JPH0340123B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field] The present invention relates to a method for producing acrylonitrile-based filament yarn having a linen-like appearance and texture and having unevenness and flatness. [Purpose] The purpose is to improve the luster and sliminess characteristic of synthetic fibers, and to provide a method for producing a novel flat, uneven acrylonitrile filament yarn that has both linen-like appearance and texture. [Background technology] Acrylonitrile-based filament yarn has made use of its silk-like characteristics and has entered the field of spring/summer clothing, but it is still infrequently used in this field. As mentioned above, it has been pointed out that the cause of this is that synthetic fibers still have a slimy feel characteristic of synthetic fibers and lack a smooth texture. In order to improve these drawbacks of acrylonitrile fibers, intensive development studies are underway, and a common method to remove the slimy feeling is to add inorganic substances such as titanium oxide, silicon dioxide, kaolin, aluminum hydroxide, etc. to the spinning dope. There is a method of imparting a crunchy texture by blending additives to roughen the fiber surface. However, this level of surface roughening does not lead to a significant improvement in the fiber surface, and it is difficult to impart linen-like appearance and texture to the fiber. In view of the above-mentioned current situation, the present inventors aimed to obtain an acrylonitrile-based filament yarn suitable for spring/summer materials that has a hemp-like appearance and texture without taking complicated measures. The present invention was completed by paying attention to the fact that the yarn is made of a bundle, and conducting intensive studies with a focus on yarns with irregular cross sections. [Structure of the Invention] That is, the gist of the present invention is to spin a spinning dope of an acrylonitrile polymer by adjusting the hole spacing (L) and hole diameter radius of a set of spinning holes in which a plurality of circular holes are arranged in a straight line. The relationship (L/R) of (R) is 0.3~
2.0, and the spinning hole area per set is 50 to 10 ^-2
It is discharged into an inert medium, which is a non-coagulable gas, through a spinneret consisting of mm ² or less, immediately led to a coagulation bath, and after forming a coagulation, it is washed and stretched to produce an uneven and flat acrylonitrile filament yarn. . The cross section of the fiber of the present invention is shown in FIG. 2, and the perspective view of the fiber is shown in FIG. 3. As shown in FIG.
is applied discontinuously in the fiber axial direction. Therefore, the light is diffusely reflected and the linen-like appearance has a calm appearance (dull tone).
has. In addition, the fiber cross section has multiple unevenness,
In addition, the uneven surface has small folds discontinuously added in the fiber axis direction, which creates a large frictional resistance between the fibers, giving the fiber a natural hemp-like texture (smooth feel). be. As described above, the degree of unevenness, the condition of pleats, and the number of unevenness in the fiber cross section of the present invention have a very large effect on the appearance and texture. Fibers whose cross section simply has continuous unevenness include threads with irregular cross sections such as triangular, six-lobed, and eight-lobed.
These have a fairly smooth texture, but since the cross section of the fibers is gear-like, the fibers interlock with each other, so they have a rough and stiff feel and are inferior in bulk. Although the fibers of the present invention have irregularities, the irregularities are on a flat surface and do not exhibit a gear-like phenomenon, so the fibers are characterized by not giving a rough and stiff feel despite the large frictional resistance between the fibers. . Such fibers are completely new and are expected to have great effects in developing new uses for acrylic filaments. The detailed method for producing the fiber of the present invention will be explained below. The acrylonitrile polymer used in the present invention requires a polymer of 40% to 98% by weight of acrylonitrile, and if necessary, other copolymerizable vinyl monomers such as acrylamide and derivatives thereof, vinylidene chloride. , vinyl acetate, methyl acrylate, methyl methacrylate, ethyl acrylate, 2-ethylhexyl acrylate, lauryl methacrylate, acrylic acid, methacrylic acid, itaconic acid, α-methylene glitaric acid, vinyl sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, Examples include p-styrenesulfonic acid. In order to produce the fiber of the present invention using the above polymer by a dry-wet spinning method, it is necessary to dissolve the above polymer in a solvent to prepare a spinning stock solution. Organic solvents such as dimethyl sulfoxide, ethylene carbonate, and dimethyl acetamide are preferred. The solid content concentration of the spinning dope is preferably 20 to 30% by weight. Further, as the coagulation bath, it is preferable to use an aqueous solution containing a solvent of an acrylonitrile polymer. The spinneret used in producing the fiber of the present invention by dry-wet spinning the spinning dope of the above polymer is the first spinneret.
As shown in the figure, a plurality of circular holes 1 are arranged in a straight line to constitute a set of spinning holes, and the spinning stock solution discharged from each circular hole in the set is bonded while passing through the air. It forms an uneven flat shape and is formed into threads in a coagulation bath. In this way, in order to obtain uneven flat fibers from a plurality of circular holes, the relationship (L/R) between the hole spacing (L) and the hole diameter radius (R) is important, and L/R is 0.3 to 0.3.
If the range exceeds 2.0, spinning conditions such as coagulation conditions and the distance between the spinneret and the coagulation bath liquid level (hereinafter referred to as DJ
Even if D) is changed, the uneven flat fiber as the object of the present invention cannot be obtained. For example, when L/R is less than 0.3, only fibers with a small aspect ratio (fiber cross-sectional long axis/fiber cross-sectional short axis) with almost no unevenness can be obtained. Further, when L/R exceeds 2.0, a phenomenon occurs in which the spinning dope extruded from each hole in a set does not adhere. However, if the DJD is extremely long, although it will adhere, it will not be possible to obtain fibers with irregularities, and as a result, fibers with linen-like characteristics will not be obtained. Therefore, L/R must be between 0.3 and 0.2, preferably between 0.5 and 1.5. In addition, the number of circular holes in one set of spinning holes is also important from the perspective of producing hemp-like fibers. If the amount is too large, the appearance and texture will be improved, but problems such as extremely reduced spinning stability will occur. In the present invention, the number of holes is usually 4 to 20, preferably 5 to 15. The pore area per set of these spinning holes varies depending on the purpose of use of the fiber, but if it is limited to the general clothing field, it needs to be 50 × 10 ^-2 mm ² or less, and preferably 31 × 10 ^{- 2 mm2} or less. Since the spinning method of the present invention is a dry-wet spinning method, the spinning stock solution discharged from the spinning hole is plastically deformed, so the DJD is preferably 2 to 25 mm, and the DJD is 2 mm.
If the ratio is less than 1, development will occur in which the spinning stock solution discharged from each circular hole in a set does not adhere, although it varies depending on L/R. Furthermore, if the DJD exceeds 25 mm, the fiber will become a flat cross-section fiber with no irregularities, which is not preferable. Therefore, DJD is preferably 2 to 25 mm, and further 3 to 20 mm.
is preferred. On the other hand, with other dry or wet spinning methods, it is not possible to obtain fibers with an uneven cross section and pleats on the uneven surface as in the present invention. The reason for this is that dry spinning is difficult because the coagulation mechanism is different, resulting in fibers with a cross-sectional shape that is completely different from the spinning hole shape, and in wet spinning, the spinning dope discharged from the spinning hole is difficult. This is because coagulation proceeds from the moment it is discharged into the coagulation bath, making it difficult to discharge and adhere. According to the present invention constructed as described above, it is possible to obtain a novel uneven, flat acrylonitrile filament yarn that has a hemp-like appearance and texture with improved luster and sliminess characteristic of synthetic fibers. [Example] Hereinafter, the present invention will be explained in more detail with reference to Examples. % represents weight %. Example 1 Specific viscosity consisting of 93% acrylonitrile, 6.5% vinyl acetate, and 0.5% sodium methallylsulfonate
A spinning stock solution was prepared by dissolving a 25% copolymer of 0.207 in dimethylacetamide, the temperature of this spinning stock solution was raised to 60°C, and a set of spinning holes (L/R0. 27 to 2.53, the number of circular holes is 3 to 25, and the pore area is 5 to 44 × 10 ^-2 mm ² ).
After setting the DJD to 5mm and expelling it into the air,
It was introduced into a coagulation bath with a dimethylacetamide concentration of 65% and a temperature of 40°C, and taken up with a godet roll at 70 m/min while forming threads. After washing, it was stretched 3 times in a boiling water bath, and after drying, it was further stretched with a hot pin at 180°C for 2 times. A filament yarn having a 150 denier/30 filament was obtained by subjecting it to double stretching and 7% relaxation treatment on a hot plate at 250°C. This filament was twisted, false-twisted, dyed, and knitted using conventional methods, and its appearance and texture were evaluated. The evaluation results of the obtained processed yarn are shown in Table 1.

[Table] Notes (1) Appearance and texture were evaluated by visual and tactile tests using standard yarn as a control. (2) Those whose experiment numbers in Tables 1 to 3 are circled satisfy the conditions of the present invention. Example 2 The same kind of spinning dope as in Example 1 was heated to 60°C, and 1
Set of spinning holes (L/R0.8, number of circular holes 10, hole area
DJD from 2 to 30 with a spinneret consisting of 18 × 10 ^-2 mm ²
150 mm under the same spinning conditions as Example 1.
A filament yarn having a denier/30 filament was obtained. This filament yarn was processed and evaluated in the same manner as in Example 1 to obtain the results shown in Table 2.

[Table] Example 3 The same spinning solution as in Example 1 was heated to 60°C, and 1
^{DJ _}
D was set to 5 mm and the spinning conditions were the same as in Example 1.
A filament yarn with 150 denier/30 filaments was obtained. This filament yarn was processed and evaluated in the same manner as in Example 1 to obtain the results shown in Table 3.

【table】

Claims (1)

[Claims] 1. The relationship between the hole spacing (L) and the hole radius (R) (L/
R) is 0.3 to 2.0, and the spinning hole area per set is 50 x 10 ^-2 mm ² or less,
Discharged into an inert gas medium that is a non-coagulable gas,
Immediately introduced into a coagulation bath, after being coagulated, the fiber is washed and stretched to create a flat acrylonitrile-based fiber with multiple irregularities on its cross section, and small folds discontinuously added to the surface of these irregularities in the direction of the fiber axis. Method of manufacturing filament yarn. 2 The distance between the spinneret and the coagulation bath liquid level is 2 to 25 mm.
A method for producing an acrylonitrile filament yarn according to claim 1.