JP4053471B2 - Dry-wet spinneret - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dry and wet spinning die that spins a spinning dope into air from a spinning die having a large number of spinning holes, and introduces the spun dope into a coagulation bath to form a fiber.
[0002]
[Prior art]
High-strength synthetic fibers, typified by para-aramid fibers, have excellent physical properties such as high strength, high modulus, and high heat resistance, so they are used in various fields as industrial fibers that take advantage of their high functionality. . Synthetic fibers having such high functions are solidified after spinning an optically anisotropic or isotropic spinning solution from a die into an inert gas using a so-called “dry and wet spinning method”. A manufacturing method is generally used in which the fiber is brought into contact with a coagulating liquid in a bath.
[0003]
For example, as a dry and wet spinning method for para-type aramid fibers, a solution having optical anisotropy made of polyparaphenylene terephthalamide (hereinafter also referred to as “PPTA”) is extruded through a discharge hole, and once into an inert gas. A dry-wet spinning method is known in which, after spinning, the fiber is continuously passed through a coagulation liquid filled in a coagulation bath to form a fiber (see, for example, JP-A-47-39458).
[0004]
However, in this method, since the coagulating liquid also advances along with the progress of the filament group entering the coagulation bath, the coagulating liquid forms a flow parallel to the liquid surface while forming the entrance part of the filament group. Will be supplied. Then, with respect to filament group enters, these coagulating liquid flow becomes collide perpendicularly from the outer side of the filament group, so that the filament group is focused moves to the center. In this way, when the spun filament group becomes to be focused, of course, that it Do and the filaments are in close contact. In particular, in the case of spinning the filament group by using a die densely discharge hole is bored, such adhesion occurs remarkably.
[0005]
In order to solve such a problem, a spin tube is provided at the bottom of the coagulation bath, the spun filament group is guided to the spin tube, and the filament group is dropped simultaneously with the coagulation liquid flowing down the spin tube. The so-called “flow tube spinning method” has been carried out. Certainly, if this “flow tube spinning method” is used, the coagulating liquid flowing down in the spin tube can be forcibly formed, so that the liquid surface flow that collides perpendicularly with the filament group is reduced. be able to.
[0006]
However, it is difficult to make the coagulation liquid flowing down in the spin tube into a uniform flow, and the vortex is generated in the coagulation liquid supplied to the spin tube immersed in the coagulation bath. Then, there is a problem that the running state of the filament group becomes unstable or disturbed, and single fiber breakage occurs, and the spinning process condition deteriorates (for example, JP-A-53-78320, (See JP-A-61-47814).
[0007]
Therefore, as a method for solving such a problem, for example, as proposed in Japanese Patent Publication No. 11-513757, a base in which the perforated areas of the discharge hole group are grouped into a plurality of rectangular areas is used. Thus, a PPTA production method for performing the above-described flow tube spinning method is known. Certainly, according to this method, the effect of suppressing the adhesion of the filament group and the single fiber breakage is recognized.
[0008]
However, this method requires the use of a special device called a “spin tube”. In the method for producing para-aramid from an optically isotropic spinning solution having an ether bond in a part of polyamide repeating unit as proposed in British Patent No. 1501948, coagulation is performed. The strength of the filament in the liquid is very low, and when the flow tube spinning method is used, it is difficult to stably spin in the coagulating liquid for a long time without breaking the single fiber.
[0009]
In general, as proposed in the above-mentioned Japanese translations of PCT publication No. 11-513757, JP-A-2002-348723, etc., as a die for spinning a polymer solution in wet spinning and dry-wet spinning, A base in which no discharge hole group is formed at the center of the base is used. The reason why such a die is used is that when the spinning solution spun from the die is passed through the coagulating liquid and fiberized, the coagulating liquid enters the center of the spun filament group. This makes it difficult to produce unevenness in the temperature of the coagulation liquid, or unevenness in the concentration of the coagulation liquid. It is mentioned that the fluctuation tends to be large.
[0010]
[Patent Document 1]
Japanese Patent Laid-Open No. 47-39458
[Patent Document 2]
Japanese Patent Laid-Open No. 53-78320
[Patent Document 3]
JP-A-61-47814 [0013]
[Patent Document 4]
JP 11-513757 A Publication [0014]
[Patent Document 5]
British Patent No. 1501948 Specification
[Patent Document 6]
JP-A-2002-348723
[Problems to be solved by the invention]
However, when the present inventors use a base that does not have a discharge hole formed in the central part of the base as conventionally used, the filament group travels because no perforated area is provided in the central part. A uniform coagulation bath flow cannot be formed in the same direction as the direction, and turbulent flow is generated at the center of the filament group traveling in the coagulation liquid, and the renewal of the coagulation liquid at this center deteriorates. I found out. Moreover, it has been found that in such a conventional die, concentration spots are generated in the solvent extracted from the filament group into the coagulation liquid, and it is difficult to realize a stable and uniform coagulation state.
[0017]
The present invention has been made against the background of the above-described prior art, and its object is to produce fibers by passing a spinning solution having optical isotropic or anisotropy from a die through an inert gas and a coagulation bath. An object of the present invention is to provide a dry / wet spinning die that can be stably spun from a single die at high density without using a flow tube spinning method in the dry / wet spinning method.
[0018]
[Means for Solving the Problems]
Here, according to the research of the present inventors, the above-mentioned problem is that “the polymer discharge surface has a circular shape and a large number of polymer discharge holes are substantially equal over the entire surface of the polymer discharge surface. In the base for dry and wet spinning drilled at a drilling density,
The number of all discharge holes formed in the base is 1000 to 3000, and an annular non-perforated zone region is formed at a position spaced from the center of the base by a predetermined distance from the radius side, Further, the invention is solved by an invention of “a wet and dry spinning die having a plurality of radial non-perforated zone regions extending from the annular non-perforated zone region toward the outer peripheral side”.
[0019]
In that case, as described in claim 2, the present invention is as follows: “10 to 40% of all discharge holes are arranged in a circular shape in the center portion of the base surrounded by the annular non-perforated zone region. It is preferable to use the “wet and dry spinning die”.
[0020]
Further, according to a third aspect of the present invention, as described in the third aspect, the dry and wet spinning according to the first or second aspect, wherein the width of the non-perforated zone region is at least three times the distance between adjacent discharge holes. It is preferable to use a “base”.
[00 21 ]
In addition, as described in claim 4 , the present invention may be a “wet and spin spinning die according to any one of claims 1 to 3 , in which the radial non-perforated zone regions are arranged equally”. preferable.
[00 22 ]
The present invention, as set forth in claim 5, "each other semi-wet according to any one of claims ratio and the discharge hole the distance between adjacent discharge holes diameter of 3 to 30 1-4 It is preferable to use a spinneret.
[00 23 ]
The present invention, as set forth in claim 6, the ratio between the maximum distance and the minimum distance between "adjacent to each other discharge holes according to any of claims 1-5 is 1 to 1.5 It is preferable to use a “wet and wet spinning die”.
[00 24 ]
And, according to the present invention, as described in claim 7 , "polyparaphenylene terephthalamide fiber, copolyparaphenylene 3,4'-oxydiphenylene terephthalamide fiber, polyparaphenylene benzoxazole fiber, high-strength polyethylene fiber" Or a spinneret for dry and wet spinning according to any one of claims 1 to 6 , wherein high-strength polyvinyl alcohol fibers are spun.
[00 25 ]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments relating to the above-described dry and wet spinning base of the present invention will be described in detail below with reference to the drawings.
[00 26 ]
Synthetic fibers manufactured using the dry and wet spinning base of the present invention include polyparaphenylene terephthalamide fiber, copolyparaphenylene 3,4'-oxydiphenylene terephthalamide fiber, polyparaphenylene benzoxazole fiber, high Examples include strong polyethylene fibers and high strength polyvinyl alcohol fibers.
[00 27 ]
FIG. 1 is a schematic explanatory view (plan view) illustrating an embodiment of a dry and wet spinning base of the present invention, and FIG. 2 is a schematic explanatory view (plan view) illustrating a conventional dry and wet spinning base. In each case, only one third of them are taken out and shown. Needless to say, FIG. 1 illustrates one embodiment of the present invention, and the present invention is not limited to the embodiment illustrated in FIG. 1 as long as the gist of the present invention is satisfied.
[00 28 ]
In FIG. 1, reference numeral 1 denotes a base body, and 2 denotes a perforated region where a discharge hole group is formed. Here, as shown in the figure, the polymer discharge surface of the base 1 has a circular shape, and the circular polymer discharge surface has a discharge hole group 2 (in FIG. 1, “ A large number of small circles "indicate discharge holes). In addition, in this invention, it cannot be overemphasized that the area | region (white background part of FIG. 1) where the discharge hole is not pierced exists in the polymer discharge surface of the nozzle | cap | die 1 outside the outermost periphery part.
[00 29 ]
Here, in the base of the present invention, an annular non-perforated zone region 3 is formed in the perforated region 2 as described above at a position spaced a predetermined distance R from the center O of the base 1 toward the radial side. Has been. In FIG. 1, the annular non-perforated zone region 3 corresponds to a portion that is filled in by hatching upward. Accordingly, the perforated region 2 of the discharge hole is separated into the base 2A of the base and the outer peripheral portion 2B of the base by the annular non-perforated zone region 3.
[00 30 ]
As described above, the discharge holes are formed in the central portion of the base 1 of the present invention with substantially the same perforation density. First, this point is greatly different from the conventional base. In other words, in a base that has been conventionally used, since a discharge hole is not formed in the central portion thereof, a uniform coagulation bath flow can be stably formed in the same direction as the direction in which the filament group travels. However, turbulent flow is generated at the center of the filament group traveling in the coagulating liquid, and the renewal of the coagulating liquid at the center is deteriorated. However, such a phenomenon hardly occurs in the die 1 of the present invention, and the coagulation liquid flows along with the filament group with respect to the filament group spun from the perforated region 2A formed in the central part of the die. . For this reason, the flow of the coagulating liquid is formed in the same direction as the traveling direction of the filament group.
[00 31 ]
Furthermore, a plurality of radial non-perforated zone regions 4 are formed in the base 1 of the present invention. The radial non-perforated zone regions 4 are formed from the annular non-perforated zone region 3 to the base 1 as shown in the figure. It consists of a plurality of strip-shaped non-perforated regions extending radially toward the outer peripheral side. In FIG. 1, the radial non-perforated zone region 4 corresponds to a portion that is filled with a left-upward hatching. Accordingly, the annular non-perforated zone region 3 and the radial non-perforated zone region 4 allow a fresh coagulation liquid to easily enter into the spun filament group, and the spinning solution is made into a fiber. The concentration spots of the coagulating liquid due to the staying spots of the solvent coming out of the solvent are also eliminated. For this reason, the fineness unevenness of the spun filaments is reduced, the single fiber breakage that occurs is reduced, the spinning process is stabilized and the quality of the resulting filaments is improved at the same time. Become.
[00 32 ]
In the above, the characteristic structure which concerns on the dry-wet spinning die of this invention was demonstrated roughly. Therefore, in the following, a more detailed configuration will be described.
[00 33 ]
In the base 1 shown as an embodiment in FIG. 1, a perforated region 2A is provided at the center of the base having a circular shape, and an annular non-perforated zone region 3 is disposed so as to surround the outer periphery of the perforated region 2A. ing. As described above, the annular non-perforated zone region 3 is provided to allow the coagulation liquid to enter the filament group satisfactorily. However, with such an annular non-perforated zone region 3 alone, the coagulation liquid does not sufficiently enter the perforated region 2B formed outside the annular non-perforated zone region 3. This is because the number of ejection holes perforated with equal perforation density on the polymer ejection surface of the base 1 is proportional to the square of r (r ² ), where r is the radial distance from the base O. This is because a larger amount of coagulating liquid is required for the filament group spun from these discharge hole groups. Therefore, it is important to divide and separate the perforated region 2B extending outside the annular non-perforated zone region 3 into a plurality of regions having an appropriate number of ejection holes.
[00 34 ]
Therefore, in order to achieve the object, a plurality of radial non-perforated zone regions 4 extending from the annular non-perforated zone region 3 toward the outer peripheral side are formed. Then, the accompanying liquid flowing along with the spun filament group flows uniformly in the direction of the die center O through the radial non-perforated zone region 4, and is uniformly dispersed in the perforated region 2B on the outer peripheral side. Can flow.
[00 35 ]
At this time, the number of ejection holes perforated in the perforated region 2A is preferably 10 to 40%, more preferably 15 to 30% of the total ejection holes perforated in the die. This is because if the number of holes is less than 10%, a uniform coagulation bath flow cannot be formed in the same direction as the filament group in the coagulation bath, turbulence occurs near the center of the die, and This is because there is little renewal of the liquid in the vicinity, so that coagulation liquid concentration spots are generated, and it becomes difficult to create a stable and uniform coagulation state .
[0036]
Other hand, when the number of holes exceeds 40%, becomes the accompanying flow generated in the perforated region 2A portion formed on the mouthpiece center increases, it flows from the liquid surface of the coagulation bath to the entry portion of the filament group The flow rate of the coagulation liquid will increase. Then, the liquid surface flow collides with the filament group entering the coagulation bath vertically from the lateral direction, and the filament group spun at a predetermined interval converges, and the filament Adhesion between the fibers frequently occurs and single fiber breakage is also induced, so that the filament group cannot be spun at high density with a stable spinning condition.
[0037]
Next, it is preferable that the annular non-perforated zone region 3 and the radial non-perforated zone region 4 have a width of at least three times the interval between adjacent discharge holes. This is because if the width of the non-perforated zone regions 3 and 4 is less than three times the interval between the adjacent discharge holes, the non-perforated zone regions 3 and 4 have insufficient penetration of the coagulation liquid between the filaments. This is because the coagulation liquid stays and it is difficult to uniformly coagulate the filament group.
[0038]
As described above, by determining the widths of the annular non-perforated zone region 3 and the radial non-perforated zone region 4, the associated flow generated as the filament group travels surrounds the perforated regions 2 A and 2 B. It can flow uniformly from the non-perforated zone regions 3 and 4. Moreover, by providing the non-perforated zone regions 3 and 4 as buffer zones, the concentration of the coagulating liquid flow that suddenly flows from the lateral direction along the liquid level of the coagulating bath is reduced with respect to the filament group entering the coagulating bath. It is also possible to suppress the filament group from converging and causing close contact. That is, the filament group is focused by dispersing and supplying the coagulating liquid from the non-perforated zone regions 3 and 4 provided as buffer zones flowing along the liquid surface to the filament group entering the coagulation bath. Can be alleviated.
[0039]
At that time, the number of the radial non-perforated zone regions 4 is the speed of the coagulating liquid accompanying the traveling filament group, the spinning speed, the flow state and viscosity of the coagulating liquid, the number and the density of the discharge holes perforated in the die, or Since it depends on the spinning conditions such as the spinneret shape, it is necessary to select an optimal number appropriately according to these conditions. For example, by making a large number of non-perforated zone regions 3 and 4 exist in a wide range, it is possible to prevent the filaments from sticking to each other, but in this case, the number of discharge holes that can be perforated in one die is reduced. Therefore, it is necessary to determine the optimum state within a range that does not reduce the production efficiency, and it is preferable to finally determine the optimum number by experiment.
[0040]
In addition, the upper limit of the number of discharge hole groups perforated in one die is 3000, and in the present invention, it is important to achieve 1000 to 3000 in order to achieve the object of the present invention. This is because if the number of discharge holes is less than 1000, the close contact between single fibers and the occurrence of single fiber breakage can be suppressed without employing the dry and wet spinneret of the present invention. This is because if the number of holes exceeds 3000, it is necessary to provide a large number of non-perforated zone regions 3 and 4, and the diameter of the die becomes so large that it becomes impractical.
[0041]
In the perforation region, the ratio (D / d) between the distance (D) between the perforations adjacent to each other and the discharge hole diameter (d) is preferably 3 or more and 30 or less. This is because when the ratio (D / d) is less than 3, a uniform flow of the coagulating liquid flowing in the same direction as the running direction of the yarn can be formed in the coagulating bath. This is because the distance between the single yarns is short, and the single yarns frequently adhere to each other and stable spinning cannot be performed. On the other hand, when the ratio (D / d) exceeds 30, the filament group cannot be spun at high density, and thus productivity is lowered.
[0042]
Next, FIG. 2 is a schematic view illustrating an array of discharge holes for obtaining a uniform flow in the perforated region, where H is a discharge hole and D _max is the maximum distance between the centers of adjacent discharge holes. , D _min indicate the minimum distance between the centers of adjacent discharge holes. At this time, the ratio (D _max / D _min ) between the maximum distance (D _max ) and the minimum distance (D _min ) is preferably 1 or more and 1.5 or less, and more preferably 1. This is because when the ratio (D _max / D _min ) exceeds 1.5, the holes are perforated in a state where the distance between the discharge holes varies, and the flow of the coagulating liquid in the perforated region is uneven. This is because the single fibers are brought into close contact with each other and stable spinning cannot be performed. Further, since the discharge hole interval is increased, spinning cannot be performed at a high density and productivity is lowered. When the ratio (D _max / D _min ) is 1, the filament group can be spun at the highest density, the productivity can be increased, and the flow of the coagulating liquid in the perforated region can be increased. Uniform and stable spinning is possible.
[0043]
It should be further noted here that when fibers are produced using the dry and wet spinning die according to the present invention, the close contact between filaments reduces the air gap, which is the distance between the die and the coagulation bath. Can also be reduced. Therefore, it is preferable to adopt the configuration of the base according to the present invention and to select a preferable air gap range, and such an air gap is 3 mm or more. This is because if the air gap is less than 3 mm, the coagulating liquid comes into contact with the surface of the base due to vibrations or small waves on the surface of the coagulating bath, and single fiber breaks frequently occur on the surface of the base.
[0044]
Hereinafter, the present invention will be described in more detail and specifically by experimental examples using the die of the present invention. However, these experimental examples are for helping the understanding of the present invention, and the description does not limit the examples consistent with the gist of the present invention.
[0045]
Reaction of 112.9 parts of N-methyl-2-pyrrolidone (hereinafter referred to as “NMP”) having a moisture content of 100 ppm or less, 1.506 parts of paraphenylenediamine, and 2.789 parts of 3,4′-diaminodiphenyl ether at room temperature After putting in a container and dissolving in nitrogen, 5.658 parts of terephthalic acid chloride was added with stirring. The reaction was finally carried out at 85 ° C. for 60 minutes to obtain a transparent viscous polymer solution. Next, 9.174 parts of NMP slurry containing 22.5 wt% calcium hydroxide was added to carry out a neutralization reaction. The logarithmic viscosity of the polymer obtained at this time was 3.33. Then, using the spinning solution with the spinning solution as a stock solution and having a hole diameter of 0.20 mm and a number of holes of 2000, a spinneret having a discharge hole group is used, and without relying on flow tube spinning, Japanese Patent Laid-Open No. 1-15605 As described in the publication, dry and wet spinning was performed according to a conventional method.
[0046]
At this time, the distance (air gap) between the polymer discharge surface of the die and the coagulation bath liquid surface is set to 10 mm, and the spinning solution spun from the die is once passed through the air gap, and then the coagulating liquid composed of NMP is added. It was introduced into a circulated coagulation bath and coagulated for fiberization. Next, the filament group (yarn) drawn from the coagulation bath is washed with water, and then the washed yarn is completely dried with a drying roller having a surface temperature of 200 ° C. and then stretched 10 times at 530 ° C. The film was wound at a speed of 500 m / min. The number of filaments of the obtained fiber was 2000, the single yarn fineness was 0.84 dtex, and the fineness was 1670 dtex.
[0047]
Then, the number of close contact was evaluated by observing the cross section of the yarn composed of 2000 filament groups obtained in this way with a transmission optical microscope. As a result, adhesion between filaments was not observed.
[0048]
However, the dry and wet spinneret used at this time was substantially the same as that illustrated in FIG. That is, the polymer discharge surface having a discharge hole group for discharging the spinning solution is a circular die having an outer diameter of 107 mm, and 302 discharge hole groups are formed in the perforated region at the center of the die, and the outer periphery thereof. The discharge hole groups each having 283 discharge hole groups are separated from each other by six radial non-perforated band regions so as to be divided into six groups of perforated regions. It was.
[0049]
At that time, in the perforated region, the ejection hole group was perforated so as to have a substantially equal perforation density by arranging in a staggered pattern so that the interval between adjacent ejection holes was about 1.75 mm. At this time, in the perforated region, the annular non-perforated band region has a band width of 7. 7 in the radial direction from a position approximately 17.5 mm away from the die center O (a distance indicated by reference symbol R in FIG. 1). It was formed to be 5 mm. Also, for the outer perforated area separated by the annular non-perforated band area, the band width is 13.6 mm so that the discharge holes perforated in this area are arranged in six groups. It was separated by six radial non-perforated zone regions.
[0050]
【The invention's effect】
According to the above-described die of the present invention, in the dry-wet spinning method in which a fiber is produced by passing an optically isotropic or anisotropic spinning solution from the die through an inert gas and a coagulation bath. It is possible to provide a dry and wet spinning die that can be stably spun from a single die at a high density and without being brought into close contact without using a tube spinning method.
[0051]
Furthermore, by using the base of the present invention, when a base that has not been provided with a perforated region at the center of the base used in the past is used, the flow of the coagulation bath is uniform in the same direction as the filament group travels. The problem that the turbulent flow is generated at the central portion of the filament group traveling in the coagulating liquid and the renewal of the coagulating liquid at the central portion is deteriorated can be solved. The concentration of the coagulation liquid can be suppressed by the solvent extracted into the coagulation liquid, and stable and uniform coagulation of the filament group can be realized, thereby disturbing the process condition of the high quality fiber. There is a remarkable effect that it can be manufactured without any problems.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic explanatory view (plan view) of an embodiment of a circular die for spinning according to the present invention, in which only one third of the die is taken out and illustrated.
FIG. 2 is a schematic plan view showing a positional relationship of discharge holes drilled in a drilling area.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Spinneret 2A, 2B Perforation area of discharge hole 3 Circular non-perforated zone area 4 Radial non-perforated zone area O Center of base R Distance from center of base of annular non-perforated zone

Claims (7)

In the base for dry and wet spinning, in which the polymer discharge surface has a circular shape, and a large number of polymer discharge holes are drilled at substantially equal perforation density over the entire surface of the polymer discharge surface,
The number of all discharge holes formed in the base is 1000 to 3000, and an annular non-perforated zone region is formed at a position spaced from the center of the base by a predetermined distance from the radius side, Furthermore, a dry and wet spinning die having a plurality of radial non-perforated zone regions extending from the annular non-perforated zone region toward the outer peripheral side.   2. The dry and wet spinning die according to claim 1, wherein 10 to 40% of all discharge holes are arranged in a circular shape in a central part of the die surrounded by the annular non-perforated zone region.   The dry / wet spinning die according to claim 1 or 2, wherein a width of the non-perforated belt region is at least three times a distance between adjacent discharge holes. The dry / wet spinning die according to any one of claims 1 to 3 , wherein the radial non-perforated belt regions are provided in a uniform manner. The dry / wet spinning die according to any one of claims 1 to 4 , wherein a ratio between a distance between the discharge holes adjacent to each other and a discharge hole diameter is 3 or more and 30 or less. The dry / wet spinning die according to any one of claims 1 to 5 , wherein a ratio of a maximum distance and a minimum distance between discharge holes adjacent to each other is 1 or more and 1.5 or less. Polyparaphenylene terephthalamide fibers, copolymer polyparaphenylene-3,4'-di-phenylene terephthalamide fibers, polyparaphenylene benzoxazole fibers, according to claim 1 to 6 for spinning high-strength polyethylene fibers, or high-strength polyvinyl alcohol fiber The dry / wet spinning die according to any one of the above.

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