Conjugate fiber and multifilament

Abstract

A conjugate fiber includes two or more types of polymers, and having a fiber cross section in which a plurality of interfaces is formed, in which the conjugate fiber has a value, which is obtained by dividing a sum of lengths of interfaces between two types of the polymers by an area of the fiber cross section, of 0.0010 nm−1 or more, and each of the interfaces is continuous in a fiber axis direction.

1 - 11 . (canceled) 
     
     
         12 . A conjugate fiber comprising two or more polymers, and having a fiber cross section in which a plurality of interfaces is formed, wherein
 the conjugate fiber has a value obtained by dividing a sum of lengths of interfaces between the two polymers by an area of the fiber cross section, of 0.0010 nm −1  or more, and   each of the interfaces is continuous in a fiber axis direction.   
     
     
         13 . The conjugate fiber according to  claim 12 , wherein the value obtained by dividing the sum of the lengths of interfaces between the two types of the polymers by the area of the fiber cross section, is 0.0050 nm −1  or more. 
     
     
         14 . The conjugate fiber according to  claim 12 , wherein the fiber cross section comprises a multilayer laminated structure in which the two polymers are alternately laminated. 
     
     
         15 . The conjugate fiber according to  claim 14 , wherein at least one of the polymers has a variation (CV value) in layer thickness of 10% or more. 
     
     
         16 . The conjugate fiber according to  claim 14 , wherein at least one of the polymers has an average layer thickness of 1000 nm or less. 
     
     
         17 . A multifilament consisting of flat ultrafine fibers each comprising one polymer that remains by removing another polymer among the two polymers constituting the multilayer laminated structure from the conjugate fiber according to  claim 14 . 
     
     
         18 . The multifilament according to  claim 17 , wherein the flat ultrafine fibers each have a fiber cross section having a flat shape, a flatness, which is a value obtained by dividing a length of a major axis of the fiber cross section by a length of a minor axis of the fiber cross section, of 15 or more, and have an average thickness of 1000 nm or less. 
     
     
         19 . The multifilament according to  claim 17 , wherein the flat ultrafine fibers have a variation (CV value) in thickness of 10% or more. 
     
     
         20 . The multifilament according to  claim 17 , wherein the polymer constituting the flat ultrafine fibers comprises at least one polymer selected from the group consisting of polyester, polyamide, and polyolefin. 
     
     
         21 . The multifilament according to  claim 17 , wherein a functional substance is enclosed in a fiber bundle comprising the flat ultrafine fibers. 
     
     
         22 . A fiber product at least partially comprising the conjugate fiber according to  claim 12 . 
     
     
         23 . A fiber product at least partially comprising the multifilament according to  claim 17 .