KR20020004200A - An airtextured polyester yarn, and a process of preparing for the same - Google Patents

Abstract

PURPOSE: A polyester blending yarn and a manufacturing method thereof are provided, which is characterized by improving productivity, increasing processability of spinning and blending, improving touch and bulkiness, and producing partly oriented yarn of polyester by retarding spinning-crystallization though high-speed spinning is done. CONSTITUTION: The polyester blending yarn is obtained by a process containing the steps of: mixing 0.5-5.0wt.% of crystal orientation inhibitor with 95-99.5wt.% of polyester polymer having at least 85wt.% of polyethylene terephthalate unit; spinning at over 4000m/min.; winding to produce partly oriented yarn having at least 120% of breaking elongation; using partly oriented yarn as an effect yarn; using a polyester twisted yarn having 85wt.% of polyethylene terephthalate unit as a core yarn; and then blending them.

Description

Polyester blended yarn and manufacturing method thereof {An airtextured polyester yarn, and a process of preparing for the same}

The present invention relates to a polyester blend fiber yarn and a method for producing the same, which can effectively delay the phenomenon in which the crystallization on the radiation increases rapidly during high-speed spinning of the polyester fiber, and excellent in the touch and bulkiness in the fabric manufacturing.

As a method of preparing the polyester blended yarn, a method of firstly preparing a polyester partial alignment yarn and then blending it with a polyester drawn yarn is widely used.

When spinning a polyester polymer at a high speed of more than 4,000m / min, the phenomenon of "Spinning Crystallinity" occurs due to the rapid increase in the radial tension, which causes severe process instability factors such as cutting and moor. The sex is significantly lowered. As a result, when spinning the polyester fiber, there is a limit of spinning speed, and currently the mass production of polyester partial alignment yarns is usually produced at spinning speeds of 3,500 to 4,000 m / min.

At the spinning speed of 4,000m / min as the critical point, the increase in molecular orientation increases without increasing the crystallinity, but when the spinning speed exceeds 4,000m / min, the molecular orientation and crystallinity increase simultaneously. Therefore, as the spinning speed increases, the crystallinity increases rapidly with the increase of the radial tension and the alignment crystallization accordingly. As the spinning speed increases, the density and birefringence also increase. Ziabicki and H. Kawai Edited, 'High Speed Fiber Spinning', John Wiley & Sons, New York, 1985].

Until now, the process of delaying the rapid increase of the crystallization on the radiation by increasing the spinning speed in the polyester fiber production process overcomes the existing limit spinning speed and spins the polyester partial alignment yarn at a high speed of 4,000 m / min or more. Much research has been conducted on. Known methods to date can be roughly classified into first, through the modification of the raw polymer (copolymerization, molecular chain crosslinking, etc.) and second, by mixing the polymer material.

As a first method, EP 0 263 020 and US Pat. No. 4,518,744 add compounds pentaerythrite, trimethylropropane, melitic acid and trimellitic acid, which have side chains to the molecular chain, before or after transesterification or polymerization. US Patent 4,966,740 proposes a method for adding tetraethyl silicate before or after the transesterification reaction, US Patent 4,092,299 proposes a molecular chain crosslinking method using a tetrafunctional material have. However, the first methods must specifically select the polymerization conditions, and the workability in the draw combustion process is lowered. In particular, the high cutting rate in the combustion process causes a problem of difficult combustion.

As a second method, US Pat. No. 4,609,710 discloses a method of mixing polystyrene, polyamide, polymethylmethacrylate, or the like as a molecular alignment regulator during or after the polymerization of a polyester. In addition, a method of reducing the radiation orientation by adding a small amount of liquid crystal polymer material, polyethylene, polyethylene glycol, etc. in the conventional polyester polymerization is known. Appl. Polym. Sci., 31 , 2753 1986)]

In this case, the flowability of the polymer melt in the spinning process is drastically changed, which greatly affects the spinning characteristics, in particular, the spinning speed, thereby lowering the spun orientation. However, the method is difficult to spin stably due to the problem of uniformly mixing the added polymer, and the mixed polymer is moved to the fiber surface in the drawing and burning process to inhibit the workability, the occurrence of wool and fine dye stains Occurrence is a cause of deterioration of the final false twist quality.

Due to such problems, until now, polyester partial alignment yarns have been manufactured at a spinning speed of 4,000 m / min or less, and then mixed with polyester stretched yarn to produce polyester mixed yarns. As a result, the productivity of polyester blended yarn could not be improved.

The present invention is to provide a method for producing a polyester blended yarn with high productivity while effectively delaying the phenomenon that the crystallization on the radiation rapidly increases when spinning the polyester fiber at a winding speed of 4,000m / min or more. In addition, the present invention is excellent in the workability of the spinning, blending process, it is possible to prevent the crystal orientation inhibitor to move to the fiber surface to reduce the yarn quality, to provide a polyester blended yarn excellent in the touch and bulkiness in the fabric manufacturing I would like to.

The present invention relates to a polyester blend fiber yarn and a method for producing the polyester fiber which can effectively delay the spinning crystallization phenomenon during high-speed spinning, and excellent in the touch and bulkiness in the fabric manufacturing.

More specifically, the present invention uniformly mixes 95.0 to 99.5 wt% of a polyester polymer having a polyethylene terephthalate repeating unit of 85 wt% or more and 0.5 to 5.0 wt% of a crystal orientation suppressor in a molten state and then continuously 4,000 m or more per minute Spinning and winding at a speed to produce a partial orientation yarn having a cut elongation of 120% or more, the partial orientation yarn as an effect yarn and a polyester drawn yarn with a polyethylenetetephthalate repeating unit of 85% by weight or more as a core yarn is mixed It is related with the manufacturing method of polyester blend fiber.

In addition, the present invention is a mixture of polyester partial alignment yarn composed of 95 to 99.5% by weight of the conventional polyester as the main component and 0.5 to 5.0% by weight of the crystal orientation suppressor and polyester drawn yarn having a polyethylene terephthalate repeating unit of 85% by weight or more. It relates to a polyester blend fiber, characterized in that 5 to 40 entangled points per 1 m of yarn length, the residual shrinkage is 5 to 40%.

Hereinafter, the present invention will be described in detail.

First, the present invention uniformly mixes 95.0 to 99.5% by weight of polyester polymer and 0.5 to 5.0% by weight of crystal orientation inhibitor having a glass transition temperature of 100 ° C. or higher in the molten state to prepare a polyester partial alignment yarn, and then continuously Spin and wind at a speed of over 4,000m per minute. As the crystal orientation suppressor, polymethyl methacrylate resin, polystyrene resin, or methyl methacrylate-styrene copolymer resin is used.

The glass transition temperature (Tg) of the crystal orientation suppressor is 100 ° C. or more. The reason is to maintain the difference in the solidification behavior of the polyester polymer having a glass transition temperature (Tg) of 80 ° C. on the radiation and the crystallization inhibitor, thereby suppressing the crystal orientation behavior of the polyester polymer.

If the glass transition temperature (Tg) of the crystallization inhibitor is less than 100 ℃, the difference in the solidification behavior between the polyester polymer and the crystallization inhibitor is small, it is difficult to effectively suppress the crystal orientation behavior of the polyester polymer on the radiation. As a result, the winding speed cannot be made higher than 4,000 m / min.

Due to the attractive force between the aromatic ring included in the crystallization inhibitor and the aromatic ring included in the polyester molecule, it is possible to more effectively inhibit the orientation crystallization occurring during the spinning and stretching process. It is well known that an aromatic ring is composed of double bonds between constituent carbon atoms, and therefore, an attractive force exists between adjacent aromatic rings.

In addition, the aromatic part is a rigid part inside the molecular chain, while the aliphatic part means a flexible part. Therefore, the presence of an appropriate aromatic part can maintain the mechanical properties of the polymer chain, a crystallization inhibitor, thereby minimizing the loss of mechanical properties, such as a decrease in strength by the crystallization inhibitor fibrils distributed in the polyester. .

From this point of view, by using the crystallization inhibitor of the present invention, it is possible to maintain a similar level of physical properties, particularly strength, to the polyester partial-orientated yarn prepared by the general method.

The amount of the crystallization inhibitor added is 0.5 to 5.0% by weight based on the weight of the entire polymer (polyester polymer + crystallization inhibitor). If the added amount is less than 0.5% by weight, the effect of suppressing radiocrystallization is insignificant, and when the added amount is more than 5.0% by weight, the stretching and flammability processability deteriorate.

In the present invention, the mixing of the polyester polymer and the crystallization inhibitor is first performed by supplying the polyester chip to the extruder and melting the same, followed by supplying the molten polyester to the two-stage biaxial screw extruder and simultaneously crystallizing the same. An orientation inhibitor chip is supplied to melt and mix them. More preferably, the melt mixed in the two-stage twin screw extruder is continuously kneaded with a stationary kneader.

Meanwhile, the polyester polymer chip and the crystal orientation suppressor chip may be simultaneously supplied to the extruder to melt and mix them, and then the melt may be continuously kneaded with a stationary kneader.

The stationary kneader serves to make the crystal orientation suppressor distribution more uniform in the melt. In the case of the present invention, since more uniform kneading is required, it is preferable to pass a stationary kneader of 20 stages or more. In other words, kneading of 1 million (2 ²⁰ ) times or more is preferable to prevent uniform distribution of crystallization inhibitors and occurrence of plaque in the final product of mixed fiber.

Otherwise, if the stationary kneader of less than 20 stages is adopted, deterioration of quality may occur due to the occurrence of fine salt spots in the mixed fiber yarn state, and workability decreases in processes such as stretching, resulting in stable workability. There is a possibility of becoming difficult.

As described above, the conventional polyester polymer and the crystal orientation suppressor are uniformly melted and mixed, and then they are continuously spun and wound at a speed of at least 4,000 m / min. The take-up speed increases productivity by 40% at least 4,000 meters per minute. Winding speeds of less than 4,000m / min have little productivity gains, so there is no economic benefit in terms of return on facility investment.

In the present invention, it is preferable to maintain the shear rate in the spinneret during spinning at 7,000 to 15,000 per second. The shear rate at the spinneret during spinning determines whether the crystallization inhibitors within the spun yarn are radially distributed in the radial direction of the fiber. If the shear rate is low, the degree of orientation of the crystallization inhibitor in the fiber axis direction is lowered, which may cause a problem that the effect of suppressing the orientation crystallization of the polyester fiber is reduced. On the other hand, if the shear rate is too high, The problem that the distribution is concentrated on the surface portion of the fiber occurs, which may cause a problem of lowering the strength.

Therefore, if the shear rate in the spinneret is maintained within the range of 7,000 or more and 15,000 or less per second, the effect of suppressing the orientation crystallization of the polyester fiber is sufficiently exerted, and the distribution of the crystallization suppressor in the radial direction of the fiber is appropriately maintained and partially aligned. The strength of the yarn and the false twisted yarn can be maintained properly.

Next, the polyester partial alignment yarn and the stretched yarn prepared above are mixed with air in an air entanglement device. As the polyester drawn yarn, a polyester yarn having a polyethylene terephthalate repeating unit of 85% by weight or more is used. If the polyethylene terephthalate repeating unit is less than 85% by weight, the elongation and residual shrinkage of the stretched yarn is increased, so that the difference in shrinkage with the polyester partial alignment yarn is insignificant. The air pressure is preferably 1 to 3.5kg when air entangled, and the polyester partial orientation yarn is supplied to the effect yarn, and the polyester drawn yarn is supplied to the core yarn.

The polyester blend fiber of the present invention prepared as described above has 95 to 99.5% by weight of the main polyester and the polymethyl methacrylate resin, the polystyrene resin or the methyl methacrylate-styrene copolymer resin as the crystal orientation inhibitor. Polyester partial orientation yarn composed of ~ 5.0% by weight and polyester stretched yarn having a polyethylene terephthalate repeating unit of 85% by weight or more are mixed with each other, 5 to 40 entangled points per 1m of yarn length, and 5-40% residual shrinkage.

In the present invention, the residual shrinkage rate is measured by the following method.

Residual shrinkage (%)

After shrinking the bishrink horn-yom yarn in a tensionless state at 100 ° C. boiling water, measure the length (ℓ ₂ ), dry it sufficiently, and then shrink it for 15 minutes in the tensionless state at 170 ° C. under dry heat to measure the length (ℓ ₃ ). Then, substitute them by the following equation.

Residual Shrinkage (%) = × 100

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited only to the following examples.

Example 1

Polyethylene terephthalate having an intrinsic viscosity of 0.64 was dried at 155 ° C. for 4.5 hours. After melting the chip with a melt extruder, a continuous screw extruder having a glass transition temperature of 105 DEG C and 0.9% by weight of methyl methacrylate / styrene-based copolymer and 91.1% by weight of the polyethylene terephthalate melt (35 mm diameter twin screw extruder (temperature 300 ° C.). In addition, the fine kneading was continuously passed through a 20-stage stationary kneader.

In addition, the polymer melt thus mixed is spun through 36 spinneret perforated spinnerets, and the cooling air at 22 ° C. is blown at a speed of 0.5 m per second to cool and solidify, followed by a take-up roller. The polyester partial alignment yarn of the was prepared. At this time, the shear rate in the spinneret was 9,000 per second and the winding speed was 4,200 m / min.

The polyester partial-orientated yarn thus prepared was supplied to the air entanglement device as an effect yarn, and at the same time, the polyester drawn yarn having 87% polyethylene terephthalate repeating unit was supplied to the same air entanglement device as the core yarn. Polyester blend yarns are prepared.

After weaving the plain fabric using the polyester blended yarn as warp and weft yarn, it was dyed at 130 ° C. for 60 minutes using a disperse dye, and dyeing quality of the salt spot was examined. Table 2 shows the results of evaluating the yarn workability, elongation of partially oriented yarns, the number of interlaced yarns and residual shrinkage, and the quality of the fabrics.

Example 2 to Example 6 and Comparative Example 1 to Comparative Example 2

The polyester blended yarn and its fabric were manufactured under the same process and conditions as Example 1 except that the resin type, glass transition temperature, and mixed weight% of the crystallization inhibitor and the mixed blended condition of the partially aligned yarn were changed as shown in Table 1. . Table 2 shows the results of evaluating the yarn workability, elongation of partially oriented yarns, the number of interlaced yarns and residual shrinkage, and the quality of the fabrics.

Manufacturing condition of polyester blended yarn division Partial alignment company manufacturing conditions (additional conditions for crystal alignment inhibitor) Blending condition Resin type Glass transition temperature (℃) Addition amount (% by weight) Polyethylene terephthalate repeat unit content (wt%) in polyester drawn yarn Air pressure (kg) Example 1 Methyl methacrylate-styrene copolymer 105 0.9 87 3 Example 2 Methyl methacrylate-styrene copolymer 105 2.5 90 2.5 Example 3 Polymethyl methacrylate 106 1.5 88 2.8 Example 4 Polymethyl methacrylate 106 3.5 86 1.5 Example 5 polystyrene 107 2.9 95 2.8 Example 6 polystyrene 107 4.0 85 1.9 Comparative Example 1 - - - 70 2.5 Comparative Example 2 Polymethyl methacrylate 106 0.1 87 2.5

Workability and Yarn Property Evaluation Results division Radiation workability Partial Incliner Elongation (%) Intertwineability Fabric quality Platter touch Bulky castle Interlocking water (per 1m) Residual Shrinkage (%) Example 1 Good 125 Good Good Good 10 12 Example 2 Good 132 Good Good Good 15 18 Example 3 Good 138 Good Good Good 17 26 Example 4 Good 143 Good Good Good 9 22 Example 5 Good 147 Good Good Good 30 16 Example 6 Good 123 Good Good Good 32 31 Comparative Example 1 Bad 83 Bad Bad Bad 10 8 Comparative Example 2 Somewhat defective 110 Bad usually usually 17 26

The present invention can effectively delay the "radiation crystallization" in which the crystallization on the radiation is rapidly increased during high-speed radiation to produce a polyester partial alignment yarn at a winding speed of 4,000m / min or more. As a result, productivity is improved. In addition, the present invention is excellent in stretching processability by uniformly mixing the polyester polymer and the crystal orientation inhibitor. In addition, the present invention can effectively prevent the phenomenon that the crystal orientation inhibitor is moved to the yarn surface to lower the yarn quality, and excellent in the touch and bulkiness during fabric manufacturing.

Claims (6)

95.0 to 99.5% of the polyester polymer having a polyethylene terephthalate repeating unit of 85% or more by weight and 0.5 to 5.0% by weight of the crystallization inhibitor are uniformly mixed in the molten state, and then continuously spun and wound at a speed of 4,000 m or more per minute. A polyester blended yarn comprising a partially oriented yarn having a cut elongation of 120% or more, and blending the partially oriented yarn as an effect yarn and a polyester drawn yarn having a polyethylenetetephthalate repeating unit of 85 wt% or more as a core yarn. Manufacturing method. The method according to claim 1, wherein the glass transition temperature of the crystallization suppressor is 100 ° C or higher. The method for producing a polyester blended yarn according to claim 1, wherein the molten crystal orientation suppressor and the conventional polyester are mixed with a stationary kneader. The method according to claim 1, wherein the conventional polyester in molten state and the crystal orientation suppressor on the solid are melted and mixed in a twin screw extruder. Polyester partial alignment yarn composed of 95 to 99.5% by weight of ordinary polyester as a main component and 0.5 to 5.0% by weight of crystallization inhibitor and polyester drawn yarn having a polyethylene terephthalate repeating unit of 85% or more by weight are mixed with each other, and the yarn length per 1m Polyester entangled yarn, characterized in that 5 to 40 entangled point, the residual shrinkage is 5 to 40%. The polyester blend fiber of claim 5, wherein the crystallization inhibitor is a polymethyl methacrylate resin, a polystyrene resin, or a methyl methacrylate-styrene copolymer resin.