JP2002194621A - Modified cross-section conjugate fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conjugate fiber having a good stretching property and good elastic recovery and capable of giving a fabric which has the approximately same characteristics, such as swell, tension, stiffness, and repulsion, as those of a wool fabric and has a high grade touch and a good finish appearance. SOLUTION: This modified cross-section fiber has a multi-lobar cross-section which comprises a core portion comprising a thermoplastic polymer (A) and extended in the axial direction of the fiber and three or more projections connected to the core portion and extended in the axial direction of the fiber. Therein, the core portion comprises the thermoplastic polymer (A) having a heat shrinkage stress of >=0.3 g/d and a heat shrinkage rate of >=15%, and at least one part of the projections comprises a thermoplastic (B) having a smaller heat shrinkage rate than that of the thermoplastic polymer (A).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stretchy, irregularly shaped, cross-section conjugate fiber and a fabric obtained from the conjugate fiber. More specifically, the present invention relates to a conjugate fiber having elasticity and elasticity of wool and recoverability thereof, and a fabric obtained from the conjugate fiber.

[0002]

2. Description of the Related Art Conventionally, various types of fabrics made of natural fibers have been used to impart excellent characteristics such as tension, waist, swelling, sliminess, suppleness, and softness to fabrics made of synthetic fibers. A method has been proposed. For example, as a method of imparting a silky feel to synthetic fibers, the fiber cross-section is deformed, the fibers of different shrinkage are mixed, the fibers are entangled by fluid treatment, the fibers of different fineness are mixed, and the fibers are made finer. Proposed. Further, as a method of imparting the feeling of wool to synthetic fibers, a method of applying post-processing such as false twisting, fluid processing, and gear crimping of the fibers to impart mechanical crimp; A method of performing anisotropic heating; a method of combining polymers having different thermal properties into a side-by-side type or a core-sheath type and crimping due to a difference in the thermal properties of the polymer;

[0003] In the case of the above-mentioned conventional method, although properties similar to natural fibers can be imparted to synthetic fibers to some extent, they are still not sufficiently satisfactory. The fact is that it is extremely difficult to apply it to fibers. Synthetic fiber fabrics with small waving have little vertical / horizontal elongation, do not look tailored when tailored as clothing, and do not have a high-class feel as in clothing tailored from natural fiber fabrics.

Further, in order to generate voids in a synthetic fiber woven fabric to impart elasticity to the woven fabric, the fiber cross section is shown in FIG.
As shown in (a) or (b), it has been proposed to generate twist in the yarn as a bilobal conjugate fiber in which a relatively high shrinkage polymer C and a low shrinkage polymer D are bonded in a side-by-side type. [JP-A-59-59920]
FIG. 2 (a), JP-A-3-287810-FIG. 2 (b)]. However, in the case of the fiber shown in FIG. 2A, the twist occurs only in one direction. Therefore, in the case of a woven fabric in which the yarn is not so strongly restrained, such as satin, voids are generated in the woven fabric due to the appearance of the twist, and the woven fabric is warped. Although the stretch of the weft is imparted to some extent, in a woven fabric in which the yarn is strongly constrained, such as a plain weave, there is no space in which the yarn can freely move to some extent.
It cannot give a horizontal stretch or volume. FIG.
In the case of the fiber (b), a twist that intermittently reverses around the high-shrinkable polymer C develops, but since the fiber cross section is flat, a sufficient void is maintained in the woven fabric by the twist alone. And the fabric has insufficient stretchability and volume.

Further, as a method for obtaining elastic synthetic fibers, it has been proposed to produce synthetic fibers from a thermoplastic elastomer (Japanese Patent Publication No. 2-36683).
However, synthetic fibers made of thermoplastic elastomers are extremely high in elasticity, so they are suitable for special applications requiring extremely high elasticity, such as sportswear. It lacks the natural elasticity it has and is not suitable for ordinary clothing. Further, since the fiber made of a thermoplastic elastomer has a small heat shrinkage stress of 0.1 to 0.2 g / denier, when it is made into a fabric, it has elasticity but does not easily exhibit swelling and has a poor feeling. .

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a synthetic wool which has almost the same natural and good stretchability and elastic recovery properties as natural wool and can produce a tailor-made cloth. An object of the present invention is to provide a fiber and a fabric made of such a synthetic fiber.

[0007]

As a result of various studies to achieve the above object, the present inventors have found that a specific composite form and cross-sectional structure can be obtained from specific thermoplastic polymers having different heat shrinkage rates. The present invention has been completed by finding that the above object can be achieved by producing a composite fiber having the same.

That is, the present invention is directed to a center portion of the thermoplastic polymer (A) extending in the fiber axis direction, and three or more protrusions extending in the fiber axis direction provided surrounding the center portion and connected to the center portion. Wherein the central portion is made of a thermoplastic polymer (A) having a heat shrinkage stress of 0.3 g / denier or more and a heat shrinkage ratio of 15% or more, Further, at least a part of each protruding portion is a modified cross-section conjugate fiber characterized by being formed of a thermoplastic polymer (B) having a smaller heat shrinkage than the thermoplastic polymer (A). And the present invention
The present invention also includes a fabric manufactured using the above-mentioned modified cross-section composite fiber.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. Although not limited, in order to facilitate understanding of the present invention, FIG. 1 showing an example of a cross section of a modified cross-section conjugate fiber of the present invention (a cross section of a fiber is referred to as a cross section in the present specification) is shown in FIG. The present invention will be described with reference to FIG. The modified cross-section conjugate fiber of the present invention includes, for example, a central portion 1 made of a thermoplastic polymer (A) extending in the fiber axis direction, as shown in FIGS. It is a conjugate fiber having a multi-lobe cross-sectional shape comprising three or more protruding portions 2 extending in the fiber axis direction provided in connection with the central portion.

In FIGS. 1A to 1H, the number of the protruding portions 2 is 3 to 5, but the number of the protruding portions may be 3 or more, and is not limited to that of FIG. . The number of protrusions is preferably set to about 3 to 8 from the viewpoints of ease of production of the conjugate fiber and the feeling of the fabric obtained from the conjugate fiber. The angle between adjacent protrusions may be equal or different, and the lengths of the protrusions may be all the same or different, and are not particularly limited. The shape of the protruding portion is not particularly limited.For example, the tip is thinner than the root, the tip is thicker than the root, the tip is flat, or the tip is rounded. You may. Further, the shape of the fiber cross section may be geometrically or mechanically symmetric or asymmetric.

[0011] In the modified composite fiber of the present invention,
The central part is made of a thermoplastic polymer (A),
It is necessary that at least a part of the projection is made of the thermoplastic polymer (B). In this case, "at least a part of the protruding portion is made of the thermoplastic polymer (B)" means that the protruding portion 2 as shown in FIGS.
Is composed entirely of the thermoplastic polymer (B),
Alternatively, as shown in FIGS. 1A to 1D, a case where only a part of the protruding portion 2 is made of the thermoplastic polymer (B) is included.

When only a part of the protruding portion 2 is made of the thermoplastic polymer (B), the other portion of the protruding portion 2 [for example, in FIG. It is preferable that the connecting portion 3] is formed integrally with the central portion 1 by the thermoplastic polymer (A). Forming only the intermediate portion of the protrusion 2 from the thermoplastic polymer (B), or combining the thermoplastic polymer (A) and the thermoplastic polymer (B) at the protrusion 2 in an intricate (mixed) state. However, the boundary between the thermoplastic polymer (A) and the thermoplastic polymer (B) can be clearly formed at the tip portion of the protrusion 2, at any position between the tip portion and the root portion, or at the root portion. Preferably, the protrusion 2 is formed from the thermoplastic polymer (B) to be composited. In particular, at least the tip of the protrusion 2 is formed of the thermoplastic polymer (B).
It is preferable to be constituted from the above because twisting in the fiber is improved. Further, it is preferable that 30% or more of the cross-sectional area of the protruding portion 2 is made of the thermoplastic polymer (B) from the viewpoint of easy generation of twist. Furthermore, in the composite fiber of the present invention, the thermoplastic polymer (B) portion provided on each protrusion 2 as long as the thermal shrinkage of the thermoplastic polymer (B) is smaller than the thermal shrinkage of the thermoplastic polymer (A). Can be the same polymer or different polymers.

In the present invention, the central portion 1 of the above-mentioned modified cross-section conjugate fiber is made of a thermoplastic polymer (A) having a heat shrinkage stress of 0.3 g / denier or more and a heat shrinkage of 15% or more, In addition, it is necessary that at least a part of each protrusion is made of the thermoplastic polymer (B) having a smaller heat shrinkage than the thermoplastic polymer (A). The term "thermal shrinkage stress of the thermoplastic polymer (A)" used herein means the same conditions as those used when the thermoplastic polymer (A) is used alone and the modified cross-section conjugate fiber of the present invention is produced under the same conditions. Means the heat-shrinkage stress per unit fineness (denier) of the deformed cross-section fiber of the thermoplastic polymer (A) obtained by producing the deformed cross-section fiber having the same cross-sectional shape. It refers to the value measured by the method described in the examples.

In the present invention, the term "thermoplastic polymer"
"(A) or the heat shrinkage of the thermoplastic polymer (B)" means that the thermoplastic polymer (A) or the thermoplastic polymer (B) alone is used alone to produce the modified cross-section conjugate fiber of the present invention. Using the same apparatus as in the previous case, the modified cross-section fiber having the same cross-sectional shape under the same conditions is produced, and the resulting cross-section fiber of the thermoplastic polymer (A) or the cross-section fiber of the thermoplastic polymer (B) is obtained. It means the heat shrinkage, specifically, a value measured by the method described in the following Examples.

When the heat shrinkage stress of the thermoplastic polymer (A) is less than 0.3 g / denier, the swelling of the obtained fabric is reduced and the feeling is reduced. If the heat shrinkage of the thermoplastic polymer (A) is less than 15%, the obtained fabric will be hard, and comfortable clothes cannot be obtained. As the thermoplastic polymer (A), the heat shrinkage stress is 0.4 g /
It is preferable to use one having denier or more and a heat shrinkage of 20% or more. The upper limits of the heat shrinkage stress and the heat shrinkage of the thermoplastic polymer (A) are not particularly limited, but from the viewpoint of preventing the feeling from becoming hard, the heat shrinkage stress is 0.7 g / denier or less. Is preferably 50% or less.

As the thermoplastic polymer (A), any fiber-forming thermoplastic polymer having a heat shrinkage stress of 0.3 g / denier or more and a heat shrinkage of 15% or more can be used. Is preferably 0.3 g / denier or more and a polyester having a heat shrinkage of 15% or more. Such polyesters include, for example, terephthalic acid, aromatic dicarboxylic acids such as isophthalic acid, azelaic acid, one or more dicarboxylic acid components selected from aliphatic dicarboxylic acids such as sebacic acid, and ethylene glycol,
Diol components such as aliphatic diols such as 1,4-butanediol, aromatic diols such as ethylene oxide addition diol of bisphenol A or bisphenol S, alicyclic diols such as cyclohexane dimethanol, and, if necessary, p-hydroxybenzoate A polyester formed by using a hydroxycarboxylic acid component such as an acid can be mentioned. In particular, it is preferable to use a polyester in which 80 mol% or more of the repeating unit is ethylene terephthalate. Even for the same polyester, the heat shrinkage stress and the heat shrinkage can be increased or decreased by adjusting the intrinsic viscosity, the type and ratio of the copolymer component, and the like.

Further, as the thermoplastic polymer (B),
Any fiber-forming thermoplastic polymer having a heat shrinkage smaller than that of the thermoplastic polymer (A) can be used. For example, nylon 6, nylon 66, nylon having a smaller heat shrinkage than the thermoplastic polymer (A) can be used. 610, nylon 1
Polyamides such as 1, nylon 12, nylon 13, etc .; polyethylene terephthalate, polybutylene terephthalate, polypropylene terephthalate, or 5 of them
-Polyesters made of copolymerized sodium sulfoisophthalic acid. If the thermoplastic polymer (B) has a smaller heat shrinkage than the thermoplastic polymer (A), its heat shrinkage stress may be the same as that of the thermoplastic polymer (A) or may be smaller than that of the thermoplastic polymer (A). It may be large. The thermoplastic polymer (A) and the thermoplastic polymer (B) may be the same type of polymer or different types of polymers.

The thermoplastic polymer (A) and the thermoplastic polymer (B) are compatible with each other so that the two components do not peel off during the steps such as spinning, drawing, post-processing and fabric-making, so that the composite form can be maintained. It is necessary to select and combine those having good properties such as bonding property. In particular, in order to impart a suitable wool-like elasticity and elastic recovery to the obtained conjugate fiber, the difference in heat shrinkage between the two components is 5 to 20.
%, Particularly preferably in the range of 10 to 20%. The difference in heat shrinkage between both polymers is 5
%, The twist of the fiber is reduced, and the resulting fabric tends to have insufficient elasticity. On the other hand, when the difference between the thermal shrinkage rates of both polymers exceeds 20%, although the twist is developed, the thermal shrinkage rate of the conjugate fiber itself increases, and the processing shrinkage rate at the stage of processing into the fabric becomes too large. The texture of the resulting fabric is likely to be hard.

In the modified cross-section conjugate fiber of the present invention, the composite ratio of the thermoplastic polymer (A) and the thermoplastic polymer (B) is 20/80 to 80/20, particularly 30/80 by weight.
It is preferably from 70 to 70/30 in order to develop twist in the conjugate fiber. When either one of the thermoplastic polymer (A) and the thermoplastic polymer (B) is extremely small, twisting of the composite fiber is less likely to occur.

Further, the thickness of the central portion and the protruding portion in the multi-lobal cross-section conjugate fiber of the present invention is not particularly limited. However, when a fabric is used, a flexible and good-feel fabric can be obtained. Preferably, the protrusion and the protrusion have substantially the same fineness, or the center has a larger fineness than the protrusion, and more preferably the center and the protrusion have substantially the same fineness. The composite fiber itself is usually about 50 denier / 36 filaments to 150 denier / 4
It is preferable to use about 8 filaments.

The modified cross-section conjugate fiber of the present invention may be used, if necessary, with additives usually used for the fiber, such as stabilizers such as ultraviolet absorbers and antioxidants, fluorescent whitening agents, dyes and pigments, inorganic It may contain a filler, a flame retardant, and the like.

The modified cross-section conjugate fiber of the present invention can exhibit a twisted structure in which the twist is intermittently reversed by the heat history during the fiber manufacturing process or the heat treatment during fabric processing. In the contracted state, the modified cross-section conjugate fiber of the present invention has a thermoplastic polymer (A) having a large heat shrinkage as a core and a thermoplastic polymer (B) having a small heat shrinkage intermittently around the core. The structure is twisted while being inverted. The intermittent reversal of the twist is a phenomenon that occurs because the fiber (yarn) absorbs rotational distortion caused by the twisted state and reduces the torque of the entire yarn. As a result, the fiber (yarn) of the present invention has an excellent feature that a strong torque is not generated even by expansion and contraction.

The modified cross-sectional conjugate fiber of the present invention having the above-mentioned twisted structure has a fiber (yarn) as a whole having an expansion / contraction ratio of 10 to 70%, particularly 25 to 60%, by a measuring method described later.
When fabrics are manufactured using fibers having the stretch ratio in such a range, the stretch ratio of the obtained fabric is 5 to 25.
%, Which is a value very close to the expansion and contraction rate of a fabric obtained from natural fibers, particularly wool.

It is generally considered that when fabricating clothing, the tailoring of clothing is considered to be due to the horizontal stretching of the cloth, which is a significant factor. Since the modified cross-section conjugate fiber of the present invention has appropriate stretchability and elastic recovery similar to wool as described above, the fabric made from the conjugate fiber of the present invention, at least the conjugate fiber of the present invention The woven fabric produced using the weft yarn has an appropriate stretchability (weft elongation), and has a good tailoring look.

The modified conjugate fiber of the present invention is obtained by using a spinneret having a spinneret (spinneret) having a multi-leaf cross section, using a thermoplastic polymer (A) and a thermoplastic polymer (B).
Can be produced by melt-composite spinning by a conventional method, and preferably by drawing and heat treatment. In this case, in the melt conjugate spinning of the multi-lobal cross-section conjugate fiber, particularly, the thermoplastic resin (A) having the above-mentioned heat shrinkage stress and heat shrinkage rate forming the center is subjected to the thermoplastic flow. Three or more flows of the thermoplastic polymer (B) having a smaller heat shrinkage than the polymer (A) are separated from each other by surrounding the central flow before reaching a spinning hole (counter bore) provided in a die plate. Are introduced at right angles or substantially at right angles from the set positions to form a composite flow composed of the thermoplastic polymer (A) and the thermoplastic polymer (B), and the composite flow is provided on three or more protrusions provided on a die plate. When a method of spinning from a multi-leaf cross-section spinning port (ejection port) having a portion is adopted, the thermoplastic polymer (B) is supplied with good measurement properties, there is no denier spot, and the tip of the protruding portion of the irregular cross-section fiber In a state where the boundary between the thermoplastic polymer (A) and the thermoplastic polymer (B) is clearly defined at a predetermined position between the tip portion and the root portion or at the root portion, the both polymers are joined and compounded, and furthermore, the protrusion is made. It is possible to obtain a conjugate fiber having a clear multi-leaf cross section with a clear contour without causing any collapse in the shape or size of the portion.

The above method can be carried out extremely smoothly by using a base device as shown in FIG. FIG. 3 is a view showing a part of a base device (a base plate and a distribution plate provided thereon), and FIG.
FIGS. 4B to 4D are plan views taken along the line LL of FIG.

In the base device shown in FIG.
A spinneret (discharge port) 5 having a multi-lobe cross section having at least one protrusion is formed, and a distribution plate 6 is provided on the upstream side of the die plate 4 in contact with the die plate 4. The distribution plate 6 has a center conducting hole 7 and three or more side conducting holes 8, and the three or more side conducting holes 8 surround the center conducting hole 7 and are separated from each other. It communicates with the central conducting hole 7 in a direction perpendicular or almost perpendicular. The flow of the thermoplastic polymer (A) is supplied from the central conducting hole 7 of the distribution plate 6 to form a central flow, and the flow of the thermoplastic polymer (B) is supplied from the side conducting hole 8, and the thermoplastic polymer (A) is supplied. ) And the flow of the thermoplastic polymer (B) are combined to form a composite polymer flow by combining both polymers, and the composite polymer flow is transferred to a counterbore 9 provided on the back surface of the base plate 4.
As it is, and the center is a thermoplastic polymer (A)
Constituted, at least a part of the protruding portion of the multi-lobal section
In particular, a composite fiber having a multi-lobed cross section, at least a part of which includes the tip of the protruding portion, is made of the thermoplastic polymer (B) is spun from the spinning port 5.

In FIG. 3, (b) is a view showing a distribution plate for forming a multi-lobal cross-section conjugate fiber having three projections, and (c) and (d) are four and five, respectively.
FIG. 4 is a view showing a distribution plate for forming a multi-lobal conjugate fiber having a plurality of protrusions. In the case of using a die device having a distribution plate as shown in FIG. 3, the heat shrinkage of the thermoplastic polymer (B) is reduced by the heat shrinkage of the thermoplastic polymer (A) supplied to the central hole 7. As long as the flow rate is less than the same, the three or more side holes (8) may be supplied with the same thermoplastic polymer (B) stream or may be supplied with a different type of thermoplastic polymer (B) stream. Alternatively, a wide variety of composite fibers can be obtained by selecting and combining the thermoplastic polymer (A) and the thermoplastic polymer (B). Further, the die device as shown in FIG. 3 is made of a thermoplastic polymer (A).
This is effective when the viscosity difference between the thermoplastic polymer (B) and the thermoplastic polymer (B) is large. In particular, the flow of the thermoplastic polymer (A) supplied to the central conductive hole 7 has a high viscosity and is supplied to the side conductive holes 8. The effect is more exhibited when the flow of the thermoplastic polymer (B) has a low viscosity, and a composite fiber having a desired multi-lobed cross section can be accurately produced with good processability.

Then, in the base device as shown in FIG.
The side holes 8 are not necessarily exactly perpendicular to the center hole 7 (9
0 °). Further, in the spinneret shown in FIG. 3, the position and the number of the side guide holes 8 in the distribution plate 6 are matched with the positions and the number of the protrusions in the spinneret 5 provided in the spinneret 4, so that the multi-lobal cross-section conjugate fiber In the above, the thermoplastic polymer (B) can be more accurately and precisely arranged at a position including at least the tip portion of the protrusion. And the spinneret device of the present invention,
Any shape may be used as long as it has a distribution plate and a base plate having the above structure, and the shape, structure,
The size and the like are not particularly limited. In addition, such a spinneret is useful not only for the production of the composite fiber having a multi-leaf cross section of the present invention, but also for the production of a composite fiber having a complicated shape and comprising a polymer of two or more components.

When, for example, a conventional spinneret equipped with a distribution plate as shown in FIG. 4 is used in place of the spinneret according to the present invention as shown in FIG. 3 [FIG. FIG. 4B is a longitudinal sectional view of the apparatus, and FIG.
In other words, the annular supply path 10 for supplying the flow of the thermoplastic polymer (B) in an annular state around the entire central conductive hole 7 for supplying the flow of the thermoplastic polymer (A) in the distribution plate 6. In the case of using a spinneret provided with the distribution plate 6 having the following characteristics, in the obtained multi-lobal composite fiber, (1) the thermoplastic polymer (B) is mixed also in the center, and (2) the heat The boundary between the thermoplastic polymer (A) and the thermoplastic polymer (B) at the protrusion becomes unclear at the intersection of the thermoplastic polymer (A) and the thermoplastic polymer (B). (3) Thermoplastic at the protrusion Various troubles such as irregularities in the composite ratio and composite state of the polymer (A) and the thermoplastic polymer (B), and (4) lack of sharpness or variation in size due to the rounded outline of the projection I As a result, kneading on the discharge surface of the die plate, uneven discharge of polymer, breakage of single yarn, etc. occur, poor processability during spinning, winding of fluff during drawing, uneven drawing, abnormal tension, Contraction spots, stain spots, streak spots, and the like are likely to occur. In particular, when the difference in viscosity between the thermoplastic polymer (A) and the thermoplastic polymer (B) is large,
Such troubles are more likely to occur.

As described above, the modified cross-section conjugate fiber of the present invention is produced by melt conjugate spinning and then preferably subjected to drawing (drawing and heat setting) and heat treatment, in which case, for example, 1000 to 4000 m. / Spinning at a normal spinning speed such as / min, cooling, winding while lubricating as needed, and then stretching and heat-treating at an appropriate temperature. Even when adopting a method of producing a fiber drawn at the same time as spinning and applying a heat treatment to it,
Alternatively, a direct spinning drawing method in which the film is directly stretched and heat-treated after spinning may be employed. In any case, if the difference between the melt viscosities of the thermoplastic polymer (A) and the thermoplastic polymer (B) is extremely large, kneading is apt to occur in the spinneret and the spinning processability is deteriorated. Use of the apparatus enables good spinning without such troubles. It goes without saying that both polymers having an appropriate viscosity difference are selected depending on the application.

The stretching temperature and the heat setting temperature employed in the stretching step (drawing and heat setting) of the conjugate fiber are determined by the shrinkage and stretchability of the conjugate fiber and the fabric obtained therefrom.
Since it is a factor that often directly affects swelling, flexibility, and the like, it is necessary to pay sufficient attention to the stretching temperature and the heat setting temperature when performing the stretching treatment. In particular, the thermoplastic polymer (A) constituting the composite fiber
Of the thermoplastic polymer (B), it is preferable to perform stretching at a temperature equal to or higher than the Tg of a polymer having a high glass transition point (Tg) from the viewpoints of processability, product swelling, and tailoring. For example, when the thermoplastic polymer (A) and the thermoplastic polymer (B) are both polyester-based polymers, the stretching temperature is set to 75 ° C. or higher, and the heat setting temperature is set to 90 °.
The temperature is preferably set to 160 ° C. If the stretching temperature is lower than 75 ° C., unevenness in stretching is likely to occur due to winding of fluff or fluctuation in tension, which tends to cause deterioration in quality. The heat setting temperature is 90
If the temperature is lower than ℃, the shrinkage can be kept large, but the texture becomes hard and sticky, while the heat setting temperature is 160 ℃
If it is higher than this, the shrinkage of the composite fiber becomes low, and a low-quality cloth with a flat feeling without swelling tends to be obtained. Further, it is preferable that the tension applied at the time of drawing is low in order to improve the development of the twisted structure in the conjugate fiber.

The heat treatment performed after stretching (stretching and heat setting) may be performed continuously with the stretching process or as a process separated from and independent of the stretching process. The heat treatment may be performed in the state of fibers or yarns, or may be performed during the fabric manufacturing process or after fabric manufacturing (for example, a refining process, a preset process, or a dyeing process). The heat treatment temperature can be appropriately selected according to the type of the thermoplastic polymer (A) and the thermoplastic polymer (B) used for producing the conjugate fiber, the crystallization temperature, and the like. When the plastic polymers (B) are both polyester-based polymers,
It is preferable to employ a temperature in the range of 90 to 160 ° C. in terms of stretchability, swelling, flexibility, tailoring and the like of the obtained product.

The modified cross-section conjugate fiber of the present invention obtained as described above may be entangled with a fluid or the like, if necessary, alone or in combination with another fiber; false twisting, fluid processing , Crimping by gear crimping, etc .; Taslan (Hevaline Fiber Technology In
c. May be further applied. The conjugate fiber of the present invention can be used alone or blended with other synthetic fibers or natural fibers, etc. to form a fabric by blending. Particularly in the case of woven fabrics, at least the weft yarn uses a yarn made of the conjugate fiber of the present invention. It is possible to obtain a well-tailored good fabric which is rich in elasticity and swelling.

Hereinafter, the present invention will be described specifically with reference to Examples and the like, but the present invention is not limited thereto. In addition,
In the following examples and the like, the intrinsic viscosity [η] of the polymer,
Heat shrinkage stress of thermoplastic polymer (A), heat shrinkage of thermoplastic polymer (A) and thermoplastic polymer (B), processability during spinning, processability during stretching, heat shrinkage of obtained composite fiber, The measurement or evaluation of the number of twists and the cross-sectional shape, the stretchability of the resulting fabric and the tailored look were performed as follows.

[0036] The intrinsic viscosity of the polymer [η]: phenol /
This is a value measured at 30 ° C. by dissolving a polymer in a mixed solvent of tetrachloroethane (weight ratio: 1: 1).

Thermal shrinkage stress of thermoplastic polymer (A): Using thermoplastic polymer (A) alone, under the same conditions and under the same conditions using the same equipment as in the production of the conjugate fiber in each of the Examples and Comparative Examples. Spinning and drawing irregular shaped fibers having a shape, size and thickness, collecting 10 cm of the obtained drawn yarn, connecting both ends to form a loop. Using an autograph (“AG-2000A type” manufactured by Shimadzu Corporation),
Dry heat treatment is performed at a rate of 1 ° C./min from room temperature under a load of 0.5 g / denier, and the maximum shrinkage stress (g) at that time is read and divided by the total fineness (total denier number) of the yarn. Then, the heat shrinkage stress per single fineness (g / denier) is determined.

Thermoplastic polymer (A) and thermoplastic poly
Heat shrinkage of mer (B) : using thermoplastic polymer (A) or thermoplastic polymer (B) alone, under the same conditions using the same apparatus as for the production of the conjugate fiber in each of the Examples or Comparative Examples, Spun and drawn fibers having the same cross-sectional shape, dimensions and thickness are spun and drawn, and 50 cm of the obtained drawn yarn is collected. A load of 100 mg / denier was applied to one end of the drawn yarn, and the length (L ₀ ) (c
m) is measured. Then, the load applied to the drawn yarn is 1
mg / denier, soak it in boiling water for 20 minutes, then take out and air dry. The load applied to the drawn yarn replacing the 100mg / denier, the length of the drawn yarn at that time (the L ₁₎ (cm) was measured, obtaining the thermal shrinkage rate (%) using Equation 1 below.

[0039]

## EQU1 ## Thermal shrinkage (%) = {(L ₀ −L ₁ ) / L ₀ } × 100

Processability at the time of spinning : Processability at the time of spinning is evaluated according to the four-step evaluation criteria shown in Table 1 below.

[0041]

[Table 1]

The stretching process at the time of resistance: To assess the processability in stretching the evaluation criteria of four levels as shown in Table 2 below.

[0043]

[Table 2]

Heat shrinkage of conjugate fiber : A drawn yarn of the conjugate fiber obtained in each of Examples and Comparative Examples is collected. Using this drawn yarn, 1 was measured in the same manner as when measuring the thermal shrinkage of the thermoplastic polymer (A) or the thermoplastic polymer (B).
Length of drawn yarn when a load of 00 mg / denier is applied
(L ₀ ) (cm), the load applied to the drawn yarn was changed to 1 mg / denier, immersed in boiling water for 20 minutes, taken out and air-dried, and then the load applied to the drawn yarn was 100 mg.
/ Length of drawn yarn after changing to denier (L ₁ ) (cm)
Is measured, and the heat shrinkage (%) is obtained by the above equation (1).

Number of twists of conjugate fiber : A bundle of drawn yarn of conjugate fiber obtained in each of Examples and Comparative Examples is skein-shaped and immersed in boiling water for 30 minutes, heat-treated, and air-dried. A) is attached to the slide glass one by one in the length direction so that the crimped state of the above) is kept almost as it is, and the number of twists for a length of 1 inch is visually counted. At that time, as shown in FIG. 5, the number of twists is counted as one point where the protrusions to the left and right cross each other along the length direction of the fiber.

Cross-sectional shape of conjugate fiber : The quality of the cross-sectional shape of the conjugate fiber obtained according to the four-level evaluation criteria shown in Table 3 below is evaluated.

[0047]

[Table 3]

The fabric of the stretch: by using a fabric sample of 20cm width, carried out a tensile test using a texture measuring instrument [Kato Tech Co., Ltd. "KES System"], 500g / cm
The elongation at the time of pulling in the horizontal direction by the force of E is defined as Emax, and the value is defined as the elasticity (%) of the fabric.

Tailoring Cloth : Each of the fabrics obtained in Examples and Comparative Examples is tailored into a men's suit, and the appearance is sensory-evaluated according to the four-level evaluation criteria shown in Table 4 below.

[0050]

[Table 4]

Example 1 As the thermoplastic polymer (A), [η] was 1.1 dl / g, and the heat shrinkage stress was 0.35 g.
/ Denier and a polybutylene terephthalate having a heat shrinkage of 20% were used, and as the thermoplastic polymer (B), polyethylene terephthalate having a [η] of 0.68 and a heat shrinkage of 7% was used as the thermoplastic polymer (B) (FIG. 3). B) a spinning apparatus provided with a spinneret having a distribution plate, and a thermoplastic polymer (A):
The thermoplastic polymer (B) is fed at a weight ratio of 1: 1, spun out, wound up at a take-up speed of 1000 m / min, and
0 denier / 36 filament composite fiber (spun yarn)
I got The spun yarn obtained above was drawn (drawn and heat-set) using a heating roller at a temperature of 78 ° C and a plate at a temperature of 120 ° C to produce a drawn yarn of 75 denier / 36 filaments. The drawn yarn was twisted using a spindle false twisting machine at a false twist number of 3500 times / m and a false twisting temperature of 200 ° C., and then a 2/2 twill fabric was woven. The obtained woven fabric was desizing, refining and drying, and then subjected to dry heat treatment at a temperature of 170 ° C. to cause swelling. After presetting, a 20% by weight reduction treatment, dyeing, and finishing setting steps were sequentially performed. In Example 1, the processability during spinning, the processability during stretching, the heat shrinkage of the obtained conjugate fiber, the number of twists and the cross-sectional shape,
When the stretchability and tailoring look of the obtained fabric were measured or evaluated by the above-mentioned methods, all of them were extremely good as shown in Table 5 below.

Comparative Example 1 Production, drawing, weaving, and post-processing of a conjugate fiber were performed in the same manner as in Example 1 except that the distribution plate in the spinneret was changed to the structure shown in FIG. Table 5 shows the results.

Example 2 As the thermoplastic polymer (A), polyethylene terephthalate obtained by copolymerizing 8% by mole of isophthalic acid having [η] of 0.76, heat shrinkage stress of 0.35 and heat shrinkage of 18% was used. The production, drawing, weaving, and post-treatment of a conjugate fiber were performed in the same manner as in Example 1 except for using. Table 5 shows the results.

<Comparative Example 2> Production, drawing, weaving, and post-processing of a conjugate fiber were performed in the same manner as in Example 2 except that the distribution plate in the spinneret was changed to the structure shown in FIG. Table 5 shows the results.

Example 3 Two moles of a bisphenol S ethylene oxide ethylene oxide diol having a [η] of 0.70, a heat shrinkage stress of 0.40 and a heat shrinkage of 26% were used as the thermoplastic polymer (A). The production, drawing, weaving, and post-treatment of a conjugate fiber were performed in the same manner as in Example 1 except that polyethylene terephthalate copolymerized by mol% was used. Table 5 shows the results.

Comparative Example 3 Production, drawing, weaving, and post-processing of a conjugate fiber were carried out in the same manner as in Example 3 except that the distribution plate in the spinneret was changed to the structure shown in FIG. Table 5 shows the results.

Example 4 As the thermoplastic polymer (A), polyethylene terephthalate obtained by copolymerizing 12% by mole of isophthalic acid having [η] of 0.82, heat shrinkage stress of 0.45 and heat shrinkage of 32% was used. Example 1 except for using
Production, drawing, weaving, and post-treatment of a conjugate fiber were performed in the same manner as described above. Table 5 shows the results. As shown in Table 5, since the thermoplastic polymer (A) in Example 4 had a slightly higher heat shrinkage, the processability during spinning and stretching was slightly lower than that in Example 1. Although the stretchability of the fabric obtained from the conjugate fiber was slightly larger than that of Example 1, the obtained fabric was sufficiently effective as wool-like clothing.

Comparative Example 4 Production, drawing, weaving, and post-processing of a conjugate fiber were performed in the same manner as in Example 4 except that the distribution plate in the spinneret was changed to the structure shown in FIG. Table 5 shows the results.

Example 5 (1) As the thermoplastic polymer (A), [η] was 0.7.
5, a polyethylene terephthalate obtained by copolymerizing 2 mol% of an ethylene oxide 2 mol addition diol of bisphenol A having a heat shrinkage stress of 0.41 and a heat shrinkage ratio of 27% and 8 mol% of isophthalic acid was used. A composite fiber having the cross-sectional shape of FIG. 1F was spun out in the same manner as in Example 1 except that the distribution plate was replaced with the structure shown in FIG. 3C. Winding was performed at a speed to obtain a composite fiber of 100 denier / 12 filaments. The heat shrinkage of this composite fiber was 17%.

(2) On the other hand, using polyethylene terephthalate having [η] of 0.68 and a heat shrinkage of 7%,
Spin at a take-off speed of 0 m / min and 100 denier / 3
Six filament fibers were obtained. (3) The conjugate fiber obtained in (1) and the polyester fiber obtained in (2) were drawn and twisted while being aligned, and subjected to Taslan processing to obtain a yarn of 150 denier / 48 filaments. (4) A plain fabric was produced using the yarn obtained in (3) above as a warp yarn and a weft yarn, and was subjected to post-processing in the same manner as in Example 1. (5) As shown in Table 5 below, the results show that the processability during spinning, the processability during stretching, and the false twisting processability are all good, and the woven fabric as the final product has swelling, It was soft and had good elasticity comparable to that of wool fabric.

Comparative Example 5 Production, drawing, weaving, and post-processing of a conjugate fiber were performed in the same manner as in Example 5 except that the distribution plate in the spinneret was changed to the structure shown in FIG. Table 5 shows the results.

Comparative Example 6 An example was made except that polyethylene terephthalate having [η] of 0.70, a heat shrinkage stress of 0.20 g / denier and a heat shrinkage of 8% was used as the thermoplastic polymer (A). Production, drawing, weaving, and post-treatment of a conjugate fiber were performed in the same manner as in 1. Table 5 shows the results.

Table 5 shows the stretchability of the woven fabric obtained from natural wool for reference.

[0064]

[Table 5]

From the results shown in Table 5, in Examples 1 to 5, conjugate fibers having good processability during spinning and processability during stretching, a large heat shrinkage and a large number of twists, and a good cross-sectional shape can be obtained. In addition, the stretchability of the fabric obtained from the conjugate fiber has almost the same good value as the stretchability of the fabric made of wool, and it can be tailored. In contrast, in the case of Comparative Examples 1 to 6, It can be seen that the processability at the time of spinning and the processability at the time of stretching are poor, and the cross-sectional shape of the obtained conjugate fiber is poor, so that the fabric does not look tailored.

Example 6 In Example 2, the temperature of the heating roller and the temperature of the plate during stretching were set to the values shown in Table 6 below.
In the same manner as in Example 2,
Stretching, weaving, and post-processing were performed to produce a twill fabric, and the results shown in Table 6 were obtained.

[0067]

[Table 6]

From the results shown in Table 6 above, in order to maintain good drawing processability and the properties of the conjugate fiber and the fabric, the drawing temperature and the heat setting temperature at the time of drawing and heat setting the conjugate fiber are set in more suitable ranges. It can be seen that it is preferable to perform

[0069]

EFFECT OF THE INVENTION The modified cross-section conjugate fiber of the present invention has good stretchability and elastic recovery, and the conjugate fiber of the present invention has a bulge, tension, almost the same level as a natural fiber, particularly a wool fabric. It is possible to obtain a luxuriously tailored fabric having extremely good properties such as waist and resilience.

The conjugate fiber of the present invention having the above-mentioned excellent properties is a distribution plate having a center conducting hole and three or more side conducting holes, and the three or more side conducting holes are provided at the center conducting hole. The spinneret is provided with a distribution plate which is located separately from each other and communicates at right angles or substantially at right angles to the center hole, and heat shrinkage stress is applied to the center hole. A thermoplastic polymer (A) having a flow rate of 0.3 g / denier or more and a heat shrinkage of 15% or more is supplied, and at the same time, a thermoplastic polymer having a smaller heat shrinkage than the thermoplastic polymer (A) in the side holes. By supplying the flow of (B), it can be manufactured extremely smoothly.

[Brief description of the drawings]

FIG. 1 is a view showing an example of a cross-sectional structure of a modified cross-section conjugate fiber of the present invention, and FIGS. 1 (a) to 1 (h) are one embodiment thereof.

FIG. 2 is a diagram showing a cross-sectional structure of a conventional two-leaf conjugate fiber.

FIG. 3 is a diagram showing an example of a spinneret device preferably used for producing the conjugate fiber of the present invention. In FIG. 3, (A) is a longitudinal sectional view and (B) to (D) are () in FIG. It is a top view in the cutting line LL part of a).

FIG. 4 is a view showing an example of a conventional spinneret device provided with a distribution plate. In FIG. 4, (A) is a longitudinal sectional view thereof, and (B) is a plan view taken along the line LL of FIG. It is.

FIG. 5 is a diagram showing a method for measuring the number of twists of a conjugate fiber.

[Explanation of symbols]

 A Thermoplastic polymer (A) B Thermoplastic polymer (B) C High shrinkable polymer D Low shrinkable polymer 1 Central part 2 Projection part 3 Connection part 4 Cap plate 5 Spinning port (discharge port) 6 Distribution plate 7 Center hole 8 Side guide hole 9 Counter bore 10 Annular supply path

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Keiji Fukuda 1621 Sakurazu, Kurashiki-shi, Okayama Pref. Kuraray Co., Ltd. (72) Inventor Isao Tokunaga 1621 Sakurazu, Kurashiki-shi, Okayama F-term (reference) 4L041 AA07 BA04 BA05 BA11 BA21 BA35 BA38 BA39 BB08 BC05 CA06 CA12 CA13 DD01 DD10 4L045 AA05 BA10 BA16 BA17 CB16 4L048 AA21 AA22 AA28 AA30 AA37 AA46 AA50 AA51 AB07 AB09 AC12 CA04 DA03

Claims (2)

[Claims] 1. A central portion of a thermoplastic polymer (A) extending in the fiber axis direction, and three or more projecting portions extending in the fiber axis direction provided around the center portion and connected to the central portion. A fiber having a multi-lobed cross section, wherein the central portion is made of a thermoplastic polymer (A) having a heat shrinkage stress of 0.3 g / denier or more and a heat shrinkage ratio of 15% or more; Characterized in that at least a part of the composite fiber is composed of a thermoplastic polymer (B) having a smaller heat shrinkage than the thermoplastic polymer (A). 2. A fabric produced using the modified cross-section conjugate fiber according to claim 1.