KR100506884B1 - High Self-Crimping Polyester conjugate yarn and process of producing thereof - Google Patents

Abstract

The present invention is a heterogeneous polymer having different intrinsic viscosity, that is, a polyethylene terephthalate having an intrinsic viscosity of 0.40 to 0.59 as a first component low viscosity polymer and a second component high viscosity polymer as a second component high viscosity polymer through a specially designed inclination circular nozzle. The present invention relates to a polyester-based composite fiber and a method for producing the same, wherein the polyethylene terephthalate of 0.85 is spun in such a manner that each component is arranged in a side by side structure in the fiber length direction.

According to the present invention, it is possible to obtain a polyester-based latent crimping yarn with remarkably improved spinning workability and bactericidal agent, and exhibits spontaneous high crimping properties in the post-processing heat treatment process. Can be prepared.

Description

Polyester composite fiber with excellent crimping property and its manufacturing method {High Self-Crimping Polyester conjugate yarn and process of producing}

The present invention relates to a polyester-based composite fiber, and more particularly to a polyester-based side by-side composite fiber excellent in latent crimping property and a method of manufacturing the same.

The conventional side-by-side composite fiber composed of two kinds of polymers has latent crimping properties, and when the heat treatment is performed while undergoing the RELAX process, the spontaneous fiber is spontaneously in accordance with the principle of bimetal with different thermal expansion coefficients. It is well known that uniform spiral high elasticity is expressed.

Until now, in the manufacture of crimping fibers, there have been proposed methods of varying the quenching rate by single spinning of one polymer alone and a method of complex spinning by selecting two different polymers. . The manufacturing method of crimped yarn by double cooling has a lack of crimping performance compared to the composite spinning method of two kinds of polymers, and there is a lot of equipment limitations to equip large-scale production facilities. Most commonly commercialized.

As a criterion for selecting heterogeneous polymers, first, a method using the same polymer having only an intrinsic viscosity, and second, copolymers having different shrinkage properties as in situ polymers, for example, general Copolymer with polyester and high shrinkage properties The method which makes polyester one component and two components, respectively, is proposed. However, these manufacturing methods have disadvantages in that the physical properties of the copolymer are generally weak, so that the spinning processability is poor, the crimping performance of the composite fiber is excessive, and the axis of the knitted fabric is excessive in post-processing. There is a lot of demand for development. However, in case of using only the inherent viscosity difference, it is difficult to mass-produce until now to design a special spinneret to offset the viscosity difference between the two polymers to form a stable discharge.

Therefore, the present invention is to provide a side-by-side type polyester composite fiber that can solve all the problems of the prior art as described above as a technical problem.

In order to solve the above problems, the inventors of the present invention first designed a special spinneret and a nozzle capable of complex spinning of polymers having different intrinsic viscosity. In detail, a special spinneret developed by itself to solve process defects such as bending and kneading at the nozzle surface caused by the difference in intrinsic viscosity between low viscosity polyethylene terephthalate and high viscosity polyethylene terephthalate And nozzles. As a result of producing spun and stretched composite fibers using these specially designed spinnerets and nozzles, the spun-woven fabrics not only exhibit spontaneous high crimping properties in the post-processing heat treatment process, but also have a soft touch, drape and bulkiness. Could be prepared. In addition, it was possible to produce a polyester-based latent crimping yarn with significantly improved spinning workability and bactericidal agent, and as a result, the present invention has been completed.

Therefore, according to the present invention, in the production of latent crimping polyester-based side-by-side composite fibers, the melting point of spinning low-viscosity polyethylene terephthalate with an intrinsic viscosity of 0.40 to 0.59 and high viscosity polyethylene terephthalate with an intrinsic viscosity of 0.60 to 0.85 The angle of inclination is 1200-3000 poise There is provided a method for producing a latent crimping polyester-based side-by-side composite fiber characterized in that the side-by-side type composite spinning through a 20 ° ~ 70 ° circular nozzle.

In addition, there is provided a latent crimping polyester-based side-by-side composite fiber produced by the composite fiber production method of the present invention. Here, the composite fiber is composed of a low viscosity polyethylene terephthalate having an intrinsic viscosity of 0.40 to 0.59 and a high viscosity polyethylene terephthalate having an intrinsic viscosity of 0.60 to 0.85, and has a cross section satisfying the following formulas (1) and (2).

Equation 1 0 ≤ (interface = length of the line segment CD ÷ length of the line segment AB) ≤ 0.6

<Equation 2> 1 ≤ (Form = length of line segment EF ÷ length of line segment GH) ≤ 1.4

-Line segment AB: long axis length of the interface between high viscosity and low viscosity

-Line Segment CD: Shortened length of interface between high and low viscosity / 2

-Line segment EF: maximum length of the major axis of the yarn cross section

     -Line segment GH: maximum length of short axis of yarn cross section

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

In the present invention, a heterogeneous polymer having a large intrinsic viscosity difference used for side by side type composite spinning is abbreviated as low viscosity polyethylene terephthalate (hereinafter referred to as "low viscosity PET") having an intrinsic viscosity of 0.40 to 0.59. ) And high viscosity polyethylene terephthalate (hereinafter referred to as "high viscosity PET") having an intrinsic viscosity of 0.60 to 0.85. A significant difference in intrinsic viscosity occurs between the low viscosity PET and the high viscosity PET. As a result, when a general circular straight nozzle (see FIG. 1) is used, a difference in melt viscosity occurs due to a difference in intrinsic viscosity directly under the spinning nozzle during the spinning process. As the yarn is bent toward the higher melt viscosity (Bending or Kneeling) occurs, the spinning processability is poor, and in severe cases it is impossible to wind the mass production is impossible. Therefore, the inventors of the present invention have developed an inclined angle circular nozzle (see Fig. 2) to offset such melt viscosity difference and secure stable radioactivity without warping of yarn thread, and the inherent viscosity of the inclined angle circular nozzle has a high flow rate. On the contrary, when the slow polymer is radiated to the "B" plane, and the polymer having a high intrinsic viscosity is radiated to the "A" plane, the inclination angle gives a path difference to the two polymers having a large difference in intrinsic viscosity. Accordingly, stable spinning is possible without the bending curvature of the discharge polymer.

In the present invention, the inclination angle of the nozzle face of the circular nozzle ( Is preferably in the range of 20 ° to 70 °. If a high inclination angle nozzle with an inclination angle of more than 70 ° is used, it is advantageous for the weaving processability of polymer pairs having a low intrinsic viscosity difference (less than 600 poises of melt viscosity difference), but the unstretched yarn is drawn by stretching In the case of manufacturing a small difference in viscosity occurs the phenomenon that the crimp rate of the final yarn is lowered, and as a result, the elasticity is reduced when manufacturing into a knitted fabric. On the contrary, when a low inclination nozzle of less than 20 ° is used, it is advantageous for the weaving processability of polymer pairs having a large difference in intrinsic viscosity (more than 3100 poise difference in melting viscosity), and the produced yarn also has excellent crimping rate. However, due to the low inclination angle, there are many problems in maintenance and repair of nozzle cleaning and inspection, etc. (see Fig. 3).

In addition, the polyester composite fiber produced according to the present invention preferably has a crimp ratio of 20% or more measured by the method described below. The side by side composite fiber of low and high viscosity PET has a crimp ratio of 20% or more to enable the manufacture of a woven fabric having a desired stretch property. If the crimp ratio is less than 20%, the stretch fabric is stretched. Characteristic expression becomes poor (refer FIG. 4).

Therefore, in the spinning using the inclined nozzle, the final yarn has excellent crimping performance, and in order to express good stretchability when fabricating a woven fabric, the larger the difference in melt viscosity between the two polymers is, the better the crimping rate is. It's better to have a poise. When the viscosity difference is less than 1200 poise, the viscosity difference is small and the crimping rate of the final yarn is lowered. As a result, there is a problem that the stretch phase is lowered when manufacturing the knitted fabric. When the difference in melt viscosity exceeds 3000 poise, the yarn is a high viscosity polymer. The warpage becomes more severe and radiation is impossible (see Figure 3).

In the present invention, the control of the difference between the melt viscosity of the two components can be achieved by varying the thermal history of each component polymer melt by varying the temperature conditions of the extruder of each component, or by controlling the spinning temperature of the high viscosity PET and the low viscosity PET. Can be. It is appropriate to adjust the spinning temperature within the range of 275 ° C to 300 ° C in order to maintain the difference in melt viscosity between the two polymers during spinning in the proper range of 1200 to 3000 poise. In addition, the extruder temperature range of the low viscosity PET is preferably 265 ° C to 295 ° C, and the extruder temperature range of the high viscosity PET is adjusted to 270 ° C to 300 ° C.

As shown in the attached drawings 5 and 6, the cross section of the yarn woven by the difference in melting viscosity forms a circular cross section, and the interface forms a round shape with a high viscosity side due to the difference in melting viscosity. Is moved within the range satisfying the following equation due to the difference in melt viscosity.

Equation 1 0 ≤ interface (= length of line segment CD ÷ length of line segment AB) ≤ 0.6

-Line segment AB: long axis length of the interface of high viscosity and low viscosity

-Line segment CD: (short axis length of interface between high viscosity and low viscosity) ÷ 2

Moreover, it is preferable that the ratio in the composite fiber of low viscosity PET is 30 to 70% of the total weight, and it is preferable that the ratio in the composite fiber of high viscosity PET is 70 to 30% of the total weight. In addition, as the respective discharge ratio is changed, the yarn cross-sectional shape moves within a range that satisfies the following equation.

<Equation 2> 1 ≤ form (= length of line segment EF ÷ length of line segment GH) ≤ 1.4

-Line segment EF: Max. Of long axis of yarn cross section. Length

-Line segment GH: Max length of short axis of yarn cross section

In the present invention, the spinning winding speed is suitable for 1600m / min ~ 4000m / min, stretching temperature is 70 ℃ ~ 100 ℃, heat treatment temperature is suitable 140 ~ 250 ℃, stretching D / R is the elongation of the final yarn It is preferable to set it so that it may be 20 to 40%, Especially, it is more preferable to improve spinning workability and crimping performance so that spinning winding speed may be 2000 m / min-3500 m / min, and draw ratio may be 1.3 to 2.5 times. In other words, if the stretching temperature is too low, there is a problem of abrasion defects, if too high, the degree of unfavorable degree of sagging acts in a direction adverse to fairness. In addition, when the heat treatment temperature is too low, the setting (poor) setting is poor, the probability of failure when manufacturing a woven fabric in the post-processing is high, and if the heat treatment temperature is too high, the yarn properties decrease.

The polyester composite fiber produced by the present invention has a strength of 2.0 g / de 'to 3.6 g / de', and preferably has 20% to 40% elongation. If the strength is less than 2.0g / de`, the strength is lowered, so there is a lot of trimming during spinning, poor workability during the manufacture of the knitted fabric, and the tear strength of the knitted fabric is reduced, and the strength is 3.6g / de`. If it exceeds, there is a problem that the touch is poor after fabric production. In addition, when the elongation is less than 20%, there is a problem that the cows are likely to occur during spinning, when the elongation exceeds 40%, the leveling agent (= U%) due to the unrest in the spinning process is poor.

Hereinafter, the present invention will be described in detail by way of preferred examples and comparative examples. However, the present invention is not limited to the following examples.

Various physical property evaluation methods used in the following Comparative Examples and Examples are as follows. Physical property evaluation results of Comparative Examples and Examples are shown in Table 1.

* Intrinsic Viscosity (= I. V., Intrinsic Viscosity): After dissolving each polymer sufficiently in 1% concentration in ortho-chlorophenol at 120 ° C, it is measured using a Ubelrod viscometer in a 30 ° C thermostat.

* Melt Viscosity (= M.V., Melt Viscosity): The polymer to be measured is sufficiently dried at 160 ° C using a vacuum dryer, and then measured at a temperature of 280 ° C using a capillary type rheometer (= Capillary Type Rheometer).

* Crimping rate (Tc,%): Take a sample of 3000 deg. In a given amount of 50mg / de. When crimping is performed during hydrothermal treatment, this sample is treated with hot water (100 ° C) for 20 minutes under a load of 0.5 mg / de, which is a level at which no entanglement occurs between the fiber strands. Leave to dry for 24 hours. After the natural drying (2) After giving a load of 2mg / de` to the sample, measure the length L1 after 1 minute and measure the length L2 after 1 minutes after applying a load of 2mg / de` + 200mg / de`. The crimp rate is calculated by substituting the measured value into the following Equation 3.

<Equation 3> Tc (%) = {(L2-L1) / L2} × 100

Fabric Shrinkage: The fabric shrinkage specified in the present invention is obtained by the following equation.

Fabric Shrinkage (%) = (width of final processed fabric (= elasticity is expressed) / raw fabric width after weaving) x 100

* 30% elongation elastic recovery rate of fabric (FR30,%): make 3 pieces of fabric 5.5cm x 30cm in the direction of light and weft, and then install the test piece with the width of 5cm in the tensile tester and give super load Make it flat. Elongation at the time of stress-extension curve in the stress-extension curve by stretching to 30% elongation at a rate of 100% / min using low-speed elongation measuring method (JIS L 1018-70) ( ) Is calculated, and the average of each of the warp and weft directions is calculated by Equation 5.

Equation 5 FR30, (%) = {(30- ) / 30} × 100

EXAMPLES 1-5

In order to overcome the difference in inherent viscosity of the two polymers in the composite spinning equipment, an inclined angle circular nozzle was used. The polymer "A" uses PET with intrinsic viscosity 0.460 and 0.550, and the polymer "B" uses PET with intrinsic viscosity 0.635, 0.654 and 0.809, and the inclination angle of the nozzle face is 30 ° in the radiation temperature range of 275 ℃ to 290 ℃. The test was conducted using inclined angle nozzles of 45 ° and 60 °. The discharge ratio was wound at a spinning speed of 2000 to 3500 m / min in the range of 3: 7 to 7: 3, the stretching ratio is 1.3 to 2.5 times, the stretching temperature is 75 to 100 ℃ and the heat treatment temperature to 160 to 250 ℃ Was prepared. Cooling air at 23 ° C. was supplied at a speed of 0.35 m / sec at 5 to 120 cm directly under the nozzle, and the amount of oil deposition was given in the range of 0.5 to 1.1 wt%. The fiber thus prepared was made into a fabric having 100 g / m ² using both light and weft yarns and then dyed at 120 ° C.

Comparative Example 1

In the comparative example of the present invention, the polyethylene terephthalate polymer and the high shrink polyester polymer (hereinafter, abbreviated as "high shrink PET") are spun by using a general circular nozzle (see Fig. 1) in an extruder and a spinning facility. It was. Polyethylene terephthalate polymer is composed mainly of terephthalic acid and ethylene glycol, and the third functional ester-forming component is not copolymerized and has an intrinsic viscosity of 0.60 to 0.70, and a dry heat shrinkage at 180 ° C of yarn at 15 to 25%. The term "high shrinkage polyester" refers to a polyester having 1 to 15 mole% of isophthalic acid copolymerized with terephthalic acid and ethylene glycol as a main component and a third functional component for suppressing crystal orientation. The high shrink polyester has an inherent viscosity in the range of 0.62 to 0.70 and has a dry heat shrinkage of 30 to 50% at 180 ° C. in yarn production.

50% polyethylene terephthalate with an intrinsic viscosity of 0.635, with an intrinsic viscosity of 0.67 50% of high shrink polyester was wound up at the spinning speed of 2500 m / min in the spinning temperature of 280 degreeC-290 degreeC, and the draw ratio was extended | stretched 2.1 times, extending | stretching temperature 95 degreeC, and heat processing temperature 200 degreeC. Cooling air at 23 ° C. was supplied at a rate of 0.35 m / sec at 5 to 120 cm under the nozzle during spinning, and the amount of oil deposition was given in the range of 0.5 to 1.1 wt%. The fiber thus prepared was made into a fabric having 100 g / m ² using both light and weft yarns and then dyed at 120 ° C.

As a result, as shown in Table 1, it was possible to obtain latent crimped yarns capable of producing woven fabrics having excellent elastic properties such as crimping rate and elasticity. It has the disadvantage of being over%.

 [Comparative Examples 2 to 4]

In order to overcome the difference in inherent viscosity of the two polymers in the composite spinning equipment, an inclined angle circular nozzle was used. Polymer "A" uses 50% PET with intrinsic viscosity of 0.550 and 0.460, and Polymer "B" uses 50% PET with intrinsic viscosity of 0.654, 0.635 and 0.796, and the inclination angle of the nozzle surface in the radiation temperature range of 275 ℃ to 290 ℃ The test was conducted using inclined angle nozzles with degrees 15 °, 60 ° and 75 °. It was wound at a spinning speed of 2000 to 3500 m / min, a draw ratio of 1.3 to 2.5 times, a stretching temperature of 75 to 100 ℃, a heat treatment temperature of 160 to 250 ℃ to prepare a composite fiber. Cooling air at 23 ° C. was supplied at a speed of 0.35 m / sec at 5 to 120 cm directly under the nozzle, and the amount of oil deposition was given in the range of 0.5 to 1.1 wt%. The fiber thus prepared was made into a fabric having 100 g / m ² using both light and weft yarns and then dyed at 120 ° C.

→ interface ^* = length of line segment CD ÷ length of line segment AB

Reference) surfactant ^* is a number between the following limits, expressed by "Equation 1"

0 ≤ interface ^* ≤ 0.6

→ form ^** = length of line segment EF ÷ length of line segment GH

Type ^** has values in the following range and is represented by "Equation 2".

1 ≤ mode ^** ≤ 1.4

→ Radiation Fairness ^*** : ◎ (very good), ○ (excellent), △ (good), × (bad)

As shown in Table 1, the larger the difference in intrinsic viscosity, the lower the inclination of the nozzle should be used for spinning, and the high winding yarn was made possible. In addition, when the inherent viscosity difference is too large, the discharge is unstable and the spinning processability is not good due to the reason that the inclination angle is too low. On the contrary, when the difference in intrinsic viscosity is small, spinning is possible even with a high inclination angle nozzle, so that spinning processability is very good, but it is difficult to manufacture a stretchable knit fabric due to a low crimp rate.

       In addition, as mentioned in Comparative Example 1, when the high shrinkage polyester is used as the final fabric, the shrinkage of the fabric should be imposed, although the shrinkage should be more than 45%.

As described above, according to the present invention, the two types of polymers having different intrinsic viscosity differences are used to perform side by side type composite spinning using inclined angle circular nozzles to maximize the crimping characteristics, thereby providing excellent spontaneous high crimping characteristics. By using the polyester-based composite fibers produced by the invention it is possible to produce a latent crimping yarn having excellent soft touch and drape and bulkiness in the production of knitted fabrics. In addition, it is possible to produce a polyester-based latent crimping yarn having excellent spinning workability, especially no curvature phenomenon and significantly improved bactericidal agent.

In addition, the polyester-based potential crimps using the intrinsic viscosity difference produced by the present invention has the advantage that the fabric shrinkage is 30% or less, the cost is reduced when mass production.

1 is a schematic view of a conventional general straight straight nozzle type spinneret.

2 is a schematic diagram of a composite spinneret used in the present invention.

3 shows an appropriate melt viscosity range between two polymers that can be spun according to the inclination angle of the nozzle.

4 shows the crimp rate of the final composite fiber according to the difference in intrinsic viscosity of the two polymers.

5 is a schematic view of the yarn cross section of the polyester-based composite fiber produced by the present invention.

6 is a schematic diagram showing the deformation of the yarn cross-section according to the manufacturing conditions of the composite fiber produced by the present invention.

Claims (9)

In the production of latent polyester-based side-by-side composite fibers, the difference in melting viscosity between the low viscosity polyethylene terephthalate with intrinsic viscosity 0.40 to 0.59 and the high viscosity polyethylene terephthalate with intrinsic viscosity 0.60 to 0.85 is 1200 ~ To 3000 poise A method for producing a latent crimping polyester-based side-by-side composite fiber, characterized in that the side-by-side type composite spinning through a 20 ° ~ 70 ° circular nozzle. delete The method of claim 1, wherein the low viscosity polyethylene terephthalate and high viscosity polyethylene terephthalate is composed of terephthalic acid and ethylene glycol as a main component of the third functional ester forming component is copolymerized polyethylene terephthalate or 0.1 mol to 20 mol% copolymerization Method for producing a latent crimping polyester-based side-by-side composite fiber, characterized in that using one or more polyethylene terephthalate selected from the group consisting of a polymer. According to claim 1, wherein the low viscosity polyethylene terephthalate is 30 to 70% of the total weight of the polyester-based composite fiber, high viscosity polyethylene terephthalate is latent characterized in that 70 to 30% of the total weight of the polyester-based composite fiber Method for producing a crimped polyester-based side by-side composite fiber. The method of claim 1, wherein the spinning speed is 2000 m / min to 3500 m / min, and the draw ratio is 1.3 to 2.5 times during the composite spinning. The method of claim 1, wherein the prepared polyester-based composite fiber has a strength of 2.0 to 3.6 g / denia, the elongation is 20% to 40% of the latent crimping polyester-based side-by-side composite fiber Way. The method for producing a latent crimpable polyester-based side by-side composite fiber according to claim 1, wherein the produced polyester-based composite fiber has a crimp ratio of 20% or more. A latent crimpable polyester-based side-byside composite fiber produced by the method of claims 1 to 7. The low-strength polyethylene terephthalate having an intrinsic viscosity of 0.40 to 0.59 and the high viscosity polyethylene terephthalate having an intrinsic viscosity of 0.60 to 0.85, and having a cross section satisfying the following formulas (1) and (2): Polyester side by side composite fiber: <Equation 1> 0 ≤ (interface = length of line segment CD ÷ length of line segment AB) ≤ 0.6 <Equation 2> 1 ≤ (Form = length of line segment EF ÷ length of line segment GH) ≤ 1.4 -Line segment AB: long axis length of the interface between high viscosity and low viscosity -Line Segment CD: Shortened length of interface between high and low viscosity / 2 -Line segment EF: maximum length of the major axis of the yarn cross section -Line segment GH: maximum length of short axis of yarn cross section