JP2020133030A - Dry-wet spinning device - Google Patents

Abstract

To provide a dry-wet spinning device capable of simultaneously achieving both reduction in tension of a yarn in a coagulation step by a high-speed spinning, and reduction in variation in physical properties of a single yarn.SOLUTION: A dry-wet spinning device is composed of a spinneret a which has an extrusion hole for extruding a spinning solution and a coagulation auxiliary liquid jetting device c which adjoins the spinning solution extrusion side of the spinneret a and is installed in a coagulation liquid for coagulating the spinning solution. The coagulation auxiliary liquid jetting device c has openings for jetting the coagulation auxiliary liquid. The coagulation auxiliary liquid is jetted from the openings b toward a traveling yarn d which is extruded from the extrusion hole and then is coagulated.SELECTED DRAWING: Figure 1

Description

The present invention relates to a dry-wet spinning apparatus suitable for producing all-aromatic polyamide fibers, and more specifically, to assist coagulation of yarns discharged and coagulated into a coagulating liquid from a discharge hole through an air gap. It relates to a dry-wet spinning apparatus that ejects a liquid.

The dry-wet spinning method is a spinning method in which an air layer is interposed between the spinneret and the coagulation bath, and is used when the temperature difference between the spinneret and the coagulation bath is large, for example, for spinning para-type total aromatic polyamide fibers. It is known to be.

Para-type total aromatic polyamide fibers have been in increasing demand in recent years due to their characteristics such as high strength, high elastic modulus, high dimensional stability and high chemical resistance, and in order to meet the demand, productivity is achieved at the manufacturing site. Studies for improvement are being actively conducted. One example of a means for improving productivity is to increase the spinning speed. That is, by increasing the amount of yarn to be spun per unit time, the amount of yarn produced per unit time can be increased.

An example of the solidification step in dry-wet spinning is shown in Japanese Patent Application Laid-Open No. 56-128312. In the publication, when the spinning dope discharged into the air from the spinneret is guided into the spinning cylinder, and the coagulating liquid ejected from a plurality of small diameter nozzles or slits installed in the spinning cylinder coagulates the dope. At the same time, a method of accelerating the yarn by utilizing the flow of the coagulating liquid in the direction of taking over the yarn is adopted. However, this method has a problem that when the spinning speed is increased, the frictional resistance at the interface between the yarn and the coagulating liquid increases, so that the spinning tension increases.

When the spinning tension increases, not only the yarn breaks easily in the solidification step, but also the orientation of the polymer chains advances in the solidification step due to the application of the tension, and the elongation of the undrawn yarn decreases. The decrease in the elongation of the undrawn yarn becomes a factor of single yarn breakage and yarn breakage in the subsequent drawing step.

Another problem when the spinning speed is increased is an increase in variation in the physical properties of the single yarn. When the spinning speed is increased, the flow of the coagulating liquid is disturbed, and the tension fluctuation between the single yarns becomes large. As a result, the physical properties of the single yarn vary at the stage of the undrawn yarn, which leads to the occurrence of single yarn fluff and breakage in the drawing step. Japanese Patent Application Laid-Open No. 56-128312 shows an advantage that the frictional resistance at the interface between the thread and the coagulating liquid can be reduced, and the tension applied to the tow during the coagulation process can be reduced.

On the other hand, it is practically impossible to control the direction of the flow of the coagulating liquid flowing in only one of the directions of taking up the threads, and in reality, there is a flow orthogonal to the direction of taking over the threads. .. The flow orthogonal to the take-up direction of the threads causes fluctuations in the tension of each single thread constituting the toe, resulting in variations in the physical properties of the single threads of the undrawn yarn, and thus in the drawing process. It causes thread breakage. That is, although this spinning method is effective in reducing the tension applied to the yarn, the variation in the physical properties of the yarn when the solidification rate is increased cannot be sufficiently reduced, and the spinning speed is increased. There is room for improvement as a coagulation device for conversion.

Japanese Unexamined Patent Publication No. 56-128312

An object of the present invention is to provide a dry-wet spinning apparatus that solves the problems in the prior art and simultaneously achieves reduction of yarn tension in a solidification process in which the spinning speed is increased and reduction of variation in single yarn physical properties. It is in.

As a result of diligent studies to solve the above problems, the present inventor assists coagulation of the threads discharged from the discharge holes and then coagulated through the openings provided in the coagulation auxiliary liquid ejection device. We have found that the above problems can be solved when the liquid is ejected, and have completed the present invention.

That is, according to the present invention, it is installed in a spinneret provided with a discharge hole for discharging the spinning solution and in a coagulating liquid adjacent to the spinning solution discharge side of the spinneret and for coagulating the spinning solution. It is a dry-wet spinning apparatus composed of a coagulation auxiliary liquid ejection device, and the coagulation auxiliary liquid ejection device has a hole for ejecting the coagulation auxiliary liquid, and is discharged from the discharge hole and then coagulated. A dry-wet spinning apparatus, characterized in that a coagulation auxiliary liquid is ejected from the perforated portion of the running yarn while simultaneously satisfying the following conditions (a) to (d).
(A) The value of the flow velocity ratio obtained by dividing the flow velocity of the coagulation auxiliary liquid by the flow velocity of the coagulation liquid toward the threads on the coagulation liquid surface is 0.8 to 1.2.
(B) The concentration of the good solvent for the polymer constituting the spinning solution in the coagulation auxiliary solution is smaller than the concentration of the good solvent for the polymer constituting the spinning solution in the coagulation solution.
(C) The coagulation auxiliary liquid is ejected in the range of 0 ° to 90 ° with respect to the traveling direction of the thread.
(D) A hole for ejecting the coagulation auxiliary liquid is opened in a range of 5 mm to 800 mm from the liquid surface of the coagulation liquid along the thread traveling direction.
Is provided.

By using the dry-wet spinning apparatus of the present invention, it is possible to simultaneously reduce the tension of the yarn in the solidification process in which the spinning speed is increased and the variation in the physical properties of the single yarn.

The schematic diagram which shows an example of the structure of the dry-wet spinning apparatus of this invention. The schematic diagram which shows an example of the structure of the dry-wet spinning apparatus of this invention. (A case where the ejection direction of the coagulation auxiliary liquid is opposite to the traveling direction of the thread)

Hereinafter, embodiments of the present invention will be described in detail.
<Spinning solution>
The polymer in the spinning solution used in the present invention is a polymer in which one kind or two or more kinds of divalent aromatic groups are linked by an amide bond. Two or more aromatic rings may be present in the aromatic group, and the aromatic rings may be directly bonded or may be bonded via an oxygen or sulfur atom. The hydrogen atom of the divalent aromatic group may be substituted with a halogen atom, an alkyl group, or a phenyl group.

The polymer in the spinning solution used in the present invention can be obtained by reacting an aromatic dicarboxylic acid dichloride with an aromatic diamine in an amide-based polar solvent. As the aromatic dicarboxylic acid chloride used, generally known ones can be used. As the aromatic diamine component used, generally known ones can be used. In order to improve the elongation of the coagulated yarn in the coagulation step and reduce the variation in the physical properties of the coagulated yarn more remarkably, which is the effect of the present invention, p-phenylenediamine and 3,4-diaminodiphenyl ether are combined. It is preferable to use it.

<Spinning cap>
As the spinning base used in the present invention, it is preferable to use a base in which the discharge holes are arranged concentrically with respect to the discharge surface of the circular base excluding the central portion of the circle, as illustrated in FIG. When the spinning speed is increased, the amount of the spinning dope discharged from the mouthpiece increases. At this time, the spinning dope discharged from the discharge holes arranged concentrically (so-called donut shape) excluding the center of the circle. Since the coagulating liquid can come into contact with both the inside and the outside of the circumference, the solidification of the spinning dope can be promoted as compared with the case of using the mouthpiece in which the discharge holes are arranged on the entire surface of the mouthpiece including the center of the circle. The discharge holes arranged concentrically may be arranged with a plurality of slits provided between the discharge hole groups.

<Coagulation auxiliary liquid ejection device>
An example of the outline of the coagulation auxiliary liquid ejection device is shown in FIG. The spin dope released from the spinneret deposits into a coagulation bath filled with a coagulation liquid. In this example, in this coagulation bath, a cylindrical coagulation auxiliary liquid ejection device is installed at a position closer to the center of the mouthpiece than the innermost circumference of the concentric discharge holes. The length of the cylinder depends on the depth of the coagulation bath, but if the cylinder and the running thread come into contact with each other in the coagulation bath, the physical properties of the single yarn of the coagulated yarn vary. It is preferably 300 mm to 1000 mm.

An opening for ejecting the coagulation auxiliary liquid is provided on the side surface of the cylinder, and the coagulation auxiliary liquid supplied into the cylinder is ejected from this hole to promote the solidification of the threads. The coagulation auxiliary liquid ejection hole needs to be opened at a position 5 mm to 800 mm from the coagulation liquid surface. If the coagulation auxiliary liquid is ejected just below the coagulation liquid surface, that is, at a position less than 5 mm from the coagulation liquid surface, the coagulation auxiliary liquid will be applied without sufficiently forming the threads, so that the threads will be damaged. The variation in the physical properties of the single yarn increases.

On the other hand, even if the coagulation liquid is ejected on the downstream side of 800 mm from the coagulation liquid surface, the coagulation of the threads progresses and the threads are almost formed, so that the effect of this device is difficult to be expressed as the physical properties of the threads. Become. A more preferable opening position of the coagulation auxiliary liquid ejection hole is a position 5 mm to 400 mm from the coagulation liquid surface.

When the discharged threads land on the coagulating liquid and proceed downward, the coagulating liquid has the same downward flow as the discharged threads, but on the coagulating liquid surface, the coagulating liquid progresses downward and becomes insufficient. The coagulant collects from the circumferential direction of the base toward the discharge thread group in an attempt to supplement the above. The flow parallel to the surface of the coagulating liquid causes the threads that have landed on the liquid to sway, and increases the variation in the physical properties of the coagulated yarn. The flow parallel to the coagulation liquid surface can be offset by ejecting the coagulation auxiliary liquid from the cylindrical coagulation auxiliary liquid ejection device, and the yarn sway can be suppressed. As a result, the single yarn physical properties of the solidified yarn vary. Can be reduced. The flow velocity is optimized by adjusting the diameter of the coagulation auxiliary liquid ejection hole and the supply amount of the coagulation liquid.

<Coagulation immersion length>
In order to reduce the toe tension in the solidification step, it is preferable that the solidification immersion length is short. When the coagulation auxiliary liquid is ejected from the cylindrical coagulation auxiliary liquid ejection device described above, the coagulation of the spinning dope is promoted, so that the rise of the yarn tension after the discharged yarn has landed in the coagulation liquid is accelerated. By shortening the solidification immersion length by the amount that solidification is promoted, the tension of the discharged threads can be reduced, and the decrease in elongation of the solidified yarn in the solidification step can be reduced.

<Spout angle of coagulation aid>
It is very important at what angle the coagulation auxiliary liquid is brought into contact with the threads running in the coagulation liquid. Regarding the ejection angle of the coagulation auxiliary liquid, the direction in which the thread travels is 0 °, the direction perpendicular to the direction in which the thread travels, and the direction away from the thread is 90 °, and the direction in which the thread travels. Assuming that the opposite direction is 180 °, the ejection angle of the coagulation auxiliary liquid needs to be in the range of 0 ° to 90 °. In the range where the ejection angle of the coagulation auxiliary liquid is larger than 90 ° and 180 ° or less, when the coagulation auxiliary liquid comes into contact with the thread, a flow reverse to the direction in which the thread travels occurs, and the tension applied to the thread. Will increase. When the tension increases, the elongation of the coagulated yarn is greatly reduced, and the yarn is easily broken in the drawing step after the coagulation step, which is not preferable.

<Spouting speed of coagulation aid>
The ejection speed of the coagulation auxiliary liquid that comes into contact with the threads is important because it affects the variation in the physical properties of the solidified yarn. As described above, when the discharged threads land on the coagulating liquid and proceed downward, the coagulating liquid flows downward in the same direction as the discharged threads travel, but on the coagulating liquid surface. In the vicinity, the coagulant collects from the circumferential direction of the mouthpiece toward the thread in an attempt to make up for the coagulant that has progressed downward and is insufficient.

The flow parallel to the surface of the coagulating liquid causes the threads to sway, and increases the variation in the physical properties of the coagulated yarn. In order to cancel the flow parallel to the coagulation liquid surface, the flow velocity of the flow parallel to the coagulation liquid surface and the flow velocity of the coagulation auxiliary liquid flow that is opposite to the flow parallel to the coagulation liquid surface. Ideally they are equal. Practically, it is effective when the flow velocity ratio is defined as the value obtained by dividing the flow velocity of the ejected coagulation auxiliary liquid by the flow velocity of the coagulation liquid toward the threads, and the flow velocity ratio is 0.8 or more and 1.2. It is as follows.

<Concentration of coagulation aid>
The role of the coagulation auxiliary liquid is to promote the coagulation of the spinning solution in the coagulation step and shorten the coagulation length. In order to further promote the coagulation of the spinning solution, it is preferable that the liquid constituting the coagulation auxiliary liquid has a high ratio of the poor solvent of the polymer constituting the spinning solution. A mixed solution of a good polymer solvent and a poor solvent is used as the coagulation solution. By lowering the concentration of the good solvent in the coagulation auxiliary solution than the concentration of the good solvent in the coagulation solution, the spinning solution is used. Can promote coagulation. On the other hand, if the concentration of the good solvent in the coagulation auxiliary solution is higher than the concentration of the good solvent in the coagulation solution, the coagulation of the spinning solution is not promoted.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited by these descriptions.
Each characteristic value in Examples and Comparative Examples was measured by the following method.

(1) Coagulation yarn elongation The coagulation yarn obtained after coagulation is collected, and a tensile tester (manufactured by INTESCO, trade name: INTESCO, model: 201X type) is used with a yarn test chuck under the following conditions. The single yarn strength and elongation of the solidified yarn was measured. The measurement was performed 6 times, and the average value of the obtained elongations was taken as the single yarn elongation of the coagulated yarn.
(2) Variation in coagulation yarn elongation The single yarn strength elongation of the coagulation yarn was carried out by the same method as in (1). The measurement was carried out for 30 single yarns, the standard deviation of the obtained values was divided by the average value, and the value multiplied by 100 was calculated as the variation in the elongation of the single yarn of the solidified yarn.
(3) Flow velocity of coagulation liquid and coagulation auxiliary liquid After setting the spinning conditions, insert an in-liquid flow velocity meter into the coagulation liquid, and the flow velocity of the components parallel to the coagulation liquid surface at a position 5 mm away from the threads in the coagulation liquid. Was measured for 30 seconds, and the average value was taken as the flow rate of the coagulant. The flow velocity of the coagulation auxiliary liquid was similarly measured at a position 5 mm away from the coagulation auxiliary ejection hole of the coagulation apparatus.
The value obtained by dividing the flow velocity of the coagulation auxiliary liquid by the flow velocity of the coagulation liquid toward the threads was defined as the flow velocity ratio.

<Comparative example 1>
As a spinning solution, an NMP solution of copolyparaphenylene and 3,4-oxydiphenylene terephthalamide (a para-type total aromatic polyamide having a copolymerization molar ratio of 1: 1) was used. In the spinning step, the spinning solution is discharged from a mouthpiece in which discharge holes are concentrically arranged, spun into an aqueous solution at 50 ° C. having an NMP concentration of 30% by mass through an air gap, and a coagulation auxiliary liquid as shown in FIG. A coagulated yarn was obtained without installing an ejection device.

Table 1 shows the coagulation yarn elongation and the single yarn elongation variation of the obtained coagulation yarn. When the device was not installed, coagulation was not promoted and the coagulation length could not be shortened, so that the coagulation yarn elongation was low. In addition, the single yarn elongation varies due to the difference in the solidification rate between the inside and the outside of the yarn, and the solidified yarn tends to break in the drawing step after the solidification step.

<Example 1>
As a spinning solution, an NMP solution of copolyparaphenylene and 3,4-oxydiphenylene terephthalamide (a para-type total aromatic polyamide having a copolymerization molar ratio of 1: 1) was used. In the spinning step, the spinning solution was discharged from a mouthpiece in which the discharge holes were concentrically arranged, and spun into an aqueous solution at 50 ° C. having an NMP concentration of 30% by mass through an air gap to obtain a coagulated yarn.

At this time, as shown in FIG. 1, a coagulation auxiliary liquid ejection device having a length of 50 mm is installed so that the flow velocity ratio is 1.0 from the coagulation auxiliary liquid ejection device within a range of 5 mm to 105 mm from the coagulation liquid surface. The coagulation auxiliary liquid was ejected by adjusting the ejection amount. The composition of the liquid to be ejected was water. The angle at which the coagulation auxiliary liquid was ejected was adjusted by changing the angle of the ejection hole of the coagulation auxiliary liquid to be 90 °.

Table 1 shows the coagulation yarn elongation and the single yarn elongation variation of the coagulation yarn thus obtained. Since coagulation is promoted and the coagulation length can be shortened, the coagulated yarn has high elongation and excellent drawability, and since there is little yarn sway, the variation in single yarn elongation is small, and coagulation suitable for the subsequent drawing process. It became a thread.

<Example 2>
As a spinning solution, an NMP solution of copolyparaphenylene and 3,4-oxydiphenylene terephthalamide (a para-type total aromatic polyamide having a copolymerization molar ratio of 1: 1) was used. In the spinning step, the spinning solution was discharged from a mouthpiece in which the discharge holes were concentrically arranged, and spun into an aqueous solution at 50 ° C. having an NMP concentration of 30% by mass through an air gap to obtain a coagulated yarn.

At this time, as shown in FIG. 1, a coagulation auxiliary liquid ejection device having a length of 50 mm is installed so that the flow velocity ratio is 0.8 from the coagulation auxiliary liquid ejection device within a range of 5 mm to 105 mm from the coagulation liquid surface. The coagulation auxiliary liquid was ejected by adjusting the ejection amount. The composition of the liquid to be ejected was water. The angle at which the coagulation auxiliary liquid was ejected was adjusted by changing the angle of the ejection hole of the coagulation auxiliary liquid to be 90 °.

Table 1 shows the coagulation yarn elongation and the single yarn elongation variation of the coagulation yarn thus obtained. Since coagulation is promoted and the coagulation length can be shortened, the coagulated yarn has high elongation and excellent drawability, and since there is little yarn sway, the variation in single yarn elongation is small, and coagulation suitable for the subsequent drawing process. It became a thread.

<Example 3>
As a spinning solution, an NMP solution of copolyparaphenylene and 3,4-oxydiphenylene terephthalamide (a para-type total aromatic polyamide having a copolymerization molar ratio of 1: 1) was used. In the spinning step, the spinning solution was discharged from a mouthpiece in which the discharge holes were concentrically arranged, and spun into an aqueous solution at 50 ° C. having an NMP concentration of 30% by mass through an air gap to obtain a coagulated yarn.

At this time, as shown in FIG. 1, a coagulation auxiliary liquid ejection device having a length of 50 mm is installed so that the flow velocity ratio is 1.2 from the coagulation auxiliary liquid ejection device within a range of 5 mm to 105 mm from the coagulation liquid surface. The coagulation auxiliary liquid was ejected by adjusting the ejection amount. The composition of the liquid to be ejected was water. The angle at which the coagulation auxiliary liquid was ejected was adjusted by changing the angle of the ejection hole of the coagulation auxiliary liquid to be 90 °.

Table 1 shows the coagulation yarn elongation and the single yarn elongation variation of the coagulation yarn thus obtained. Since coagulation is promoted and the coagulation length can be shortened, the coagulated yarn has high elongation and excellent drawability, and since there is little yarn sway, the variation in single yarn elongation is small, and coagulation suitable for the subsequent drawing process. It became a thread.

<Comparative example 2>
As a spinning solution, an NMP solution of copolypareffenylene and 3,4-oxydiphenylene terephthalamide (a para-type total aromatic polyamide having a copolymerization molar ratio of 1: 1) was used. In the spinning step, the spinning solution was discharged from a mouthpiece in which the discharge holes were concentrically arranged, and spun into an aqueous solution at 50 ° C. having an NMP concentration of 30% by mass through an air gap to obtain a coagulated yarn.

At this time, a coagulation auxiliary liquid ejection device as shown in FIG. 2 is installed, and the amount of ejection is adjusted from the coagulation auxiliary liquid ejection device so that the flow velocity ratio is 1.0 in the range of 5 mm to 105 mm from the coagulation liquid surface. A coagulation aid was ejected. The composition of the liquid to be ejected was water. The angle at which the coagulation auxiliary liquid was ejected was adjusted by changing the angle of the ejection hole of the coagulation auxiliary liquid to be 135 °.

Table 1 shows the coagulation yarn elongation and the single yarn elongation variation of the coagulation yarn thus obtained. Although the variation in single yarn elongation is small because the yarn sway is suppressed, the tension received by the yarn in the solidification process increases because the ejection direction of the coagulation auxiliary liquid to be ejected is opposite to the traveling direction of the yarn. As a result, the coagulation yarn elongation was low, and the coagulation yarn was prone to breakage in the drawing step after the coagulation step.

<Comparative example 3>
As a spinning solution, an NMP solution of copolyparaphenylene and 3,4-oxydiphenylene terephthalamide (a para-type total aromatic polyamide having a copolymerization molar ratio of 1: 1) was used. In the spinning step, the spinning solution was discharged from a mouthpiece in which the discharge holes were concentrically arranged, and spun into an aqueous solution at 50 ° C. having an NMP concentration of 30% by mass through an air gap to obtain a coagulated yarn.

At this time, a coagulation auxiliary liquid ejection device as shown in FIG. 1 is installed, and the amount of ejection is adjusted from the coagulation auxiliary liquid ejection device so that the flow velocity ratio is 1.5 in the range of 5 mm to 105 mm from the coagulation liquid surface. A coagulation aid was ejected. The composition of the liquid to be ejected was water. The angle at which the coagulation auxiliary liquid was ejected was adjusted by changing the angle of the ejection hole of the coagulation auxiliary liquid to be 90 °.

Table 1 shows the coagulation yarn elongation and the single yarn elongation variation of the coagulation yarn thus obtained. Since the amount of the coagulation auxiliary liquid ejected was too large, the thread swayed so much that the coagulation thread was frequently broken during the coagulation process and the coagulated thread could not be collected.

<Comparative Example 4>
As a spinning solution, an NMP solution of copolyparaphenylene and 3,4-oxydiphenylene terephthalamide (a para-type total aromatic polyamide having a copolymerization molar ratio of 1: 1) was used. In the spinning step, the spinning solution was discharged from a mouthpiece in which the discharge holes were concentrically arranged, and spun into an aqueous solution at 50 ° C. having an NMP concentration of 30% by mass through an air gap to obtain a coagulated yarn.

At this time, a coagulation auxiliary liquid ejection device as shown in FIG. 1 is installed, and the amount of ejection is adjusted from the coagulation auxiliary liquid ejection device so that the flow velocity ratio is 0.5 in the range of 5 mm to 105 mm from the coagulation liquid surface. The coagulation aid was ejected. The composition of the liquid to be ejected was water. The angle at which the coagulation auxiliary liquid was ejected was adjusted by changing the angle of the ejection hole of the coagulation auxiliary liquid to be 90 °.

Table 1 shows the coagulation yarn elongation and the single yarn elongation variation of the coagulation yarn thus obtained. Since the amount of the coagulation auxiliary liquid ejected is too small, neither the coagulation promoting effect nor the thread sway suppressing effect is sufficiently exhibited, the coagulation thread elongation is low and the single thread elongation variation is large, and the drawing step after the coagulation step. It has become a coagulated thread that is prone to thread breakage.

<Comparative Example 5>
As a spinning solution, an NMP solution of copolyparaphenylene and 3,4-oxydiphenylene terephthalamide (a para-type total aromatic polyamide having a copolymerization molar ratio of 1: 1) was used. In the spinning step, the spinning solution was discharged from a mouthpiece in which the discharge holes were concentrically arranged, and spun into an aqueous solution at 50 ° C. having an NMP concentration of 30% by mass through an air gap to obtain a coagulated yarn.

At this time, a coagulation auxiliary liquid ejection device as shown in FIG. 1 is installed, and the amount of ejection is adjusted from the coagulation auxiliary liquid ejection device so that the flow velocity ratio is 1.0 in the range of 5 mm to 105 mm from the coagulation liquid surface. A coagulation aid was ejected. The composition of the liquid to be ejected was an aqueous solution having an NMP concentration of 50% by mass. The angle at which the coagulation auxiliary liquid was ejected was adjusted by changing the angle of the ejection hole of the coagulation auxiliary liquid to be 90 °.

Table 1 shows the coagulation yarn elongation and the single yarn elongation variation of the coagulation yarn thus obtained. Since coagulation was suppressed, coagulation did not proceed easily in the coagulation process, and thread breakage occurred frequently in the coagulation process, and the coagulated threads could not be collected stably.

<Comparative Example 6>
As the spinning solution, an NMP solution of copolyparaphenylene / 3,4-oxydiphenylene terephthalamide (para-type having a copolymerization molar ratio of 1: 1) was used. In the spinning step, the spinning solution was discharged from a mouthpiece in which the discharge holes were concentrically arranged, and spun into an aqueous solution at 50 ° C. having an NMP concentration of 30% by mass through an air gap to obtain a coagulated yarn.

At this time, a coagulation auxiliary liquid ejection device as shown in FIG. 1 is installed, and the amount of ejection is adjusted from the coagulation auxiliary liquid ejection device so that the flow velocity ratio is 1.0 in the range of 985 mm to 1000 mm from the coagulation liquid surface. A coagulation aid was ejected. The composition of the liquid to be ejected was water. The angle at which the coagulation auxiliary liquid was ejected was adjusted by changing the angle of the ejection hole of the coagulation auxiliary liquid to be 90 °.

Table 1 shows variations in the coagulation yarn elongation and the single yarn elongation of the coagulation yarn thus obtained. Since the ejection position of the coagulation auxiliary liquid was too deep, the coagulation auxiliary liquid was brought into contact with the coagulation auxiliary liquid after the coagulation was completed, and the coagulation promoting effect and the thread sway suppressing effect were not exhibited, so that the coagulation thread elongation was slightly low. The single yarn has a large variation in elongation, and the solidified yarn is likely to break in the drawing step after the solidification step.

a. Spinning cap b. Opening part c. Coagulation auxiliary liquid ejection device d. Running thread

Claims (3)

A spinneret provided with a discharge hole for discharging the spinning solution, and a coagulation auxiliary liquid ejection device adjacent to the spinning solution discharge side of the spinneret and installed in the coagulating liquid for coagulating the spinning solution. It is a dry-wet spinning apparatus composed of, and the coagulation auxiliary liquid ejection device has a hole for ejecting the coagulation auxiliary liquid, and the running yarn that is discharged from the discharge hole and then solidified is A dry-wet spinning apparatus characterized in that a coagulation auxiliary liquid is ejected from the opening while simultaneously satisfying the following conditions (a) to (d).
(A) The value of the flow velocity ratio obtained by dividing the flow velocity of the coagulation auxiliary liquid by the flow velocity of the coagulation liquid toward the threads on the coagulation liquid surface is 0.8 to 1.2.
(B) The concentration of the good solvent for the polymer constituting the spinning solution in the coagulation auxiliary solution is smaller than the concentration of the good solvent for the polymer constituting the spinning solution in the coagulation solution.
(C) The coagulation auxiliary liquid is ejected in the range of 0 ° to 90 ° with respect to the traveling direction of the thread.
(D) A hole for ejecting the coagulation auxiliary liquid is opened in a range of 5 mm to 800 mm from the liquid surface of the coagulation liquid along the thread traveling direction. The dry-wet spinning apparatus according to claim 1, wherein the discharge holes are concentrically arranged on the mouthpiece. The dry-wet spinning device according to claim 1 or 2, wherein the coagulation auxiliary liquid ejection device is installed on the center side of the mouthpiece with respect to the discharge hole.

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