JP3021731B2 - Polyester latent crimped yarn and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a latent crimped yarn composed of hollow inner and outer layer conjugate fibers, and more particularly, the outer shape of an inner layer portion in a fiber cross section is constituted by a highly linear side portion and a sharp vertex. And a latent latent crimped yarn potentially having a non-uniform heat shrinkage rate between each single fiber in the same cross section of the yarn constituted by the single fiber and the length direction of the single fiber, and a method for producing the same It is.

[0002]

2. Description of the Related Art There have been many proposals to use fibers of irregular cross-section or hollow fibers to impart high-grade feeling such as glossiness, dry touch and light weight to woven or knitted fabric for polyester clothing. Typical irregularly shaped fibers include T,
Y, flat, and the like, and examples of the hollow section fiber include a hollow round section. These woven and knitted fabrics having irregular cross-section fibers and hollow cross-section fibers have characteristic glossiness, texture, and lightness as compared with the round cross-section, and are preferably used for clothing. In addition, excellent texture properties of irregular cross-section fibers,
Several fibers have been proposed that combine the two properties of the light weight of hollow cross-section fibers. For example, Japanese Patent Publication No. 44-18
No. 923 and Japanese Patent Publication No. Sho 58-4092 propose a fiber having a polygonal cross section having a hollow portion.
No. 49650 proposes a hollow fiber having a hollow cross section. However, since these modified cross-section fibers are all produced by single-component spinning, the apex of the fiber cross section is rounded due to the effect of surface tension during the cooling process after discharging from the die, and a cross-sectional shape having a sharp portion is obtained. Absent. Therefore, these characteristics are not satisfied in the field of clothing that requires a glossiness, a sense of fashion, and the like.

[0003] In recent years, under various demands, there have been proposed several modified cross-section fibers having a sharp apex portion to which a composite spinning technique is applied. For example, Japanese Unexamined Patent Publication No. 56-159316 proposes a method of obtaining a modified cross-section fiber having a sharp edge by hydrolyzing one component of a multi-layered composite yarn. Although some technologies have good textures such as dry touch, they have unevenness in the fiber cross section, so that high-quality, brilliant luster cannot be obtained, and components with large hydrolyzability are partially removed. There is also a drawback such that spots are apt to appear after dyeing the woven or knitted fabric because it remains.

[0004] Further, in order to express natural fine crimping and good bulkiness, Japanese Patent Application Laid-Open No. 56-148931 proposes a latent crimped yarn obtained by giving a non-uniform heat treatment to a yarn. The latent crimped yarn of the publication has a solid constituent fiber,
Since the top is rounded, the refreshing feeling such as dry touch and lightness is not satisfactory.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a latently crimped yarn composed of hollow inner and outer layer conjugate fibers, which could not be achieved by the above-mentioned prior arts or a combination thereof, and to elute the outer layer components. Due to the high linearity of the side part after elution and the small radius of curvature of the apex part, it has a distinctive glossy shine, dry touch without waxy feeling, feeling of shaking, tension and waist, lightweight It is an object of the present invention to provide a latently crimped yarn suitable for a woven or knitted fabric for high-grade clothing, which is excellent in texture, silky fine crimp, and bulge, and a method for producing the same.

[0006]

An object of the present invention is to provide a polyethylene terephthalate in which an outer layer component is copolymerized with a 5-sodium sulfoisophthalic acid component in an amount of 1.0 mol% or more in an inner / outer layer composite fiber having a hollow portion. The outer peripheral shape of the inner layer portion in the fiber cross section is a polygonal shape having a triangle shape or more and a hexagonal shape or less, and is non-uniform between the length direction of the single fiber and each fiber in the same cross section of the yarn constituted by the single fiber. This can be achieved by using a polyester latent crimped yarn characterized by potentially having a heat shrinkage.

Hereinafter, the present invention will be described in detail. It is essential that the single fiber constituting the latent crimped yarn of the present invention has a hollow portion in the cross section of the fiber. This is because having a hollow portion increases the excluded volume by that much, so that a material having a lighter feeling than that of a woven or knitted fabric obtained by a conventional polyester fiber can be obtained. The hollow ratio is represented by the cross-sectional area of the hollow portion with respect to the sum of the cross-sectional area of the inner layer component and the cross-sectional area of the hollow portion in the fiber cross section. The higher the hollow ratio, the higher the lightness. On the other hand, if the hollow ratio is too high, the shape retention of the fiber cross section is significantly reduced, so that the hollow portion is crushed in the process after weaving and the cross section is easily deformed, so that it is difficult to achieve the object of the present invention. Become. As described above, the hollow ratio is 10 to 4
A range of 0% is preferable, and a range of 20 to 35% is more preferable.

The fiber constituting the latent crimped yarn of the present invention has an inner / outer layer composite structure, and the outer layer component is copolymerized with 1.0 mol% of 5-sodium sulfoisophthalic acid component. is necessary. In the conjugate fiber, the outer layer component is dissolved and removed by solvent treatment after weaving.In this case, the inner layer component polyethylene terephthalate is left as it is, and only the outer layer component is dissolved and removed. It is necessary to have a dissolution rate difference. At this time, as a solvent for dissolving and removing only the outer layer components, an alkali solution (for example, a hot aqueous solution of sodium hydroxide) is preferably used.
If it is less than 50%, the dissolution rate difference between the inner layer component and the alkali solution is small, so that the top portion of the inner layer portion is dissolved and rounded. Therefore, in order to leave the top of the inner layer as it is, the copolymerization rate is preferably 2.0 mol% or more, more preferably 4.0 mol% or more. On the other hand, if the copolymerization ratio is too high, not only the strength of the conjugate fiber is significantly reduced, but also the solubility in hot water increases, and there are defects such as the occurrence of sticking between single fibers in the high-order process, which is preferable. Has a copolymerization ratio of 6.0 mol% or less.

Next, the radius of curvature of the apex and the rate of change of the side in the outer peripheral shape of the inner layer of the composite fiber constituting the latently crimped yarn of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a cross-sectional view of a conjugate fiber for explaining the cross-sectional shape of the conjugate fiber constituting the latently crimped yarn of the present invention, wherein 1 is an outer fiber layer, 2 is an inner fiber layer, and 3 is a hollow fiber. Department,
Reference numeral 4 denotes a composite fiber having an apex portion and 5 a hollow portion having a side portion. First, the top 4 in the cross section of the inner layer of the composite fiber
Is preferably 2d ^0.5 μm or less. For example, if the single fiber fineness of the composite fiber is 2 denier and the composite ratio of the inner layer portion is 50%, the fineness of the inner layer portion (hereinafter, referred to as the single fiber inner layer portion fineness d) is 1 denier, and the top portion 3
Is preferably 2.0 μm or less. Further, the single fiber fineness of the composite fiber is 6 denier and the composite ratio of the inner layer portion is 50.
%, The fineness d of the single fiber inner layer portion is 3 deniers, and the radius of curvature r of the apex portion 3 is preferably about 3.5 μm or less. With a cross-sectional shape composed of gentle vertices with a radius of curvature r exceeding 2d ^0.5 μm, it is difficult to weave and fully exhibit the texture such as dry touch and feeling of shaking when the outer layer components are dissolved and removed. This is because More preferably the curvature radius r of the vertex portion is less than d ^{0. 5} μm.

Next, in the present invention, the variation rate of the side portion between the adjacent vertices is important. In FIG. 1, a reference line L is drawn on each side between the adjacent vertices 3. The reference line L is L
Is drawn so as to minimize the area of the side portion formed by adding the concave portion and the convex portion. At this time, the reference line L
Let T be the point farthest away from T and t be the distance between T and L.
On the other hand, in the reference line L corresponding to the side where T exists, the variation rate of the side in the cross section of the fiber is determined by the following equation, where the length between the intersections with the adjacent reference line is s. Fluctuation rate (%) = (t / s) × 100 In the outer peripheral shape of the inner layer of the composite fiber constituting the latently crimped yarn of the present invention, the fluctuation rate of the side portion between adjacent apexes is 10% or less. Preferably, there is. The fluctuation rate is closely related to glossiness and surface touch, and a peripheral shape having sides whose fluctuation rate exceeds 10% does not exhibit a distinctive gloss. The fluctuation rate is more preferably 8% or less.

FIG. 2 is a cross-sectional view showing an example of the cross-sectional shape of the conjugate fiber constituting the latently crimped yarn of the present invention. 2 (a) shows an example in which the inner layer is triangular, FIG. 2 (b) shows an example in which the inner layer is square, FIG. 2 (c) shows an example in which the inner layer is pentagonal, and FIG. 2 (d) shows an example in which the inner layer is hexagonal It is.

In order to exhibit the effect of the present invention, the cross-sectional shape of the inner layer portion needs to be a polygonal cross-section from a triangle to a hexagon. When it becomes a heptagon or more polygonal cross section, weaving it because the apex in the cross section is not sharp,
When the components of the outer layer are eluted, the texture such as dry touch and sensation, which are the objects of the present invention, cannot be satisfied. Further, in order to further exhibit the above-mentioned characteristics, the shape is preferably a pentagon or less.

The latently crimped yarn of the present invention is required to have non-uniform heat shrinkage between the single fibers in the same cross-section of the yarn constituted by the single fibers and the length direction of the single fibers. is there. When post-heat treatment is performed in the next step, natural fine crimping and good bulkiness are developed due to the uneven heat shrinkage, and after the outer layer is dissolved and removed, the sharp apex of the fiber cross section becomes the surface of the woven or knitted fabric. Because it protrudes as a loop, the sense of dryness and dryness is further enhanced.

Here, the non-uniformity of the heat shrinkage in the fiber length direction in the present invention is defined as follows. From the target yarn, an arbitrary single fiber is taken out with as little tension as possible, and the single fiber is cut into about 3 cm pieces and divided into 20 pieces. One end of the divided single fiber is fixed with a pin clip, and the other end is fixed with a load of 0.1 g / d.
Under a load of d, the length L1 of the single fiber between the pin clip and the 0.1 g / d load is read with a cassette meter. Then, after treating at 170 ° C. for 5 minutes in a state where the distance between the pin clip and the load is slackened so that the single fiber can sufficiently shrink by heat shrinkage, the pin clip and the 0.1 g are loaded under a load of 0.1 g / d.
The length L2 of the single fiber between the / d load is read with a cassette meter. The dry heat shrinkage of each single fiber is determined by the following equation, and the measured values show a distribution, and the difference between the maximum value and the minimum value is 2% or more,
Preferably, the ratio of 3% or more, more preferably 5% or more is defined as non-uniform heat shrinkage in the length direction of the single fiber. Dry heat shrinkage (%) of single fiber = {(L1 -L2) / L1} × 100 The non-uniform heat shrinkage between single fibers in the same cross section in the present invention is defined as follows. Is done.

The target yarn is cut into approximately 3 cm at an arbitrary position, and all the single fibers constituting the yarn are separated while applying as little tension as possible. Then, all the separated single fibers were measured for dry heat shrinkage by the same measurement method as the dry heat shrinkage in the longitudinal direction of the same single fiber as described above, and the measured values showed distribution, and the maximum value and the minimum value were measured. The difference is 2% or more, preferably 3
% Or more, more preferably 5% or more, is defined as a non-uniform heat shrinkage rate between single fibers in the same cross section.
In addition, the latently crimped yarn according to the present invention has excellent bulkiness by post-heat treatment in the next step, and the bulkiness can be 10 cc / g or more.

The latent crimped yarn according to the present invention is preferably interlaced from the viewpoint of high process passability.
In this case, the CF value measured by a measuring method described later is preferably from 5 to 200, and more preferably from 10 to 150. When the CF value is less than 5, the interlacing effect is small, and when the CF value exceeds 200, the obtained fabric tends to suffer from irritability and the quality of the woven or knitted fabric tends to deteriorate.

The fiber of the present invention contains titanium oxide in an amount of 0.1%.
It is preferable that the compounding amount be from 0.5 to 1.0% by weight. If the blending amount of titanium oxide is less than 0.05% by weight, there is glaring reflection and high-grade gloss cannot be obtained. On the other hand, if the amount of titanium oxide exceeds 1.0% by weight, the sharpness after dyeing is lowered due to the dull effect, which is not preferable.

Next, a specific example of the method for producing a latently crimped yarn composed of the conjugate fiber of the present invention will be described in detail. In producing a latent crimped yarn composed of the composite fiber of the present invention, first, a composite fiber having a hollow portion composed of an outer layer and an inner layer portion is obtained, and then stretched and brought into contact with the first heating body in a relaxed state. Then, heat treatment is performed by the second heating element.

The outer layer component of the composite fiber used in the present invention is required to copolymerize polyethylene terephthalate with 5-sodium sulfoisophthalic acid component in an amount of 1.0 mol% or more. This is because, as described above, when the outer layer component is dissolved and removed after weaving the conjugate fiber, it is necessary to leave the inner layer component polyethylene terephthalate as it is and to dissolve and remove only the outer layer component. For this purpose, the copolymerization ratio needs to be 1.0 mol% or more, preferably 2.0 mol% or more, more preferably 4.0 mol% or more in order to have a difference in dissolution rate with respect to the solvent. On the other hand, if the copolymerization ratio is too high, not only the strength of the conjugate fiber is significantly reduced, but also the solubility in hot water increases, and there are defects such as the occurrence of sticking between single fibers in the production process. The copolymerization rate is 6.0 mol% or less.

Next, the intrinsic viscosity [η] of polyethylene terephthalate, which is an inner layer component used for the conjugate fiber constituting the latently crimped yarn of the present invention, is preferably 0.70 or more. As described later, in the fiber of the present invention, the hollow portion plays a large role in improving the feeling of the fabric. In order to obtain a higher hollow ratio at the stage of forming the hollow portion, the higher the melt viscosity of the polymer at the stage of spinning, the better. Furthermore, the fiber of the present invention is subjected to a high rate of weight reduction in the state of a fabric in the next step, but at this stage, there is a problem that the strength of the fabric is significantly reduced and the tear strength is low. Therefore, in order to maintain the tear strength which does not pose a practical problem even after the outer layer is eluted, the intrinsic viscosity [η] of polyethylene terephthalate used for the inner layer component is preferably higher. For the above two reasons, the intrinsic viscosity [η] is more preferably 0.75 or more. If the intrinsic viscosity [η] is too high, various problems such as a high pressure loss at the spinning stage occur, so the intrinsic viscosity [η] is preferably 1.0 or less.

The two kinds of polymers composed of the inner layer component and the outer layer component as described above are separately melted and weighed to obtain hollow composite fibers. FIG. 3 is a longitudinal sectional view of a main part of a composite die device preferably used in the present invention. FIG. 4 is a bottom view of a base showing an example of a base hole shape used in the present invention. FIG. 5 is a bottom view of the base for explaining the base hole shape of FIG. 3 to 5, reference numeral 6 denotes an upper introduction plate, 7 denotes a lower introduction plate, 8 denotes a base, and 9 denotes a slit. The polymer A of the inner layer component is introduced from the upper introduction plate 5, and the polymer B of the outer layer component is introduced.
Is introduced from the lower introduction plate 7, becomes a combined flow of the inner and outer layers at the base 8, and is discharged from the slit 9.

As described above, the two kinds of polymers are discharged from the slit 9 as an inner / outer layer composite stream. In the present invention, the melt viscosity of the inner layer component (polymer A) is set to 1 of the outer layer component (polymer B). It is necessary to make it 2 times or more and 6 times or less. By making the melt viscosity of the inner layer component (Polymer A) higher than that of the outer layer component (Polymer B), the composite flow of polymer discharged from each slit bends inward of the slit,
Both ends collide and fuse with each other to form a composite fiber having a hollow cross section in which the outer peripheral shape of the inner layer is polygonal.

By the way, in order to ensure that the composite polymer flow discharged from each slit collides and fuses, and to stably produce the intended inner layer having a sharp cross-sectional shape, the melt viscosity of the inner and outer layer components is required. Need to be optimized. If the melt viscosity of the inner layer component is less than 1.2 times the melt viscosity of the outer layer component, the sides in the cross section of the inner layer will swell in an arc, and the apex will also be rounded. Cannot be in form. Further, in the present invention, in order to make the apex portion in the outer peripheral shape of the inner layer portion more sharp, and to improve the linearity of the side portion, the melt viscosity of the inner layer component is set to 1.5 times or more of the outer layer component. More preferred.
When the melt viscosity of the inner layer component exceeds 6 times that of the outer layer component, collision and fusion of the polymer composite flow immediately below the mouthpiece become unstable, and as a result, a composite abnormality occurs and the cross section changes with time. Therefore, it becomes impossible to form a composite fiber having a target hollow portion. To achieve more stable production, the melt viscosity of the inner layer component should be 5 times the melt viscosity of the outer layer component.
It is preferably at most 4 times, more preferably at most 4 times.

Here, the shape of the base hole to be finally discharged will be described with reference to FIG. 5B, which illustrates a base hole composed of four divided slits in FIG. 4B. The radius of curvature h of the slit 9 is
From the hole center Q to the slit center P (slit length x
It is preferable that the annular arrangement is 0.8 to 1.2 times the distance (hereinafter, referred to as a die radius i) to the intermediate point in the width w. This is because, when the shape of the slit is within the above-mentioned range, when viewed at the stage of the conjugate fiber, the outer peripheral shape of the cross section becomes circular.For example, when the outer layer component is dissolved and removed after weaving, the conjugate fiber is multiplied at the time of weaving. Even if the outer peripheral component in the cross section of the fiber becomes polygonal after dissolving and removing the outer layer component, it is arranged in a random state in the knitted fabric, and the knitted fabric is likely to be randomly arranged in the filament. Because it gives a natural texture. In addition, as shown in FIGS. 4B and 5, four slits having the same hole shape and the same size are preferably arranged in a point-symmetrical manner as shown in FIG. As shown in FIG. 4A, three slits are formed.
In the case of five divisions, five slits are arranged as shown in FIG. 4C, and in the case of six divisions, six slits are arranged point-symmetrically as shown in FIG. 4D.

The number of slits forming the base hole is three.
It is essential that the number is not less than 6 and not more than 6. The number of vertices and sides of the fiber whose inner layer portion is polygonal in shape is equal to the number of slits forming the base hole. This is because it becomes a hexagonal hollow section fiber. Therefore, if the number of slits constituting the base hole is not in this range, the hollow composite fiber aimed at by the present invention cannot be obtained.

Further, as described above, the two kinds of polymers are discharged in each slit in the state of the inner and outer layers. The compounding ratio of the inner layer portion at the time of ejection is set to be within a range of 40% by weight or more and 75% by weight or less in order to keep the variation rate of the side portion of the outer peripheral shape of the inner layer portion within a desired range and to make the apex portion sharp. is necessary. Preferably, the composite ratio of the inner layer portion is in the range of 45 to 65% by weight.

When the composite fibers obtained by the above-described method are used with the ferrules shown in FIGS. 4A, 4B, 4C and 4D, the composite fibers shown in FIGS. (B),
As shown in (c) and (d), it is possible to form a conjugate fiber having a hollow portion in which the outer peripheral shape of the inner layer portion is polygonal. Further, the undrawn yarn obtained by the method described above,
After stretching and allowing the first heating element to contact and travel in a relaxed state, and giving a non-uniform heat shrinkage rate to each single fiber in the length direction of the single fiber and the same cross section of the yarn, 2 Heat treatment with a heating element.

FIGS. 6 and 7 are schematic views showing one example of an embodiment of the present invention for drawing and heat-treating the undrawn yarn. In FIG. 6, reference numeral 10 denotes an undrawn yarn, which is drawn between a heating roller 12 and a roller 13 through a guide 11, and the yarn is opened by a compressed air nozzle 14 in a relaxed state between the roller 13 and the roller 16. After being woven and migrated, the fiber is brought into contact with the first heating member 15 so as to give an uneven heat shrinkage between the single fibers in the longitudinal direction of the single fiber and between the single fibers in the same cross section of the yarn. Through the second heating element 17 between the roller and the roller 18, the loop and the slack generated in the above-described process are eliminated, and the roll is wound around the winder 19.
FIG. 7 shows a method in which after the processing is performed in the same manner as described above, an interlace processing is performed by an interlace nozzle 20 between the roller 18 and the roller 21, and the film is wound around a winder 19.

In the manufacturing method of the present invention, after the stretching, the first state is set between the roller 13 and the roller 16 in a relaxed state.
It is necessary to allow the heater 15 to travel in contact with the heater. If the first heating element is run in contact with the first heating element in a fixed length or in a tensioned state, an uneven heat shrinkage cannot be given between the single fibers in the length direction of the single fiber and between the single fibers in the same cross section of the yarn. However, the silk-like fine crimp and bulkiness desired by the present invention cannot be obtained.

The temperature of the heating element may be at least the temperature at which thermal shrinkage of the undrawn yarn to be used occurs, but is preferably in the range from the glass transition point to the melting point of the yarn.

It is preferable to use a pressurized air nozzle between the roller 4 and the first heating element 15 because a moderately migrated non-uniform heat treatment for applying vibration to the yarn can be performed.

Further, the above rollers 13 and 16
If the yarn having a loop or slack generated in the first heating element 15 is wound as it is, the releasability of the wound yarn is deteriorated and the high-order processability is deteriorated. It is necessary to remove the loops and slacks generated between the first and second layers by heat treatment. At this time, it is preferable that the temperature of the second heating element 17 for eliminating the loop and the slack is equal to or lower than that of the first heating element 15. When the temperature of the second heating element 17 is higher than the temperature of the first heating element 15, the non-uniform heat shrinkage once applied between the single fibers in the length direction of the single fiber and in the same cross section of the yarn becomes uniform. Therefore, it becomes difficult to develop the silk-like fine crimp and bulkiness, which are the objects of the present invention, even if heat treatment is performed in the next step.

In the production method of the present invention, as shown in FIG. 7, when the yarn exiting the roller 18 is interlaced, the high-order process passability becomes very good. Preferably, the strip is interlaced via an interlace nozzle 20. In this case, it is preferable that the CF value by a measuring method described later is 5-200.

As described in detail above, the latent crimped yarn constituted by the composite fiber having a hollow portion obtained by the present invention is:
By weaving and dissolving and removing the outer layer components by solvent treatment and applying high-order processing, it has a distinctive glossy shine, excellent opacity, dry touch without waxy feeling, feeling of tension, tension -A woven or knitted fabric for clothing having excellent waist, lightness, and swelling close to silk can be obtained.

[0036]

The present invention will be described in more detail with reference to the following examples. Each characteristic value in the examples was obtained by the following method. A. Feeling characteristics (smoothness, tension and waist, glossiness, lightness,
Swelling) For each item, a sensory test was performed by a pairwise comparison of the sample with a reference sample, and evaluated on a four-point scale. And when they are comprehensively evaluated, "Excellent" is ◎, "Excellent"
Is ○, inferiority is △, and “extremely inferior” is ×
Indicated by As the reference sample, a Y-section polyester filament yarn having the same fineness and the same number of filaments as that of the sample raw yarn usually used as a standard product was woven and processed in the same manner as the sample. Yes. " B. Intrinsic viscosity [η] orthochlorophenol (hereinafter referred to as OCP) 10 ml
Was dissolved in 0.10 g of the sample, and the temperature was measured at 25 ° C. using an Ostwald viscometer. C. Melt viscosity The melt viscosity is a value measured by a melt indexer type MX-101-B manufactured by Takara Kogyo Co., Ltd. at the same temperature as the spinning temperature at a shear rate of 30 (1 / sec).

D. CF value The CF value was measured by a method according to US Pat. No. 3,290,932. The outline is shown below. FIG. 8 is a schematic view of a CF value measuring device, and FIG. 9 is an enlarged view of the needle part of FIG. In the apparatus shown in FIG. 8, the sample 22 is released by a roller 23 and wound around a waist roller 24. 1cm / s of yarn
In the state of traveling at a speed of ec, the magnet type tension applying device 25 is adjusted, and the tension applying device 25 and the roller 23 are adjusted.
Set the tension between them to the initial tension. Initial tension is denier x 0.
2 g, and fixed between the tension applying device 25 and the roller 23. It is detected by the tension meter 26. After the initial tension is set, the running of the yarn is stopped, and the measuring needle 27 is pierced into the yarn at a position where the yarn is substantially bisected as shown in FIG. Next, when the sample yarn is run again at 1 cm / sec, the needle is hooked on the entanglement point 28, and the tension between the needle 27 and the roller 23 is increased.
The roller 23 is set to stop when the tension value reaches [initial tension + average denier of a single fiber], and the travel distance hi of the yarn from the time when the needle is stabbed to the time when the yarn is stopped again is set.
(Mm) is read from the rotation angle of the roller 23. The same operation is repeated to calculate the CF value by the following equation.

[0038]

(Equation 1)

The measurement is performed with n = 3 and the average value is displayed. The CF value in the present invention is the value of R manufactured based on the above principle.
The measurement was performed using an entanglement tester (model R2040) manufactured by hthschild.

Example 1 The intrinsic viscosity [η] of the inner layer component (polymer A) was 0.75.
A polyethylene terephthalate blended with 0.3% by weight of titanium oxide was used as an outer layer component (Polymer B) to have an intrinsic viscosity [η] of 0.44 and a 5-sodium sulfoisophthalic acid component of 4.5 mol%. Using the modified polyester obtained by copolymerization, using a core-sheath composite die shown in FIG. 3 at a spinning temperature of 295 ° C. using a general composite spinning machine, the die hole radius i shown in FIG. And the radius of curvature h of the slit
Is 0.6 mm from an annular four-slit slit hollow hole,
When the inner layer has a composite ratio of 50% by weight,
Winded at a speed of minutes. The melt viscosities of the single polymers of the inner layer component and the outer layer component were 4400 poise and 1700 poise, and the ratio of the viscosities was about 2.6 times. This undrawn yarn is drawn at a draw ratio of 2.5 times by using the apparatus shown in FIG. 7 and made to contact and run with a first heating body at 230 ° C. at a relaxation rate of 10%.
Heat treatment is performed with a second heating body at 150 ° C. in a fixed length state, and the multifilament composite fiber obtained by interlacing at an air pressure of 2 kg / cm 2 is woven as a warp and a weft. Relaxing scouring at 98 ° C., 180 ° C. And then treated with a 4% by weight sodium hydroxide hot aqueous solution at 98 ° C. to elute the outer layer components into 75 denier and 36 filaments, and finish set at 170 ° C. to obtain Habuta. Sensory evaluation was performed on each of the obtained samples, and as a result, the texture was unattainable with the conventional woven fabric using a modified cross-section polyester filament, and all of the texture characteristics were extremely excellent. Table 1 shows the results
And Table 2.

Examples 2 and 3 In Examples 2 and 3, the composite ratio of the inner layer was 6
The test was performed under the same conditions as in Example 1 except that the weights were set to 0% by weight and 75% by weight, and the temperatures of the first heating body and the second heating body were set to 210 ° C. using the apparatus shown in FIG. The results of the obtained samples are shown in Tables 1 and 2. The sample of Example 2 in which the composite ratio of the inner layer portion was 60% by weight was similar to that of Example 1,
All of the texture characteristics were excellent. In addition, the sample of Example 3 in which the composite ratio of the inner layer portion was 75% by weight was superior to the conventional product in that it had a moderate feeling of squatting, a feeling of tension and waist, a swelling like silk, and a lightweight feeling. Was.

Comparative Example 1 An experiment was carried out under the same conditions as in Example 1 except that the composite ratio of the inner layer portion was 90% by weight. Table 1 and Table 2 show the results of the obtained samples.
It was noted in. Although the obtained sample had swelling, the cross section of the inner layer was not a target polygonal cross section but a circular shape, and after elution of the outer layer, there was no refreshing feeling such as smoothness, tension, waist, etc. The feeling was inferior.

Comparative Example 2 An experiment was performed under the same conditions as in Example 1 except that the first heating member was brought into contact with the fixed length state. The obtained results are shown in Tables 1 and 2. The obtained sample had a feeling of smoothness, tension, waist, etc., but had no silk-like swelling and was paper-like.

Examples 4, 5, and 6 The same procedures as in Example 1 were carried out except that the polymer composition and melt viscosity of the outer layer component were changed as shown in Table 1. Table 2 shows the obtained results. Example 4 in which polyethylene terephthalate obtained by copolymerizing 1.8-mol% of 5-sodium sulfoisophthalic acid component was used as the outer layer component, and Example in which the ratio of the melt viscosity of the inner layer component to the outer layer component was 1.2 times. All of the samples of No. 5 were excellent in characteristics such as smoothness, tension and waist, brilliant luster, and silky swelling. Further, the sample of Example 6 in which the ratio of the melt viscosity of the inner layer component to the outer layer component was 6 times was excellent in the sense of smell.

Comparative Example 3, Comparative Example 4, Comparative Example 5 The same procedure as in Example 1 was carried out except that the polymer composition and the melt viscosity of the outer layer component were changed as shown in Table 1. The obtained results are shown in Tables 1 and 2. In the sample of Comparative Example 3 in which polyethylene terephthalate obtained by copolymerizing 5-sodium sulfoisophthalic acid component with 0.9 mol% as the outer layer component, the outer layer portion was completely treated by a 4% by weight sodium hydroxide 98 ° C. hot aqueous treatment after weaving. As a result, the apex of the inner layer section was also dissolved and removed, so the apex became rounded,
Not only was he feeling stiff, but he was inferior in tension and waist.
In the sample of Comparative Example 4 in which the viscosity ratio of the inner layer component to the outer layer component was 1.1 times, the cross section of the inner layer portion became circular, and there was no feeling of smear even after dissolution and removal of the outer layer portion, and the texture was rough and glossy. Was inferior. Further, the viscosity ratio is 6.5.
In Comparative Example 5, which was twice as large, a composite abnormality occurred during spinning, and a sample could not be obtained because of poor spinning properties.

Embodiment 7 When the base to be discharged has a base hole radius i shown in FIG.
Example 3 was carried out under the same conditions as in Example 1 except that the hole was a three-segment hollow hole having a slit of 6 mm and a curvature radius h of the slit of 0.6 mm. The obtained results are shown in Tables 1 and 2. The sample had the cross-sectional shape shown in FIG. 2 (a), and had a distinctive glossiness that was even higher than that of the sample of Example 1 as well as a sense of shaking, tension and waist.
It was excellent in opacity.

Embodiment 8 When the base to be discharged has a base hole radius i shown in FIG.
Example 6 was carried out under the same conditions as in Example 1 except that the slit was a 6-segment hollow hole having a slit of 6 mm and a radius of curvature h of 0.6 mm. Table 1 shows the obtained results.
And Table 2. The sample had the cross-sectional shape shown in FIG. 2 (d), had good glossiness, opacity, tightness and waistiness, and was favorable because of its soft feeling and soft texture.

Comparative Example 6 Example 1 was repeated except that the die to be discharged was a seven-segment hollow hole composed of slits having a die hole radius i of 0.6 mm and a curvature radius h of the slit of 0.6 mm. The same conditions were used. The obtained results are shown in Tables 1 and 2. The sample of Comparative Example 6 was a hollow fiber having an inner layer portion having a heptagonal outer peripheral shape, but lacked a refreshing feeling such as squatting feeling, tension and waist, and had no characteristic.

[0049]

[Table 1]

[0050]

[Table 2]

[0051]

The present invention relates to a latent crimped yarn composed of inner and outer layer conjugate fibers having a hollow portion, which could not be achieved by the prior art. More specifically, the outer peripheral shape of the inner layer portion in the fiber cross section is linear. Having a highly uniform side portion and a sharp apex portion, and potentially having a non-uniform heat shrinkage rate between the single fibers in the same cross section of the yarn in the longitudinal direction of the single fiber and the yarn constituted by the single fiber Because of this, it has excellent characteristics such as brilliant unique luster, dry touch, shaping, tension and waist, light weight, silky crimp, and bulge. It is ideal as a refreshing material for clothing that could not be obtained with fiber.

[Brief description of the drawings]

FIG. 1 is a cross sectional view of a fiber for explaining a cross sectional shape of a conjugate fiber of the present invention.

FIG. 2 is a cross-sectional view showing an example of a cross-sectional shape of the conjugate fiber of the present invention.

FIG. 3 is a longitudinal sectional view of a main part of a composite die device preferably used in the present invention.

FIG. 4 is a bottom view of a base showing an example of a base hole shape used in the present invention.

FIG. 5 is a bottom view of the base for explaining the base hole shape of FIG. 4;

FIG. 6 is a schematic view showing one example of an embodiment of a stretching and heat treatment step of the present invention.

FIG. 7 is a schematic view showing another cooling of FIG. 7;

FIG. 8 is a schematic diagram of a CF value measuring device.

FIG. 9 is an enlarged view of the needle part of FIG. 8; ■

──────────────────────────────────────────────────の Continued on the front page (58) Investigated field (Int.Cl. ⁷ , DB name) D02G 1/18 D01F 6/62 303 D01F 6/62 306 D01F 8/14 D02J 1/22 F-term theme code 4L036 , 4L 035,4L041

Claims (4)

(57) [Claims] 1. An inner / outer layer composite fiber having a hollow portion, wherein the outer layer component is polyethylene terephthalate obtained by copolymerizing a 5-sodium sulfoisophthalic acid component in an amount of 1.0 mol% or more, and the outer periphery of the inner layer portion in the fiber cross section is It is a polygonal shape having a triangle shape or more and a hexagonal shape or less, and is characterized by potentially having a non-uniform heat shrinkage rate between each fiber in the same cross section of the yarn constituted by the single fiber and the length direction of the single fiber. Polyester latent crimped yarn. 2. The fiber according to claim 1, wherein the radius of curvature of the apex portion in the outer peripheral shape of the inner layer portion in the fiber cross section satisfies the following range, and the variation rate of the side portion between adjacent apex portions is 10% or less. Polyester latent crimped yarn. r ≦ 2d ^0.5 r: radius of curvature at the apex of the inner layer cross section (μm) d: fineness of single fiber inner layer (denier) 3. An interlace is applied, and a CF value is 5 to 3.
The latently crimped polyester yarn according to claim 1 or 2, wherein the range is 200. 4. A polyethylene terephthalate copolymerized with 1.0 mol% or more of 5-sodium sulfoisophthalic acid component as an outer layer component, and a polyethylene terephthalate having a melt viscosity of 1.2 to 6 times the outer layer component is used. As the polymer of the inner layer component, the inner / outer layer composite stream having a composite ratio of the inner layer portion of 40% by weight or more and 75% by weight or less is divided into 3 or more and 6%
The inner and outer layer composite fibers having a hollow portion wound and discharged by joining the polymer composite flow just below the die, are discharged from the annular die hole formed by the slits or less, and are stretched to the first heating element in a relaxed state. After contact non-uniformity is given to each filament in the same cross section of the filament in the length direction of the filament and the filament in the same cross-section, heat treatment is performed by the second heating body. A method for producing a latently crimped polyester yarn.