JP2003129337A - Polytrimethylene terephthalate fiber and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polytrimehylene terephthalate (PTT) fiber having a high elastic limit range and a low heat shrinkage, concretely exhibiting >=10% elastic limit range and at least 5% elastic limit range after its heat treatment, and a method for producing the same fiber. SOLUTION: This PTT fiber constituted by >=90 mol % trimethylene terephthalate recurring units is provided b having 0.7-1.3 dl/g intrinsic viscosity of the trimethylene terephthalate, >=90% degree of crystal orientation measured by a wide angle X-ray scattering method, 20-39% breaking elongation and 2-7% boiling water shrinkage, and the method for producing the PTT fiber is provided by melt-spinning the trimethylene terephthalate resin constituted by >=90 mol % trimethylene terephthalate recurring units and having 0.7-1.3 dl/g intrinsic viscosity, stretching the fiber by <40% of its breaking elongation, performing a heat treatment at 0-4% relaxing rate to make 2-7% boiling water shrinkage.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to polytrimethylene terephthalate fibers. More specifically, it is possible to maximize the elasticity derived from the crystal structure peculiar to polytrimethylene terephthalate (hereinafter referred to as “PTT”),
The present invention relates to a PTT fiber having excellent elastic recovery property.

[0002]

2. Description of the Related Art PTT fibers are described in J. Polymer S
science: Polymer Physics Ed
edition Vol. 14 P263-274 (197)
6) and Chemical Fibers Inte
national Vol. 45, April (19
95) 110-111, JP-A-52-5320,
It is known in the prior art such as JP-A-52-8123, JP-A-52-8124, International publication (WO) 99/27168 pamphlet, and International publication (WO) 00/22210 pamphlet. The general characteristics of the PTT fiber are that it has a relatively small tensile elastic modulus, has a wide elastic limit range when pulled, or has a large elastic recovery rate, and is generally soft and elastic.

Japanese Unexamined Patent Publication No. 11-81042 and Japanese Unexamined Patent Publication No.
Japanese Patent Laid-Open No. 1-107038 proposes a high thermal stress fiber of PTT. This prior art PTT fiber has a high strength of 2
It has a breaking elongation on the order of 0%, exhibits an elastic limit of 10% or more, and has elasticity, but has a heat shrinkage stress extreme value of 0.35 cN.
/ Dtex or more and a boiling water shrinkage ratio of 13 to 15%, the heat shrinkage is large in the relaxation heat treatment performed during the post-processing, and the elastic limit range is reduced to about 3%. It was This means that it is initially more elastic, but it loses its elastic properties after being subjected to a relaxation heat treatment during commercialization. International Publication (WO) 00 /
No. 22210 pamphlet has a breaking elongation of 35 to 50.
%, The heat shrinkage stress has a stress extreme value of 0.25 to 0.38 g / d, and a PTT fiber suitable for clothing has been proposed. This PTT fiber has already reached the elastic limit range of 10 from the raw yarn stage.
%, And even less than 5%. Further, since the heat shrinkage stress extreme value and the boiling water shrinkage rate are large, when the relaxation heat treatment is performed in the dyeing step or the like, the heat shrinkage causes shrinkage, resulting in loss of elastic properties.

Japanese Patent Application Laid-Open No. 11-48631 and Japanese Patent Application No. 20
JP-A-00-93724 proposes a PTT monofilament suitable for screen paper and toothbrushes. The PTT fiber disclosed in this publication is characterized in that the elongation at break of the fiber after stretching is as high as 40% or more, and the heat shrinkage rate is suppressed to a low level by relaxation heat treatment after stretching, and as a result, the elongation at break is high. The degree is 40% or more, and the elastic limit range is less than 5% at the stage of the raw yarn. As described above, the prior art exhibits an elastic limit range of 10% or more at the stage of the raw yarn, and can maintain a high elastic limit range even after the heat treatment at the post-processing stage or under the use condition of the fiber. No possible PTT fiber is known.

[0005]

In material applications, the fibers in the final product are often subjected to repeated loading, and it is desirable for the fibers to have higher elastic properties. Further, it is desirable that the heat shrinkage of the fiber is small for material use. If the elastic limit range is small, the dimensional change of the fiber product is likely to occur due to repeated loading. If the heat shrinkage is large, the dimensional change due to heat is large, and the elastic limit range is reduced due to the heat shrinkage. An object of the present invention is to provide a PTT fiber suitable for material use, that is, a PTT fiber having good dimensional stability mechanically and thermally. An object of the present invention is to provide a PT having a high elastic limit range and a small heat shrinkability.
Creation of T fiber. Specifically, it is the creation of a PTT fiber that exhibits an elastic limit range of 10% or more at the raw yarn stage, and exhibits an elastic limit range of at least 5% after heat treatment. The elastic limit range referred to in the present invention, when measured by the measuring method described later, when the fiber is directly recovered after stretching,
It means an elongation rate which can be recovered by 100%.

[0006]

As a result of intensive studies, the present inventors have found that it is necessary to reduce the elongation at break and to reduce the heat shrinkability in order to keep the elastic limit range of the PTT fiber large. And completed the present invention. That is, the first invention of the present invention is a polytrimethylene terephthalate fiber in which 90 mol% or more is composed of a trimethylene terephthalate repeating unit, and the intrinsic viscosity of the trimethylene terephthalate is 0.7 to 1.3 dl / g, the crystal orientation measured by the wide-angle X-ray scattering method is 90% or more, the elongation at break is 20 to 39%, and the boiling water shrinkage is 2 to 7%. Polytrimethylene terephthalate fiber.

The second invention of the present invention is 90 mol%
The above is polytrimethylene terephthalate composed of a repeating unit of trimethylene terephthalate, which is melt-spun polytrimethylene terephthalate having an intrinsic viscosity of 0.7 to 1.3 dl / g, and the elongation at break of the fiber is less than 40%. And then heat treatment at a relaxation rate of 0 to 4% at a temperature of 100 to 200 ° C. to obtain a boiling water shrinkage rate of 2 to 7%, which is a method for producing a polytrimethylene terephthalate fiber. . In the present invention, PTT is 90
Targets are those in which mol% or more consists of trimethylene terephthalate repeating units. When the trimethylene terephthalate repeating unit is less than 90 mol%, the melting point of PTT is 2
It becomes a low temperature of 00 ° C or less and is not suitable for material use.

In the present invention, the intrinsic viscosity of PTT should be 0.7 to 1.3 dl / g. When the intrinsic viscosity is less than 0.7 dl / g, the fiber toughness (breaking strength x
It has a small breaking elongation) and is not suitable for material applications. Due to the decrease in intrinsic viscosity due to thermal decomposition during melt spinning, it is difficult to manufacture PTT fibers having an intrinsic viscosity exceeding 1.3 dl / g. The preferred range of intrinsic viscosity is 0.8 to 1.2 dl /
It is g. In the present invention, the measuring method of the intrinsic viscosity is a measurement under the measuring conditions described in the section “(1) Intrinsic viscosity” described later. The fiber of the present invention needs to have a crystal orientation degree of 90% or more as measured by the method described below. If the degree of crystal orientation is less than 90%, no matter how small the elongation at break is, the dimensional change due to heat is large and the elastic limit range of the final product is lowered, so that the object of the present invention cannot be achieved. The preferable range of the crystal orientation degree is 92 to 97%.

In the present invention, the breaking elongation is 20 to 39.
%Must. When the elongation at break is less than 20%, the elastic limit range becomes larger, but when the fiber is manufactured, yarn breakage or
Industrial production is impossible due to frequent fuzz. Break elongation is 4
If it exceeds 0%, the elastic limit range of the fiber does not exceed 10%, no matter how the other requirements are adjusted. Considering the yarn breakage, the occurrence of fluff and a higher elastic limit range, the preferred range of the elongation at break is 25 to 35%. In the present invention, it is necessary that the boiling water shrinkage of the fiber is 2 to 7%. By setting the boiling water shrinkage rate within this range, it becomes possible to suppress the shrinkage ability and make the elastic limit range after post-processing 5% or more. When the boiling water shrinkage exceeds 7%, the shrinkage is large, and the elastic limit range after the post-processing is reduced, so that the object of the present invention cannot be achieved. If the boiling water shrinkage ratio is less than 2%, the heat shrinkage stress extreme value becomes large, and the elastic limit range after the post-processing decreases. The preferable boiling water shrinkage is 3 to 6%.

In the present invention, the heat shrinkage stress extreme value is 0.
It is preferably less than 1 cN / dtex. If the extreme value of the heat shrinkage stress exceeds 0.1 cN / dtex, the heat shrinkage is large during the heat treatment in the later step or the temperature rise under the use condition, and not only the dimensional change but also the elastic limit range is lowered. . The preferable range of the extreme value of thermal stress is 0.07 cN /
It is less than or equal to dtex. If the boiling water shrinkage rate is combined with 2 to 7% and the heat shrinkage stress value is less than 0.1 cN / dtex, the dimensional change due to heat will be smaller and it is possible to maintain a high elastic limit range. Become. In the present invention, it is preferable that the minimum value of the differential Young's modulus in the fiber elongation range of 3 to 15% is 7 cN / dtex or more.
The higher the differential Young's modulus, the larger the elastic limit range tends to be. FIG. 1 shows an example of measuring the differential Young's modulus. The preferred range of the minimum value of the differential Young's modulus is 10 to 20.
It is cN / dtex.

The fiber of the present invention is characterized in that it has an elastic limit range of 10% or more before the boiling water treatment. Furthermore,
Even after the boiling water treatment, the elastic recovery limit is 5% or more, preferably 10% or more. The fibers of the present invention may be multifilaments or monofilaments. In the case of a multifilament, it may be a chopped short fiber. In the case of multifilament, the single yarn fineness is preferably 0.5 to 20 dtex.
Also, in the case of monofilament, single yarn 20-100
0 dtex is preferred. The PTT of the present invention may be produced by a known polymerization method, that is, a combination of melt polymerization and solid phase polymerization, or a melt continuous polymerization method.

The remaining 10 mol% in the PTT of the present invention
The following may be a repeating unit other than the ester repeating unit, but is preferably an ester repeating unit other than the trimethylene terephthalate repeating unit. In this case, the copolymerization comonomer is preferably dicarboxylic acid such as isophthalic acid and adipine, or glycol such as ethylene glycol and tetramethylene glycol. Further, the PTT of the present invention may contain additives such as a matting agent, an antistatic agent, an ultraviolet absorber and an antibacterial agent.

The method for producing the PTT fiber according to the second aspect of the present invention will be described below. In the production method of the present invention, it is necessary to stretch the stretched fiber to a breaking elongation of less than 40%. If the breaking elongation of the fiber after stretching exceeds 40%, the breaking elongation increases by heat treatment, and exceeds 40%, so that the object of the present invention is not achieved. In the manufacturing method of the present invention, the drawn fiber is further heated at a temperature of 100 to 200 ° C.,
It is necessary to apply heat treatment at a relaxation rate of 0 to 4%. When the heat treatment temperature is less than 100 ° C, the boiling water shrinkage ratio exceeds 7%. If the heat treatment temperature exceeds 200 ° C., yarn breakage increases and stable heat treatment becomes difficult. When the relaxation rate is less than 0%, the boiling water shrinkage rate exceeds 8%, and the object of the present invention cannot be achieved. If the relaxation rate exceeds 4%, the elastic recovery limit is lowered and the object of the present invention is not achieved. A preferable heat treatment is 120 to 180 ° C. and a relaxation rate of 0 to 2%.

<When the PTT fiber is a multifilament> To obtain the PTT multifilament of the present invention,
A PTT unstretched multifilament is spun using a known air-cooling type melt spinning machine as shown in FIG. 2 and wound to form an unstretched multifilament package. First, it is necessary to draw and draw the unstretched multifilament from the unstretched multifilament package and perform tension heat treatment. And the breaking elongation of the drawn fiber is 40%.
It must be less than.

The method for producing the PTT multifilament of the present invention will be described in more detail. First, in FIG. 1, an extruder 2 in which PTT pellets dried to a moisture content of 30 ppm or less in a dryer 1 are set to a temperature of 255 to 265 ° C.
And melt. The molten PTT is then sent through the bend 3 to the spin head 4 set at 250 to 265 ° C. and measured by the gear pump. After that, through the spinneret 6 having a plurality of holes mounted on the spin pack 5, the multifilament 7 is extruded into the spinning chamber. The optimum temperature of the extruder and the spin head is selected from the above range depending on the intrinsic viscosity and shape of the PTT pellet.

The PTT multifilament extruded into the spinning chamber is cooled to room temperature by the cooling air 8 and is rotated at a predetermined speed.
It is thinned by 11 and solidified, and wound as an undrawn yarn package 12 having a predetermined fineness. Undrawn yarn 12
Before being brought into contact with the take-up godet roll 10, the finishing agent is applied by the finishing agent applying device 9. The undrawn yarn is taken out from the take-up godet roll 11 and then taken up by the winder 12 as an undrawn yarn package. In the production method of the present invention, an aqueous emulsion type is used as the finishing agent applied to the unstretched fibers. The concentration of the aqueous emulsion of the finishing agent is 15% by weight or more, preferably 20 to 35% by weight. In the production of unstretched yarn, it is preferable to wind at a winding speed of 3000 m / min or less. The more preferable winding speed is 1000 to 2000 m / min, and more preferably 1200 to 1800 m / min.

The undrawn yarn is then supplied to the drawing process and drawn by a drawing machine as shown in FIG. Before being supplied to the drawing step, the storage environment of the undrawn yarn has an ambient temperature of 10 to 10.
It is preferable to keep the temperature at 25 ° C. and the relative humidity at 75 to 100%. The unstretched fibers on the stretching machine are preferably maintained at this temperature and humidity throughout the stretching. On the drawing machine, first, the undrawn yarn package 12 is heated on the supply roll 13 set to 45 to 65 ° C. and drawn to a predetermined fineness by using the peripheral speed ratio between the supply roll 13 and the drawing roll 15. It The fiber is 100 to 100% after or during the drawing.
The vehicle runs while contacting the hot plate 14 set at 150 ° C., and undergoes a tension heat treatment. The fiber that has exited the drawing roll is wound as a drawn yarn pan 16 while being twisted by a spindle. The supply roll temperature is more preferably 50 to 60 ° C, further preferably 52 to 58 ° C.

The ratio between the supply roll 13 and the stretching roll 15, that is, the stretching ratio and the hot plate temperature are such that the stretching tension is 0.5.
It is preferable to set it to be about 0.9 cN / dtex. The stretched fiber further has a temperature of 100 to 200 ° C.,
It is necessary to perform heat treatment at a relaxation rate of 2 to 4%. The heat treatment in the present invention may be continuous with the stretching or may be carried out in another step. As a method to carry out in another step,
For example, it is achieved by using a known false twisting machine and performing only heat treatment without adding twist.

<When the PTT fiber is a monofilament>
To obtain the PTT monofilament of the present invention, FIG.
A PTT monofilament is spun using a known water-cooled spinning machine and a continuous drawing heat treatment machine as shown in FIG. Then, at that time, by adjusting the stretching temperature, the stretching ratio and the heat treatment temperature, the breaking elongation and the boiling water shrinkage rate of the present invention are adjusted to the specified values. If necessary, the heat treatment may be performed offline after the stretching, or may be performed in multiple stages online.

The method for producing the PTT monofilament of the present invention will be described in more detail. In FIG. 4, the PTT pellets are dried in the dryer 18 and then the pellets are extruded in the extruder 1
9 to prepare a melt of PTT. The PTT melt is then sent to the spin head 22 via the bend 20, measured by the gear pump 21 mounted therein, and spun on the spinneret 23.
More spun out. The spinning temperature is 240 to 280 ° C, preferably 250 to 270 ° C. Spun PT
The T melt becomes a filament 24, which is guided into the cold water bath 25 to be cooled while rotating at a constant speed.
The unrolled monofilament yarn is pulled by the roll group 26 and thinned to a predetermined fineness. The temperature of the cold water bath is 20 to 60 ° C, preferably 30 to 50 ° C.

After passing through the first roll group 26, the undrawn monofilament yarn is heated in a hot water bath 27 at a predetermined temperature,
The first roll is pulled by the second roll group 28 rotating at a constant speed.
Stage stretching is applied. The temperature of the hot water bath is 40 to 90 ° C,
Preferably, 50 to 70 ° C is adopted. Thereafter, the monofilament yarn is subjected to a fixed length or relaxation heat treatment in a heating medium bath 29 at a predetermined temperature, passes through a third roll group 30, and then is wound by a winding machine 31. The temperature of the heat medium bath is 100 to 200.
It must be in ° C. Preferably, it is 120-18
0 ° C is adopted. The stretching in the warm water bath is not limited to the one-stage stretching, and the stretching may be performed plural times. Then PT
The T monofilament yarn is heat-treated at a predetermined temperature, for a predetermined time, and at a predetermined relaxation rate or constant length rate to adjust the boiling water shrinkage rate.

The heat medium used in the heat medium bath 29 is selected from hot air, steam, silicon oil, alkylene glycol and the like. The heat treatment time is preferably long as long as the productivity is not impaired. Usually, 1 second to 1 minute is adopted. The PTT monofilament yarn of the present invention is preferably provided with a finishing agent having a function of lowering frictional resistance, imparting antistatic property, or the like in order to improve the process passing property of the subsequent process. Further, a water repellent, a water absorbent, or the like may be added depending on the required function. It is preferable to apply the finishing agent after the third roll group 30.

[0023]

The PTT fiber of the present invention has a larger elastic limit range and a smaller heat shrinkage stress than other synthetic fibers as well as ordinary PTT fibers, so that it undergoes dimensional changes under repeated loading or at high temperatures. No or very small.
Therefore, it has good suitability for industrial material applications or chair materials for vehicles.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in more detail below with reference to Examples, but it goes without saying that the present invention is not limited to the Examples. The measuring methods and measuring conditions of the physical properties used in the present invention and the examples are as described below. (1) Intrinsic viscosity Intrinsic viscosity [η] is a value obtained based on the definition of the following equation. Ηr in the definition is a value obtained by dividing the viscosity of a diluted solution of a PTT polymer dissolved in 0-chlorophenol having a purity of 98% or more at 35 ° C. by the viscosity of the solution measured at the same temperature. It is defined. C is g /
Polymer concentration expressed in 100 ml. (2) Breaking elongation It was measured based on JIS-L-1013.

(3) Degree of crystal orientation Using an X-ray diffractometer, a diffraction intensity curve with a diffraction angle 2θ of 7 degrees to 35 degrees was drawn under the following conditions with the thickness of the sample being about 0.5 mm. Measurement conditions are 30 KV, 80 A, scanning speed 1 degree / minute, chart speed 10 mm / minute,
Time constant 1 second, receiving slit 0.3
mm. The reflections drawn at 2θ = 16 degrees and 22 degrees are (010) and (110), respectively. Furthermore, (010)
A diffraction intensity curve is drawn in the azimuth direction of -180 degrees to +180 degrees on the surface. The average value of the diffraction intensity curve obtained at ± 180 degrees is taken, and the horizontal line is drawn as the baseline. A vertical line is drawn from the apex of the peak to the baseline, and the midpoint of the height is calculated. A horizontal line passing through the midpoint is drawn, the distance between two intersections of this and the diffraction intensity curve is measured, and a value obtained by converting this value into an angle is defined as an orientation angle H. The crystal orientation degree is given by the following equation. Crystal orientation degree (%) = (180−H) × 100/180

(4) Thermal shrinkage stress: An extreme value thermal stress measurement device (for example, Kanebo Engineering Co., Ltd .: trade name KE-2) is used for measurement. 20 drawn yarns
Cut into a length of cm, connect both ends of this to make a ring, and load it into the measuring instrument. The initial load is 0.044 cN / dtex and the temperature rise rate is 100 ° C./min. The measurement is performed, and the temperature change of the heat shrinkage stress is written on the chart. In the measured chart, the temperature at which the heat shrinkage stress starts to be expressed is the stress expression start temperature. The heat shrinkage stress draws a mountain-shaped curve in the high temperature region, and the stress that develops this peak value is the extreme stress.

(5) Differential Young's modulus The elongation-stress curve was measured based on JIS-L-1013. The stress at each point of the elongation-stress curve obtained here was differentiated by the elongation to obtain it. Elongation 3 ~ from differential Young's modulus curve
The lowest value of the differential Young's modulus of 5% was determined. (6) Elasticity limit range It was measured by the following method according to JIS-L-1013 (7.9 elongation elastic modulus) measurement method. JIS-L-10
In the measurement method of 13, the elastic recovery rate was measured by changing the elongation rate. Then, after 3 minutes, perform the same measurement,
The elastic recovery rate was measured. This measurement is repeated 10 times, and the elastic recovery rate is 1 in all measurements.
The elongation range at which it reaches 00% is defined as the elastic limit range.

[0028]

Examples 1 to 5 and Comparative Examples 1 to 5 In this example, the breaking elongation of multifilaments and the effect of heat treatment will be described. 84 dtex / 36 filament PT was prepared from PTT pellets containing 0.4% by weight of titanium oxide and having an intrinsic viscosity of 0.91 by using a spinning machine and a stretching machine as shown in FIGS.
T-fiber was produced. The spinning conditions and the drawing conditions in this example and comparative examples are as follows. (Spinning Conditions) Pellet drying temperature and water content reached 110 ° C., 25 ppm Extruder temperature 260 ° C. Spin head temperature 265 ° C. Spinneret hole diameter 0.40 mm Polymer discharge amount It was adjusted to 84 dtex after stretching. Cooling air condition Temperature 22 ° C, relative humidity 90% Speed 0.5m / sec Collection speed 1500m / min

(Stretching Conditions) Stretching machine supply roll 55 ° C. With a stretching pin Hot plate temperature 130 ° C. Stretching roll temperature Unheated (room temperature) Winding speed 800 m / min Winding amount 2.75 kg / 1 Pane Breaking of the obtained stretched fiber The elongation is shown in Table 1. Then
Using a 33H false twisting machine manufactured by Murata Kikai Seisakusho without twisting the obtained drawn fiber, a yarn speed of 300 m /
Min, heat treatment was performed at 170 ° C. at a relaxation rate shown in Table 1.
The physical properties of the obtained fiber are shown in Table 1.

[0030]

[Table 1]

As is apparent from Table 1, the fiber of the present invention has an elastic limit range of 10% or more and has a good elongation recovery property. Furthermore, the elastic recovery limit is 5% even after boiling water treatment.
It had the above excellent recoverability. The fibers of Comparative Examples 1 and 5 had a high boiling water shrinkage ratio and a heat shrinkage stress extreme value after stretching, and thus the elastic limit range was lowered after the boiling water treatment. The fibers of Comparative Examples 2, 3, and 4 have a large breaking elongation after the relaxation heat treatment,
The elastic limit range was reduced.

[0032]

Examples 6 to 10 and Comparative Examples 6 to 9 In this example, examples of monofilaments will be shown. Intrinsic viscosity [η] is 0.92d
A PTT monofilament yarn was produced under the following production conditions using 1 / g of PTT polymer containing no titanium oxide. Polymer discharge rate 2.52 g / min Spinning temperature 260 ° C Cooling bath water temperature 40 ° C Take-up roll (first roll) peripheral speed 15.8 m / min Drawing bath water temperature 55 ° C Drawing roll (second roll) peripheral speed Varies depending on draw ratio Heat treatment Bath temperature 160 ° C Heat treatment medium Hot air Third roll peripheral speed 72m / min Winding speed 72m / min

The elongation at break of the PTT monofilament obtained is shown in Table 2. Next, the PTT monofilament yarn was heat-treated again using a heating medium bath at 160 ° C. while changing the relaxation rate between the second roll and the third roll as shown in Table 2. The heat treatment time in this case was 10 seconds. The physical properties of the obtained PTT monofilament are shown in Table 2.

[0034]

[Table 2]

As is clear from Table 2, the PT of the present invention
The T monofilament had a good elastic recovery property even after the boiling water treatment. The elongation-stress curve and differential Young's modulus of Example 7 are shown in FIG. The fibers of Comparative Examples 6 and 9 had a high boiling water shrinkage ratio and a high heat shrinkage stress extreme value after stretching, and thus the elastic limit range decreased after the boiling water treatment. The fibers of Comparative Examples 7 and 8 had a large elongation at break after the relaxation heat treatment and had a reduced elastic limit range.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a differential Young's modulus of a monofilament of the present invention.

FIG. 2 is a schematic view showing a spinning machine of the present invention.

FIG. 3 is a schematic view showing a stretching machine of the present invention.

FIG. 4 is a schematic view showing a monofilament spinning and drawing machine of the present invention.

[Explanation of symbols]

1: Polymer chip dryer 2: Extruder 3: Bend 4: Spin head 5: Spin pack 6: Spinneret 7: Filament 8: Cooling air 9: Finishing agent applying device 10: Godet roll 11: Godet roll 12: Undrawn yarn package 13: Supply roll 14: Hot plate 15: Stretching roll 16: Stretched yarn pan 17: Traveler ring 18: Dryer 19: Extruder 20: Bend 21: Gear pump 22: Spin head 23: Spinneret 24: filament yarn 25: Cold water bath 26: First roll group 27: Hot water bath 28: Second roll group 29: Heat medium bath 30: Third roll group 31: Winding machine

Claims (7)

[Claims] 1. A polytrimethylene terephthalate fiber comprising 90 mol% or more of trimethylene terephthalate repeating units, wherein the polytrimethylene terephthalate has an intrinsic viscosity of 0.7 to 1.3 dl / g.
Polytrimethylene having a crystal orientation of 90% or more, a breaking elongation of 20 to 39%, and a boiling water shrinkage of 2 to 7% as measured by a wide-angle X-ray scattering method. Terephthalate fiber. 2. The extreme value of heat shrinkage stress is 0.1 cN / dtex.
The polytrimethylene terephthalate fiber according to claim 1, which is less than 1. 3. The polytrimethylene terephthalate fiber according to claim 1, wherein the minimum value of the differential Young's modulus in the elongation range of 3 to 15% is 7 cN / dtex or more. 4. The polytrimethylene terephthalate fiber according to claim 1, which has a breaking elongation of 25 to 35%. 5. The polytrimethylene terephthalate fiber according to any one of claims 1 to 4, wherein the fiber is a multifilament or a short fiber obtained by cutting it. 6. The polytrimethylene terephthalate fiber according to any one of claims 1 to 4, wherein the fiber is a monofilament. 7. Polytrimethylene terephthalate having 90 mol% or more of trimethylene terephthalate repeating units and having an intrinsic viscosity of 0.7 to 1.3 dl.
Melt-spun poly (trimethylene terephthalate) / g,
After stretching so that the breaking elongation of the fiber is less than 40%,
A method for producing poly (trimethylene terephthalate) fiber, which comprises heat-treating at a temperature of 100 to 200 ° C. and a relaxation rate of 0 to 4% to make a boiling water shrinkage rate of 2 to 8%.