JP2013185283A - Composite spinneret and method for producing conjugated fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite spinneret which, when a sea-island type conjugated fiber is produced, can prevent island component polymers from merging with each other while increasing hole packing density of extrusion holes of the island component polymers, and can maintain the dimensional stability of the cross-sectional shapes at a high level.SOLUTION: A composite spinneret is used for extruding a composite polymer stream composed of an island component polymer and a sea component polymer. The composite spinneret includes: at least one distribution plate in which distribution holes and distribution grooves for distributing each polymer component are formed; and a lowermost layer distribution plate located on the downstream side in the polymer spinning passage direction of the distribution plates, in which a plurality of island component extrusion holes and a plurality of sea component extrusion holes are formed. The composite spinneret comprises: n island component extrusion holes (n represents an integer of 3 or more, and the same applies hereinafter) arranged on a virtual circumferential line C1 of a radius R1 with a virtual center O as a center; n sea component extrusion holes arranged on a virtual circumferential line C2 of a radius R2 with the virtual center O as the center; and n virtual group centers P on a virtual circumferential line C3 of a radius R3 with virtual center O as a center.

Description

  The present invention relates to a composite die and a method for producing a composite fiber.

  Fibers using thermoplastic polymers such as polyester and polyamide are excellent in mechanical properties and dimensional stability, so their uses have diversified and many fibers with various functionalities have been developed.

  For example, in apparel applications, single yarn fine cross-section with the aim of giving fine texture, soft filament, etc., improving water absorption, quick drying, changing glossiness, etc. Improvements such as polymer modification have been made with the aim of imparting new functionality such as realization of dyeing with excellent sharpness. For industrial materials, in addition to making single yarn finer, multifilament, and single yarn irregular cross-section, new functionalities such as high strength, high elasticity, weather resistance, flame resistance, etc. Improvements such as targeted polymer modifications have been made. In addition to the above improvements, composite fibers that combine two or more polymers to complement performance that is insufficient with a single component polymer or that give a completely new function are being actively developed. ing.

  The composite fiber includes a core-sheath type, a side-by-side type, and a sea-island type fiber obtained by using a composite die, and an alloy type obtained by melt-kneading polymers. In the core-sheath type, the sheath component coats the core component, so that it is possible to impart sensibility effects such as texture and bulkiness that cannot be achieved with a single fiber, and mechanical properties such as strength, elastic modulus, and wear resistance. Become. Further, in the side-by-side type, it is possible to express crimpability, which is impossible with a single fiber, and to impart stretchability and the like.

  And in the sea-island type, by eluting the easily-eluting component (sea component) after melt spinning, only the difficult-to-elute component (island component) remains, and it is possible to obtain ultrafine fibers with a single fiber diameter of nano-order. It becomes possible. When it becomes such an extra fine fiber, in the use for clothing, a soft touch and fineness that cannot be obtained with ordinary fibers are expressed, and it can be applied to artificial leather, new touch textiles, etc., and the fiber spacing becomes dense. Therefore, it can be developed as a high-density woven fabric for sports clothing that requires windproof and water repellency. In industrial material applications, it can be applied to high-performance filters, etc., because the specific surface area is increased and dust collection is improved, and precision equipment is used by wiping off dirt by inserting ultrafine fibers into fine grooves. It can also be applied to wiping cloths, precision polishing cloths, and the like. In addition, the core-sheath type has a core component covered with a sheath component, so that it can provide a sensory effect such as a texture and bulkiness that cannot be achieved with a single fiber, and mechanical properties such as strength, elastic modulus, and wear resistance. It becomes possible. Further, in the side-by-side type, it is possible to express crimpability, which is impossible with a single fiber, and to impart stretchability and the like.

  In addition, generally the method of manufacturing a composite fiber with a composite nozzle | cap | die is called a composite spinning method, and the method of manufacturing by melt kneading of polymers is called a polymer alloy method. Although the polymer alloy method can be used to produce the ultrafine fibers as described above, the control of the fiber diameter is limited, and it is difficult to obtain uniform and homogeneous ultrafine fibers. On the other hand, the composite spinning method precisely controls the composite polymer flow with a composite die, and in particular, it can form a highly accurate yarn cross-sectional form uniformly and homogeneously in the running direction of the yarn, compared with the polymer alloy method. The superiority is considered high. As a matter of course, the composite die technique in this composite spinning method is extremely important for stably determining the cross-sectional shape of the yarn, and various proposals have been made conventionally.

  For example, Patent Document 1 discloses a composite base as shown in FIG. (B) of FIG. 11 is a plan view of the composite base of Patent Document 1, and (a) of FIG. 11 is a partially enlarged plan view of (b). In the figure, black circle 1 indicates an island component discharge hole for discharging an island component polymer, white circle 4 indicates a sea component discharge hole for discharging a sea component polymer, 5 indicates a lowermost layer distribution plate, and 8 indicates a distribution groove. Hereinafter, in each drawing, when a member corresponding to the already-explained drawing exists, the description may be omitted by using the same reference numerals.

  In Patent Document 1, a plurality of distribution plates are stacked, and a lowermost layer distribution plate 5 provided with distribution grooves 8, island component discharge holes 1, and sea component discharge holes 4 is disposed in the lowermost layer of the distribution plate. After distributing the island component polymer, which is difficult to elute, and the sea component polymer, which is easy to elute, to a large number in advance, both polymers are discharged from the island component discharge hole 1 and the sea component discharge hole 4 of the lowermost layer distribution plate 5 respectively. In addition, it is described that a sea-island type composite fiber can be manufactured by combining immediately after discharge. Further, it is described that by using this composite die, 61 uniformly distributed composite fibers having an island shape of a hexagonal cross section (honeycomb shape) can be manufactured. This composite base is generally called a distribution plate type base.

  However, according to the knowledge of the present inventors, in the composite base of Patent Document 1, the sea component discharge holes 4 are arranged around the island component discharge holes 1 as a hole group arrangement pattern. By doing so, the island shape has a hexagonal cross section, but the arrangement pattern of the other hole groups is not presented, and sea-island type composite fibers having various island shapes may not be obtained. Moreover, as described in the Examples of Patent Document 1, the obtained fiber is 0.06 denier (trial calculation of fiber diameter: about φ2.5 μm), the fiber diameter is micron size, and it has not reached the nano order.

  Moreover, FIG. 9, FIG. 10 is disclosed as a hole arrangement | positioning pattern different from patent document 1. FIG. 9 and 10 are partially enlarged plan views of the composite caps of Patent Document 3 and Patent Document 5. FIG. According to the knowledge of the present inventors, Patent Document 3 and Patent Document 5 are patterns in which the sea component discharge holes 4 are arranged in three or four equal arrangements (staggered arrangement) around the island component discharge holes 1. At first glance, it seems that a sea-island type composite fiber in which the island components are polygonal is likely to be obtained, but according to the knowledge of the present inventors, the island component polymers may actually merge. In particular, since the sea component polymer is eluted after being melt-spun, from the viewpoint of productivity, the polymer discharge rate ratio is preferably less sea component polymer to be eluted and more island component polymers. The confluence of the island component polymers becomes more prominent. Further, according to the knowledge of the present inventors, once the island component polymers join together, the problem may not be solved even if the spinning conditions such as the discharge amount of each component polymer and the discharge amount ratio are changed. Yes, in the worst case, if the composite base is not changed, production becomes impossible and productivity may deteriorate.

  Further, although a detailed hole arrangement pattern is not described, Patent Document 2 discloses a composite die for producing sea-island type composite fibers having various island shapes. FIG. 14A is a cross-sectional view showing a cross-sectional form of a composite fiber manufactured by the composite base of Patent Document 2. FIG. The composite die of Patent Document 2 describes that an island shape can be made an arbitrary cross-sectional shape by collecting and arranging a plurality of island component discharge holes 1 in an arbitrary shape. Thus, as shown in FIG. 14 (a), it is described that the resulting composite fiber has a plurality of star-shaped cross-sectional shapes in one composite fiber, as shown in FIG.

  However, according to the knowledge of the present inventors, in the composite base of Patent Document 2, in order to form one arbitrary island shape, a plurality of island component discharge holes 1 are densely arranged (arbitrary cross section). The island component discharge holes 1 are required to be densely arranged so as to surround the shape of the ridge), so that the number of island component discharge holes 1 that can be arranged per one base cannot be increased. In the composite fiber, there may be a case where a composite fiber having a large number of islands cannot be obtained.

  Moreover, although it is an example of the core-sheath type which has one island shape in one composite fiber, as a composite nozzle | cap | die which manufactures the composite fiber which employ | adopts a distribution plate system and has a complicated island shape, patent document 5 Is disclosed. 12 is a partially enlarged plan view of the lowermost layer distribution plate of the composite base of Patent Document 5, and FIG. 14B is a cross-sectional view showing a cross-sectional form of the composite fiber manufactured by the composite base of Patent Document 5. It is. 14 (c) and 14 (d) do not describe the hole arrangement pattern of the lowermost layer distribution plate 5, but a composite obtained by using the composite base (adopting the distribution plate method) of Patent Document 4. It is sectional drawing which showed the cross-sectional form of the fiber. In the composite cap of Patent Document 5, it is described that a cross-shaped cross-sectional shape can be obtained by arranging four sea component discharge holes 4 on the outer periphery of the island component discharge hole 1. Therefore, it is described that the cross-sectional form of the obtained composite fiber has one cross shape in one composite fiber, as shown in FIG. Further, in Patent Document 4, a plurality of island component discharge holes 1 are arranged so as to form a star shape and a trilobal shape, thereby providing one star shape and a trilobal cross section in one composite fiber. It is described that it can be.

  However, according to the knowledge of the present inventors, in the composite caps of Patent Document 4 and Patent Document 5, the core-sheath type is a single island-shaped cross section in one composite fiber, like the sea-island type. In some cases, a plurality of island shapes cannot be formed, that is, the hole arrangement pattern of the core-sheath type composite base cannot be directly applied to the sea-island type composite base. In addition, since it is not a sea-island type, the obtained fiber diameter may not reach the micron order, that is, the nano order. As described above, in the composite caps of Patent Document 4 and Patent Document 5, a composite fiber having a complex cross-sectional shape of an island shape and hundreds to thousands of island components in one fiber is obtained. It may not be possible.

  A composite base as shown in FIG. 13 is disclosed as a base that can produce sea-island fibers by a method different from the distribution plate type base. FIG. 13 is a schematic cross-sectional view of the composite base of Patent Document 6 and is called a pipe-type base. In the figure, 30 is a pipe, 31 is a sea component polymer introduction flow path, 32 is an island component polymer introduction flow path, 33 is an upper base plate, 34 is a middle base plate, 35 is a lower base plate, and 40 is a sea component polymer distribution chamber. , 41 is a pipe insertion hole, and 42 is a base discharge hole. In Patent Document 6, an upper base plate 33 provided with a sea component polymer introduction channel 31, an island component polymer introduction channel 32, and a pipe 30, and a pipe insertion hole 41 having a diameter equal to or larger than the outer diameter of the pipe 30 are provided. The inner base plate 34 is provided, and the lower base plate 35 is provided with a base discharge hole 42. Therefore, the easily eluted component sea component polymer is guided from the ocean component polymer introduction channel 31 to the ocean component polymer distribution chamber 40 and fills the outer periphery of the pipe 30, whereas the hardly eluted component island component polymer is: After being guided from the island component polymer introduction flow path 32 to the pipe 30 and discharged from the pipe 30, the polymers of both components merge to form a sea-island composite cross section, and then through the pipe insertion hole 41 and from the die discharge hole 42. It is described that a composite polymer can be discharged to produce a sea-island type composite fiber.

  However, the major problem of the pipe-type base of Patent Document 6 is that the pipe thickness is added to produce one island, so the area per pipe increases. In addition, since the pipe 30 is press-fitted into the upper base plate 33 and fixed by welding for manufacturing the base, a welding allowance is required, and further, a hole for inserting the pipe 30 is provided. The gap between pipes cannot be reduced due to problems. For this reason, the pipes 30 cannot be densely arranged per unit area, and it may be difficult to produce ultra-fine fibers having a fiber diameter of nano-order. In addition, since the cylindrical pipe 30 is used, the island shape obtained is limited to a circular shape or an elliptical shape similar to the circular shape. Therefore, a sea-island type composite fiber having a complex shape, for example, a polygonal island shape. May not be able to get. This is because the degree of freedom of the arrangement of the pipes 30 is low, the fiber cross-sectional shape that can be controlled is limited, and it may be difficult to manufacture a fiber having a complex cross-section in multiple layers.

  In addition, in order to obtain a desired fiber form, it is necessary to make a plurality of composite die prototypes and repeat the spinning evaluation several times. However, since the structure of this composite die is very complex, In this respect, there is a problem that the equipment cost is excessive. Further, since the sea component polymer introduction flow path 31 is disposed on the outer periphery of the pipe group in which the pipes 30 are densely disposed, it is difficult to sufficiently supply the sea component polymer to the center of the pipe group. In particular, the island component polymers discharged from the pipe 30 at the center of the pipe group may merge. In particular, if the pipes 30 are arranged more densely in order to increase the hole packing density, the above problem becomes more prominent. According to the knowledge of the present inventors, it may be structurally difficult to freely dispose the sea component polymer introduction channel 31 in the pipe group of the pipe 30. This is because, for example, in order to arrange in the pipe group, it is necessary to bend the pipe 30 in the middle and to provide the sea component polymer introduction channel 31, so that the structure of the base is very complicated. Therefore, there is a problem that the equipment cost becomes excessive.

JP 7-26420 A JP 2011-208313 A JP 2008-38275 A International Publication No. 2011/093311 International Publication No. 1989/02938 JP 2001-192924 A

  As described above, while increasing the hole packing density of the island component discharge holes, it is possible to prevent the island component polymers from joining together at a high island component ratio (= low sea component ratio), and to obtain an unusually shaped ultrafine fiber. Although eagerly desired, as described above, various problems remain, which has hindered the production of sea-island type composite fibers. Therefore, solving this problem has important industrial significance. Therefore, the purpose of the present invention is to prevent the island component polymer from joining together while expanding the hole packing density of the discharge holes of the island component polymer in the distribution plate type die for producing the sea-island type composite fiber. Various fiber cross-sectional forms, in particular, complex bases that can form high-profile deformed cross-sections with high precision and maintain high dimensional stability of this cross-sectional form, and composites that perform melt spinning by a composite spinning machine using the composite base It is in providing the manufacturing method of a fiber.

In order to solve the above problems, the composite base of the present invention has the following configuration. That is, according to the present invention, a composite base for discharging a composite polymer flow composed of an island component polymer and a sea component polymer, wherein distribution holes and distribution grooves for distributing each polymer component are formed. Consists of one or more distribution plates and a lowermost layer distribution plate that is located downstream of the distribution plate in the polymer spinning path direction and has a plurality of island component discharge holes and a plurality of sea component discharge holes N island component discharge holes (n is a natural number of 3 or more, the same shall apply hereinafter) arranged on a virtual circumference C1 having a radius R1 around the virtual center O, and a radius R2 around the virtual center O. And n virtual group centers P on a virtual circumferential line C3 having a radius R3 centered on the virtual center O, and n virtual group centers P arranged on the virtual circumferential line C2. N pieces arranged on a virtual circumferential line C5 having a radius R1 around the group center P There are a plurality of hole groups composed of the island component discharge holes and n sea component discharge holes arranged on a virtual circumferential line C6 having a radius R2 with the virtual group center P as a center. Provided is a composite base that satisfies 1) and (2) and has the following conditions (3) and (4).
(1) R1 ≦ R2 · cos (180 / n [degree])
(2) R3 = 2 · R2
(3) C1, C5: n island component discharge holes equally divided at a central angle of 360 / n degrees C2, C6: n sea component discharge holes equally divided at a central angle of 360 / n degrees C3 : N virtual group centers are equally divided at a central angle of 360 / n degrees θ1: phase angle between discharge holes arranged at C1 and C2, C5 and C6 is 180 / n degrees θ2: discharge holes with C2 The phase angle between the virtual group centers of C3 is 0 degree (4) The sea component discharge hole is at the intersection of the line segment connecting the virtual center O and the virtual group center P, the virtual circumferential line C2, and the virtual circumferential line C6. Arrangement According to a preferred embodiment of the present invention, there is provided a composite die that satisfies the formula (5) when the number of ejection holes is n = 4.
(5) R1 ≦ R2 / 2
Moreover, according to the preferable form of this invention, the composite nozzle | cap | die which satisfy | fills Formula (6) in the number of discharge holes n = 6 is provided.
(6) R1 ≦ R2 · 3√3 / 8
Moreover, according to the preferable form of this invention, even when the said virtual group center P adjacent to the said virtual center O is made into the said virtual center O, the composite nozzle | cap | die which has the same hole arrangement | positioning is provided.

  Further, according to another embodiment of the present invention, in the composite base, flow path pressure loss in each flow path from the distribution plate to the island component discharge hole of the lowermost layer distribution plate is equal, and the distribution plate Provided is a method for producing a composite fiber, in which melt spinning is performed by a composite spinning machine using a composite base in which the flow path pressure loss in each flow path to the sea component discharge hole of the lowermost layer distribution plate is equal.

  According to another embodiment of the present invention, there is provided a method for producing a composite fiber in which melt spinning is performed with an island component polymer ratio of 50% or more by a composite spinning machine using the composite base.

  In the present invention, the “distribution hole” means a hole in which a hole is formed by a combination of a plurality of distribution plates and serves to distribute the polymer in the direction of the polymer spinning path.

  In the present invention, the “distribution groove” means that a groove is formed by a combination of a plurality of distribution plates and plays a role of distributing the polymer in a direction perpendicular to the polymer spinning path direction. Here, the distribution groove may be an elongated hole (slit), or an elongated groove may be dug.

  In the present invention, the “polymer spinning path direction” refers to the main direction in which each polymer component flows from the measuring plate to the die discharge hole of the discharge plate.

  In the present invention, the “direction perpendicular to the direction of polymer spinning path” refers to a direction perpendicular to the main direction in which each polymer component flows from the metering plate to the die discharge hole of the discharge plate.

  In the present invention, the “virtual circumferential line C1 of radius R1” is a virtual polygon formed by line segments connecting the centers of n island component discharge holes, and the center of gravity of the virtual polygon is defined as a virtual center O. A virtual circumferential line C1 having a radius R1 as the distance between the center points of the center O and the island component discharge holes forming the virtual polygon.

  In the present invention, the “virtual circumferential line C2 having the radius R2” means the virtual circumferential line C2 having the radius R2 as the distance between the center point between the sea component discharge hole closest to the virtual center O and the virtual center O. Say.

  In the present invention, the “virtual circumferential line C3 having a radius R3” is an island component discharge hole that is located on the outer peripheral side of the virtual circumferential line C2 and forms n virtual polygons closest to the virtual center O. A virtual circumferential line C3 in which the center of gravity of the hole group is a virtual group center P and the distance between the center points of the virtual center O and the virtual group center P is a radius R3.

  In the present invention, the “virtual circumferential line C5 having a radius R1” means a virtual circumferential line having a radius R1 as the distance between the center points of the island component discharge hole closest to the virtual group center P and the virtual group center P. Refers to C5.

  In the present invention, the “virtual circumferential line C6 having a radius R2” means a virtual circumferential line having a radius R2 as the distance between the center points of the sea component discharge hole closest to the virtual group center P and the virtual group center P. Say C6.

  In the present invention, the phase angle θ1 between the discharge holes arranged at C1 and C2 is a line segment connecting the virtual center O and the center point of the sea component discharge holes arranged on the virtual circumference line C2. , An angle at which the virtual center O and a line segment connecting the center points of the island component discharge holes arranged on the virtual circumferential line C1 intersect. Further, the phase angle θ1 between the discharge holes arranged in C5 and C6 is a line segment connecting the virtual group center P and the center point of the sea component discharge hole arranged on the virtual circumference line C6, and An angle at which the virtual group center P intersects with a line segment connecting the center points of the island component discharge holes arranged on the virtual circumferential line C5.

  In the present invention, the phase angle θ2 is a line segment connecting the virtual center O and the center point of the sea component discharge hole disposed on the virtual circumferential line C2, and the virtual center O and the virtual circumferential line. This is the angle at which the line segment connecting the virtual group center P arranged on C3 intersects.

In the present invention, the “center angle” means the virtual center O, the center point of two island component discharge holes adjacent to each other in the circumferential direction arranged on the virtual circumferential lines C1 and C2, and the sea component discharge hole. The angle at which the line segment connecting the center points intersects, or the center point of the virtual group center P and the two island component discharge holes adjacent to each other in the circumferential direction respectively disposed on the virtual circumferential lines C5 and C6, and the sea An angle at which a line segment connecting the center points of the component discharge holes intersects, or the virtual center O and two virtual group centers P adjacent to each other in the circumferential direction virtually disposed on the virtual circumferential line C3. The angle at which line segments intersect.
In the present invention, the “polymer flow path” refers to a path formed by communication between a distribution hole and a distribution groove formed inside the distribution plate.

  In the present invention, the “hole filling density” refers to n island component discharge holes 1 arranged on the virtual circumference C1 as one island component hole group, and the number of island component hole groups is the number of discharge introduction holes. The value obtained by dividing by the cross-sectional area. The larger the pore packing density, the more the composite fiber is composed of a larger number of island component polymer components.

  According to the composite die of the present invention, while expanding the hole filling density of the discharge holes of the island component polymers, the island component polymers are uniformly distributed, and the island component polymers are prevented from merging with each other. Particularly, the irregular cross section can be formed with high accuracy, and the dimensional stability of the cross section can be maintained high.

It is a partial enlarged plan view of the lowest layer distribution board used for the embodiment of the present invention. It is the elements on larger scale of the lowest layer distribution board used for another embodiment of this invention. It is the elements on larger scale of the lowest layer distribution board used for another embodiment of this invention. It is the cross-sectional schematic of the representative composite fiber manufactured with the composite nozzle | cap | die used for embodiment of this invention. It is a schematic sectional drawing of the composite nozzle | cap | die used for embodiment of this invention. It is a schematic sectional drawing of the composite nozzle | cap | die used for embodiment of this invention, a spinning pack, and a cooling device periphery. It is XX arrow line view of FIG. It is a general | schematic fragmentary sectional view of the distribution plate used for embodiment of this invention, and a lowermost layer distribution plate. It is the elements on larger scale of the lowermost layer distribution plate of the composite nozzle | cap | die of a prior art example. It is the elements on larger scale of the lowermost layer distribution plate of a prior art example. It is the elements on larger scale of the lowermost layer distribution plate of the composite nozzle | cap | die of a prior art example. It is the elements on larger scale of the lowermost layer distribution plate of a prior art example. It is a schematic sectional drawing of the composite nozzle | cap | die of a prior art example. It is sectional drawing which showed the cross-sectional form of the typical composite fiber manufactured with the composite nozzle | cap | die used for embodiment of a prior art example.

  Hereinafter, embodiments of the composite base of the present invention will be described in detail with reference to the drawings. 5 is a schematic cross-sectional view of the composite base used in the embodiment of the present invention, FIG. 7 is a view taken along the line XX of FIG. 5, and FIG. 1 is a partially enlarged plan view of FIG. 2 and 3 are partially enlarged plan views of a lowermost layer distribution plate used in another embodiment of the present invention, and FIG. 6 is a schematic view of the periphery of a composite base, a spin pack, and a cooling device used in the embodiment of the present invention. FIG. 8 is a schematic partial sectional view of a distribution plate and a lowermost layer distribution plate used in the embodiment of the present invention. These are conceptual diagrams for accurately transmitting the main points of the present invention, which are simplified, and the composite base of the present invention is not particularly limited, and the number of holes and grooves and the size ratio thereof are not limited. These can be changed according to the embodiment.

  As shown in FIG. 6, the composite base 18 used in the embodiment of the present invention is mounted on the spin pack 15 and fixed in the spin block 16, and a cooling device 17 is configured directly below the composite base 18. Therefore, after the polymer of two or more components led to the composite base 18 passes through the measuring plate 9, the distribution plate 6, and the lowermost layer distribution plate 5 and is discharged from the base discharge hole 42 of the discharge plate 10, After being cooled by the air flow blown out by the cooling device 17 and given an oil agent, it is wound up as a sea-island type composite fiber. In addition, in FIG. 6, although the cyclic | annular cooling device 17 which blows off airflow in cyclic | annular inward is employ | adopted, you may use the cooling device which blows off airflow from one direction. In addition, as for the member provided on the upstream side of the measuring plate 9, the flow path used in the existing spinning pack 15 may be used, and it is not necessary to dedicate specially.

  As shown in FIG. 5, the composite base 18 used in the embodiment of the present invention is configured by laminating a measuring plate 9, at least one distribution plate 6, a lowermost layer distribution plate 5, and a discharge plate 10 in order. In particular, the distribution plate 6 and the lowermost layer distribution plate 5 are preferably formed of thin plates. In that case, the measuring plate 9 and the distribution plate 6, and the lowermost layer distribution plate 5 and the discharge plate 10 are positioned by the positioning pins so that the center position (core) of the spinning pack 18 is aligned, You may fix with a volt | bolt etc. and you may carry out metal joining (diffusion joining) by thermocompression bonding. In particular, since the distribution plates 6 and the distribution plate 6 and the lowermost layer distribution plate 5 use thin plates, it is preferable to perform metal bonding (diffusion bonding) by thermocompression bonding.

  Here, the plate thickness of the thin plate is preferably in the range of 0.01 to 0.5 mm, and more preferably in the range of 0.05 to 0.3 mm. By reducing the thickness of the thin plate, there is an advantage that the hole diameter and groove width of the holes that can be processed, the distance between holes, and the pitch between grooves can be reduced, and the hole filling density can be increased. Specifically, the hole diameter DMIN that is the smallest among the island component discharge holes 1 and the thickness BT of the lowermost layer distribution plate 5 in which the minimum holes are formed satisfy the expression (7). The hole filling density can be further increased. When the distribution groove 8 is formed, the groove width is set to DMIN, and the plate thickness BT of the distribution plate 6 satisfies the formula (7), so that the hole filling density is increased as described above. can do.

BT / DMIN ≦ 2 (7)
Here, in the case of BT / DMIN> 2, as described above, it is possible to further increase the hole filling density. However, when it is attempted to minimize the discharge spots of the island component polymer, the equation (7) It is more preferable to satisfy.

  However, if the thickness of the distribution plate 6 and the lowermost layer distribution plate 5 is reduced within the range of 0.01 to 0.5 mm, the strength of the thin plate is reduced and bending tends to occur. The type may be limited (high-viscosity polymer will have a large pressure loss and bend). In that case, a plurality of thin plates may be stacked and metal-bonded to increase the overall thickness and improve the strength. Further, by increasing the thickness of the thin plate, the strength per sheet is improved, so that there is an advantage that the types of polymers that can be used increase. However, if it is too thick, the hole diameter, groove width, and hole-groove pitch that can be processed cannot be reduced, and the hole filling density may not be increased. In that case, the thickness of the distribution plate having a large number of holes may be reduced, and the thickness may be increased as the number of holes decreases.

  Therefore, the polymer of each component supplied from the measuring plate 9 passes through the distribution groove 8 and the distribution hole 7 of the distribution plate 6 laminated at least one, and then discharges the island component polymer of the lowermost distribution plate 5. By discharging from the island component discharge hole 1 and the sea component discharge hole 4 for discharging the sea component polymer, the polymers of the respective components merge to form a composite polymer flow. Thereafter, the composite polymer flow passes through the discharge introduction hole 11 and the reduction hole 12 of the discharge plate 10 and is discharged from the base discharge hole 42. Here, the hole diameters of the island component discharge holes 1 provided in the lowermost layer distribution plate 5 are preferably all equal, and the hole diameters of the sea component discharge holes 4 are preferably all equal. Thereby, since the discharge speed of the island component polymer discharged from the island component discharge hole 1 and the sea component polymer discharged from the sea component discharge hole 4 can be made uniform, an island component cross section with excellent uniformity can be obtained. it can. Moreover, the hole diameters of the island component discharge hole 1 and the sea component discharge hole 4 may be different, and may be appropriately determined depending on the island component / sea component polymer ratio. This is because when the ratio of the island component polymer is increased, the discharge speed of the island component polymer discharged from one island component discharge hole 1 (the discharge speed is the discharge flow rate is the island component discharge hole 1 or the sea component discharge hole). 4), and the diameter of the island component discharge hole 1 having a large amount of polymer discharge so that the discharge speed of the sea component polymer discharged from one sea component discharge hole 4 is approximately equal. It is preferable to reduce the diameter of the sea component discharge hole 4 with a large polymer discharge amount or a small polymer discharge amount. Thereby, the cross-sectional form of the island component obtained can be remarkably stabilized and the form can be accurately maintained. The diameters of the island component discharge holes 1 and the sea component discharge holes 4 are preferably in the range of 0.01 to 0.5 mm, and more preferably in the range of 0.05 to 0.3 mm. .

  First, the polymer of island components, which is the most important point of the present invention, is prevented from joining, and various fiber cross-sectional forms, in particular, cross sections having a high degree of irregularity (the irregularity referred to in the present invention is the circumscribing of irregularly-shaped cross-section yarns). The principle by which the ratio of the circle to the inscribed circle (the circumscribed circle / inscribed circle) having a higher degree of irregularity) can be formed with high accuracy and can be achieved with a high hole packing density will be described.

  Here, in order to prevent the island component polymers from joining together and form a deformed cross section, for example, as shown in FIG. 11, the sea where the sea component polymer is discharged around one island component discharge hole 1. If the component discharge hole 4 is arranged so as to surround from the six directions, the sea polymer discharged from the six sea component discharge holes 4 surrounds the island polymer discharged from the island component discharge hole 1. A fiber having an island component having a hexagonal cross section can be obtained while suppressing merging of adjacent island component polymers. However, according to the knowledge of the inventors, the hexagonal cross section of the obtained fiber has an edge portion, but has a large angle for forming an edge (corner), so that a high degree of irregularity is obtained. I can't.

  Further, as shown in FIGS. 9 and 10, when the island component discharge holes 1 and the sea component discharge holes 4 are regularly arranged, at first glance, it is expected that fibers with island components having a triangular or quadrangular cross section can be obtained. However, according to the knowledge of the present inventors, the island component polymers actually merge between the edge portions of adjacent island components. According to the knowledge of the present inventors, in the case where the cross-sectional shape of the island component is a round shape or a cross-sectional shape similar to the cross-section (such as a hexagonal cross-section), the confluence of the island component polymers is adjacent to the island. Whereas it occurs mainly on the line connecting the centers of the component discharge holes 1, it has an acute edge (corner) and has a cross-sectional shape with a high degree of irregularity. On the line connecting the centers of gravity of the island component discharge holes 1 In addition, the island component polymers also merge with each other between the edge portions of the adjacent island components. Furthermore, considering the production efficiency, since the sea component polymer is eluted after melt spinning, it is preferable to increase the island component polymer ratio as much as possible and reduce the sea component polymer ratio, but in this case, the island component polymers are joined together. Occurrence becomes more prominent. In other words, according to the knowledge of the present inventors, the greater the irregularity of the cross-sectional shape of the island component, the easier it is for the island component polymers to merge, and in order to achieve this under high production efficiency. Further, the difficulty level becomes higher.

  Further, in order to form a cross-sectional shape having a high degree of irregularity, a plurality of island component discharge holes 1 are arranged so as to have a desired shape, and the island polymers discharged from the island component discharge holes 1 are joined together. Can be mentioned. However, according to the knowledge of the present inventors, since a plurality of island component discharge holes 1 are required to form a cross-sectional form of one island component, there are restrictions on the number of holes that can be arranged in the composite die. As a result, the hole filling density cannot be increased, and there is a limit in forming a cross-sectional shape of hundreds or thousands of island components.

  Further, as another means capable of forming a high degree of profile, as shown in FIG. 12, as an example of a core-sheath type composite mouthpiece, four sea component discharge holes 4 are arranged diagonally around the island component discharge holes 1. For example. In this case, the island polymer discharged from the island component discharge hole 1 and the sea polymer discharged from the sea component discharge hole 4 merge to finally obtain a shuriken cross-sectional shape. However, according to the knowledge of the present inventors, as shown in FIG. 12, when the above-described hole arrangement is applied to the sea-island type as it is, merging occurs between the island component polymers discharged from the adjacent island component discharge holes 1. As a result, a shuriken-shaped cross-sectional shape cannot be obtained. In this way, the hole arrangement of the lowermost distribution plate 5 obtained in the core-sheath type (one island component is surrounded by the sea component) is directly applied to the sea-island type having hundreds or thousands of island components. Not applicable.

  Therefore, it is an extremely important technique to increase the hole packing density, suppress the merging of the island component polymers, and produce a fiber having a highly accurate fiber cross-sectional form. Accordingly, the present inventors have conducted extensive studies on the above-mentioned problem, which was not considered in the conventional technology, and as a result, have found a new technology of the present invention.

  That is, the lowermost layer distribution plate 5 according to the embodiment of the present invention includes n island component discharge holes 1 that form a virtual polygon on a virtual circumferential line C1 having a radius R1 and a radius R2. The n sea component discharge holes 4 arranged on the virtual circumference line C2 and the n virtual group centers P on the virtual circumference line C3 having the radius R3, the radius centering on the virtual group center P. The n island component discharge holes 1 disposed on the virtual circumferential line C5 of R1 and the n sea component discharge holes 4 disposed on the virtual circumferential line C6 of radius R2 are combined into one hole. A plurality of hole groups are arranged. When n is 3, 4, or 6, even when the virtual group center P adjacent to the virtual center O is set as the virtual center O, a plurality of hole groups can be formed by arranging them so as to have the same hole arrangement. It can be periodically arranged, and the arrangement density of the hole group can be increased, and the hole filling density can be increased. In addition, when n is another number, for example, five, the hole groups cannot be arranged periodically, but the hole groups are arranged at regular intervals, and the sea component discharge holes 4 are arranged between the hole groups. By doing so, a composite fiber having a plurality of island component cross sections can be obtained.

  Here, when n is 3, the island component is a Y-shaped cross section, when n is 4, a cross-shaped cross section, and when n is 6, a so-called starfish type in which a protrusion is formed at the edge of a hexagonal cross section. An arrangement pattern of island component discharge holes 1 and sea component discharge holes 4 which are cross sections is shown. When n is any other number, the edge portion of the n-gonal cross section has a shape having a protrusion. Further, a smaller number of n can obtain a cross-sectional shape with a higher degree of irregularity.

As shown in FIG. 1, a pattern with three n is formed by forming a virtual polygon by line segments connecting the centers of three adjacent island component discharge holes 1a, 1b, 1c, and the center of gravity of the virtual polygon. Is the virtual center O, the distance between the center points of the virtual center O and the island component discharge hole 1 is radius R1, and then the center point distance between the virtual center O and the sea component discharge hole 4 closest to the virtual center O is radius R2. Then, the center of gravity of the hole group of the island component discharge holes 1 that are located on the outer peripheral side of the virtual circumferential line C2 and form the three virtual polygons closest to the virtual center O is defined as the virtual group center P, and the virtual center The distance between the center points of O and the virtual group center P is assumed to be a radius R3, and they are arranged so as to satisfy the expressions (1) and (2) and satisfy the conditions (3) and (4). Here, Equation (1) is calculated by rounding off the fourth decimal place.
(1) R1 ≦ R2 · cos (180 / n [degree]) Formula (1)
(2) R3 = 2 · R2 Formula (2)
(3) C1, C5: n island component discharge holes equally divided at a central angle of 360 / n degrees C2, C6: n sea component discharge holes equally divided at a central angle of 360 / n degrees C3 : N virtual group centers are equally divided at a central angle of 360 / n degrees θ1: phase angle between discharge holes arranged at C1 and C2, C5 and C6 is 180 / n degrees θ2: discharge holes with C2 The phase angle between the virtual group centers of C3 is 0 degree (4) The sea component discharge hole is at the intersection of the line segment connecting the virtual center O and the virtual group center P, the virtual circumferential line C2, and the virtual circumferential line C6. Arrangement As a result, the island component polymers discharged from the three island component discharge holes 1a, 1b, 1c on the virtual circumferential line C1 merge to form a dent on the corner of the triangular cross section, and the most merged Between the hole group of the island component discharge hole 1 on the virtual circumferential line C1 and the hole group of the island component discharge hole 1 on the virtual circumferential line C3, which are likely to occur By preventing the confluence between definitive island component polymer, the island component is uniform, it is possible to obtain a fiber comprising a high irregular cross section (Y-shaped cross-section) form.

  Explaining the principle of the present invention along the flow form of the polymer, both the island component polymer and the sea component polymer are simultaneously discharged toward the discharge introduction hole 11 on the downstream side of the lowermost layer distribution plate 5, As each polymer widens in a direction perpendicular to the direction of the polymer spinning path, the polymer flows along the direction of the polymer spinning path, and the two polymers merge to form a composite polymer stream. At that time, the island component polymers discharged from the hole group of the island component discharge holes 1a, 1b, and 1c around the virtual center O and the hole group of the three island component discharge holes 1 around the virtual group center P It is effective to intervene the sea component polymer that physically divides the island component polymer, and this role is discharged from the sea component discharge hole 4 on the virtual circumferential line C2. The sea component polymer plays. To achieve this, a group of island component discharge holes 1 (island component discharge holes 1a, 1b, 1c) arranged on the virtual circumferential line C1 and an island sentence written on the virtual circumferential line C5 When the sea component discharge hole 4 is disposed between the hole group of the discharge hole 1 and the radius R2 of the virtual circumferential line C2 forming the hole group of the sea component discharge hole 4, the equations (1) and (2 ) Should be satisfied.

  Another important point of the present invention is that island component polymers discharged from the three island component discharge holes 1a, 1b, and 1c merge to form a deformed cross section of one island component. . When the island component polymers discharged from the three island component discharge holes 1a, 1b, and 1c merge, a triangular cross section is formed with each island component discharge hole 1 as a vertex. At that time, the sea component polymer is discharged from the sea component discharge holes 4 between the island component discharge holes 1a and 1b, between the island component discharge holes 1b and 1c, and between the island component discharge holes 1c and 1a. And by allowing a part of the sea component polymer to enter between the joining island component polymers, a dent can be formed on the corner of the triangular cross section, and as a result, a cross-sectional form having a high degree of irregularity (Y-shaped cross section) Can be formed.

  That is, as the discharge hole arrangement to achieve this, the island component discharge holes 1a, 1b, and 1c arranged on the virtual circumference C1 around the virtual center O are equally arranged at a central angle of 120 degrees, The sea component discharge holes 4 on the virtual circumferential line C2 are equally divided at a central angle of 120 degrees with a phase angle of 60 degrees, and a virtual group similar to the hole arrangement pattern centered on the virtual center O Centering on the center P, the three island component discharge holes 1 arranged on the virtual circumference C5 having the radius R1 are equally arranged at a central angle of 120 degrees, and on the virtual circumference C6 having the radius R2. The sea component discharge holes 4 are equally arranged at a central angle of 120 degrees with a phase angle of 60 degrees. And the sea component discharge hole 4 is arrange | positioned at the intersection of the line segment which connects the center point of the virtual center O and the virtual group center P, the virtual circumference line C2, and the virtual circumference line C6.

  Here, in the case of R1> R2 · cos (60 [degrees]) in the formula (1) (when n = 3), it is discharged from the island component discharge hole 1 arranged on the virtual circumferential line C1. The island component polymer and the island component polymer discharged from the island component discharge hole 1 disposed on the virtual circumferential line C5 may merge. Further, if R1 in the formula (1) is reduced, it is possible to suppress the merging of the island component polymers as described above. R1 may be determined according to the above. Here, as the lower limit for reducing R1, when the radius r of the island component discharge hole 1 is set, it is preferable to satisfy R1 ≧ √3 · r. Y-shaped cross-section yarn can be obtained.

  As a feature of the hole arrangement pattern that becomes the Y-shaped cross-section yarn, the island component polymer ratio can be increased, and even at a high island ratio of 70% or more, there is no merging of the island component polymers, and the island component is uniform. A fiber having a cross section can be obtained. Furthermore, since a large number of islands can be arranged and the island packing density can be increased, it is suitable for obtaining a composite fiber called nanofiber, which has a fiber diameter of nanosize.

Next, as an arrangement in which the island component has a cross-section, as shown in FIG. This is because the four island component discharge holes 1 arranged on the virtual circumference C1 with the radius R1 are equally divided at a central angle of 90 degrees with the virtual center O as the center, and the virtual circumference C2 with the radius R2 The upper four sea component discharge holes 4 are equally divided at a central angle of 90 degrees with a phase angle of 45 degrees, and on a virtual circumferential line C5 having a radius R1 with the virtual group center P as the center. The four arranged island component discharge holes 1 are equally divided at a central angle of 90 degrees, and the four sea component discharge holes 4 on the virtual circumferential line C6 having the radius R2 have a phase angle of 45 degrees. The sea component discharge holes 4 are arranged equally at a central angle of 90 degrees, at the intersection of the line segment connecting the center point of the virtual center O and the virtual group center P, the virtual circumferential line C2, and the virtual circumferential line C6. Place. The feature of the hole arrangement pattern serving as the cross-section thread is that a group of holes of the island component discharge holes 1 on the virtual circumference C1 so as to satisfy Expression (5), which is a condition narrower than Expression (1), The sea component discharge hole 4 on the virtual circumference line C2 is disposed between the hole group of the island component discharge holes 1 on the virtual circumference line C5.
(5) R1 ≦ R2 / 2 Formula (5)
The lower limit for reducing R1 is preferably R1 ≧ 1.5 · √2 · r when the radius r of the island component discharge hole 1 is set. With this arrangement, the islands discharged from the hole group of the four island component discharge holes 1 on the virtual circumference line C1 and the hole group of the four island component discharge holes 1 on the virtual circumference line C5 are arranged. It is possible to prevent the component polymers from joining each other, and in particular, when the island component polymer ratio is 50% or more, a fiber having a high profile (cross section) can be obtained.

Next, as an arrangement in which the island component has a starfish-shaped cross section, as shown in FIG. This is because six island component discharge holes 1 arranged on a virtual circumferential line C1 having a radius R1 are equally divided at a central angle of 60 degrees around a virtual center O, and a virtual circumferential line C2 having a radius R2 The upper six sea component discharge holes 4 are equally divided at a central angle of 60 degrees with a phase angle of 30 degrees, and center on the virtual group center P on a virtual circumferential line C5 having a radius R1. Six arranged island component discharge holes 1 are equally divided at a central angle of 60 degrees, and six sea component discharge holes 4 on a virtual circumferential line C6 having a radius R2 have a phase angle of 30 degrees. The sea component discharge holes 4 are arranged equally at a central angle of 60 degrees, at the intersection of the line segment connecting the center point of the virtual center O and the virtual group center P, the virtual circumferential line C2, and the virtual circumferential line C6. Place. The feature of the hole arrangement pattern serving as the starfish-type cross-section thread is that the island components on the virtual circumference C1 are discharged so as to satisfy Expression (6), which is a narrower condition than Expression (1) and Expression (5). The sea component discharge hole 4 on the virtual circumferential line C2 is arranged between the hole group of the hole 1 and the hole group of the island component discharge hole 1 on the virtual circumference line C5.
(6) R1 ≦ R2 · 3√3 / 8 Equation (6)
Further, as a lower limit for reducing R1, it is preferable that R1 ≧ 3 · r when the radius r of the island component discharge hole 1 is set. With such an arrangement, the islands discharged from the hole group of the six island component discharge holes 1 on the virtual circumference line C1 and the hole group of the six island component discharge holes 1 on the virtual circumference line C5 are arranged. It is possible to prevent the component polymers from joining each other, and in particular, when the island component polymer ratio is 50% or more, a fiber having a high degree of profile (starfish cross section) can be obtained.

  As described above, as the number of n increases to 3, 4, and 6, the range of the radius R1 of the virtual circumferential line C1 becomes narrower than the radius R2 of the virtual circumferential line C2. Accordingly, the inventors have found a range of R1 that can achieve a cross-sectional form with a high degree of irregularity at a high island component polymer ratio while preventing the island component polymers from joining together.

  Further, as shown in FIG. 8, in the plurality of stacked distribution plates 6, the number of distribution holes 7 formed in the distribution plate 6 is configured to increase toward the downstream side in the polymer spinning path direction. The distribution plate 6 in which the distribution holes 7 for guiding the polymer in the direction of the polymer spinning path are formed, and the distribution plate 6 in which the distribution grooves 8 for guiding the polymer in the direction perpendicular to the direction of the polymer spinning path are formed. Distributing grooves 8 are formed so as to communicate alternately with the distribution holes 7 positioned upstream in the polymer spinning path direction and the distribution holes 7 positioned downstream in the polymer spinning path direction. ing.

  Therefore, a single distribution groove 8 that communicates with the single distribution hole 7 at a position downstream in the direction of the polymer spinning path is formed, and a plurality of distribution grooves 8 that communicate with the end of the distribution groove 8 (in FIG. 8). A flow path for a tournament-type polymer constituting the two distribution holes 7 is formed.

  In this tournament type polymer flow path, the path length from the distribution hole 7 of the distribution plate 6 located at the upper end of the polymer spinning path direction or the distribution groove 8 to the island component discharge hole 1 of the lowermost distribution plate 5 is as follows. Are equal. In the plurality of distributed distribution plates 6, each distribution plate 6 has a structure in which the hole diameter of the distribution hole 7, the groove width, the groove depth, and the groove length of the distribution groove 8 are equal. In this case, as the number of tournament flow paths decreases toward the upstream side in the direction of the polymer spinning path, the flow rate of the polymer passing through the distribution grooves 8 and the distribution holes 7 sequentially increases, and the flow path pressure loss increases. Accordingly, it is preferable to increase the diameter of the distribution hole 7, the width of the distribution groove 8, and the depth of the distribution groove in order to suppress the increase in flow path pressure loss. Also, as shown in FIG. 8, a two-branch tournament polymer flow path in which one distribution groove 8 communicates with the two distribution holes 7 on the downstream side in the polymer spinning path direction is preferable. However, this is not a limitation. When the distribution groove 8 communicates with two or more distribution holes 7 (in the case of a tournament type flow path having two or more branches), the distribution holes 7 on the downstream side are distributed from the distribution holes 7 on the upstream side in the polymer spinning path direction. It is preferable that the flow path pressure loss of the flow path of each polymer is equalized by equalizing the groove length, groove width, and groove depth of the distribution groove 8 that reaches the center. Further, disposing the distribution hole 7 at the end of the distribution groove 8 eliminates the abnormal retention of the polymer, has the advantage of high polymer distribution and precise control.

  Here, as a structure for equalizing the flow path pressure loss of the other polymer flow paths, a plurality of polymer flow paths inside the distribution plate 6 formed by the distribution holes 7 and the distribution grooves 8 can be used. It is mentioned that the diameter of the distribution hole 6 in the path having a relatively long polymer flow path from the upper end to the lowermost layer distribution plate 5 is larger than the diameter of the distribution hole 6 in the relatively short path. This makes it possible to equalize the flow path pressure loss. Further, as a structure for equalizing the flow path pressure loss of the other polymer flow paths, the hole diameter of the island component discharge hole 1 of the lowermost layer distribution plate 5 is set to the flow path in each flow path of the distribution plate 6 on the upstream side. A structure for adjusting the pressure loss difference to be equal can be mentioned. Specifically, by increasing the diameter of the island component discharge hole 1 communicating with the flow path having a large flow path pressure loss and reducing the island component discharge hole 1 communicating with the upstream flow path having a small flow path pressure loss, It is possible to equalize the flow path pressure loss.

  Next, each member common to the composite base 18 of the embodiment of the present invention shown in FIG. 1, FIG. 2, FIG. 3, FIG. 5, FIG. .

  The composite base 18 in the present invention is not limited to a circular shape, and may be a quadrangle or a polygon. Further, the arrangement of the base discharge holes 42 in the composite base 18 may be appropriately determined according to the number of sea-island composite fibers, the number of yarns, and the cooling device 17. As the cooling device 17, in the case of an annular cooling device, the base discharge holes 42 are preferably arranged in a ring or in a row over a plurality of rows, and in the case of a one-way cooling device, the base discharge holes 42 are arranged in a staggered manner. Is good. The cross section of the nozzle discharge hole 42 in the direction perpendicular to the polymer spinning path direction is not limited to a round shape, and may be a cross section other than a round shape or a hollow cross section. However, in the case of a cross-sectional shape other than a round shape, it is preferable to increase the length of the die discharge hole 42 in order to ensure the meterability of the polymer.

  Moreover, the island component discharge hole 1 in the present invention is not limited to a round cross section in the direction perpendicular to the polymer spinning path direction, and may have a non-round cross section or a hollow cross section. In this case, it is preferable that the shape of the island component discharge holes 1 arranged in the lowermost layer distribution plate 5 is the same. In the case of a shape other than the round cross section, it is easy to obtain a fiber having a deformed cross section by making the island component discharge holes 1 similar in advance so that the island component has a desired shape. In addition, in the irregular cross-section fiber of the island component, it becomes easier to form corners more sharply. (It is easy to reduce the radius of curvature.) However, when the island component discharge hole 1 has a cross-sectional shape other than a round shape, a round cross-sectional distribution hole 7 is arranged in communication with the island component discharge hole 1 immediately above the circular cross-section. It is preferable to discharge the polymer through the island component discharge holes 1 having a cross-sectional shape other than the round shape after securing the polymer meterability through the distribution holes 7.

  Further, the discharge introduction hole 11 in the present invention is provided with a constant running section from the lower surface of the lowermost layer distribution plate 5 in the polymer spinning path direction, so that the flow velocity difference immediately after the island component polymer and the sea component polymer merge. Can be relaxed and the composite polymer stream can be stabilized. Further, the hole diameter of the discharge introduction hole 11 is larger than the outer diameter of the virtual circle 19 of each discharge hole group of the island component discharge hole 1 and the sea component discharge hole 4 disposed in the lowermost layer distribution plate 5 and is virtual. It is preferable that the cross-sectional area of the circle 19 and the cross-sectional area ratio of the discharge introduction hole 11 be as small as possible. Thereby, the widening of each polymer discharged from the lowermost layer distribution plate 5 is suppressed, and the composite polymer flow can be stabilized.

  Further, the reduction hole 12 in the present invention can reduce the size of the composite base 18 by setting the reduction angle α of the flow path from the discharge introduction hole 11 to the base discharge hole 42 in the range of 50 to 90 °, and Instability phenomena such as draw resonance of the composite polymer stream can be suppressed, and the composite polymer stream can be supplied stably.

  The island component discharge hole 1, sea component discharge hole 4 and distribution hole 7 in the present invention preferably have a constant hole cross-sectional area in the polymer spinning path direction, but the cross-sectional area gradually decreases or increases, Alternatively, it may be gradually decreased and gradually increased. This is because, in the distribution plate 6 and the lowermost layer distribution plate 5 according to the present invention, the hole cross-sectional area may not be constant when a minute hole is processed since the hole processing is mainly performed using an etching process. In this case, the processing conditions and the like may be appropriately optimized.

  Further, the lowermost layer distribution plate 5 in the present invention may be one, or a plurality of layers may be laminated. In this case, in the single lowermost layer distribution plate 5, when the polymer meterability of the island component discharge hole 1 and the sea component discharge hole 4 cannot be obtained and the fiber form changes with time, a plurality of sheets are laminated. Thus, the meterability of the polymer can be ensured.

  Further, one distribution plate 6 of the present invention may be provided with a distribution hole 7 on the upstream side of the distribution plate 6 and a distribution groove 8 (downstream side) in communication therewith. The distribution groove 8 may be disposed on the upstream side of the distribution plate 6, and the distribution hole 7 (downstream side) may be disposed in communication therewith. In this way, the polymer can be distributed by communicating the distribution hole 7 and the distribution groove 8 and repeating this one or more times.

  Here, the hole filling density of the island component discharge holes 1 of the lowermost layer distribution plate 5 is increased, that is, the island component discharge holes 1 on the virtual circumference line C1 and the virtual circumference line C5, and the virtual circumference line C2. In order to reduce the distance from the sea component discharge hole 4 on the virtual circumferential line C6, the distribution plate 6 and the lowermost layer distribution plate 5 of the present invention have a laminated structure of thin plates. The distribution holes 7 arranged in the distribution plate 6 distribute the polymer mainly in the polymer spinning path direction, and the distribution groove 8 distributes the polymer mainly in the direction perpendicular to the polymer spinning path direction. By alternately laminating the distribution plate 6 provided with the distribution holes 7 and the distribution plate 6 provided with the distribution grooves 8, the polymer can be distributed freely and easily in the fiber cross-sectional direction. By utilizing this, the island component discharge hole 1 and the sea component discharge hole 4 can be arranged in a very narrow region.

  Next, the manufacturing method of the composite fiber common to the composite nozzle | cap | die 18 of embodiment of this invention shown in FIG.1, FIG.2, FIG.3, FIG.5 and FIG. 6 is demonstrated in detail.

  The composite fiber manufacturing method of the present invention may be a known composite spinning machine using the composite base 18 of the present invention. For example, in the case of melt spinning, the spinning temperature is set to a temperature at which a high melting point or high viscosity polymer mainly exhibits fluidity among two or more types of polymers. The temperature indicating the fluidity varies depending on the molecular weight, but the melting point of the polymer is a guideline and may be set at a melting point + 60 ° C. or lower. If it is less than this, the polymer is not thermally decomposed in the spinning head or the spinning pack, and the molecular weight reduction is suppressed, which is preferable. The spinning speed varies depending on the physical properties of the polymer and the purpose of the composite fiber, but can be about 500 to 6000 m / min. In particular, when high mechanical properties are required for industrial material applications, it is preferable to use a high molecular weight polymer, set to 500 to 2000 m / min, and then stretch at a high magnification. In stretching, it is preferable to appropriately set the preheating temperature using as a guide the temperature at which the polymer can be softened, such as the glass transition temperature of the polymer. The upper limit of the preheating temperature is preferably a temperature at which yarn path disturbance does not occur due to spontaneous elongation of the fiber during the preheating process. For example, in the case of PET having a glass transition temperature in the vicinity of 70 ° C., this preheating temperature is usually set at about 80 to 95 ° C.

  Moreover, it is preferable to control the discharge rate ratio of the polymer of each component discharged from the island component discharge hole 1 and the sea component discharge hole 4 of the present invention by the discharge amount, the hole diameter, and the number of holes. The range of the discharge speed is as follows. When the discharge speed Va of the island component polymer per single hole and the discharge speed of the sea component polymer are Vb, the ratio (Va / Vb or Vb / Va) is 0.05-20. More preferably, it is in the range of 0.1 to 10, and in this range, the polymer discharged from the lowermost layer distribution plate 5 is formed as a laminar flow through the discharge introduction hole 11 and the reduced hole 12. Therefore, the cross-sectional shape is remarkably stable, and the shape can be maintained with high accuracy.

  Moreover, the composite polymer flow can be stably formed by setting the melt viscosity ratio of the polymer used in the present invention to less than 2.0. When the melt viscosity ratio is 2.0 or more, the island component polymer and the sea component polymer become unstable when they merge, and there are cases where uneven thickness of the yarn occurs in the traveling direction of the obtained fiber cross section.

  Next, as a manufacturing method of the distribution plate 6 and the lowermost layer distribution plate 5 of the present invention, a pattern is transferred to a thin plate, which is usually used for processing of electric / electronic parts, and fine processing is performed by chemical processing. Etching is preferred. Here, etching is a processing method that applies a chemical reaction and corrosive action of chemicals such as an etchant to etch a thin plate (dissolution processing / chemical cutting), and masks the required processing shape (necessary) The target processed shape can be obtained with very high accuracy by removing the unnecessary portion with a corrosive agent such as an etching solution. It is sufficient to use a general corrosive agent such as an etchant. For example, nitric acid, sulfuric acid, hydrochloric acid and the like can be used. Since this processing method does not require consideration for distortion of the workpiece, the lower limit of the thickness of the workpiece is not limited as compared with the other processing methods described above, and the present invention refers to an extremely thin metal plate. The junction groove 8, the distribution hole 7, the island component discharge hole 1, and the sea component discharge hole 4 can be formed. In addition, since the distribution plate 6 and the lowermost layer distribution plate 5 manufactured by etching can be reduced in thickness per sheet, the effect on the total thickness of the composite base 18 even if a plurality of sheets are stacked. There is almost no need to newly install another pack member in accordance with the composite fiber having a desired cross-sectional shape. In other words, if only the distribution plate 6 and the lowermost layer distribution plate 5 are exchanged, the cross-sectional shape can be changed. Further, as another manufacturing method, it is possible to use a lathe, machining, press, laser processing, or the like, which is a drill processing or metal precision processing used in conventional base manufacturing. However, since these processes are limited in the lower limit of the thickness of the processed plate from the viewpoint of suppressing distortion of the workpiece, the thickness of the distribution plate 6 is applicable to the composite die of the present invention in which a plurality of distribution plates are laminated. Need to be considered.

  Next, the fiber obtained by the composite base of the present invention means a fiber in which two or more kinds of polymers are combined, and two or more kinds of polymers are present in the form of a sea island or the like in the fiber cross section. Say the fiber you are doing. Here, it is needless to say that the two or more types of polymers referred to in the present invention include the use of two or more types of polymers having different molecular structures such as polyester, polyamide, polyphenylene sulfide, polyolefin, polyethylene, and polypropylene. However, matting agents such as titanium dioxide, silicon oxide, kaolin, anti-coloring agents, stabilizers, antioxidants, deodorants, flame retardants, yarn friction reducing agents, coloring, as long as the yarn-making stability is not impaired. Examples include various functional particles such as pigments and surface modifiers, additives such as organic compounds, and different amounts of particles added, different molecular weights, and copolymerization.

  Further, the single yarn cross section of the fiber obtained by the composite base 18 of the present invention may be not only a round shape but also a shape other than a round shape such as a triangle or a flat shape, or a hollow shape. Further, the present invention is an extremely versatile invention, and is not particularly limited by the single yarn fineness of the composite fiber, is not particularly limited by the number of single yarns of the composite fiber, and further, the number of yarns of the composite fiber Is not particularly limited, and may be a single yarn or a multi-yarn of two or more yarns.

  As shown in FIGS. 4A, 4B, and 4C, the sea-island type composite fiber obtained by the composite die of the present invention has a cross section in which two or more different polymers are perpendicular to the fiber axis direction. A fiber in which a sea-island structure (a sea-island structure referred to herein is a structure in which an island portion constituted by the island component polymer 13 is divided into a plurality by the sea portion constituted by the sea component polymer 20) is formed. Say. By arranging the island component discharge holes 1 and the sea component discharge holes 4 as shown in FIG. 1, a Y-shaped cross section as shown in FIG. 4 (a) is obtained, and the hole arrangement as shown in FIG. By doing so, a cross-section as shown in FIG. 4B is obtained, and by arranging the holes as shown in FIG. 3, a sea-island type composite fiber having a starfish-type section as shown in FIG. 4C is obtained. be able to.

  Further, regarding the number of islands obtained using the composite base of the present invention, it is theoretically possible to produce an infinite number of islands within the range allowed by the space, but the practically feasible range is 2 to 2. 10,000 islands is a preferred range. The range for obtaining the superiority of the composite die of the present invention is more preferably 100 to 10,000 islands.

Moreover, in this invention, it is preferable that a hole filling density is 0.5 hole / mm < ² > or more. If the hole filling density is 0.5 hole / mm ² or more, the difference from the conventional composite die technology becomes more clear. In the range studied by the present inventors, the hole filling density could be implemented if it was in the range of 0.5 to 20 holes / mm ² . From the viewpoint of the hole filling density, a range in which the superiority of the composite die of the present invention is obtained is preferably 1 to 20 holes / mm ² .

  In addition, the sea-island type composite fiber in the present invention is a very fine deformed fiber that cannot be obtained by single spinning by eluting the sea component polymer 20, so that the circumscribed fiber diameter is 10 to 1000 nm and the fiber diameter varies. It is possible to produce a long-fiber nanofiber having excellent uniformity with a fiber diameter CV% representing 0 to 30%. By forming the long fiber type nanofibers into a sheet-like material, the long fiber type nanofibers can be suitably used for finishing the aluminum alloy substrate or the glass substrate used for a magnetic recording disk or the like with ultrahigh precision. As another application, it is also possible to produce a sheet-like material in which some islands are intentionally joined and the fiber diameter distribution is freely controlled.

  As described above, the composite form that can be manufactured by the composite base 18 of the present invention has been described by exemplifying a conventionally known cross-sectional form. However, in the composite base 18 of the present invention, the cross-sectional form can be arbitrarily controlled. Therefore, a free form can be produced without being restricted by the above form.

  In addition, the strength of the composite fiber of the present invention is preferably 2 cN / dtex or more, and is preferably 5 cN / dtex or more in view of mechanical properties required for industrial material applications. A practical upper limit is 20 cN / dtex. The elongation is preferably 2 to 60% for drawn yarn, particularly 2 to 25% in the industrial material field where high strength is required, and 25 to 60% for clothing. Further, the conjugate fiber of the present invention can be used in various fiber products such as fiber winding packages, tows, cut fibers, cotton, fiber balls, cords, piles, woven and knitted fabrics, non-woven fabrics, paper, and liquid dispersions.

  Hereinafter, the effects of the composite die of the present embodiment will be specifically described with reference to examples.

(1) Precipitation of island component of sea-island type composite fiber In order to deposit island component from sea-island type composite fiber, the sea-island type composite fiber is soaked and removed in a solution that can elute sea component of elution easily. The multifilament of the island component of the eluted component was obtained. When the easily eluting component was copolymerized PET or polylactic acid (PLA) in which 5-sodium sulfoisophthalic acid or the like was copolymerized, an alkaline aqueous solution such as an aqueous sodium hydroxide solution was used. Further, when the aqueous alkali solution is heated to 50 ° C. or higher, the progress of hydrolysis can be accelerated, and if it is processed using a fluid dyeing machine or the like, it can be processed in a large amount at a time.

(2) Multifilament fiber diameter and fiber diameter variation (CV%)
The resulting multifilament composed of ultrafine fibers was embedded with an epoxy resin, frozen with a Reichert FC-4E cryosectioning system, and cut with a Reichert-Nissei ultracut N (ultra microtome) equipped with a diamond knife. The cut surface was photographed at a magnification of 5000 times with a VE-7800 scanning electron microscope (SEM) manufactured by Keyence Corporation. 150 ultra-fine fibers randomly selected from the obtained photos are extracted, all circumscribed circle diameters (fiber diameters) are measured using image processing software (WINROOF), and the average fiber diameter and fiber diameter standard are measured. Deviation was determined. Here, the circumscribed circle refers to the broken line 14 in FIG. From these results, the fiber diameter CV% (coefficient of variation) was calculated based on the following formula. All of the above values are measured for each of the three photographs, averaged at the three positions, measured in nm to the first decimal place, and rounded off to the nearest decimal place.

Fiber diameter variation (CV%) = (fiber diameter standard deviation / average fiber diameter) × 100
(3) Deformity and irregularity variation (CV%)
The cross section of the multifilament is photographed by the same method as the fiber diameter and fiber diameter variation described above, and the diameter of the perfect circle circumscribing the cut surface is defined as the circumscribed circle diameter (fiber diameter) from the image. Using the diameter of the circle as the inscribed circle diameter, the degree of irregularity = the circumscribed circle diameter ÷ the inscribed circle diameter was obtained up to the third decimal point, and the figure rounded to the third decimal place was obtained as the irregularity. Here, the inscribed circle refers to the broken line 19 in FIG. This extraordinary degree was measured for 150 ultrafine fibers randomly extracted in the same image, and from the average value and standard deviation, irregularity degree variation (CV% (coefficient of variation)) was calculated based on the following formula. Calculated. About this irregularity variation, the second decimal place is rounded off.

Variation in irregularities (CV%) = (standard deviation of irregularities / average value of irregularities) x 100 (%)
(4) Fineness Sea-island type composite fibers are made into a circular knitting, and 99% or more of the readily soluble components are dissolved and removed by immersing them in a 3% by weight sodium hydroxide aqueous solution (80 ° C. bath ratio 1: 100), and then the knitting is released Then, a multifilament made of ultrafine fibers was extracted, the weight of 1 m was measured, and the fineness was calculated by multiplying by 10,000. This was repeated 10 times, and the value obtained by rounding off the second decimal place of the simple average value was defined as the fineness.

(5) Melt viscosity of polymer The chip-like polymer was adjusted to a moisture content of 200 ppm or less by a vacuum dryer, and the melt viscosity was measured by changing the strain rate stepwise by "Capillograph 1B" manufactured by Toyo Seiki. The measurement temperature is the same as the spinning temperature, and the melt viscosity of 1216 s ⁻¹ is described in the examples or comparative examples. By the way, it took 5 minutes from putting the sample into the heating furnace to starting the measurement, and the measurement was performed in a nitrogen atmosphere.
[Example 1]
Polyethylene terephthalate (PET melt viscosity: 120 Pa · s) with an intrinsic viscosity (IV) of 0.63 dl / g as an island component, and 5.0 mol% of 5-sodium sulfoisophthalic acid with an IV of 0.58 dl / g as a sea component polymer Copolymerized PET (copolymerized PET melt viscosity: 140 Pa · s) is melted separately at 290 ° C., weighed, and flowed into a spin pack incorporating the composite die of this embodiment shown in FIG. A sea-island composite polymer stream was discharged from the hole. In the lowermost layer distribution plate, 700 island component discharge holes are formed at regular intervals for one discharge introduction hole for the island component polymer. The sea-island ratio is 30/70, and the discharged composite polymer stream is cooled and solidified, then applied with oil, wound at a spinning speed of 1500 m / min, and unstretched with 110 dtex-15 filament (single hole discharge rate 2.25 g / min) Fiber was collected. The wound unstretched fiber is stretched 3.0 times between rollers heated to 90 ° C. and 130 ° C. to obtain a sea-island type composite fiber of 50 dtex-15 filaments, and 99% or more of sea components are dissolved by the method described above. 11,000 multifilaments were collected.

Here, in the composite base used in Example 1, the distribution plate in which the distribution holes are perforated and the distribution plate in which the distribution grooves are perforated are alternately laminated, and the lowermost layer as shown in FIG. Distribution plates are stacked. The distribution plate is perforated with a thickness of 0.1 mm, a hole diameter of 0.2 mm, a groove width of 0.3 mm, a groove depth of 0.1 mm, and a minimum hole pitch of 0.4 mm. The thickness of the lowermost distribution plate is 0.1 mm, the diameter of the island component discharge hole and the sea component discharge hole is 0.2 mm, the radius R1 on the virtual circumferential lines C1 and C5 is 0.22 mm, the virtual circle When the radius R2 on the peripheral lines C2 and C6 is 0.44 mm, n = 3 of the conditions of the expressions (1), (2), and (3) are arranged. As shown in Table 1, the island component has a Y-shaped cross section, there is no merging between the island component polymers, the fiber diameter variation is 5.3%, the irregularity degree 2.3, and the irregularity variation 4.5%. The filament diameter was 870 nm.
[Example 2]
As shown in FIG. 2, the arrangement of the island component discharge holes and the sea component discharge holes of the lowermost distribution plate is arranged so that n = 4 in the conditions of the expressions (1), (2), and (3). Otherwise, the same composite die as in Example 1 was used. In the lowermost layer distribution plate, 600 island component discharge holes are formed at regular intervals for one discharge introduction hole for the island component polymer. The sea-island ratio was 50/50, and other than that, spinning was performed under the same polymer, the same fineness, and spinning conditions as in Example 1, and 9000 multifilaments were collected. Here, the composite base used in Example 2 has an island component discharge hole and a sea component discharge hole having a hole diameter of 0.2 mm, a radius R1 of the virtual circumferential line C1 is 0.25 mm, and a virtual circumferential line. Perforated with a radius R2 of C2 of 0.5 mm. As shown in Table 1, the island component has a cross-section, there is no merging of the island component polymers, the fiber diameter variation is 5.9%, the irregularity degree is 2.4, and the irregularity variation is 4.4%. This multifilament The fiber diameter was 710 nm.
[Example 3]
As shown in FIG. 3, the arrangement of the island component discharge holes and the sea component discharge holes of the lowermost distribution plate is arranged so that n = 6 in the conditions of the expressions (1), (2), and (3). Otherwise, the same composite die as in Example 1 was used. In the lowermost layer distribution plate, 500 island component discharge holes are formed at regular intervals for one discharge introduction hole for the island component polymer. The sea-island ratio was 50/50, and spinning was performed under the same conditions as in Example 1, the same fineness, and spinning conditions, and 7500 multifilaments were collected. Here, the composite base used in Example 3 has an island component discharge hole and a sea component discharge hole with a hole diameter of 0.2 mm, a radius R1 of the virtual circumferential line C1 of 0.33 mm, and a virtual circumferential line. The C2 radius R2 is perforated at 0.51 mm. As shown in Table 1, the island component has a starfish-shaped cross section, there is no merging of the island component polymers, the fiber diameter variation is 5.9%, the irregularity degree 2.3, and the irregularity variation 4.8%. The filament diameter was 994 nm.
[Comparative Example 1]
As shown in FIG. 12, the same composite die as in Example 1 was used except that the arrangement of the island component discharge holes and the sea component discharge holes of the lowermost layer distribution plate was changed. Here, in the lowermost layer distribution plate, for the island component polymer, one island component discharge hole is formed per one discharge introduction hole, and four sea component discharge holes are formed around the island component discharge hole. As the spinning conditions, the sea-island ratio was 50/50, and the discharged composite polymer stream was cooled and solidified and then applied with oil, wound at a spinning speed of 1500 m / min, and 110 dtex-150 filament (single hole discharge rate 2.25 g / min) Of undrawn fibers were collected. The wound unstretched fiber is stretched 3.0 times between rollers heated to 90 ° C. and 130 ° C. to obtain a 36 dtex-150 filament sea-island type composite fiber, and 99% or more of sea components are dissolved by the method described above. 150 multifilaments were collected.

Here, in the composite base used in Comparative Example 1, island component discharge holes and sea component discharge holes having a hole diameter of 0.2 mm are drilled at an inter-hole pitch of 0.6 mm. As shown in Table 1, a fiber having an irregularity of 1.5 and an island component having a cross-section was obtained, but the fiber diameter was 11000 nm, which was on the order of microns.
[Comparative Example 2, Comparative Example 3]
Next, using the same composite die as in Example 1 except that the ratio of the radius R2 of the virtual circumference C2 and the radius R1 of the virtual circumference C1 is different, the same polymer, equivalent fineness, and spinning as in Example 1 are used. Comparative examples 2 and 3 will be described as comparative examples in which spinning is performed under conditions and the sea-island ratio is changed. Here, the radius R1 on the virtual circumference C1 where the island component discharge holes and the sea component discharge holes are arranged is 0.33 mm, and the radius R2 of the virtual circumference C2 is 0.44 mm. In Comparative Example 2, the sea-island ratio was 30/70, and in Comparative Example 3, the sea-island ratio was 50/50. As shown in Table 1, when the island component polymer ratio was as high as 50% or 70%, the island component polymers joined together, and a Y-shaped multifilament could not be obtained.
[Comparative Example 4]
Next, using the same composite die as in Example 2 except that the ratio of the radius R2 of the virtual circumferential line C2 and the radius R1 of the virtual circumferential line C1 is different, the same polymer, equivalent fineness, and spinning as in Example 2 are used. Comparative example 4 will be described as a comparative example in which spinning is performed under conditions and the sea-island ratio is changed. Here, the radius R1 on the virtual circumference C1 where the island component discharge holes and the sea component discharge holes are arranged is 0.35 mm, and the radius R2 of the virtual circumference C2 is 0.44 mm. The sea-island composite fiber was manufactured with a sea-island ratio of 50/50. As shown in Table 1, merging of the island component polymers occurred, and a multifilament having a cross-section could not be obtained.
[Comparative Example 5]
Next, using the same composite die as in Example 3 except that the ratio of the radius R2 of the virtual circumferential line C2 and the radius R1 of the virtual circumferential line C1 is different, the same polymer, equivalent fineness, and spinning as in Example 3 are used. Comparative Example 5 will be described as a comparative example in which spinning is performed under conditions and the sea-island ratio is changed. Here, the radius R1 on the virtual circumference C1 where the island component discharge holes and the sea component discharge holes are arranged is 0.44 mm, and the radius R2 of the virtual circumference C2 is 0.51 mm. The sea-island composite fiber was manufactured with a sea-island ratio of 50/50. As shown in Table 1, merging of island component polymers occurred, and a multi-filament having a starfish cross section could not be obtained.

  The present invention is not limited to a composite die used for a general solution spinning method, but can be applied to a melt blow method and a spun bond method, and also to a die used for a wet spinning method and a dry and wet spinning method. However, the application range is not limited to these.

1 Island component discharge hole 4 Sea component discharge hole 5 Lowermost layer distribution plate 6 Distribution plate 7 Distribution hole 8 Distribution groove 9 Measurement plate 10 Discharge plate 11 Discharge introduction hole 12 Reduction hole 13 Island component polymer (island portion)
14 circumscribed circle 15 spinning pack 16 spin block 17 cooling device 18 composite base 19 inscribed circle 20 sea component polymer (sea part)
21 Island component discharge part 22 Extension line 24 Sea component discharge part 25 Discharge hole 26 Common outer tangent line 27 Radial groove 28 Concentric upper groove 29 Upper layer plate 30 Pipe 31 Sea component polymer introduction flow path 32 Island component polymer introduction flow path 33 Upper mouth metal plate 34 Middle mouth plate 35 Lower mouth plate 40 Sea component polymer distribution chamber 41 Pipe insertion hole 42 Base discharge hole α Reduction angle L Running section

Claims (6)

A composite base for discharging a composite polymer flow composed of an island component polymer and a sea component polymer, and one or more distribution plates formed with distribution holes and distribution grooves for distributing each polymer component; Located on the downstream side of the polymer spinning path direction of the distribution plate, the distribution plate is composed of a lowermost layer distribution plate in which a plurality of island component discharge holes and a plurality of sea component discharge holes are formed. N (n is a natural number of 3 or more, the same applies hereinafter) island component discharge holes arranged on a virtual circumferential line C1 with a radius R1, and a virtual circumference C2 with a radius R2 centered on a virtual center O There are n sea component discharge holes arranged, n virtual group centers P on a virtual circumference C3 having a radius R3 centered on the virtual center O, and a radius R1 centered on the virtual group center P. N island component discharge holes arranged on the virtual circumference line C5 of the There are a plurality of hole groups composed of the n sea component discharge holes arranged on the virtual circumference C6 having the radius R2 with the imaginary group center P as the center, and satisfy the following expressions (1) and (2) And a composite base having the following conditions (3) and (4).
(1) R1 ≦ R2 · cos (180 / n [degree])
(2) R3 = 2 · R2
(3) C1, C5: n island component discharge holes equally divided at a central angle of 360 / n degrees C2, C6: n sea component discharge holes equally divided at a central angle of 360 / n degrees C3 : N virtual group centers are equally divided at a central angle of 360 / n degrees θ1: phase angle between discharge holes arranged at C1 and C2, C5 and C6 is 180 / n degrees θ2: discharge holes with C2 The phase angle between the virtual group centers of C3 is 0 degree (4) The sea component discharge hole is at the intersection of the line segment connecting the virtual center O and the virtual group center P, the virtual circumferential line C2, and the virtual circumferential line C6. Arrangement 2. The composite die according to claim 1, wherein the number of ejection holes n = 4 satisfies the formula (5).
(5) R1 ≦ R2 / 2 2. The composite die according to claim 1, wherein the number of discharge holes n = 6 satisfies the formula (6).
(6) R1 ≦ R2 · 3√3 / 8 The composite die according to any one of claims 1 to 3, wherein the same hole arrangement is provided even when the virtual group center P adjacent to the virtual center O is the virtual center O. 5. The composite base according to claim 1, wherein the flow path pressure loss in each flow path from the distribution plate to the island component discharge hole of the lowermost layer distribution plate is equal, and the lowermost layer distribution from the distribution plate. A method for producing a composite fiber, in which melt spinning is performed by a composite spinning machine using a composite base in which flow path pressure loss in each flow path to the sea component discharge hole of the plate is equal. A method for producing a composite fiber, in which melt spinning is performed with a composite spinning machine using the composite die according to any one of claims 1 to 4 at an island component polymer ratio of 50% or more.