JPH0325521B2 - - Google Patents

Description

[Detailed description of the invention]

(Technical Field) The present invention relates to an antistatic fiber and a method for producing the same, and more specifically to an antistatic fiber in which an antistatic agent is dispersed in a high density around the hollow part of a hollow fiber having a special cross-sectional shape. The present invention relates to sexual fibers and their manufacturing methods. (Prior art) Synthetic fibers represented by polyester are significantly superior to natural fibers in terms of various properties such as mechanical strength, durability, and functionality. It has the fatal flaw of extremely high resistance and easy generation of static electricity. Various methods have been proposed to prevent the generation of static electricity, but each has its advantages and disadvantages, and it is difficult to satisfy all of them in terms of spinning cost, antistatic property and its sustainability, fiber performance, etc. The current situation is that this has not yet been achieved. The simplest method is to apply or apply an antistatic agent to the fiber surface, but in this case, the antistatic agent tends to disappear during the dyeing process or repeated washing, so a permanent antistatic effect cannot be expected. There are some serious drawbacks. If we focus only on the antistatic property, the durability of the antistatic effect is a fundamentally required property, and in this sense, the method of kneading an antistatic agent into the polymer before spinning is preferable. Regarding this, the methods used in the past include (a) uniformly mixing polyoxyalkylene glycol into the fibers as seen in Japanese Patent Publication No. 39-5214, and (b) Japanese Patent Publication No. 47-11280 (and also Japanese Patent Publication No. 46-22200). (c) polyoxyalkylene glycol as seen in JP-A-53-149247; A well-known method is to use a combination of alkyl sulfonate and sodium alkyl sulfonate. In these methods, the amount of antistatic agent used is generally recommended to be 2% by weight or more (method a), 0.7 to 8% by weight (method b), and 1.0 to 2.0% by weight (method c); In order to obtain a strong antistatic effect, as shown in the examples, method a requires 6% by weight or more, method b approximately 6% by weight or more.
A relatively large amount of agent is required, such as 7.5% by weight, and 3% by weight for method c. On the one hand, such an increase in the amount of antistatic agent causes deterioration of the mechanical properties of the fiber itself, and at the same time, chemically, it causes a decrease in color fastness. Furthermore, commonly used antistatic agents naturally have a strong affinity with water, so in the case of woven and knitted fabrics that often come into contact with water during scouring, dyeing, or washing, the antistatic agents inside the fibers may It elutes and falls off, and the antistatic property itself decreases rapidly. For this reason, in reality, it is necessary to use an even larger amount of antistatic agent to account for this amount of falling off, and as a result, the physical properties of the fibers continue to deteriorate. A serious defect that cannot be overlooked even in the midst of the above deterioration in physical properties is the fibrillation phenomenon particularly observed in polyester. This is because polyester fibers originally have poor compatibility with antistatic agents, and when the latter is used in an amount of approximately 4% by weight, single fibers (filaments) tend to split into fibrils, and this tendency is further accelerated by mechanical stimulation. Ru. On the other hand, as a means to prevent the deterioration of fiber physical properties, there is a composite spinning method to obtain a core-sheath structured yarn. In this method, at least two or more types of polymers are used; the sheath component is a homopolymer, and the core component is the same or different polymer containing a large amount of antistatic agent, or a conductive material such as carbon or metal. It is composed of polymers containing a large amount or highly chemically modified. In this type of fiber, an excellent antistatic effect can be obtained even if the amount of antistatic agent used is reduced, and there is no effect on mechanical properties or dyeability. As shown in the figure, there is a significant increase in the cost of spinning silk, making it unprofitable on a commercial basis. As described above, since the advent of synthetic fibers, many antistatic methods have been proposed such as coating methods, kneading methods, and composite spinning methods, but none have achieved a practical level of antistatic effect. It has not yet been possible to simultaneously satisfy various factors such as durability, mechanical properties, fibril resistance, dyeability, and spinning cost. In this regard, in JP-A-56-134211, by agglomerating the antistatic agent around the hollow part of the hollow fiber,
Although filaments have been proposed that eliminate the above-mentioned drawbacks, these antistatic fibers have only been proposed as flat yarns, and require various higher-order processing in terms of texture. (Objective of the Invention) The object of the present invention is to solve the trade-off between antistatic properties and the mechanical and chemical properties of fibers, and thereby to provide a durable antistatic effect as well as sufficient practical use. In addition to the mechanical properties obtained, antistatic fibers have significantly improved fibrillation resistance, dyeability, and especially color tone (sharpness), and also have a high staying bulk that does not require high-order processing (unlike flat yarns). and its manufacturing method. (Structure) By the way, the present inventors have disclosed in Japanese Patent Application No. 59-5699 and Japanese Patent Application No. 59-36097 that a multifilament composed of filaments made of a melt-spun polymer is disclosed. , the constituent filament is flat and has a pair of recesses facing each other across the long axis on the outer periphery in the long axis direction, and is asymmetrical with respect to the short axis between the pair of recesses. An eccentric hollow filament having a certain cross-sectional shape and uneven thickness in the longitudinal direction of the filament,
The hollow portion is located on the side where the straight line parallel to the short axis is maximum in the fiment cross section, and the degree of orientation of the hollow portion existing portion divided by the short axis is the orientation of the adjacent solid portion. We proposed a multifilament with potential bulkiness, which is characterized by being larger than 100%. The above filament is characterized by being a flat hollow filament with uneven thickness in the longitudinal direction, and the shrinkage difference between the filaments and within the filament is large. Therefore, a multifilament made of such filaments exhibits sufficient shrinkage force, and as a result, boiling water The objective is to develop preferable bulkiness through processing and the like. The present inventors focused on the hollow part of the filament, and utilized the phenomenon of agglomeration of antistatic agent around the hollow part, which is known from the above-mentioned Japanese Patent Application Laid-Open No. 134211/1982. I have reached my goal. According to the present invention, in a multifilament made of filaments made of a melt-spun polymer, the constituent filaments are flat and have a pair of recesses facing each other on the outer periphery in the longitudinal direction with the longitudinal axis sandwiched therebetween. and a cross-sectional shape that is asymmetrical with respect to the short axis between the pair of recesses;
An eccentric hollow filament having uneven thickness in the longitudinal direction of the filament, the hollow portion being located on the side where the straight line parallel to the short axis is maximum in the cross section of the filament, and divided by the short axis. The degree of orientation of the hollow portion is greater than the degree of orientation of the adjacent solid portion, and the fiber as a whole contains at most 3% by weight of the compounds (a) and (b) in a dispersed state. (a) a polyoxyalkylene glycol that has substantially no reactivity with the polymer; and (b) an ionic antistatic agent. There is provided an antistatic fiber formed with a hollow core-like portion exhibiting a highly concentrated dispersed state. Furthermore, a pair of discharge holes with different discharge cross-sectional areas are connected to each other by a slit, and the discharge hole with a large discharge cross-sectional area is made into a hollow discharge hole with a hollow part formed by a plurality of slits, and the other discharge hole with a small discharge cross-sectional area is connected to each other by a slit. Through a spinneret with a single discharge hole,
A polymer in a molten state and containing the following compounds (a) and (b) is discharged, and at this time, the polymer stream discharged from the discharge hole having a larger discharge cross section among the pair of discharge holes is By making the discharge speed lower than that of the polymer flow discharged from the other discharge hole having a smaller discharge cross-sectional area, the high-speed polymer flow collides with the low-speed polymer flow, bounces and joins, and then A method for producing antistatic fibers is provided, which is characterized in that the antistatic fibers are cooled and solidified before being collected. (a) A glycol that has substantially no reactivity with the polymer; and (b) an ionic antistatic agent. The present invention will be explained with reference to the drawings. FIG. 1 is a cross-sectional view of a filament constituting the antistatic fiber of the present invention, and is a reproduction of an electron micrograph. FIG. 2 is a longitudinal side view of the filament constituting the antistatic fiber of the present invention, and a front view obtained by rotating the side view by 90 degrees, and FIG. Graphs showing Worcester spots of the antistatic fiber of the present invention and the conventional pulsing yarn obtained in the reference example, FIG. 4 is a cross-sectional view of the antistatic fiber of the present invention, and FIG. 5 is a graph showing the antistatic fiber of the present invention. Figure 6 is a sectional view of the discharge hole of the spinneret for obtaining the antistatic fiber of the present invention, and Figure 7 is the stress (St) - elongation (E1) curve of the antistatic fiber. FIG. 2 shows perspective views of the filaments cut along the cross section immediately after the polymer has been discharged using Fool. In Figure 1, n is the major axis, c is the minor axis, x,
x' is a pair of recesses facing each other with the long axis (n) in between, e is the hollow part, m is the cross section of the filament, and the short axis c
The length of the straight line that has the maximum value among the straight lines parallel to
g is a hollow part divided by the short axis c in the cross section including the hollow part e, h is a solid part also divided by the short axis c, and the cross-sectional area of the part g is always larger than that of the part h. It is. In addition, p is polyoxyalkylene glycol,
r, which has a larger particle size than p, is an ionic antistatic agent;
t is a hollow core-like part exhibiting a highly concentrated dispersed state of a part of the polyoxyalkylene glycol (a) around the hollow part. In the antistatic fiber of the present invention (hereinafter sometimes referred to as antistatic multifilament), the constituent filaments have a flat cross-sectional shape as shown in FIGS. Opposing 1
The hollow part e is asymmetrical with respect to the short axis c formed by connecting the pair of recesses x and x', and a hollow part e exists in the part g, that is, on the side having the maximum linear length m. The filament having the above-mentioned cross-sectional shape has a higher degree of orientation in the g section than the h section, and has thickness irregularities as shown in FIG. 2 in the longitudinal direction of the filament. FIGS. 2a and 2b show a side view of a filament constituting the antistatic multifilament of the present invention, and a front view obtained by rotating the side view by 90 degrees, respectively. The thickness irregularities in the longitudinal direction of the filaments constituting the antistatic multifilament of the present invention are shown in Fig. 2a,
As shown in b, the cross-sectional area of portion h changes more widely than the cross-sectional area of portion g in the longitudinal direction when they are joined. As described above, the filament constituting the antistatic multifilament of the present invention has a high degree of orientation in the g part, which has a larger cross-sectional area including the hollow part than the h part, as shown in FIG. Similarly, the degree of orientation is much higher than when the g part is solid due to the large shearing force that is applied during spinning, which, together with uneven thickness in the longitudinal direction, causes greater shrinkage than conventional yarns, such as bulging yarns. can have power. As a result, even a fabric with a strong binding force due to the weave structure can exhibit uniform and sufficient bulkiness with the fabric using the antistatic multifilament of the present invention. On the other hand, the provision of antistatic properties according to the present invention can be explained as follows. The present invention departs from the conventional concept of uniformly dispersing a large amount of antistatic agent in the fiber, and the physical properties of the fiber can be improved if there is a portion where the antistatic agent is dispersed in a relatively high density state in the cross-sectional direction of the fiber. The technical idea that a sufficient antistatic effect can be achieved without substantial damage is applied to the special cross-section hollow fiber. That is, when spinning hollow fibers using a molten polymer in which polyoxyalkylene glycol and an ionic antistatic agent coexist as antistatic agents, the ionic antistatic agent is almost uniformly dispersed, but the polyoxyalkylene glycol component is dispersed almost uniformly. It takes advantage of a unique phenomenon characterized by a type of bleed-out, in which most of the particles condense around hollow areas. The above phenomenon is truly surprising considering the conventional concept that antistatic agents are uniformly dispersed in fibers, and this phenomenon was achieved for the first time through the combination of antistatic agents and hollow spinning technology. It is. Although the reason for this is not yet clear, it is thought that the ionic antistatic agent acts to promote the bleed-out of polyoxyalkylene glycol only in the case of hollow fiber spinning. As described above, the portion (hollow core portion) where the antistatic agent bleeds out around the hollow portion is usually a radius portion corresponding to approximately 1/2 of the radius from the center of the fiber. Such intensive dispersion makes it possible to reduce the amount of antistatic agent used, while conversely improving the antistatic effect. This will be explained with an example. In the conventional case, where the radius of the fiber is γ and the amount of polyalkylene glycol used is x, the average density (xa) of the agent in the cross-sectional direction of the fiber is expressed as x/xr ² . On the other hand, a hollow fiber with a radius of r and a hollow ratio of 5% is made, and x amount of polyalkylene glycol is mixed into it. As a result, half (x/2) is r/
When the agent bleeds out in area 3 (i.e., a small circle with radius r/3), the density of the agent in this small circle (xb)
is expressed as follows. xb=x/2/u(1/3.γ) ² −πr ² ×5/100 ≒8.8x/πr ² On the other hand, the agent density (xc) in the annular part surrounding the bleed-out part is calculated by the following formula. shown. xc=x/2/πr ² −x(1/3γ) ² ≒1/2・x/πr ² If we organize the above, we get the following. Amount of polyoxyalkylene glycol (x)
Even if the values are the same, in the case of the present invention, the glycol density in the hollow core portion is about 9 times higher than that in the conventional method, while the density in the outer peripheral portion is reduced to about 1/2. Even if the amount of polyoxyalkylene glycol added in the present invention is reduced to half (x/2), compared to the conventional one, the density is about 4.4 times higher in the hollow core part, while the density in the outer peripheral part is 1/2. It becomes a low density of 4. Therefore, the antistatic property and physical properties, particularly fibril resistance and dyeing color tone, are significantly improved compared to conventional products. The polymer in Figure 1a and b is polyethylene terephthalate, polyoxyalkylene glycol having a molecular weight of 20,000 as an antistatic agent, and sodium alkylsulfonate having 12 to 12 carbon atoms in a ratio of 2:1, and the fiber as a whole. It was added in an amount of 0.9 parts by weight. In the figure, sodium alkylsulfonate r, which is a powder, is almost uniformly dispersed over the entire cross section. On the other hand, dot-like particles smaller than the particles are polyoxyalkylene glycol, which are particularly concentrated around the hollow part and exhibit a significantly higher dispersion density than other parts. Furthermore, the area within the circle indicated by the broken line is a so-called hollow core portion t where the polyoxyalkylene glycol bleeds out and assumes a high density state. It should be noted that within the core portion, the density of polyoxyalkylene glycol gradually increases as it gets closer to the hollow wall. The reason why the antistatic property is improved by the presence of such a core is that the antistatic agent bleeds out near the inner wall of the hollow portion that is continuous in the fiber direction, forming a substantially continuous layer of the antistatic agent. formation, while the charge on the fiber surface reaches the substantially continuous layer by electrical breakdown, and the charge leaks in the direction of the fiber through the substantially continuous layer. It seems to be. The term "substantially continuous layer" as used herein means that the antistatic agent bleeds out near the inner wall of the hollow portion and is aggregated in a state favorable for conducting charge. In terms of the continuous layer alone, it goes without saying that the higher the weight fraction of the antistatic agent contained in the fibers, the better. In addition, in the antistatic fiber of the present invention, Fig. 1a,
As shown in b, some of the antistatic agent bleeds out to the surface layer of the fibers, but the antistatic agent in this area is a permanent antistatic agent that comes off due to alkali reduction and repeated washing. It is not a part that substantially contributes to the imparting of sex. In the present invention, preferred embodiments of the filament's cross-sectional shape are those that exhibit a substantially eyebrow shape as shown in FIG. 1a, or those that exhibit a substantially isosceles triangle shape as shown in FIG. 1b. In particular, a filament having a substantially isosceles triangular cross-sectional shape is preferred because it can exhibit a unique luster. The hollowness ratio of the g portion in such a flat hollow filament is 2 to 15%, particularly preferably 3 to 15%.
15%, cross-sectional area including hollow part e of part g
The ratio of Sg to the cross-sectional area Sh of the h portion (Sg/Sh) is 1.2 ~
3, particularly preferably 1.5 to 2. However, the hollowness ratio and cross-sectional area Sg and Sh are determined from a microscopic photograph of a cross-section of the filament. Furthermore, as shown in Figures 2a and b, a filament in which the h portion is joined to the g portion without wrapping in the longitudinal direction of the filament is preferable because the degree of deformation in the longitudinal direction, that is, the thickness unevenness is large. be. The antistatic multifilament of the present invention, which is constituted by a filament having large thickness unevenness in the longitudinal direction, naturally also has large thickness unevenness in its cross-sectional direction. This is explained in Example-1 shown in FIG. 3a below.
It is clear from the Worcester's mottling graph of the antistatic multifilament of the present invention obtained in Figure 3b, and compared with the Worcester's mottling graph of the conventional pulsing yarn obtained in the later-described reference example shown in Figure 3b. too,
The antistatic multifilament of the present invention has large thickness variations in the cross-sectional direction. Incidentally, such Worcester spots were measured using a Worcester Evenness Tester Model C manufactured by Zellbaker Worcester Co., Ltd. In addition, in the longitudinal direction of the filaments constituting the antistatic multifilament of the present invention, there are large thickness irregularities as shown in Fig. 2 (the length L from peak to peak is 0.5 to 3
m) exist randomly, in any cross section of an antistatic multifilament made of such filaments, as shown in Figure 4, the effect is similar to that of a mixture of filaments with different deniers. present. That is, in FIG. 4, A represents the filament cross section which is the maximum cross-sectional area of one antistatic multifilament, and n ₁ and m ₁ represent the long axis and maximum linear length of the filament cross section A, respectively. Also,
B indicates the filament cross section with the minimum cross-sectional area in the cross section of one antistatic multifilament shown in FIG. 4, and n ₂ and m ₂ indicate the long axis and maximum linear length of the filament cross section B, respectively. Generally, when filaments with different cross-sectional areas as shown in Figure 4, i.e. filaments with different deniers, are mixed, the filaments with a large cross-sectional area (thick denier) have a small cross-sectional area (fine denier). Because the shrinkage rate is higher than that of filaments, thick denier filaments shrink and become tension carriers through heat treatment, and fine denier filaments protrude to the outside of multifilaments, creating a firm and soft texture. can be presented. In the antistatic multifilament of the present invention,
It is preferable that the filament A having the maximum cross-sectional area and the filament B having the minimum cross-sectional area satisfy the following formula (2) because it can exhibit a firm and soft touch. n ₁ × m ₁ / n ₂ × m ₂ ≧1.5 ...[] Furthermore, the antistatic multifilament of the present invention has large irregularities in the cross-sectional direction and longitudinal direction, that is, a large shrinkage difference. Therefore, the structure is as if filaments with shrinkage differences between and within the filaments were mixed together. For this reason, the stress-elongation curve of the antistatic multifilament of the present invention is as shown in FIG. Here, Fig. 5a shows the stress (St)-elongation (E1) curve of the antistatic multifilament of the present invention obtained by spinning, and Fig. 5b shows the drawing heat setting after spinning. It is a stress (St)-elongation (E1) curve of the antistatic multifilament of the present invention obtained by applying the same method. In FIG. 5, L ₁ indicates the final elongation at break, and L ₂ indicates the elongation at maximum stress. In this way, the elongation of L ₁ and L ₂ is a characteristic of the blended yarn made by mixing filaments with the above-mentioned shrinkage difference. In a multifilament consisting of filaments, only L ₂ is usually seen. In this respect, the antistatic multifilament of the present invention can exhibit the same effect as a mixed fiber yarn made of filaments with different contractions without performing any operations such as fiber mixing. The larger the value of (L ₁ -L ₂ ) is, the larger _the shrinkage _difference is.
An antistatic multifilament whose value satisfies the following formula is preferable because it can exhibit sufficient bulk. L−L ₂ ≧20% ... [] The antistatic multifilament of the present invention can be used not only in the undrawn state, but also in the state of drawing heat setting to impart mechanical properties that can withstand practical use. It is possible to obtain a product that fully satisfies the above formula []. It is important that the antistatic multifilament of the present invention described above be spun using a spinneret having a discharge hole in which a hollow discharge hole and a single discharge hole are connected by a slit as shown in FIG. . In FIG. 6, 1a to 1c, 2, and 3 are discharge holes for discharging the polymer flow, respectively, and 4 is 1a to 1.
a hollow part formed by a plurality of slits indicated by c, 2 a single discharge hole, 3 a slit connecting the hollow discharge hole consisting of the slits 1a to 1c and the hollow part 4, and the single discharge hole 2; lA ₂ is the inner diameter of the single discharge hole, l and W are the width and length of the slit 3, and lA ₁ and lB ₁ are the outer diameter and inner diameter of the hollow discharge hole in FIG. 6a, respectively. The characteristics of such discharge holes are that they have different discharge cross-sectional areas.
As the pair of discharge holes, a hollow discharge hole composed of a plurality of slits 1a to 1c is adopted for the discharge hole with a large discharge cross-sectional area, and a single discharge hole 2 is adopted as the other discharge hole with a small discharge cross-section. This is because the hollow discharge hole and the single discharge hole 2 are connected by a slit 3. In the method for producing antistatic fibers of the present invention, the polymer flow discharged from the hollow discharge hole shown in FIG. It is necessary to combine the polymer streams discharged from one discharge hole 2 while colliding and bouncing, and then to cool and solidify before taking them off. By adopting such a manufacturing method of the present invention, it is possible to increase the shrinkage difference within the resulting antistatic multifilament and between the filaments, and the shrinkage force of the antistatic multifilament made of such filaments can be increased. It is possible to improve the Here, in the discharge holes shown in FIG. 6, if the total discharge cross-sectional area S1 of the slits 1a to _1c of the hollow discharge hole is equal to the discharge cross-sectional area S2 of the single discharge hole ₂ , then
Collision and bouncing of the polymer flow directly under the spinneret become so intense that safe spinning becomes difficult. Furthermore, if a discharge hole in which the hollow discharge hole and the single discharge hole 2 are not connected by the slit 3 is used, the shrinkage difference within and between the filaments of the resulting antistatic multifilament will be insufficient. . The filament constituting the antistatic multifilament obtained by the present invention has a cross-sectional shape shown in FIG. The degree of orientation is much higher than that of fruit, and it also has uneven thickness in the longitudinal direction. The reason why such a filament can be obtained according to the present invention is considered to be as follows. That is, in general, if the flow velocity of the polymer flow passing through each slit constituting a hollow discharge hole and a single discharge hole is equal to each other, the total pressure loss of the plurality of slits in the hollow discharge hole is equal to that of the single discharge hole. It is larger than the hole. However, in the discharge hole of the present invention shown in FIG. 1, which has a hollow discharge hole and a single discharge hole 2 in the same discharge hole through a slit 3, the pressure loss of both holes seems to be equal. A difference in flow velocity occurs between the polymer streams passing through both holes. Therefore, by adjusting the slit width of the hollow discharge hole, the inner diameter lA ₂ of the single discharge hole 2, etc., the polymer discharged from the single discharge hole 2 can be made smaller than the slits 1a to 1c of the hollow discharge hole. It is possible to provide a flow velocity difference so that the flow velocity of the flow becomes faster and to easily increase the flow velocity difference. In this way, since the flow rate of the polymer flow passing through the slits 1a to 1c of the hollow discharge hole is slower than the polymer flow passing through the single discharge hole 2, the spinning draft is discharged from the slits 1a to 1c of the hollow discharge hole. is mainly concentrated in the polymer stream. In particular, the spinning take-off speed is 2500
In high-speed spinning of m/min or more, a high draft of 500 or more concentrates on the polymer flow discharged from the slits 1a to 1c of the hollow discharge hole. The polymer stream is subjected to a greater shear force than if it were a single discharge hole, resulting in a much higher degree of orientation than if it were solid. Furthermore, since the discharge cross-sectional area S2 of the single discharge hole ₂ is smaller than the total discharge cross-sectional area _S1 of the slits 1a to 1c of the hollow discharge hole, it is smaller than the cross-sectional area on the g side including the hollow part in the obtained filament cross section. The cross-sectional area on the h side becomes smaller. In the filament cross section obtained in this way,
As shown in FIG. 1, the portion g, which has a larger cross-sectional area including the hollow portion e, than the portion h has a higher degree of orientation than the portion h. Furthermore, since the polymer flow rates discharged from the hollow discharge hole and the single discharge hole 2 are different, and the two polymer streams are connected by the polymer flow discharged from the slit 3, the hollow discharge hole The polymer flow discharged from the single discharge hole 2 collides with the polymer flow discharged from the single discharge hole 2, and as a result of bonding while pounding, a filament having uneven thickness in the longitudinal direction is obtained as shown in Fig. 2. . The arrangement shape of the slits of the hollow discharge holes and the cross-sectional shape of the single discharge hole employed in the present invention do not need to be particularly limited, and the optimum shape may be adopted depending on the purpose. For example, the slits of the hollow discharge holes may be arranged in a non-circular shape as described in British Patent No. 853062, and the triangular arrangement shown in FIG. 6b is particularly preferred. According to the discharge hole shown in FIG. 6b using such a triangular hollow discharge hole, a filament having a substantially isosceles triangular cross-sectional shape shown in FIG. 1b can be obtained,
A multifilament made of this filament can exhibit a unique luster. Further, if the slit array shape of the hollow discharge holes and the cross-sectional shape of the single discharge hole are circular as shown in FIG. 6a, the cross-sectional shape will be approximately cocoon-shaped as shown in FIG. 1a.
The discharge hole shown in FIG. 6a is preferred because it is easy to work with. Furthermore, in FIG. 6, by connecting the single discharge hole 2 and the hollow discharge hole with the single slit 3, surprisingly, the polymer flow discharged from the single discharge hole 2 is connected to the hollow discharge hole. Since the polymer stream collides and bounces on one side of the polymer flow discharged from the filament, the filament shown in Fig. 2 is obtained, in which the solid portion h is joined to the hollow portion g without wrapping, and the filament is bonded in the longitudinal direction of the filament. It is possible to give large thickness spots. In this way, a multifilament made of filaments that has a large degree of orientation difference in the cross-sectional direction of the filament and a large thickness unevenness in the longitudinal direction of the filament can be put to practical use by further drawing and heat setting after spinning. Even if mechanical properties are imparted, sufficient contractile force can be exhibited, which is preferable.
The shape of the slit 3 is not limited to the linear shape shown in FIG. 6, but may also be hook-shaped or curved. The important point is that the hollow discharge hole and the single discharge hole 2 are connected by a slit. Furthermore, by setting the length of the slit 3 so that the recesses X and X' shown in FIG. The vibration period due to the collision and bouncing of both polymer flows can be made larger, and extremely large unevenness in thickness can be imparted to the obtained filament in the longitudinal direction. As a result, an arbitrary cross-section of an antistatic multifilament made of such filaments has a difference in filament cross-sectional area as shown in FIG. 4, and the value of nn ₁ ×m ₁ /n ₂ ×m ₂ is 1.5. In addition to the above, also in the stress (St)-elongation (E1) curve of the antistatic multifilament, the value of (L ₁ -L ₂ ) is 20% or more. Then, a flat hollow filament having the cross-sectional shape shown in FIG. 1 can be obtained using the discharge hole shown in FIG. %,
Particularly preferably, it is 3 to 15%, and the hollow part e of the part g
It is preferable that the ratio (Sg/Sh) of the cross-sectional area Sg including the cross-sectional area Sg to the cross-sectional area Sh of the h portion is 1.2 to 3, particularly 1.5 to 2. In the discharge holes adopted in the present invention, the single discharge hole 2 shown in FIG. 6 may be connected to one or more hollow discharge holes, and the shape of the single discharge hole 2 may also be triangular, square, Y-shaped, etc. It may be non-circular. The specific dimensions of the discharge hole of the present invention described so far are shown below for the discharge hole of FIG. 1a. 1.5≦S ₁ ／S ₂ ≦15 0.04≦(lA ₁ −lB ₁ ) /2≦0.30 0.10≦lA ₂ ＜lB ₁ ＜lA ₁ ≦1.5 0.05≦l≦1.30 0.03≦W＜lA ₂ ≦1.0 However, The units of lA ₁ , lB ₁ , lA ₂ , l, and W are (mm). ] By employing a spinneret having such discharge holes, it is possible to easily obtain an antistatic multifilament as if filaments of different deniers were mixed together. In addition, in the method for producing an antistatic multifilament of the present invention, the flow velocity V ₁ of the polymer flow discharged from the hollow discharge hole and the flow velocity of the single discharged polymer flow
The discharge speed ratio (V ₁ /V ₂ ) with V ₃ is 1/1.5 to 1/
7. It is particularly preferable to set it to 1/2.3 to 1/3.4, and the polymer discharge rate ratio (discharge rate of hollow discharge hole/discharge rate of single discharge hole 2) at this time is 3/1 to 1/3.
5, particularly preferably set to 1.5/1 to 1/3.3. Now, FIG. 7 shows the shape of a spun filament obtained just below the surface of a spinneret having a discharge hole shown in FIG. 6a and within the range of the dimensions described above. Figure 7 is obtained with freefall, and the cross-sectional area on the side discharged from the hollow discharge hole hardly changes, but the cross-sectional area on the side discharged from the single discharge hole changes. It is shown that. Furthermore, FIG. 7 also shows that the polymer flow discharged from the single discharge hole vibrates in one direction without wrapping around the polymer flow discharged from the hollow discharge hole. However, since the spun filament shown in FIG. 7 was obtained in a free fall state that is not affected by the spinning draft, the cross-sectional shape is different from that of the filament constituting the multifilament obtained by the present invention. , Under the spinning draft action, the solid part bounces and joins to the hollow part, so the length of the solid part becomes longer than the hollow part.
A filament having the filament cross-sectional shape shown in FIG. 1a is obtained. The mechanical properties of the multifilament obtained by cooling and solidifying the polymer stream discharged and bonded in this manner, taking it out, stretching it, and heat setting it at a temperature of 100°C or higher can be put to practical use. It can be increased to a certain extent. Even in this case, the multifilament obtained by the present invention still has a large shrinkage difference in the cross-sectional direction and the longitudinal direction, so that it can exhibit sufficient bulk through heat treatment. In addition, if the spinning take-off speed is 4000 m/min or more, especially
At a speed of 4,500 to 5,500 m/min, the obtained multifilament can be put to practical use as it is, and it goes without saying that such a multifilament can be made sufficiently bulky by heat treatment. In the multifilament manufacturing method of the present invention described above, even if the polymer stream discharged from the spinneret is cooled with cooling air and taken out as in normal melt spinning, it is not necessary to cool the polymer stream and then heat it. You may take it. In addition, methods for stretching and heat setting after melt spinning include melt spinning, winding once, stretching in a separate process and heat setting, or melt spinning and then stretching without winding. A heat setting may also be applied. The cross-sectional shape of each filament in an arbitrary cross-section of the antistatic multifilament obtained in this way is as shown in FIG. There is a filament having a shape without recesses X and X'. Even if there are filaments with such a cross-sectional shape, an antistatic multifilament in which the number of filaments is small can sufficiently achieve the object of the present invention. The melt-spun polymer targeted in the present invention is particularly preferably a single polymer, and generally polyethylene terephthalate, in which 85 mol% or more of the repeating units are substantially composed of ethylene terephthalate; may contain additives for various purposes, such as matting and improving dyeability, as a copolymer or blend. The intrinsic viscosity of polyethylene terephthalate (measured in orthochlorophenol at 35° C.) is preferably 0.45 to 1.20, particularly preferably 0.50 to 1.00. When the intrinsic viscosity is less than 0.45, the strength level of the resulting multifilament is unfavorably low. In addition, when the intrinsic viscosity exceeds 1.20, the melt viscosity during spinning is too high and it is necessary to raise the melting temperature, which is not preferable. The polymer used in the present invention is a polyester to which a glycol and an ionic antistatic agent that have substantially no reactivity with the polymer are added. Here, the term "substantially non-reactive glycol" refers to a glycol that does not copolymerize with polyester, and glycols that are reactive with polyester make it difficult to control the blending process. Specifically, such glycols include, for example, polyoxyalkylene glycols having an average molecular weight of 6,000 or more, preferably 10,000 or more, or those containing oxyethylene units as the main component (usually 50% or more) and containing, for example, oxypropylene units. used. In addition, the terminal of such polyoxyalkylene glycol may be a hydroxyl group, or may be blocked with a non-ester-forming organic group, or may be connected to other ester-forming organic groups through an ether bond, an ester bond, a carbonate bond, etc. May be combined. In the case of polyoxyalkylene glycols whose terminal ends are blocked with non-ester-forming organic groups, the average molecular weight of the polyoxyalkylene glycol may be as low as about 800 to 4,000. The content of such polyoxyalkylene glycols in the polyester is at most 2% by weight, preferably at most 1% by weight. On the other hand, the ionic antistatic agents used in combination with the above glycols include anionic antistatic agents, cationic antistatic agents, or mixtures thereof, such as polyethylene glycol, polybutylene glycol, polyalkyl (or aryl or alkylaryl). ) Sulfonic acid metal salts, polyalkyl (or aryl, or alkylaryl) amines, polyalkylene oxide-added alkyl (or aryl, or alkylaryl) amines, etc., among others, anionic antistatic agents having -SO ₃ M Especially the general formula
Metal salts of alkylaryl or aralkylsulfonic acids represented by RSO ₃ M are preferably employed. Here, M represents an alkali metal and is usually sodium, potassium or lithium, with sodium being particularly preferred. R represents an alkyl group having 8 or more carbon atoms. In the case of an alkyl group having 7 or less carbon atoms, the compatibility with polyester becomes slightly poor. Therefore, those in which R is an alkyl group having 8 to 20 carbon atoms are usually used, and mixtures thereof are often used. The content of such alkyl sulfonic acid metal salts in the polyester is at most 1.0% by weight, preferably at most
It is 0.5% by weight. From the above, the content of glycol and ionic antistatic agent used in the present invention is at most 3% by weight, preferably 1.5% by weight, and particularly preferably 1.2% by weight, considering the fiber properties. The proportion (weight) of the former is preferably 50 to 90% by weight. The lower limit is at least 0.2% by weight; below this, the desired antistatic effect cannot be expected no matter how you change the proportion of the two used or the hollowness ratio of the fibers. . Any method can be used to blend the glycol and ionic antistatic agent into the polyester, and both can be blended into the polyester at the same time or in any order. That is, at any stage until the spinning of the polyester is completed, for example, before the start of the polycondensation reaction of the polyester, during the polycondensation reaction, at the end of the polycondensation reaction when the polyester is still in a molten state, in a powder state, at the spinning stage, etc. In this case, both may be added at the same time or in any order. Further, both may be melt-mixed in advance and then added, or they may be added in two or more portions, or both may be separately blended into polyester and then mixed before molding or the like. Furthermore, when it is added before the middle stage of the polycondensation reaction, it may be added after being dissolved or dispersed in a solvent such as ethylene glycol. In this manner, the antistatic fiber of the present invention can be obtained by discharging polyester containing glycol and an ionic antistatic agent from the discharge holes shown in FIG. In another embodiment, the polyester containing the compound is discharged from the hollow discharge hole shown in FIG. Composite spinning may be performed in which a polyester without any additives is discharged. (Function) Although the technical idea is completely different from the present invention,
So-called pulsing yarns are known in which two opposing polymer streams are brought together by colliding and bouncing below a die. The discharge holes of the spinneret for obtaining such pulsing yarns have two discharge holes with different diameters facing each other at a certain angle, and the length of the polymer guide hole (land) of the discharge hole with the smaller diameter length) is the length of the polymer guide hole (land length) of the discharge hole with a large hole diameter.
is set shorter than. With this setting, the flow rate of the polymer flow discharged from the discharge hole with a smaller diameter becomes faster than the polymer flow discharged from the other discharge hole. In this way, since the two polymer streams having different flow velocities collide and vibrate just below the spinneret surface and join together, it is possible to provide a certain degree of shrinkage difference in the cross-sectional direction and longitudinal direction of the filament. However, as mentioned above, the shrinkage force of the pulsing yarn is insufficient, so in order to increase the shrinkage force in the cross-sectional direction of the filament, the cross-sectional area of the filament on the high orientation side, which is obtained by increasing the difference in hole diameter, is increased. Even if it is not, the difference in flow velocity between the polymer flows discharged from both holes is created by adjusting the land length of the discharge hole, etc., so the larger the difference in hole diameter, the greater the difference in flow velocity. Since it becomes difficult to apply such a discharge hole, there is a limit. Furthermore, even if the vibration caused by the collision of both polymer flows is increased to increase the uneven thickness in the longitudinal direction of the filament, if the installation distance of both holes is increased, the vibration will decrease or disappear. be. On the other hand, in melt spinning the antistatic multifilament of the present invention, a spinneret with discharge holes as shown in Fig. 6 is used, so large vibrations due to collisions and bounds of the polymer flow are avoided. As a result, the effect of uneven distribution of the action points of the spinning draft on the polymer flow discharged from the hollow hole can be achieved, resulting in large thickness unevenness in the longitudinal direction of the filament.
As shown in Figure 1, in the filament cross section, g
This results in a multifilament made of filaments that also has a difference in the degree of orientation in the cross-sectional direction such that the degree of orientation on the side is higher than that on the h side. That is, by adjusting the slit width, hole diameter, etc. of the hollow discharge hole and the single discharge hole, the flow path of the polymer flow discharged from the hollow discharge hole is made faster, and the difference in flow velocity is sufficiently increased. As a result, the spinning draft can be concentrated on the polymer flow discharged from the hollow discharge hole, and since a large shearing force acts on the polymer flow discharged from the hollow discharge hole, the degree of orientation in the hollow portion is moderate. The degree of orientation can be higher than that of the solid portion, and even more highly oriented than when the hollow portion is solid. Moreover, since the cross-sectional area including the hollow portion of the hollow discharge hole is larger than the cross-sectional area of a single discharge hole, the cross-sectional area of the hollow portion is larger than that of the solid portion in the cross section of the obtained filament. In addition, even if the distance between both holes is increased, they are connected by the polymer flow discharged from the slit.
Both polymer flows can be joined while generating large vibrations due to collision and bouncing. The filaments constituting the multi-filament obtained in this way have an extremely high degree of orientation in the hollow part, which has a larger cross-sectional area than the solid part. In addition to having a high shrinkage rate, the filaments also have large thickness unevenness in the longitudinal direction, so multifilaments made of such filaments have large shrinkage differences between and within the filaments, making it difficult to heat treat. In fact, it can exhibit a large contractile force. In textiles using such multifilaments,
By heat treatment, uniform and sufficient bulkiness can be exhibited. Furthermore, even a multifilament obtained by further applying drawing heat setting to undrawn yarn obtained by melt spinning to impart mechanical properties suitable for practical use still has a sufficient shrinkage difference. Fabrics can also be made sufficiently bulky by heat treatment. Furthermore, in the present invention, if the filament has a substantially isosceles triangular cross-sectional shape, it can exhibit a unique luster, and the filaments constituting the multifilament of the present invention have large thickness irregularities randomly in the longitudinal direction. Because of this, it can also exhibit a firm and good feel like a mixed yarn made of mixed filaments of different deniers. Moreover, according to the present invention, since a small amount of antistatic agent is used, which is 3% by weight or less based on the weight of the fibers, and this is concentratedly dispersed in the hollow core, the antistatic property is further improved. On the other hand, in the outer periphery surrounding the hollow core, the amount of antistatic agent used can be reduced, and the density of the antistatic agent decreases as the agent bleeds out into the hollow core. Of course, there is no substantial decrease in strength and elongation compared to the yarns of 2009 and 2008, and the dyeing color tone and viscoelasticity are also significantly improved compared to conventional yarns. (Effects of the Invention) The antistatic multifilament of the present invention can exhibit large bulkiness simply by heat treatment, so it can be handled as a flat yarn in the weaving and knitting process, so it has good processability. Moreover, since it can be obtained from a single polymer without complicated operations, its industrial significance is extremely large. (Example) The present invention will be further explained using Examples. The physical properties used in the Examples were measured by the following method. (1) For arbitrary cross sections of n ₁ , m ₁ and n ₂ , m ₂ multifilament,
Take a cross-sectional photograph at 560x magnification, and find the long axis n ₁ of the filament cross-section where the cross-sectional area including the hollow part is maximum.
and the maximum linear length m ₁ , and the long axis n ₂ of the filament cross section where the cross-sectional area is the minimum and the maximum linear length
m ₂ were actually measured. (2) Elongation when exhibiting maximum stress L ₂ and final elongation at break L ₁ In a normal tensile tester, at room temperature 25°C and humidity 60%, sample length 10 cm, tensile speed 200 mm/
A stress-elongation curve was obtained under the condition of min, and the elongation at which the stress was maximum was defined as L ₂ and the elongation at which the stress became zero was defined as the final elongation at break L ₁ . (3) Shrinkage rate A multifilament ``skein'' was made, a corresponding load of 2 mg/d was applied to this ``skein'', and the shrinkage rate when treated with boiling water was determined from the following formula. l ₀ − l ₁ / l ₀ × 100 (%) = Shrinkage rate (%) (l ₀ : Length of “skein” before treatment) (l ₁ : Length of “skein” after treatment) (4) Texture (bulkiness) The obtained latent bulky multifilament was knitted into tubes, dyed using a disperse dye using a conventional method, dried in water, and then set at 180°C for 1 minute to evaluate texture (bulkiness). It was used as a sample. Texture (bulkness)
was evaluated by visual observation and tactile sensation. (5) Hollowness ratio (cross-sectional area of hollow part / cross-section of g part) x 100 (6) Charging friction pressure (i) Equipment and materials Rotating drum type frictional charge measuring device (rotary static tester) Ossilon Cope friction cloth Cotton broadcloth 30/One scouring, bleaching, glue-free finish (ii) Preparation of test pieces Rolling type: 3.8cm x 30cm Gold frame type: 4.0cm x 8.0cm Take 3 pieces of each vertically. In addition, add 2.5 cm of cotton broadcloth (30/-) to the friction cloth.
Collect 3 pieces, 14.0cm long. (iii) Test operation Humidity control: Leave in a desiccator at 65 ± 2% RH for at least one day and night Atmosphere of measurement chamber: 20 ± 2°C, 65°C ± 2% RH Sample: Number of stacks: 1 Drum rotation speed: 700 r.pm Charging equilibrium time: 1 minute Contact pressure load: 600g Mount one test piece face up on the rotating dome of the rotary static, and attach one piece of friction cloth to the clips at both ends of the bottom parallel to the position where it contacts the test piece. , and apply a load of 600g.
The recorder (5 cm/mm) was operated in the order of one-rotation drum and oscilloscope, and when charging equilibrium was reached, the frictional charging voltage V and extreme values (±, -) were read and expressed as the average value of the three sheets. (Up to the 10th integer place) Regarding the relationship between the antistatic effect and the frictional charging voltage, the antistatic effect will be achieved if the latter is approximately 2000V (preferably 1000V) or less. (7) Mechanical damage to fibers (fibrils)
Using a JISL0823 friction tester type, stack two sample pieces and set them on the test piece stand. Using Tetron dioset crepe fabric (white) instead of white cotton cloth, visually check the state of the fibrils after applying a load of 500 g and reciprocating 500 times. Based on this, we ranked 5th grade for those in which no fibrils were observed, 4th grade, 3rd grade, 2nd grade, and 1st grade as the amount of fibrils generated increased, and the practical range was set as 3rd grade or above. . (8) Dyeing clarity Approximately 10wt after alkaline treatment with caustic soda
Visually check the dyeing clarity of the sample piece when the weight loss is carried out by 5%, and the clarity of the sample piece obtained with only polyester fiber without antistatic agent kneaded with grade 5,
Level 4, Level 3, Level 2, Level 1 as the clarity increases.
The practical range was determined to be grade 3 or higher. [Example 1] 98.8 parts by weight of polyethylene terephthalate having an intrinsic viscosity of 0.65 measured at 25°C in orthochlorophenol was mixed with polyoxyethylene glycol having an average molecular weight of 20,000 and sodium alkyl sulfonate having an average carbon number of 12 to 13 at a ratio of 2:1. Polyethylene terephthalate mixed with 1.2 parts by weight of the mixed antistatic agent was melted at 300° C. and discharged at a discharge rate of 30.8 g/min from a nozzle having 48 discharge holes as shown in FIG. 6a. Here, the dimensions of each of the discharge holes used are shown in Table 1.

[Table] Directly below the spinneret surface, the polymer flow discharged from the single discharge hole 2 is joined to one side of the polymer flow discharged from the hollow discharge hole while colliding and bouncing. The joined polymer streams were then subjected to a temperature of 26°C and a humidity of 66°C.
% cooling air at a linear speed of 30cm/sec to cool and solidify, apply an oil agent with an oiling roller, and then turn it 13 times with a take-up roller (combined with a separate roller) at a wind speed of 1200m/min and a temperature of 100℃. Then, at a circumferential speed of 3,700 m/min, a stretching roller (separate roller) at 115°C was turned 13 times to perform stretching heat setting at a stretching ratio of 2.85 times between the pulling roller and the stretching roller. 48fil
An antistatic multifilament was obtained. The filament constituting the antistatic multifilament has a cross-sectional shape shown in FIG.
In addition, the hollow ratio of the g portion was 6%. Moreover, the filament also had large thickness unevenness in the longitudinal direction, and the Worcester unevenness of this multifilament was large as shown in FIG. 3a. Then, for the obtained antistatic multifilament, the ratio of the maximum and minimum values of the filament cross-sectional area in any cross section (n ₁ × m ₁ /n ₂ × m ₂ ), g
The ratio of the cross-sectional area Sg including the hollow part e of the section to the cross-sectional area Sh of the section h (Sg/Sh), the stress-elongation curve, and the yarn physical properties were measured and shown in Table 2.

[Table] Two antistatic multifilaments obtained in this way were combined using a 20G knitting machine to have a fabric weight of approximately 110.
After knitting into a sheeting sheet of g/m ² , a dry heat treatment was performed at 180° C. for 1 minute to obtain gray fabric A. After presetting, a weight reduction process of about 10% was performed using 3% caustic soda x Boil, and after washing and drying, a gray machine B was obtained. Next, gray fabric A and gray fabric B were dyed under the following conditions. Dyeing conditions Γ Dye [Mitsubishi Chemical Corporation Dianix Black HG−
FS〕;10o.wf Γ Nonionic dispersant〔Meisei Kasei Kogyo Co., Ltd. Disper
VG〕0.5g/Γ Bath ratio: 1:50 Γ Dyeing machine: 12-color high-pressure dyeing machine (Colorpet) Γ Dyeing temperature and time: 130℃/1hr Then, after treatment with a neutralizer (Bisnhol P-20), After washing and air drying, use hot air at 70 to 80 degrees Celsius for approx.
After drying for 1 hour, sample piece A was obtained from greige fabric A, and greige fabric B was obtained from greige fabric B. Wash in an automatic reversing washing machine with hot water at 40°C.
20 and use a commercially available synthetic detergent (product name Sub).
A method was used in which 40g was washed for 20 minutes and then rinsed under running water for 20 minutes. Table 3 shows the results of measuring antistatic properties (frictional charging voltage), mechanical damage to fibers (fibrils), and color clarity using the obtained sample pieces A and B.

[Dyeing]

Dye: Polyester Eastman Blue Dye ratio: 4% based on the tube knitting weight Auxiliary agent: Monogen (0.5%/) Bath ratio: 1/100 Temperature x time: 100℃ x 60 minutes After washing the dyed sample with water and drying, Heat set at 180°C for 1 minute. The sample thus obtained was uniform and had good dyeability, had a firm texture, and had an excellent bulky feel equivalent to that of a sample using ordinary woolly yarn. This indicates that the multifilament has a large shrinkage difference between the filaments and within the filament, and that the multifilament made of these filaments has a large shrinkage force. [Comparative Example 1] Instead of the discharge hole used in Example-1, a normal round hole was used, the discharge hole diameter was 0.27 mm, the land length was 0.54 mm, and the number of discharge holes was
Spinning and drawing were carried out in the same manner as in Example 1, except that a No. 48 spindle was used to obtain a drawn yarn consisting of a normal round cross-section filament having a fineness of 75 De, a strength of 4.0 g/de, and an elongation of 35%. This drawn yarn was knitted, processed, and dyed in the same manner as in Example-1 to obtain sample A and sample piece B. Using the obtained sample piece A and sample piece B,
Table 4 shows the results of measuring antistatic properties (frictional charging voltage), mechanical damage to fibers (fibrils), and dyeing clarity in the same manner as in Example-1. Almost no antistatic properties were observed.

[Example 2]

Using the spinneret of Example 1, the discharge rate was 55.6
Discharged at g/min, without stretching heat setting.
It was wound at a spinning speed of 5000 m/min to obtain an antistatic multifilament of 100 de/48 fil. The filaments constituting this antistatic multifilament also had the cross-sectional shape shown in FIG. Moreover, the filament had large thickness unevenness in the longitudinal direction. Table 5 shows the physical properties of this multifilament.

[Table] This multifilament has a degree of elongation of 70%.
As shown in Table 5, the shrinkage rate is 5.3%, which means that it has physical properties that can be put to practical use as it is. Sample B was obtained. The obtained sample A,
Using Sample B, antistatic properties (frictional charging voltage), mechanical damage to fibers (fibrils), and
Table 6 shows the results of measuring the color clarity.

[Reference example]

Polyethylene terephthalate (PET: containing 0.3% TiO ₂ as a matting agent) with an intrinsic viscosity of 0.64 was melted and the temperature was further raised to 300°C.
It was discharged from the discharge hole described in the publication at a discharge rate of 30.8 g/min. This discharge hole has a hole diameter of 0.15 mm and a land length of 0.30 mm.
A round hole 1 and a round hole 2 having a hole diameter of 0.27 mm and a land length of 1.3 mm are provided so that the center lines of both holes intersect at an angle of 5° directly below the spinneret surface. Further, the limit was that the discharge amount ratio and discharge speed ratio between the round holes 1 and 2 were 1.9 and 1.6, respectively. The PET flow discharged from this discharge hole is directly below the spinneret surface and is connected to the PET flow discharged from round hole 1 through round hole 2.
The PET flow discharged from the pipe wraps around the pipe, collides and vibrates, and joins. Subsequently, the joined PET streams were cooled and taken off at a take-off speed of 1300 m/min in the same manner as in Example-1, and subsequently, the undrawn yarn was subjected to drawing heat-setting under the drawing heat-setting conditions of Example-1. Although the filaments constituting the multifilament thus obtained were flat, they had no hollow portions and had small thickness irregularities in the longitudinal direction. The sample obtained by dyeing the tubular knit using this multifilament under the same dyeing conditions as in Example 1 has very little bulkiness, and has a paper-like appearance that looks like tubular knitting and dyeing using flat yarn. It was hot. This means that the difference in shrinkage between and within filaments of such bulging yarns is small;
This means that the shrinkage force of a multifilament made of such filaments is small.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a filament constituting the antistatic fiber of the present invention, and is a reproduction of an electron micrograph. FIG. 2 is a longitudinal side view of the filament constituting the antistatic fiber of the present invention, and a front view obtained by rotating the side view by 90 degrees, and FIG. Graphs showing Worcester spots of the antistatic fiber of the present invention and the conventional pulsing yarn obtained in Comparative Example-2, FIG. 4 is a cross-sectional view of the antistatic fiber of the present invention, and FIG. 5 is a cross-sectional view of the antistatic fiber of the present invention. Figure 6 is a cross-sectional view of the discharge of the spinneret for obtaining the antistatic fiber of the present invention, Figure 7 is the free fall from the discharge hole of Figure 6. Fig. 3 shows perspective views of the filaments cut along the cross section immediately after the polymer has been discharged. In Fig. 1, e: hollow part, g: hollow part divided by short axis c in the cross section including hollow part e, h: hollow part divided by short axis c in the cross section including hollow part e. Real part, p: polyalkylene glycol, r: ionic antistatic agent, t: hollow core part, in FIG. 6, 2: single discharge hole, 3:
A hollow discharge hole consisting of slits 1a to 1c and a hollow portion 4 formed by the slit, and a single discharge hole 2
This is the slit that connects the two.

Claims (1)

[Claims] 1. A multifilament composed of filaments made of a melt-spun polymer,
The constituent filament is flat and has a pair of recesses facing each other across the long axis on the outer periphery in the long axis direction, and is asymmetrical with respect to the short axis existing between the pair of recesses. An eccentric hollow filament having a cross-sectional shape and a thickness unevenness in the longitudinal direction of the filament, the hollow portion being located on the side where the straight line parallel to the short axis is maximum in the cross section of the filament,
In addition, the degree of orientation of the hollow portion existing portion divided by the short axis is greater than the degree of orientation of the solid portion adjacent thereto, and the fiber as a whole contains at most 3% by weight of the following (a) and (b). ) containing the compound of (a) in a dispersed state, (a) a polyoxyalkylene glycol having substantially no reactivity with the polymer, and (b) an ionic antistatic agent. An antistatic fiber formed by forming a hollow core in which a portion of polyoxyalkylene glycol is highly concentrated and dispersed. 2. The antistatic fiber according to claim 1, wherein the filament has a substantially eyebrow-shaped cross-sectional shape and is asymmetrical with respect to the short axis. 3. A patent claim in which the filament has a substantially isosceles triangular cross-sectional shape, has a pair of recesses on opposing long sides, and is asymmetrical with respect to a short axis between the pair of recesses. The antistatic fiber according to item 1. 4. The antistatic fiber according to claim 1, wherein the solid portion is joined to the hollow portion in the longitudinal direction of the filament without being wrapped around it. 5. The antistatic fiber according to claim 1, wherein the filament in any cross section of the multifilament satisfies the following formula. n ₁ × m ₁ / n ₂ × m ₂ ≧1.5 ...[] [However, n ₁ × m ₁ and n ₂ × m ₂ are the long axis and short axis of each filament cross section in an arbitrary cross section of the multifilament. It is the product of the maximum straight line length parallel to , and shows the maximum and minimum values, respectively. ] 6. The antistatic fiber according to claim 1, wherein the multifilament satisfies the following formula [ ]. L ₁ −L ₂ ≧20% ... [] [However, L ₁ is the final elongation at break of the multifilament, and L ₂ is the elongation when the maximum stress is exhibited. 7. The antistatic fiber according to claim 1, wherein the hollow portion of the hollow portion existing portion divided along the short axis is 15% or less. 8 The molecular weight of polyoxyalkylene glycol is
6000 or more, the antistatic fiber according to claim 1. 9. The antistatic fiber according to claim 1, wherein the ionic antistatic agent has a _-SO3M (M is an alkali metal) group. 10 The ionic antistatic agent is RSO ₃ M (however, R
represents an alkyl, aryl, aralkyl group,
The antistatic fiber according to claim 9, wherein M represents an alkali metal. 11. The antistatic fiber according to claim 1, wherein the content of polyoxyalkylene glycol and ionic antistatic agent is 0.5 to 1.5% by weight. 12. The antistatic fiber according to claim 1 or 11, wherein the ratio of polyoxyalkylene glycol to ionic antistatic agent is 9:1 to 1:1. 13. The antistatic fiber according to claim 1, wherein the radius of the hollow core portion is 1/2 or less of the fiber radius. 14. The antistatic fiber according to claim 1, wherein at least 30% by weight of polyoxyalkylene glycol is dispersed in the hollow core. 15. The antistatic fiber according to claim 1, wherein the ionic antistatic agent is almost uniformly dispersed in the cross section of the fiber. 16 A pair of discharge holes with different discharge cross-sectional areas are connected to each other by a slit, and the discharge hole with a large discharge cross-sectional area is made into a hollow discharge hole with a hollow part formed by a plurality of slits, and the other discharge hole with a small discharge area is A polymer in a molten state and containing the following compounds (a) and (b) is discharged through a spinneret having a single discharge hole, and at this time, the discharge cross section of the pair of discharge holes is discharged. By making the discharge speed of the polymer stream discharged from a discharge hole with a large discharge area lower than that of the polymer flow discharged from the other discharge hole with a small discharge cross-sectional area, the high-speed polymer flow is added to the low-speed polymer flow. A method for producing antistatic fibers, which is characterized by colliding and bouncing the combined flows to join them together, then cooling and solidifying them before taking them off. (a) a glycol having substantially no reactivity with the polymer; and (b) an ionic antistatic agent 17. Both the arrangement of the plurality of slits constituting the hollow discharge hole and the cross-sectional shape of the single discharge hole are circular. A method for producing an antistatic fiber according to claim 16. 18. The method for producing a potentially bulky multifilament according to claim 16, wherein the plurality of slits constituting the hollow discharge hole are arranged in a non-circular manner. 19. The method for producing antistatic fibers according to claim 16 or 18, wherein the plurality of slits constituting the hollow discharge holes are arranged in a triangular shape. 20. The method for producing antistatic fibers according to claim 16, which is a spinneret comprising a pair of discharge holes communicated with each other by a slit. 21 Claim 16 or 20, in which the slit connecting the pair of discharge holes is single
2. Method for producing antistatic fibers described in Section 1. 22 Claims in which the flow velocity (V ₁ ) of the polymer stream discharged from the hollow discharge hole and the flow velocity (V ₂ ) of the polymer stream discharged from the single discharge hole satisfy the following formula [] 17. A method for producing an antistatic fiber according to item 16. 1/1.5≧V ₁ >V ₂ ≧1/7 ...[] 23. The method for producing an antistatic fiber according to claim 16, wherein the glycol is a polyalkylene glycol having a molecular weight of 6000 or more. 24. The method for producing an antistatic fiber according to claim 16, wherein the ionic antistatic agent has a _-SO3M (M is an alkali metal) group. 25 The ionic antistatic agent is RSO ₃ M (however, R
represents an alkyl, aryl, aralkyl group,
17. The method for producing an antistatic fiber according to claim 16, wherein M represents an alkali metal.