JP5219107B2 - Method for producing polyester fiber - Google Patents

Description

  The present invention relates to a method for producing a polyester fiber, and in particular, relates to a method for producing a high-strength polyester fiber or a different shrinkage mixed yarn in which two types of polyester fibers having different shrinkage characteristics are mixed. Is.

Polyester fiber typified by polyethylene terephthalate fiber has well-balanced mechanical properties, chemical properties, and good moldability, and can be manufactured at low cost by melt spinning / drawing and high-speed spinning methods. Widely used for industrial use. As one of the polyester fiber products, there is a polyester mixed yarn in which two or more kinds of fiber groups having different heat shrinkage rates are mixed to give a feeling of swelling and softness when made into a fabric. As a method for obtaining such a mixed fiber, a method in which fibers having different heat shrinkage rates are separately spun and the wound yarn is processed in a separate process is adopted. There was a problem in terms of. For example, Patent Document 1 proposes a technique using polyester copolymerized with 2,2-bis [4- (β-hydroxyethoxy) phenyl] propane as a high shrinkage yarn. However, such a copolyester has a problem that light fastness deteriorates and is not preferable in terms of dyeability. Patent Document 2 proposes a technique of using two types of polyesters having different intrinsic viscosities and selecting polyester fibers having low intrinsic viscosities as high shrinkage yarns. However, since it is necessary to use a different polymer, it is disadvantageous in terms of production management, and since a polymer having a low intrinsic viscosity is used, there is an undesirable problem in terms of yarn strength. From the viewpoint of improving productivity, there has been proposed a method in which various fiber groups are simultaneously spun in the spinning process, wound after being mixed. Patent Document 3 proposes a technique in which two types of fiber groups having different take-up speeds are finally supplied to a roller having the same speed and wound after mixing. However, with this method, there is a limit to the control of the difference in shrinkage between the two fiber groups, and sufficient bulkiness cannot be obtained.
JP-A-55-057013 JP-A 64-026716 Japanese Patent Laid-Open No. 02-127514

  The present invention eliminates the above-mentioned problems of the prior art and provides a method for producing a high-strength polyester fiber, or a method for producing a polyester mixed yarn excellent in mechanical properties and bulkiness with one kind of polymer. It is to provide.

  In the present invention, when spinning polyester by spinning from a spinneret, the spinning yarn is passed through a heating device having an atmospheric temperature (melting point of polyester—100 ° C.) to 300 ° C. The present invention relates to a method for producing a polyester fiber characterized by passing through a cooling device at 50 ° C., and a method for producing a spun blended yarn characterized by using the polyester fiber as one component of a spun blended yarn.

  According to the present invention, a high-strength polyester fiber can be obtained, and a polyester mixed yarn excellent in bulkiness and mechanical properties can be produced with one kind of polymer.

The polyester referred to in the present invention is a polyester mainly composed of polyethylene terephthalate. The polyester may contain other ester-forming components less than 10 mol%.
Examples of the ester-forming component include terephthalic acid and ethylene glycol, ethylene oxide component, aromatic dicarboxylic acid such as isophthalic acid, naphthalenedicarboxylic acid and diphenyldicarboxylic acid, diol component such as propylene glycol and butylene glycol, or the former And a polymer obtained by melting and mixing a polymer obtained from the latter component into polyethylene terephthalate.
Furthermore, additives such as stabilizers, antioxidants, plasticizers, matting agents, flame retardants, and lubricants can be blended with the polyester used in the present invention.

  The intrinsic viscosity of the polyester used in the present invention [measured at 35 ° C. in a phenol / tetrachloroethane mixed solvent (mixing weight ratio = 6/4) at a mixing weight ratio of 6/4] is preferably 0.6 dl in order to develop excellent mechanical properties. / G or more, more preferably 0.8 to 2.0 dl / g.

  In the spinning process of the present invention, when the polyester melted and weighed by a conventional method is discharged from a spinneret and wound, the spinning yarn has an atmospheric temperature (melting point of polyester-100 ° C) to 300 ° C. After passing through the heating device, it is characterized by passing through a cooling device having an ambient temperature of 0 to 50 ° C. That is, in the present invention, the spun yarn is passed in the running direction of the yarn by passing the spun yarn through the heating device at the above specific ambient temperature (corresponding to one kind of drawing treatment), Next, this orientation is fixed by passing through a cooling device at a specific atmospheric temperature, and thereby high-strength polyester fibers are obtained.

  FIG. 1 shows an example of a spinning device for carrying out the method for producing a spun mixed yarn of the present invention. First, filaments a and b are melt-spun from different spinnerets 1a and 1b, respectively. Next, the filament a passes through the heating device 2 and then passes through the cooling device 3 to be cooled and solidified. On the other hand, the filament b is converged simultaneously with the application of the oil by the oil application device 4 without passing through the heating device 2 and the cooling device 3. Next, the filaments a and b are combined, entangled by the entanglement device 5, taken up by the take-up roll 6, and taken up by the take-up device 7.

  In the present invention, the heating device and the cooling device for allowing the filament a to pass have a function of supplying and circulating a heating and cooling medium therein. The type of the medium is not particularly limited and may be either a gas or a liquid, but a liquid is more preferable in that a large stress can be applied to the filament (spun yarn). The reason why a physical property difference can be given between two filaments in such a device is not clear, but a large stress is applied to the spun yarn by introducing the filament to a heating device before cooling and solidification of the spun yarn proceeds. It is considered that the filament a becomes highly oriented and can be fixed by continuing this structure to the cooling device.

  The medium temperature in the heating device (that is, the atmospheric temperature of the heating device) is (melting point of polyester—100 ° C.) to 300 ° C., preferably 180 to 220 ° C. When the medium temperature is less than (melting point of polyester—100 ° C.), cooling solidification is promoted before high stress is applied to the filament, and desired physical properties cannot be obtained. On the other hand, when it exceeds 300 ° C., thermal decomposition of the polyester is promoted, and desired physical properties cannot be obtained.

The optimum length of the filament a passing through the heating device (depth of the heating device) varies depending on other spinning parameters such as spinning temperature, spinning speed, filament fineness, intrinsic viscosity of the polyester, but is 5 to 50 cm. preferable. If it is less than 5 cm, sufficient stress is not applied to the filament and high orientation is not achieved. On the other hand, if it exceeds 50 cm, the orientation becomes high, but the crystallization proceeds so much that a sufficient difference in physical properties cannot be obtained. More preferably, it is 10-40 cm.
The optimum position of the heating device varies depending on other spinning parameters such as spinning temperature, spinning speed, filament fineness, and intrinsic viscosity of the polyester, but is preferably 100 cm or less from the spinneret surface. When it exceeds 100 cm, cooling and solidification of the filament is completed, and high orientation is not achieved. More preferably, the position is 10 to 60 cm from the spinneret surface.

  Moreover, the medium temperature (namely, atmospheric temperature in a cooling device) in a cooling device is 0-50 degreeC, Preferably it is 20-40 degreeC. When the medium temperature exceeds 50 ° C., the cooling capacity is not sufficient and desired physical properties cannot be obtained. On the other hand, if the medium temperature is less than 0 ° C., the cooling effect does not increase so much, and the cost for lowering the medium temperature increases, which is not desirable.

The optimum length of the filament a that passes through the cooling device (depth of the cooling device) varies depending on other spinning parameters such as spinning temperature, spinning speed, filament fineness, and intrinsic viscosity of polyester, but is 1 to 50 cm. preferable. If it is less than 5 cm, the cooling capacity is not sufficient, and desired physical properties cannot be obtained. On the other hand, if it exceeds 50 cm, the cooling effect does not increase so much and the apparatus becomes larger and the cost becomes higher. More preferably, it is 10-30 cm.
The optimum position of the cooling device varies depending on other spinning parameters such as the spinning temperature, spinning speed, filament fineness, and intrinsic viscosity of the polyester, but is preferably 50 cm or less from the lower surface of the heating device. When it exceeds 50 cm, the desired physical properties cannot be obtained due to cooling by the outside air before the filament enters the cooling device. More preferably, the position is 0 to 30 cm from the lower surface of the heating device .

  The take-up speed (winding speed) is usually 2,500 to 5,000 m / min, preferably 3,000 to 4,500 m / min. If it is less than 2,500 m / min, the filament group constituting the blended yarn has an increased elongation and a boiling water shrinkage rate, so that a physical property difference between the filament groups does not appear and a blended yarn exhibiting a sufficient texture is obtained. I can't. On the other hand, when it exceeds 5,000 m / min, the elongation and the boiling water shrinkage rate of each filament group are small, and sufficient bulkiness cannot be obtained.

  The elongation / boiling water shrinkage of the filament a obtained in this manner is usually 20-50%, preferably 25-40%, and the boiling water shrinkage is usually 8-35%, preferably 10%. About 20%. Further, the elongation / boiling water shrinkage of the filament b obtained is usually 25-60%, preferably 30-50%, and the boiling water shrinkage is usually 5-20%, preferably 5-10. %.

Next, FIG. 2 shows an example of a spinning device for carrying out the method for producing a polyester fiber of the present invention. First, the filament a is melt-spun from the spinneret 1a. Next, the filament a passes through the heating device 2 and then passes through the cooling device 3 to be cooled and solidified. Further, the filament a is focused simultaneously with the application of the oil agent by the oil agent applying device 4 and taken up by the take-up roll 6. Winding is performed by the winding device 7.
In FIG. 2, the take-up speed (winding speed) is usually 300 to 5,000 m / min, preferably 500 to 3,000 m / min.
2 is basically the same as the configuration and operation of FIG. 1 except that the spinneret 1b and the entanglement device 5 are not used, and the description of the other configurations and operations is omitted.

  In FIG. 2, after winding the filament with the winding device 7 or without winding, the drawing temperature is 70 to 100 ° C., preferably 80 to 90 ° C., and the draw ratio is 2.5 to 8. It may be stretched at 0, preferably 5.0 to 7.0.

In this way, the stretched filament a obtained by FIG. 2 has a high elongation / boiling water shrinkage ratio of usually 8 to 12 cN / dtex, preferably 8.5 to 10.5 cN / dtex, and an elongation of Usually, it is 8 to 15%, preferably 9 to 13%.
According to FIG. 2, a high-strength polyester fiber can be obtained.

  The yarn obtained by the method for producing the polyester fiber and spun mixed yarn of the present invention has a total fineness of 0.1 to 6,000 dtex, preferably about 2 to 2,000 dtex, and a filament count of 1 to 500 filaments, Preferably, about 1 to 300 filaments are targeted.

Hereinafter, the present invention will be described specifically and in more detail by way of examples. However, the present invention is not limited to the following examples.
In addition, the physical-property value in an Example was measured with the following method.
Intrinsic viscosity (IV)
Using Shodex GPC-101 manufactured by Showa Denko KK, measurement was performed with an eluent HFIP, a column HFIP-806M × 2, a detector RI, and a flow rate of 1.0 mL / min, and converted using polyethylene terephthalate known in IV.
Strength and elongation Measured according to JIS L 1013 (1999) using an autograph manufactured by Shimadzu Corporation at an initial sample length of 100 mm and a tensile speed of 100 mm / min.
Boiling water shrinkage (BWS)
Measure the sample length L0 by applying a load of 100 mg / de (8.83 × 10 ^-4 cN / dtex) to the filament, then treat the sample with boiling water for 30 minutes under no load, and apply a load of 100 mg / de again. The sample length L1 was measured and calculated by the following formula.
BWS (%) = [(L0-L1) / L0] × 100
Tactile Feel Evaluation After the mixed yarn was knitted to develop a shrinkage difference, the tactile sensation (softness, swelling) was evaluated in three stages: ○ (good), Δ (slightly bad), and x (bad).

Examples 1 and 2
A polyethylene terephthalate chip (IV = 0.98, melting point 265 ° C.) is discharged from a spinneret having a hole diameter of 0.5 mmφ and a hole number of 12 using a twin screw extruder at a die temperature of 300 ° C. and spinning with an apparatus as shown in FIG. , Took up. For filament a, the base-heating device distance was 50 cm, the heating device depth was 10 cm, the heating device temperature was 180 ° C., and the cooling device temperature was 40 ° C., and 1,2-propanediol was used as the heating and cooling medium. The winding speed was 3,500 m / min, and the fineness was 24 dtex for both filaments a and b (Example 1). Further, melt spinning was carried out in the same manner as in Example 1 except that the winding speed was 2,000 m / min to obtain a polyester fiber (Example 2). The physical properties of filaments a and b were evaluated, and the tactile sensation was evaluated by knitting a mixed yarn and treating it with boiling water.
Table 1 shows the physical properties of the fibers obtained. In Example 1, the physical property difference between the filaments constituting the mixed yarn appears remarkably. In Example 2, the shrinkage rate of the filaments a and b was slightly high, and the tubular knitting was slightly hard.

Example 3, Comparative Examples 1-2
A polyester fiber was obtained in the same manner as in Example 1 except that the distance between the die and the heating device was 30 cm, the heating device temperature was 170 ° C., and the cooling device temperature was 30 ° C. (Example 3). Also, the same method as in Example 3 (Comparative Example 1) except that the cooling device temperature was 120 ° C. and the same method as in Example 3 except that the heating device temperature was 90 ° C. (Comparative Example 2). The polyester fiber was obtained by melt spinning. In Example 3, the difference in physical properties between the filaments constituting the mixed yarn also appears remarkably, but the cooling of the filament a is not sufficient (Comparative Example 1) and the heating device temperature is not sufficiently high (Comparative Example 2). Then, it turns out that the contraction rate difference between the filaments a and b is not sufficient.

Example 4, Comparative Example 3
A polyethylene terephthalate chip (IV = 0.98, melting point 265 ° C.) is discharged from a spinneret having a hole diameter of 0.6 mmφ and a hole number of 1 using a twin screw extruder at a die temperature of 300 ° C. Spinning and winding were performed. At this time, the distance between the base and the heating device was 50 cm, the heating device depth was 10 cm, the heating device temperature was 180 ° C., and the cooling device temperature was 40 ° C., and 1,2-propanediol was used as the heating and cooling medium. The winding speed was 500 m / min. This fiber was drawn at a draw ratio of 4.7 times using three heating rolls at temperatures of 80 ° C., 130 ° C., and 180 ° C. (Example 4). Further, a polyester fiber was obtained by performing melt spinning in the same manner as in Example 4 except that the draw ratio was set to 5.2 times without using a heating device and a cooling device (Comparative Example 3).
Table 2 shows the physical properties of the fibers obtained. It can be seen that Example 4 has higher strength, although the elongation of the fibers is almost the same.

  According to the method for producing a polyester fiber of the present invention, a high-strength polyester fiber can be obtained, and the resulting polyester fiber is useful for industrial materials such as tire cords and seat belts. Further, according to the method for producing a spun mixed yarn of the present invention, a polyester mixed yarn excellent in bulkiness and mechanical properties can be manufactured with one kind of polymer, and the obtained mixed yarn has a feeling of swelling and high quality. It is useful for the use of woven and knitted fabrics exhibiting a good texture.

1 is an example of a spinning device for carrying out the method for producing a spun mixed yarn comprising the polyester fiber of the present invention. 1 is an example of a spinning device for carrying out the method for producing a polyester fiber of the present invention.

Explanation of symbols

1a, 1b: Spinneret 2: Heating device 3: Cooling device 4: Oil agent applying device 5: Entangling device 6: Take-up device 7: Winding device

Claims (5)

When the polyester is melted, discharged from the spinneret, and spun, the spun yarn is within 100 cm from the spinneret surface, the ambient temperature (melting point of polyester—100 ° C.) to 300 ° C., and a liquid thermostatic bath. After passing through a heating device, the manufacturing method of the polyester fiber characterized by passing the cooling device which consists of a liquid thermostat which has an atmospheric temperature of 0-50 degreeC and within 50 cm from the lower surface of this heating device .   The method for producing a polyester fiber according to claim 1, wherein the spinning speed is 2,500 to 5,000 m / min.   The method for producing a polyester fiber according to claim 1, wherein the heating device has a depth of 5 to 50 cm. The method according to claim 1 or 3 , wherein at a spinning speed of 300 to 5,000 m / min, the filament is wound or is not wound, and is further stretched at a stretching temperature of 70 to 100 ° C and a stretching ratio of 2.5 to 8.0. The manufacturing method of the polyester fiber of description. Method for producing a spun combined filament yarn, which comprises using a polyester fiber according to any one claims 1 to 4 as a component of the spinning combined filament yarn.

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