invention relates to a method for producing a polyester industrial yarn having excellent dimensional stability due to low shrinkage rate and high strength, and to an industrial yarn produced thereby.

Industrial yarn currently used as a reinforcement material for rubber products such as tires has a high modulus low shrinkage (ESM) of 7.0 to 8.0% and 19.5 to 20 kg of strength, which is an index of dimensional stability. As a method of manufacturing such yarns, according to the method proposed in Japanese Patent Application No. 63-528, the polyester polymer melt is extruded through a circular spinneret, and then wound at a speed of 2,000 m / min or more, and the unstretched yarn After the birefringence is set to 30 × 10 ^-3 or more, it is manufactured by the method of stretching the non-drawn yarn directly with a high-density controller.

However, the unstretched yarn obtained by the high-speed spinning as described above has a problem that it is difficult to express high strength because the unstretched orientation is high and the stretching of high magnification is impossible.

In order to solve this problem, there is a method of increasing the atmospheric temperature directly below the spinneret by heating using a heater to express high strength, lowering the unstretched orientation, and then stretching the film at a high magnification. In addition to poor dimensional stability of the deep cord, there is a problem in that the strong decrease during the twisting, heat treatment process.

Currently, Japanese Patent Application Laid-Open Nos. 1-282306 and 2-41413 have been proposed to increase the intrinsic viscosity of polyester chips to 1.2 or more as a method of increasing the strength of high modulus low shrink yarns.

By increasing the viscosity of the chip, this method increases the orientation of the undrawn yarn due to the increase of the radial tension, so that the dimensional stability of the deep cord is excellent, and the formation of tie chains that connect the crystals to the crystals in the yarn structure increases. By doing so, high strength properties are expressed even at low draw ratios.

However, in order to increase the intrinsic viscosity of the polyester chip, solid phase polymerization is required, and as the viscosity increases, the intrinsic viscosity difference between the surface and the center of the chip increases, resulting in a decrease in radioactivity due to uneven viscosity of the polymer and melting at a high temperature during spinning. The intrinsic viscosity of yarns produced by thermal pyrolysis and hydrolysis by heat is not as effective as increasing the viscosity of the chip, which is inefficient in terms of time and energy use. In addition, the yarn obtained when continuous high-speed spinning using high-viscosity chips causes a skin-core phenomenon in which the shear stress is concentrated on the filament surface when the circular spinneret passes, resulting in different internal and external orientations. do.

The object of the present invention is to solve the above problems and to obtain a high modulus low shrinkage high strength polyester industrial yarn by applying a spinneret of a special release cross-section to produce a high-strength characteristics while producing a high-strength characteristics It is to provide a polyester industrial yarn having a and a method of manufacturing the same.

1 is a schematic view of a heterosection spinneret used in the present invention,

Figure 2 is a schematic view of the manufacturing process of the polyester industrial yarn of the present invention.

Explanation of Main Part Codes in Drawings

1: slit 2: spinneret

3: hood 4: oil ring device

5: high power controller

That is, the present invention solid-polymerizes a polyester low chip to which an antimony compound is added to produce a solid-state polymerized polyester chip having an intrinsic viscosity of 1.0 to 1.2 and a water content of 20 to 25 ppm, and using this chip at 290 to 300 ° C. After spinning through the spinneret of the special shape as shown in FIG. 1 at the temperature of, the filament released is wound at 2,500 to 3,500 m / min, and the inherent viscosity is 0.95 to 1.10, and the orientation is 45 to 60 × 10 ^-3 . The present invention relates to a polyester industrial yarn using a release cross-section spinneret and a method of manufacturing the same, wherein the undrawn yarn is continuously drawn.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

1 is a schematic view of a release cross-section spinneret used in the present invention, the number of slits (1) is 2 or more, the self-porosity is 9%. In general, the spinneret applied to the manufacture of hollow fiber has a hollow ratio of 30% or more, so that the hollow ratio of the yarn is 20% or more. In order to reduce the skin-core effect by the same high shear stress acts on the center and the center, for this reason, the spinneret hollow ratio is less than 10%. If the hollow portion is present in the yarn, rather the radiation tension is greatly increased, resulting in a decrease in spinning workability. Therefore, in the present invention, the polymer having passed through the spinneret is fused by the die-swelling effect by using a spinneret having a self-spinning ratio of less than 10%, so that the hollow part does not exist inside the yarn. Stress acts equally on the filament surface and in the center, preventing skin-core phenomenon. In addition, the yarn produced in this way is subjected to equally high shear stress on each filament surface and the center, thereby increasing the tie chain connecting the crystals between the crystals and excellent dimensional stability.

Figure 2 is a schematic view showing the manufacturing process of the polyester industrial yarn of the present invention, and in more detail with reference to the symbols shown in the drawings, intrinsic viscosity 1.0 to 1.2 by solid-phase polymerization of the low chip of the polyester added antimony compound And melt spinning a solid-state polymerized polyester chip having a water content of 20 to 25 ppm. At this time, by spinning the temperature of the molten polymer at a temperature of 290 ~ 300 ℃ to minimize the viscosity decrease due to thermal decomposition that can occur during the spinning process to the intrinsic viscosity of the discharger passed through the spinneret (2) to 0.95 ~ 1.10. .

The moisture content of the low chip is preferably 20 to 25 ppm, because if it is out of this range, the intrinsic viscosity of the fiber is lowered by hydrolysis during the spinning process.

The yarn passed through the spinneret 2 is passed through a hood 3 having a length of 100 to 200 mm and an ambient temperature of 200 to 250 ° C., quenched and oiled using a roller oiling device 4, and then Drawing is carried out through the troller (5) to produce a final yarn.

The temperature of the hood (3) is to maintain the temperature in the above range by adjusting the hood length without a separate heating device, if the hood atmosphere temperature is less than 200 ℃ to form a hollow inside the yarn, if it exceeds 250 ℃ unstretched Since the degree of orientation is low, physical properties such as modulus are lowered. Therefore, if the temperature range is adjusted within the scope of the present invention, the orientation of the filament surface and the center is small without the hollow portion being formed, and the formation of the tie chain and the unstretched orientation can be increased to produce a yarn having high strength and dimensional stability. Will be.

The filament thus released is wound at a speed of 2,500 to 3,500 m / min using a high-tension controller (5) so that the orientation of the undrawn yarn is 45 to 60 × 10 ⁻³ , followed by three step stretching to prepare the final yarn. At this time, if the degree of orientation of the undrawn yarn is less than 45 × 10 ⁻³ , the strength decreases significantly during deep heat treatment, and the deep cord dimensional stability is lowered. When the undrawn yarn exceeds 60 × 10 ⁻³ , the draw ratio is lowered, which is disadvantageous for yarn strong expression.

Yarns produced by the spinning process as described above have an intrinsic viscosity of 0.95 to 1.10, an initial modulus of 110 to 130 g / d, strength of 8.5 to 9.2 g / d, elongation of 11.0 to 12.0%, shrinkage of 5.8 to 7.0%, and crystallinity of 48 to 52 Physical properties of% will be expressed.

In the case of producing a diff cord from this yarn, it is possible to obtain a diff cord having high strength and dimensional stability by showing physical properties of strength of 7.0 g / d or more, shrinkage ratio of 3.0 to 3.8%, and middle body (medium elongation) of 2.8 to 3.8. .

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited by the following Examples.

Example 1

The polyester low chip to which the antimony compound was added was solid-phase polymerized to melt-spun polyester chips having an intrinsic viscosity of 1.1 and a moisture content of 25 ppm. At this time, the temperature of the molten polymer was 295 ℃, and the hollow ratio of the spinneret was used was 9%. The yarn passed through the spinneret was passed through a hood with a length of 150mm and an ambient temperature of 240 ℃, quenched with a cooler at 20 ℃, oiled using a roller oil ring device, and then wound at a speed of 2,800m / min through a high-speed controller. After three steps of stretching, a final yarn was obtained.

The yarn prepared as described above did not have a hollow portion formed therein, and the spinning workability was good, and other physical properties are shown in Table 1.

Comparative Example 1

Except that the hollow ratio of the spinneret is 20%, the physical properties were evaluated in the same manner as in Example 1, and are shown in Table 1.

Comparative Example 2

Except that the hollow ratio of the spinneret is 30% was prepared in the same manner as in Example 1 and then shown in Table 1 to evaluate the physical properties.

Examples 2-4, Comparative Examples 3-4

The polyester low chip to which the antimony compound was added was solid-phase polymerized to melt-spun the polyester chip having an intrinsic viscosity of 1.10 and a water content of 25 ppm. At this time, the temperature of the molten polymer was 295 ° C, and the hollow ratio of the spinneret was 9%. After passing through the spinneret through a hood with a length of 50 to 250m, it was quenched with a cool air at 20 ℃, oiled using a roller oil ring device, and wound up at a speed of 2,800m / min through a high-speed controller. Three-stage stretching was performed to prepare 1,000 denier yarns. Two strands of yarn prepared were twisted at 470 TPM and then dipped into RFL, followed by heat treatment at 240 ° C. to prepare a diff cord, and to evaluate the physical properties of the yarn and the diff cord.

Hood temperature: Measures the ambient temperature of 100mm from the bottom of spinneret

As described above, the high-strength polyester low chip is spun through a special shape of the cross-section spinneret used in the present invention to uniformize the orientation of the filament, and improve the yarn workability and yarn properties as well as the yarn. It is possible to reduce the physical property dispersion, and to improve the strong utilization rate after manufacturing the diff code.

Therefore, the yarn produced according to the present invention has a high strength and high modulus low shrinkage property of more than 8.5g / d and the strength decreases even after deep heat treatment is suitable for use as a reinforcement of rubber products such as tires and belts and other industrial materials.

Claims (3)

After melting the solid-state polymerized polyester chip and spinning through a sectional spinneret having a slit number of 2 or more and a hollow ratio of less than 10%, it is discharged through a hood having a length of 100 to 200 mm and an ambient temperature of 200 to 250 ° C. Polyester filaments are wound at a speed of 2,500 to 3,500 m / min using a high speed controller and stretched so that the orientation of the undrawn yarn is 45 to 60 × 10 ^-3 . Manufacturing method. According to claim 1, wherein the solid-state polymerized polyester chip is a polyester low-temperature polyester yarn using a cross-sectional spinneret, characterized in that the intrinsic viscosity is 1.0 to 1.2, the moisture content is 20 to 25ppm Manufacturing method. After melting the solid-state polymerized polyester chip and spinning through a sectional spinneret having a slit number of 2 or more and a hollow ratio of less than 10%, it is discharged through a hood having a length of 100 to 200 mm and an ambient temperature of 200 to 250 ° C. The obtained filament is wound at a speed of 2,500 to 3,500 m / min using a high-tension controller, and stretched so that the orientation of the undrawn yarn is 45 to 60 × 10 ^-3. d, Polyester industrial yarn of strength 8.5-9.2g / d, elongation 11.0-12.0%, shrinkage rate 5.8-7.0%, crystallinity 48-52%.