CN101627153B - Polyester fiber, and fabric comprising the same - Google Patents

Abstract

The present invention relates to a polyester fiber in which surface smoothness is maximized by making the cross-section of the fibrils flat and uniform, and the textiles made from said fibers are better than textiles made from fibers of circular cross-section Thin, therefore, the amount of coating resin used and the weight of the product can be reduced due to low surface irregularity and porosity, and the present invention relates to textiles comprising said polyester fibers.

Description

Polyester fibers and textiles containing the polyester fibers

Cross References to Related Applications

This application claims Korean Patent Application No. 10-2007-0021632 filed on March 5, 2007 at the Korean Intellectual Property Office and Korean Patent Application No. 10-2007 filed on March 9, 2007 at the Korean Intellectual Property Office - Priority and benefit of 0023559, which is hereby incorporated by reference for all purposes as if fully set forth herein.

technical field

The invention relates to a polyester fiber and a textile containing the polyester fiber.

Background technique

Ordinary monofilament fibers have a circular cross-section. Such monofilament fibers with a circular cross section are generally used in the form of twisted yarns or in the form of textiles made from such yarns.

However, in the case of using fibers of circular cross-section to prepare textiles, there is a limitation that, because such textiles are thick and have high surface roughness and low flatness, the textiles are not suitable for coated It is not suitable for transfer fabrics such as resin or paint used for signs and so on.

In order to solve these problems, the existing technology has included the extension of the textile by reducing the adhesion coefficient of the textile during the spinning process to increase the smoothness of the final textile. However, in this case, problems such as occurrence of some filaments that cannot take up the tow, poor wrapping due to slipped tow, etc. occur during the winding process, due to the adhesion coefficient of the fibers reduced, the yield of the process is reduced, and there is a limitation that the fibers are caught in the guide due to the reduction of the adhesion coefficient of the fibers and the fuzz is generated due to friction, so that in the weaving process , the product quality is reduced.

In order to overcome these limitations, Korean Patent Publication No. 2004-0011724 discloses a monofilament fiber having a tetragonal cross section. However, the publication only defines the cross-sectional shape of the fiber, and does not provide any practical example of preparing the quadrilateral cross-sectional fiber.

In order to improve these problems of the prior art, the applicant provides a polyester fiber with a flatness of 1.2 to 5.5, a birefringence of 0.205 or more, and a crystallinity of 45% or more, and discloses that it can be obtained by using Tissue fabric with good smoothness was prepared by the same method as Korean Patent Application No. 2004-0100577. However, said publication only deals with flatness as the ratio of the major axis to the minor axis of the fiber cross-section, and does not deal with the specific shape of the shoulder cross-section, which greatly affects the properties of the fiber.

Moreover, the present applicant has disclosed a polyester fiber having a flat cross-section in Korean Patent Laid-Open No. 2006-0089858, the adhesion coefficient of which is not lowered and at the same time by using multi-step interlace (multi-step interlace) to the fiber Uniform mixing with good smoothness. However, said publication only discloses the flatness of such fibers and does not refer to the specific shape of the cross-section of the shoulder, which affects the properties of the fiber.

Since such shape and uniformity of the fiber cross-section affect the properties and smoothness of the fiber, it is important to ensure the uniformity of the cross-section, and especially, it is more effective when the shape of the cross-section has a flat form.

The existing methods for preparing industrial polyester fibers can be divided into two main methods: direct spinning-drawing (DSD, direct spinning-drawing) and warp drawing (warp drawing) (W/D: warp stretcher , where the unstretched fiber is stretched along the warp direction)

The DSD method is a direct spinning and drawing method in which the spinning process and the drawing process are directly linked by passing the undrawn fiber spun in the die of the spinning unit through the drawing in the rolls process and relaxation process to prepare fibers, wherein the execution of the spinning process, stretching process and relaxation process is associated with one processor.

The W/D method is divided into a process for preparing undrawn fibers and a process for preparing drawn fibers, and the method is performed by performing a drawing process and a relaxation process in a warp stretcher after preparing undrawn fibers to prepare fibers.

In the DSD process, an interlacer is used to blend the polyester fibers and the adhesion coefficient is usually controlled by reducing the pressure of the interlacer in order to improve smoothness.

However, when pressure control is used to control the adhesion coefficient (or bonding coefficient) of the fiber, since the gap between the strongly adhered part and the non-adhesive part is partially enlarged, and the adhesion coefficient is reduced, it is caused during the winding process. Some filaments appear which do not take up the tow and cause problems such as poor winding, reduced processability, reduced quality, and the smoothness of the fiber is very off specification.

In particular, when the adhesion coefficient is reduced, the friction between the fiber and the machine during the winding process and the weaving process causes the fiber to scatter, and some filaments of the tow will be caught by the yarn guide and some hook fibers ( pin fiber) and thus generate fluff. Thus, irregularities in smoothness cause differences in the surface roughness of the coated article and thus reduce the quality of the coated textile.

Contents of the invention

The present invention is to solve these problems, and an object of the present invention is to provide flat polyester fibers having good smoothness and uniform structure with improved shrinkage stress and shrinkage rate.

Another object of the present invention is to provide a textile comprising the flat polyester fiber.

In order to achieve the object, the present invention provides a polyester fiber, wherein the flatness of the cross section of the polyester fiber is from 2.0 to 4.0, when the two end points of the longest axis of the fiber cross section are Defined as W1 and W2, the two endpoints of the shortest axis perpendicularly passing through the longest axis at the center point O of the longest axis are defined as D1 and D2, and the line segment between W1 and D1 is defined as L1, The line segment connecting D1 and W2 is defined as L2, the line segment between W1 and D2 is defined as L3, and the line segment between W2 and D2 is defined as L4, from L1, L2, L3 and L4 to the cross-section The vertical distances of the farthest line segments are defined as R1, R2, R3, and R4, respectively, and the vertical distances from L1, L2, L3, and L4 to the center point O are defined as H1, H2, H3, and H4, respectively, when including The coefficient of variation (CV%) of R1 to R4 of all the filaments in the polyester fiber is 20% or less.

The present invention also provides a polyester fiber, wherein the flatness of the cross-section of the fiber is from 2.0 to 4.0, and the shrinkage stress (0.1g/d, 2.5°C/sec) at 150°C is from 0.005 to 0.075g/d, the shrinkage stress (0.1g/d, 2.5°C/sec) at 200°C is from 0.005 to 0.075g/d, and the shrinkage rate (190°C, 15 minutes, 0.01g/d) is from 1.5 to 5.5%.

The present invention also provides a textile comprising polyester fibers.

Description of drawings

Fig. 1 is a schematic diagram of one example of the cross section of the polyester fiber of the present invention.

Fig. 2 is a schematic process diagram of the process of preparing the polyester fiber of the present invention.

Fig. 3 is a schematic plan view of an example of a die used in the spinning process of the present invention.

Figure 4 is a schematic diagram of a cross-section of the mold used showing the capillaries of the mold.

Fig. 5 is a schematic cross-sectional view of an example of a spinning package used in the spinning process of the present invention.

Fig. 6 is a schematic bottom view of an example of a dispersion disk used in the spinning process of the present invention.

Fig. 7 is a schematic cross-sectional view of an example of a dispersion disc used in the spinning process of the present invention.

Figure 8 is a schematic diagram of an interleaver providing interlace air to the fibers in a direction perpendicular to the direction of travel of the fibers.

Figure 9 is a schematic illustration of an interleaver providing interlacing air to fibers in an oblique direction relative to the direction of motion of the fibers.

Fig. 10 is a schematic process diagram of a case where a second interleaver and an after-oiling apparatus are used in common.

Fig. 11 is an optical micrograph showing a cross-section of a flat cross-section fiber prepared according to Example 1 of the present invention.

Detailed ways

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

The present invention relates to polyester fibers and textiles comprising the polyester fibers, wherein the fibers are suitable for the preparation of coated textiles, wherein the textiles made of the fibers are more durable than those made of fibers of ordinary circular cross-section The textile is thin and has a low surface irregularity and porosity.

Compared with the existing method of preparing industrial polyester fiber, the present invention is characterized in that by using a slit-like capillary in the mold to make the cross-section of the fiber flat compared to the existing round fiber, it can be reduced by The thickness, surface irregularities, and porosity of textiles made from this fiber.

The present invention is also characterized in that when the fiber is applied to a textile such as a coated transfer textile, shape stability can be optimized by managing graphic properties, shrinkage stress and shrinkage of the fiber having a flat cross section, and Issues such as abnormal shrinkage etc. were resolved.

Fig. 1 is a schematic diagram of one example of the cross section of the polyester fiber of the present invention. As shown in FIG. 1 , preferably, the flatness, defined as the ratio of the length of the longest axis (W1-W2) to the length of the shortest axis (D1-D2), is from 2.0 to 4.0.

In addition, preferably, in Fig. 1, when the two endpoints of the longest axis of the cross-section are defined as W1 and W2, at the center point O of the longest axis perpendicular to the shortest axis of the longest axis The two endpoints are defined as D1 and D2, the line segment between W1 and D1 is defined as L1, the line segment between D1 and W2 is defined as L2, the line segment between W1 and D2 is defined as L3, and the line segment between W2 and D2 The line segment between is defined as L4, the vertical distance from L1, L2, L3 and L4 to the farthest line segment of the cross section is defined as R1, R2, R3 and R4, respectively, and the vertical distance from L1, L2, L3 and L4 to the center point O When the vertical distances are defined as H1, H2, H3, and H4 respectively, the coefficient of variation (CV%) from R1 to R4 is 20% or less.

When the coefficient of variation (CV%) exceeds 20%, the characteristics and cross-sectional shape of the fiber become irregular, and, due to the occurrence of fiber breakage, partial deformation of the shape, or distortion of the fiber, the workability and quality of the process are affected .

Also, preferably, the average value of the length ratios defined as R1/H1, R2/H2, R3/H3 and R4/H4 in the cross-section is from 0.2 to 0.9. As the average value of the length ratio increases, the shoulder of the fiber becomes larger, and as the average value of the length ratio decreases, the shoulder of the fiber becomes thinner and has an elliptical or diamond-shaped cross-section.

Also, preferably, the coefficient of variation (CV%) of R1/H1, R2/H2, R3/H3 and R4/H4 is 20% or less so that flat cross-section fibers having more stable properties can be produced. In other words, when the deviation coefficients of R1/H1, R2/H2, R3/H3, and R4/H4 exceed 20%, the shape of the cross section is distorted, and the characteristics of the fiber and the properties of the textile made of the fiber Reduced smoothness.

Also, preferably, the shrinkage stress at 150° C. corresponding to the lamination coating temperature of the general-purpose coated fabric is from 0.005 to 0.075 g/d, and, preferably, at the same temperature as the sol-coating temperature of the general-purpose coated fabric The corresponding shrinkage stress at 200°C is from 0.005 to 0.075g/d. That is, when the shrinkage stresses at 150° C. and 200° C. are at least 0.005 g/d, respectively, there is sagging of the textile due to heating during the coating process, and, when the stresses are 0.075 g/d or more hours, the relaxation stress can be released during the cooling process at room temperature after the coating process.

It is also preferable that the shrinkage rate of the polyester fiber at 190° C. is 1.5% or more in order to maintain the shape of the textile by providing tension exceeding a certain level in the heat treatment of the coating process. Preferably, the shrinkage at 190° C. is 5.5% or less in order to ensure thermal shape stability.

The shrinkage stress defined in the present invention is based on a measured value under a fixed load condition of 0.10 g/d, and the shrinkage rate is based on a measured value under a fixed load condition of 0.01 g/d.

The polyester fiber is preferably polyethylene terephthalate (PET) among general-purpose polyester fibers, and more preferably, the polyester fiber is a PET fiber including 90 mol % or more of PET.

Preferably, the intrinsic viscosity of the fiber (intrinsic viscosity) is 0.7dl/g or more, so that the polyester fiber has a shrinkage stress of 0.005g/d or more, and, in order to represent low shrinkage characteristics, preferably, the intrinsic viscosity of the fiber The viscosity is 1.2 dl/g or less, more preferably, the fiber has an intrinsic viscosity of 1.0 dl/g or less.

Furthermore, preferably, the monofilament of the polyester fiber of the present invention having a specific shape has a fineness of from 3.7 to 10.5 de, and, also preferably, the monofilament of the polyester fiber of the present invention having a specific shape has a tensile strength of The strength is from 6.5 to 8.5g/d, and its elongation at break is from 15 to 35%, so as to ensure the physical properties required by industrial fibers.

During the preparation of polyester fibers, the present invention also has a feature that the following characteristics are generated by providing interlacing air when the polyester fibers pass through a pre-interlacer in the weaving process. That is, preferably, since air in one direction within a certain range is supplied to the preinterlacer, the polyester fiber has a monofilament fineness of 3.7 to 10.5 de, which is equivalent to a fiber having a certain shape. Also, in order to maintain thermal shape stability, preferably, the crystallinity is 40% or more, more preferably, the crystallinity is 42% to 52%. Also, the polyester fiber has a tensile strength of 6.5 to 8.5 g/d and an elongation at break of 15 to 35%, an intermediate elongation (4.5 g/d) of 6.5 to 17.5%, and a shape stability index of 12 to 23 (ES) in order to ensure the physical properties required by industrial fibers.

The polyester fiber of the present invention having the above characteristics has a high yield in the process of being made into a textile and coated with a resin, and can produce a textile having good shape stability while reducing the thickness of the textile. The textile comprises a resin coating comprising polyvinyl chloride, polyethylene, polyurethane, etc., the coating is coated or laminated on the surface of the fiber, and the coated resin The types are not limited to the above materials.

Since the fibers of flat cross-section included in the textile fabric of the present invention are excellent in packing properties, and their thickness is small, and the area covered by the fibers themselves is large compared with ordinary fibers of circular cross-section, the The coated textile of the present invention made of fiber has the advantages of small thickness, small porosity, low surface roughness, and therefore, even with a small amount of coating solution, the coated textile can show better coating properties , and, when it is coated, the inferior rate in the coating process is low. Therefore, this textile is very suitable as a transfer fiber for sign boards and the like.

The polyester fiber having a flat section of the present invention can be produced by melting polyester chips having an intrinsic viscosity of 0.7 to 1.2 dl/g at a spinning temperature of 270°C to 310°C, and spinning through a slit-shaped capillary . The intrinsic viscosity of the chips is preferably 0.7 dl/g or more in order to produce fibers with ideal shrinkage stress and shrinkage rate, and the intrinsic viscosity is 1.2 dl/g or less in order to prevent the The molecular chain breaks caused by the pressure in the yarn package.

Fig. 2 is a process schematic diagram of a process for preparing polyester fibers of the present invention. As shown in Fig. 2, the manufacturing method of the fiber comprises the following steps: using quenching air to quench the melted polyester spun yarn spun through the spinning die, and injecting The undrawn fiber is supplied with oil, and the oil supplied to the undrawn fiber is uniformly dispersed to the surface of the fiber by the preinterlacer 130 under normal air pressure. After this, the drawing process is carried out by passing the undrawn fibers through a multi-step drawing device (141-146), and then the drawn fibers are mixed and The fiber is finally made by winding it with a winder (160).

Fig. 3 is a plan view of one example of a die (110) used in the spinning process of the present invention. Referring to FIG. 3, a plurality of capillaries (111) are formed on the upper portion of the spinning die of the present invention. The arrangement type of the capillaries is not particularly limited, but may preferably be triangular, rhombus or circular in which the capillaries are arranged at the same center-to-center distance (PCD).

Fig. 4 is a schematic diagram showing the capillary (111) of the mold in cross-sectional view of the mold (110) used. As shown in FIG. 4 , by forming a capillary structure for allowing liquid polyester to flow out in a slit shape, the cross section of the flowed fiber becomes flatter than the conventional circular shape.

In the shape of the slit in Figure 4, the flatness can be controlled especially by changing the ratio of the longest length (W) to the shortest length (D) of the slit, where the ratio of W/D is defined as the flatness of the mold degree, and the flatness is preferably 5.0 or more in order to express the characteristics of a flat cross section, and it is also preferably 15 or less in order to ensure stretchability and high strength characteristics.

In addition, the shear rate (sec ^-1 ) operated from the slit-shaped die is preferably 1000 to 4500 sec ^-1 in order to secure a uniform cross section in a flat shape. When the shear rate is less than 1000 sec ^-1 , the cross-section becomes uneven because the viscosity of the polymer changes sharply, and when the shear rate is greater than 4500 sec ^-1 , the textile properties deteriorate because the viscosity is excessively decreased.

The spinning package used to spin the molten polymer into fibers is not particularly limited, but preferably, a spinning package having the structure shown in FIG. 5 is used. In the spinning package device with the structure shown in Fig. 5 applied to the present invention, the main body (43) is connected to the lower part of the block (43) equipped with the polymer inlet (42), and, in the main body (43) In the interior of the layer, a dispersion disc (44) with a dispersion surface (44'), a lens ring (45), an isolator (46), a filter (47) made of metal non-woven fabric, a splitter disc (48) are stacked and mold (49), so as to be in the state leading to the polymer inlet (42), and form at least one polymer inflow hole ( 40).

By keeping the distance between the bottom (44″) of the dispersion disc (44) and the filter (47) between 4 and 44 mm, the molten polymer passes through the polymer flow path (50) outside of the dispersion disc (44) ) and the residence time of the molten polymer through the polymer flow hole (40) of the dispersion disc (44) can be kept equal, and therefore the total residence time can be shortened. The bottom (44 " of the dispersion disc (44) ) is also not particularly limited in shape, but it may preferably be planar or gently conical.

The polymer inflow hole is formed in the center of the dispersion disc, and the center-to-center diameter distance (PCD) between successively adjacent inflow holes is 5 to 40 mm, and the total area covered by the inflow holes per the circular area covered by the outer line of the dispersion disc is The area is preferably 1 to 35%. It is difficult to prepare a dispersing disk with a PCD between successively adjacent inflow holes of less than 5 mm, and at a PCD of more than 40 mm, the dispersibility of the polymer tends to decrease. Moreover, when the total area covered by the inflow holes per the total circular area covered by the outer wires of the dispersing disc is less than 1%, the dispersing disc cannot be applied to the present invention because of the reduction in polymer dispersibility and aggregation. The pressure inside the ester spin pack increases, and when it is greater than 35%, the dispersible efficiency of the polymer in the spin pack decreases.

When the molten polymer introduced into the polymer inlet (42) naturally flows down according to the inclination angle of the conical dispersion surface, a part of the polymer flows into the polymer inflow hole (40) passing vertically through the dispersion disc, and the rest flows into the outer polymer stream moving path (50), and all the polymers are extruded and formed into fibers through filter (47), dividing disc (48) and die (49) in sequence.

In the spinning package device of the present invention, when the molten polymer flows on the dispersing disc (44), the polymer flow path (50) is farthest from the central peak of the dispersing surface (44'), and due to the dispersing The inclination of the disc (44) is the shortest at the outer end of the dispersing surface (44') from the bottom (44") of the dispersing disc (44).

On the other hand, the polymer inflow hole (40) is closer to the center of the dispersion pan (44) than the polymer flow path (50), and the distance to the bottom of the dispersion pan (44″) through the polymer inflow hole (40) is longer .

Therefore, it is possible to balance the residence time of the molten polymer passing through the polymer flow path (50) to the sub-disc (48) and the residence time of the molten polymer passing through the polymer inflow hole (40) to the sub-disc (48), And thus the overall residence time can be shortened.

Moreover, in the spinning package device used in the present invention, the filter (47) is a non-woven fused metal textile instead of metal powder, so that the change of fiber properties over time can be prevented. .

The dispersion disc (44) of the present invention may have one or more grooves formed on its periphery as necessary, and preferably, the grooves are arranged at the same interval. These grooves can allow easy flow of molten polymer.

By using a spinning package with these structures, the flow of polymer in the spinning package can be made uniform, and the spinning characteristics can also be improved according to high-pressure spinning because the spinning package increases the rear pressure of the die.

The polymer extruded from the die is quenched through a delayed quench zone, which includes bell heaters (H/H) and thermal insulation plates, in order to reduce spinning tension and reduce thermal history. At this time, the temperature of the mantle heater (H/H) is preferably 200 to 350° C., the length thereof is preferably 100 to 400 mm, and the length of the heat insulating plate is preferably 70 to 400 mm. The residence time of the extruded polymer in the delayed quenching zone is preferably 0.01 to 0.1 sec, more preferably 0.02 to 0.08 sec.

When the temperature of the mantle heater is lower than 200°C and its length is less than 100mm, the stretchability decreases and spinning becomes difficult, while when its temperature is higher than 350°C and its length is greater than 400mm, because polyester Toughness decreases due to degradation, as well as flat shape stability due to reduced elasticity of the molten polymer. Also, when the length of the insulating plate is less than 70 mm, fluff is generated because the stretchability is lowered, and when it is longer than 400 mm, the spinning tension is sharply lowered and winding becomes difficult because the freezing point is excessively lowered. When the time of staying in the delayed quenching zone is less than 0.01 sec, it is difficult to perform delayed quenching, and it is also difficult to ensure drawability because the birefringence of the undrawn fiber is high, and when the time exceeds 0.1 sec, the operation It is also difficult due to fiber deflection and eddy currents due to degradation of tension in the undrawn fibers extruded from the die, resulting in fluff generation and fiber breakage, and due to excessive reduction in the elasticity of the molten polymer, It is also difficult to obtain the required cross-section of the fibers.

A spinning oil is provided to the polyester fiber which has been subjected to a quenching process by passing the polyester fiber through an oil roll. Any of the oils used in the preparation of ordinary polyester fibers can be used, and preferably, ethylene oxide/propylene oxide belonging to glycol esters, ethylene oxide belonging to glycol esters, triglyceride One or a mixture of two or more selected from esters, trimethylpropane triesters or other ethylene oxide complexes, and the spinning oil may also include an antistatic agent and the like. However, the spinning oil of the present invention is not limited to the above examples.

After the polyester fiber equipped with spinning oil passes through the pre-interlacer, it is stretched by a stretcher, and the stretching environment can follow the stretching method of ordinary polyester fibers.

Then, the polyester fiber may be passed through the pre-interlacer as such, and interlacing air having a direction within a certain range may also be selectively supplied to the pre-interlacer.

When the interlacing air is supplied to the preinterlacer, the present invention provides polyester fibers having the above-mentioned properties, and also makes it possible to provide polyester fibers having conventional properties through the post-drawing process explained hereinafter, wherein the degree of crystallinity is from 42 to 52%, tensile strength from 6.5 to 8.5g/d, elongation at break from 15 to 35%, intermediate elongation (4.5g/d) from 6.5 to 17.5%, shape stability index ( ES) is from 12 to 23.

According to the method of supplying the interlacing air to the pre-interlacer, as shown in FIG. 8, the interlacing air can be provided to the pre-interlacer in the direction perpendicular to the direction of fiber motion, and, as shown in FIG. The direction of the oblique direction provides interweaving air. Since the cross-section of the undrawn fiber is flat, it is more preferable, as shown in FIG. 9, to supply intertwined air in an oblique direction with respect to the direction of movement of the fiber to prevent eddy currents of the undrawn fiber caused by the air. , and most preferably, the direction of interweaving air has an angle of 0° to 80° to a plane perpendicular to the direction of fiber movement.

Also, preferably, the pressure of interlacing air is 0.1 kg/cm ² or more in order to sequentially collect undrawn fibers and improve stretchability while uniformly removing textile oil supplied to undrawn fibers , and, also preferably, the pressure of the interlacing air is 1.5 kg/cm ² or less in order to prevent a decrease in stretchability caused by excessive interlacing of unstretched fibers.

In the spinning process, when the spinning speed is lower than 400m/min, the fiber quality is reduced due to fiber deviation, and when the spinning speed exceeds 900m/min, the processability of the fiber is reduced due to the generation of fuzz.

Moreover, the draw ratio is preferably 4.5 to 6.2 times, because when the draw ratio in the spinning process is less than 4.5 times, it is difficult to have the required high toughness characteristics, and when the draw ratio is greater than 6.2 times, due to the fluff Produced, the quality of the fiber is reduced. The stretching process of the present invention is accomplished by a pre-stretching process carried out between devices 141 and 142 in FIG. Two stretching steps in order to ensure uniform stretchability between monofilaments, and the stretching ratio of the pre-stretching is preferably 1.01 to 1.1, and the stretching ratio of the first stretching step is preferably 60 to 1.1 of the total stretching ratio 85%.

When the temperature of the heat treatment performed in the stretching device 144 is less than 215°C, the shape stability decreases due to an increase in shrinkage, and when the temperature is higher than 250°C, fiber breakage and tar (tar) of the godet Occurs frequently and reduces machinability. Therefore, the heat treatment temperature is preferably 215 to 250°C, more preferably 230 to 245°C.

When the relaxation rate of the stretching process carried out in the multi-step stretching devices 144 and 146 is less than 4%, the cross section of the fiber may be distorted due to excessive tension, and when the relaxation rate exceeds 13%, the work is difficult. , because of excessive fiber deflection on the godet. Therefore, the relaxation rate is preferably 4 to 13% and the relaxation temperature is preferably 150 to 245°C.

Also, the present invention can interlace the fibers by applying the second interleaver again to the undrawn polyester fibers.

The second interleaver mixes polyester fibers by using air pressure. The second interleaver improves the reduction of the adhesion coefficient according to the reduction of the air pressure of the conventional interweaving, and performs uniform mixing along the length direction (or moving direction) of the fiber.

The second interlacer can be set separately or together outside the winder, or set between the guide wheels as a drawing device (equivalent to 141 to 146 in Figure 2), the interlacing air must be in the direction of the oblique direction of the fiber movement direction Provided, as shown in Figure 9, and preferably, that the direction of the interweaving air has an angle of 20° to 80° to a plane perpendicular to the direction of movement of the fibers. At this time, the air pressure is preferably 0.1 to 4 kg/cm ² .

When the air pressure is less than 0.1 kg/cm ² , it is insufficient to provide fibers having the cohesion coefficient, thus resulting in a decrease in cohesion coefficient, winding disorder and generation of fuzz. Moreover, when the air pressure exceeds 4.0kg/ ^cm2 , there is too much strong mixing (or too large CFP (needle adhesion coefficient)) between the fiber filaments, it is difficult to obtain the required smoothness, and the fiber length direction The degree of irregularity is large.

The second interleaver can be applied consecutively in multiple steps in order to increase the number of micro-mixes. Where multiple steps are used, the interleaver is preferably equipped with 2 ea or more, more preferably 2 to 4 ea. When the second interleaver is equipped with multiple steps, the step number of the multi-step interleaver is preferably at most 4 ea because its installation is difficult, and workability decreases when the multi-step number of the interleaver is 5 ea or more.

The polyester fiber passed through the second interweaver is wound by a winder, and then the polyester fiber of the present invention is finally produced.

And, the polyester fiber method of the present invention may further include providing a post-oiling process by equipping a post-oiling device between the second interweaver and the winder, so as to improve the post-oiling process by improving the antistatic properties and adhesion coefficient of the fiber. Processing machinability.

Fig. 10 is a schematic process diagram in the case of using together a second interleaver and a post-oiling device using multiple steps of two or more steps. As shown in Figure 10, the second interleaver (150) is located after the stretching device (145, 146) for polyester fibers. Also, the post-oiling device (430) is a nozzle guide type, and is installed up and down or left and right with respect to the fiber moving direction, and performs a function of applying post-oiling to the fibers.

As an auxiliary device of the post-oiling device, it includes an oil cylinder (431) for storing the post-oiling device, a metering pump (432) for quantitatively sending oil to the post-oiling device and collecting oil dripping from the post-oiling device, And the oil is delivered or recirculated to the oil cylinder and the anti-contamination oil collection cylinder (433) to the winder (440) is performed.

The amount of oil provided during the post-oiling process is preferably 0.1 to 2.0 wt% based on the weight of the polyester fiber. When the amount of oil is less than 0.1 wt%, the improvement effect of the adhesion coefficient and the required antistatic properties of polyester fibers are not significant, and when the amount of oil exceeds 2.0 wt%, pollution caused by oil may occur, And it reduces the bond strength when applied to coated textiles.

The post-oiling used for ordinary polyester fibers can be used as the post-oiling of the present invention. The post-oil is different from the oil provided before the stretching process, and post-oil containing polyethylene alkyl polyol, polyoxyethylene alkyl ether, antioxidant, antistatic agent, and the like as main components may be used.

The production method of the present invention can also (between 145 and 146 in FIG. 2 ) apply a tension yarn guide after the relaxation process in order to prevent (between 145 and 146 in FIG. 2 ) Overlapping of monofilaments.

Hereinafter, preferred examples of the present invention are described. However, the following examples are only for illustrating the present invention, and the present invention is not limited to or by the examples.

【Example】

Examples 1 to 7

Solid state polymerized polyester chips having an intrinsic viscosity (IV) of 0.85 g/dL were melted and extruded through a slot-like spinning capillary.

Delayed quenching of the extruded molten polyester fibers was performed by passing through a delayed quenching zone comprising mantle heaters and insulating plates.

Spinning oil was supplied to the quenched polyester fiber by using a roller lubricating device. At this time, the amount of oil is 0.8 parts by weight per 100 parts by weight of fibers, and ethylene oxide/propylene oxide (30 parts by weight) belonging to glycol esters, ethylene oxide which belongs to glycol esters, is used. (15 parts by weight), triglyceride (10 parts by weight), trimethylpropane triester (10 parts by weight) and a small amount of antistatic agent mixed spinning oil.

The fiber provided with oil passes through the pre-interlacer and is stretched by the guide wheel.

After the drawing process, the drawn fibers are mixed by a second interweaver and wound with a winder to finally make polyester fibers.

The conditions of the examples of the present invention, such as the shape and flatness of the capillary of the spinning die, the shear rate (sec ⁻¹ ) on the die, the structure of the spinning package used, mantle heating are listed in the following Table 1 The temperature and length of the machine, the length of the heat insulation board, the residence time of the delayed quenching zone, the spinning speed, the relaxation rate, the heat treatment temperature and so on. In addition, the shape of the spinning package is not particularly limited, but polyester fibers are preferably produced by using the spinning package having the shape in FIG. 5 .

Comparative Example 1

Polyester fibers were prepared according to several conditions in Table 1.

[Table 1]

Experiment example 1

Regarding the polyester fibers prepared according to Examples 1 to 7 and Comparative Example 1, the flatness, shrinkage pressure, shrinkage rate, intrinsic viscosity, tensile strength, elongation at break, cross-sectional shape index (R1, H1) of the fibers , R1/H1, and CV%), the yield of post-processing, the processability (F/D) of processing and the thickness of the coated textile were measured by the following methods. The measured properties of each fiber are listed in Table 2 below, and a photograph of the cross section of the flat fiber prepared according to Example 1 is illustrated in FIG. 11 .

1) Flatness

The flatness indicates the flatness of the cross-section of the fiber, and by cutting the fiber with a copper sheet, using an optical microscope to enlarge the cross-section and measuring the longest length (W) and the shortest length (D) of the cross-section of the fiber, according to the calculation formula 1 Accurately calculate the flatness of the monofilament and average all the filaments to obtain the flatness of the fiber.

Calculation formula 1

Flatness of monofilament (Fi) = W/D,

Flatness of fiber = (sum of flatness of monofilaments)/(number of monofilaments).

2) Coefficient of variation (CV%) of R1, R2, R3, and R4

As shown in Figure 1, according to the photo of the fiber cross-section enlarged by the optical microscope, measure the R1, R2, R3, and R4 of the monofilament, calculate their average value and standard deviation according to the calculation formula 2, and then obtain according to the calculation formula 3 Its coefficient of variation (CV%).

[Calculation formula 2]

Average value (R) = sum of (R1+R2+R3+R4) of all filaments/(4×n)

where n is the total number of fibrils measured and R is the average of R1, R2, R3 and R4 for all fibrils.

[Calculation formula 3]

Coefficient of variation (CV%) = standard deviation (σ) / average value (R) × 100 (%)

3) Mean and standard deviation of R1/H1, R2/H2, R3/H3, and R4/H4

Measure R1, R2, R3, and R4, and H1, H2, H3, and H4 in Figure 1 according to the cross-sectional photo of the fiber enlarged by an optical microscope, and calculate R1/H1 of all filaments according to the following calculation formula 4 , R2/H2, R3/H3, and R4/H4 mean and standard deviation, and then obtain the coefficient of variation (CV%) according to calculation formula 3.

[Calculation formula 4]

Average value (R/H) = sum of (R1/H1+R2/H2+R3/H3+R4/H4) of all filaments/(4×n)

where n is the total number of fibrils measured and R/H is the average of R1/H1, R2/H2, R3/H3, and R4/H4 for all fibrils.

4) Shrinkage stress (g/d)

Shrinkage stress was measured by using a thermal stress tester (Kanebo Co.) at 150°C and 200°C, respectively, while increasing the temperature at a scan rate of 2.5°C/sec under an initial load of 0.1 g/d. Samples were prepared by tying knots in the form of loops.

[Calculation formula 5]

5) Shrinkage (%)

Shrinkage is a value representing the percentage of change in length of a sample caused by heating at a specific temperature, which is defined according to Calculation Formula 6 below.

[Calculation formula 6]

Shrinkage (%)={(L ₀ -L ₁ )/L ₀ }×100

where _L0 is the length of the sample before heat shrinkage, and _L1 is the length of the sample after heat shrinkage.

After fixing the fiber under a normal load of 0.01 g/d, shrinkage was measured by Testrite MK-V (Testrite Co.), and the measurement conditions were based on a state at 190° C. for 15 minutes under a load of 0.01 g/d.

6) Intrinsic viscosity of fiber

After extracting the spinning oil from the sample using carbon tetrachloride and dissolving the sample in n-chlorophenol at 160±2°C, it was measured by using an automatic viscometer (Skyvis-4000) at a temperature of 25°C. The viscosity of the sample was measured in a capillary, and the intrinsic viscosity of the fiber was calculated according to formula 7.

[Calculation formula 7]

Intrinsic viscosity (IV) = {(0.0242×Re1)+0.2634}×F

in,

Re1 = (dissolution seconds x specific specific gravity of solution x viscosity coefficient)/(OCP viscosity), and

F = IV of standard section/average of three IV measurements of standard section performed using standard procedures.

7) Tensile strength (g/d), elongation at break (%)

Tensile strength and elongation at break were measured by a universal tester (UTM, Instron Co.) with a sample length of 250 mm, an extension speed of 300 mm/min, and an initial load of 0.05 g/d.

8) Machinability of processing (F/D)

As an index representing the productivity of fibers, the ratio of the number of full-cheese doffing to the total number of doffing was calculated according to the following calculation formula 8.

[Calculation formula 8]

9) The number of fluff on the warp knitting machine (ea/10 ⁶ m)

The warp knitting machine fluff count was calculated by converting the number of check times of the fluff detector to a scale of 10 ⁶ m.

10) Yield rate of post-processing

Calculate the percentage of authentic products to the total input of fibers according to the calculation formula 9 below.

[Calculation formula 9]

Yield rate of post-processing = number of genuine products / total input of fibers × 100

11) Thickness of coated textile

After fabrics were prepared from the fibers prepared in Examples 1 to 7 and Comparative Example 1 using an ordinary rapier weaving machine under the same conditions, 250 parts by weight of polyvinyl chloride (PVC) was coated on 100 parts by weight of polyester Textiles to prepare PVC-coated textiles.

After measuring the thickness of the woven fabric, the thickness (T) of the woven fabric prepared from the polyester fibers according to Examples 1 to 7 was divided by the thickness (t) of the woven fabric prepared from the polyester fiber according to Comparative Example 1, and Calculate its percentage according to formula 10.

[Calculation formula 10]

Fabric thickness (%, relative value) = T/t × 100

[Table 2]

As shown in Table 2, the polyester fibers of the present invention prepared according to Examples 1 to 7 are not only good in thermal shape stability due to low shrinkage pressure and low shrinkage rate, but also because of the uniformity of the flat shape of the fiber cross section. On the other hand, the characteristics of the fiber are good. In addition, they showed processing workability and quality (fluff level) equal to ordinary polyester fibers with a circular cross-section prepared according to Comparative Example 1, and could reduce the thickness of coated textiles and contribute to lightening the product. weight and improve surface smoothness.

Examples 8 to 14 and Comparative Example 2

Solid state polymerized polyester chips having an intrinsic viscosity (IV) of 0.85 g/dL were melted and extruded through a slot-like spinning capillary.

Delayed quenching of the extruded molten polyester fibers was performed by passing through a delayed quenching zone comprising mantle heaters and insulating plates.

Spinning oil was supplied to the quenched polyester fiber by using a roller lubricating device. At this time, per 100 parts by weight of fibers, the amount of oil is 0.8 parts by weight, and using ethylene oxide/propylene oxide (30 parts by weight) belonging to glycol esters, ethylene oxide (15 parts by weight) belonging to glycol esters ), triglyceride (10 parts by weight), trimethylpropane triester (10 parts by weight) and a small amount of antistatic agent mixed spinning oil.

The fiber provided with oil passes through the preinterlacer in Fig. 9 and is stretched by the guide wheel.

After drawing, the drawn fibers were mixed by using the second interleaver in FIG. 9 .

By using a nozzle-guided type post-oiling device, post-oiling is provided to the polyester fiber that has passed through the interlacer. At this time, per 100 parts by weight of fibers, the amount of post-oiling was 0.7 parts by weight, and polyhydroxypolyethylene alkyl compound (70 parts by weight), polyvinyl chloride alkyl compound (20 parts by weight), antioxidant (2 parts by weight) and antistatic agent (2 parts by weight) after oiling.

After the post-oiling process, it is wound with a winder to finally prepare polyester fibers.

The conditions of the present invention, such as the shape and flatness of the spinning die capillary, the temperature and length of the mantle heater, the length of the insulation board, the residence time of the delayed quenching zone, the The direction and pressure of the air, the spinning speed, the stretch ratio (the stretch ratio of the pre-stretch, and the stretch ratio of the first step compared with the total stretch ratio), relaxation rate, heat treatment temperature, Secondary interleaver number, direction and pressure of air, supply or non-supply of spinning oil and post-oiling, etc.

The air direction of the interleaver refers to the angle of the air jet based on the perpendicular direction with respect to the direction of fiber movement as shown in FIG. 9 . That is, 0° refers to the direction of motion perpendicular to the fiber, and 90° refers to the direction of motion parallel to the fiber.

[table 3]

Experiment example 2

Regarding the polyester fibers prepared according to Examples 8 to 14 and Comparative Example 2, the flatness, shrinkage stress, shrinkage, intrinsic viscosity, tensile strength, elongation at break, processed Processability, warp pile count and thickness. In addition, crystallinity, intermediate elongation and shape stability index were measured by the following methods. The measured properties are listed in Table 4 below, and as shown in FIG. 11 , a cross-sectional picture of the flat fiber prepared according to Example 8 was obtained.

12) Crystallinity (%)

The fiber density ρ was measured according to the gradient method using n-heptane and carbon tetrachloride at 25°C, and the crystallinity was calculated according to Calculation Formula 11 below.

[Calculation formula 11]

where p is the fiber density, p _c is the density of the crystalline region (1.475 g/cm ³ in the case of PET), and p _a is the density of the amorphous region (1.336 g/cm ³ in the case of PET).

13) Intermediate elongation (%) and shape stability index

The intermediate elongation is based on a value corresponding to a stress of 4.5 g/d in the stress-strain curve measured by UTM. The shape stability index was calculated based on the shrinkage rate of Testrite MK-V measured under a load of 0.01 g/d at 190°C for 15 minutes according to the following calculation formula 12.

[Calculation formula 12]

Shape Stability Index (ES) = Intermediate Elongation + Shrinkage

14) Thickness of coated textile

After preparing textiles from fibers prepared according to Examples 8 to 14 and Comparative Example 2 using a common rapier weaving machine under the same conditions, 250 parts by weight of polyvinyl chloride (PVC) was coated on 100 parts by weight of polyester textiles. , to prepare PVC-coated textiles. After measuring the thickness of the woven fabric, the thickness (T) of the woven fabric prepared according to the polyester fiber prepared according to Examples 8 to 14 was divided by the thickness (t) of the woven fabric prepared according to the polyester fiber prepared according to Comparative Example 2, Its percentage is calculated according to the calculation formula 13 below.

[Calculation formula 13]

Fabric thickness (%, relative value) = T/t × 100

[Table 4]

As shown in Table 4, the polyester fibers prepared according to Examples 8 to 14 of the present invention are good in thermal shape stability due to low shrinkage stress and low shrinkage rate, and deformation caused by heat applied during post-processing is small, And shows that its processability and quality (fluff level) are equal to ordinary polyester fibers with circular cross-section prepared according to Comparative Example 2, and in addition, the thickness of the coated textile can be reduced and contribute to the lightening of the product weight and improve surface smoothness.

The polyester fiber of the present invention maximizes surface smoothness by making the cross-section of the monofilaments flat and uniform, and has various advantages in that the textiles made of the fibers are better than those made of fibers with circular cross-sections. It is thinner and, due to the reduced surface irregularity and porosity, it is possible to reduce the amount of resin applied and reduce the weight of the product.

Claims (9)

1. A polyester fiber, wherein the flatness of the cross-section of the polyester fiber is from 2.0 to 4.0, and the coefficient of variation of R1 to R4 of all filaments included in the polyester fiber is 20% or less, wherein the two endpoints of the longest axis of the cross-section are defined as W1 and W2, and the two endpoints of the shortest axis perpendicularly passing through the longest axis at the midpoint O of the longest axis are defined as Defined as D1 and D2, the line segment between W1 and D1 is defined as L1, the line segment between D1 and W2 is defined as L2, the line segment between W1 and D2 is defined as L3, and the line segment between W2 and D2 is defined as Defined as L4, the perpendicular distances from L1, L2, L3 and L4 to the farthest line segments of the cross-section are defined as R1, R2, R3 and R4, respectively, from L1, L2, L3 and L4 to the midpoint O The vertical distances of are defined as H1, H2, H3 and H4 respectively; The average value of the length ratios defined as R1/H1, R2/H2, R3/H3 and R4/H4 in said cross section is from 0.2 to 0.9; Wherein, the polyester fiber is produced by melting polyester chips with an intrinsic viscosity of 0.7-1.2 dl/g at a spinning temperature of 270° C.-310° C. and spinning through a slit-shaped capillary. 2. The polyester fiber according to claim 1, wherein the coefficients of variation of R1/H1, R2/H2, R3/H3 and R4/H4 of all the filaments included in the polyester fiber are 20% or more Small. 3. The polyester fiber according to claim 1, wherein, under an initial load of 0.1 g/d, the temperature is increased at a scanning speed of 2.5° C./second, and the shrinkage stress measured using a thermal stress tester at 150° C. is from 0.005 to 0.075g/d; increasing temperature at an initial load of 0.1g/d at a scan rate of 2.5°C/sec, shrinkage stress measured using a thermal stress tester at 200°C from 0.005 to 0.075g/d; and The measurement conditions are based on a state at 190° C. for 15 minutes under a load of 0.01 g/d, and the shrinkage rate measured by Testrite MK-V is from 1.5 to 5.5%. 4. The polyester fiber according to claim 1, comprising polyethylene terephthalate (PET) in an amount of 90 mol% or more. 5. The polyester fiber according to claim 4, wherein the intrinsic viscosity is from 0.7 to 1.0 dl/g. 6. The polyester fiber according to claim 1, wherein the tensile strength is from 6.5 to 8.5 g/d, and the elongation at break is from 15 to 35%. 7. The polyester fiber according to claim 1, wherein the monofilament has a fineness of from 3.7 to 10.5 de. 8. A textile comprising the polyester fiber according to any one of claims 1 to 7. 9. A textile according to claim 8, comprising one or more resin layers coated or laminated on the surface of the textile.

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