Composite spinneret, multicomponent fiber, and method of producing multicomponent fiber

Abstract

A multicomponent fiber includes a sea component and an island component, wherein in cross-section observation of the multicomponent fiber, the multicomponent fiber includes a sea-island region with the plurality of island components arranged in the sea component; and one or more sea component regions formed only of the sea component between the sea-island region, and a width (H) of the sea component region is larger than a maximum value of a distance (W) between island components existing in the sea-island region and neighboring each other.

1 .- 21 . (canceled) 
     
     
         22 . A multicomponent fiber comprising a sea component and an island component, wherein, in cross-section observation of the multicomponent fiber, the multicomponent fiber comprises:
 a sea-island region with the plurality of island components arranged in the sea component; and   one or more sea component regions formed only of the sea component between the sea-island region, and   a width (H) of the sea component region is larger than a maximum value of a distance (W) between island components existing in the sea-island region and neighboring each other.   
     
     
         23 . The multicomponent fiber according to  claim 22 , wherein the sea component region extends inwardly from a surface layer of the multicomponent fiber. 
     
     
         24 . The multicomponent fiber according to  claim 23 , wherein the island components in the sea-island region are regularly arranged. 
     
     
         25 . The multicomponent fiber according to  claim 22 , wherein in cross-section observation of the sea-island multicomponent fiber, a ratio (L/D) of a length (L) of the sea component region to a diameter (D) of the multicomponent fiber is 0.25 or more. 
     
     
         26 . The multicomponent fiber according to  claim 22 , wherein in cross-section observation of the sea-island multicomponent fiber, the width (H) of the sea component region is larger than the maximum diameter (d) of the island component. 
     
     
         27 . The multicomponent fiber according to  claim 26 , wherein in cross-section observation, there exists at least one sea component region where the width (H) of the sea component region is larger than the maximum diameter (d) of the island component, and the length (L 1 ) of the sea component region is equal to or larger than ¼ of the diameter (D) of the multicomponent fiber. 
     
     
         28 . The multicomponent fiber according to  claim 27 , wherein in cross-section observation, the cross-section area (Ac) of the multicomponent fiber and the sum of areas (As) of sea component regions satisfy:
   0.05≦ As/Ac≦ 0.35.
   
     
     
         29 . The multicomponent fiber according to  claim 22 , wherein in cross-section observation, the sea component region is cruciform. 
     
     
         30 . A composite spinneret that discharges a composite polymer composed of an island polymer and a sea polymer, the composite spinneret satisfying (1) and (2):
 (1) the composite spinneret comprises:   a distribution device that distributes polymers;   a nozzle plate situated on a downstream side of the distribution device in a polymer spinning passage direction and which has a plurality of sea discharge holes, and at least one kind of discharge holes selected from a plurality of island discharge holes and a plurality of composite polymer discharge holes; and   a flow contraction plate situated on the downstream side of the nozzle plate in the polymer spinning passage direction and which has a introducting hole communicating with discharge holes in a combination of discharge holes selected from the combinations of:
 the sea discharge holes and the island discharge holes; 
 the sea discharge holes and the composite polymer discharge holes; and 
 the sea discharge holes, the island discharge holes and the composite polymer discharge holes; and 
   (2) the nozzle plate has a nozzle hole collection including a plurality of discharge holes, and the nozzle hole collection includes a sea component region forming hole group including the sea discharge holes, and at least one sea-island discharge hole group including any of (i) to (v):
 (i) the sea discharge holes and the island discharge holes; 
 (ii) the composite polymer discharge holes; 
 (iii) the sea discharge holes and the composite polymer discharge holes; 
 (iv) the island discharge holes and the composite polymer discharge holes; and 
 (v) the sea discharge holes, the island discharge holes and the composite polymer discharge holes. 
   
     
     
         31 . The composite spinneret according to  claim 30 , wherein the composite spinneret further satisfies (3):
 (3) the sea component region forming hole group is continuously arranged inwardly from an outer periphery of the nozzle hole collection with a part of the sea-island discharge hole group held between both sides.   
     
     
         32 . The composite spinneret according to  claim 30 , wherein the distribution device has a plurality of composite polymer discharge holes, and comprises:
 a plurality of pipes that supply the island polymer to the polymer discharge hole, the pipes arranged at positions corresponding to the composite polymer discharge holes of the nozzle plate on a one-to-one basis;   a sea polymer introduction channel that supplies the sea polymer; and   a sea polymer distribution chamber provided to communicate with the sea polymer introduction channel and surround the plurality of pipes, and   the composite polymer discharge hole of the nozzle plate communicates with the pipe and the sea polymer distribution chamber.   
     
     
         33 . The composite spinneret according to  claim 31 , wherein the sea component region forming hole group is continuously arranged from an outer periphery of a circumscribed circle of the nozzle hole collection having a radius of R to the inside of a circle having a radius of 0.5R or less from the center with the sea component region forming hole group held between both sides of the sea-island discharge hole group. 
     
     
         34 . The composite spinneret according to  claim 30 , wherein the composite spinneret is used for production of a multicomponent fiber including a sea component and an island component, wherein, in cross-section observation of the multicomponent fiber, the multicomponent fiber includes:
 a sea-island region with the plurality of island components arranged in the sea component; and   one or more sea component regions formed only of the sea component between the sea-island region, and   width (H) of the sea component region is larger than the maximum value of distance (W) between island components existing in the sea-island region and neighboring each other.   
     
     
         35 . A multicomponent fiber including a sea component and an island component, wherein, in cross-section observation of the multicomponent fiber, the multicomponent fiber includes:
 a sea-island region with a plurality of island components arranged in the sea component; and   more than one sea component region formed only of the sea component between the sea-island region, and   a width (H) of the sea component region is larger than a maximum value of a distance (W) between island components existing in the sea-island region and neighboring each other.   
     
     
         36 . The multicomponent fiber according to  claim 35 , wherein the sea component region extends inwardly from a surface layer of the multicomponent fiber. 
     
     
         37 . The multicomponent fiber according to  claim 36 , wherein the island components in the sea-island region are regularly arranged. 
     
     
         38 . The multicomponent fiber according to  claim 35 , wherein, in cross-section observation of the sea-island multicomponent fiber, a ratio (L/D) of a length (L) of the sea component region to a diameter (D) of the multicomponent fiber is 0.25 or more. 
     
     
         39 . The multicomponent fiber according to  claim 35 , wherein, in cross-section observation of the sea-island multicomponent fiber, the width (H) of the sea component region is larger than the maximum diameter (d) of the island component. 
     
     
         40 . The multicomponent fiber according to  claim 39 , wherein, in cross-section observation, there exists at least one sea component region where the width (H) of the sea component region is larger than the maximum diameter (d) of the island component, and a length (L 1 ) of the sea component region is equal to or larger than ¼ of the diameter (D) of the multicomponent fiber. 
     
     
         41 . The multicomponent fiber according to  claim 40 , wherein, in cross-section observation, a cross-section area (Ac) of the multicomponent fiber and a sum of areas (As) of sea component regions satisfy:
   0.05≦ As/Ac≦ 0.35.