Crimped composite fiber, and fibrous mass and testile product using the same

Abstract

A crimped conjugate fiber of the present invention is a conjugate fiber containing a first component and a second component, the first component containing polybutene-1 and linear low density polyethylene, the linear low density polyethylene content being 2 to 25 mass %, the second component 2 containing a polymer having a melting peak temperature at least 20° C. higher than the melting peak temperature of polybutene-1 or a polymer having a melting initiation temperature of 120° C. or higher, when viewed from a fiber cross-section, the first component occupies at least 20% of the surface of the conjugate fiber 10 and the centroid position of the second component not overlapping the centroid position of the conjugate fiber, the conjugate fiber is an actualized crimping conjugate fiber in which three-dimensional crimps have been developed or a latently crimpable conjugate fiber in which three-dimensional crimps are developed by heating. Accordingly, a crimped conjugate fiber having high elasticity, a high level of bulk recovery properties, and high durability against repetitive compression as well as high elasticity, a high level of bulk recovery properties, and high durability when used at high temperatures, and a fiber assembly that uses the crimped conjugate fiber are provided.

1 . A crimped conjugate fiber comprising a first component and a second component,
 the first component comprising polybutene-1 and linear low density polyethylene,   the content of the linear low density polyethylene in the first component is 2 to 25 mass %,   the second component comprising a polymer having a melting peak temperature at least 20° C. higher than a melting peak temperature of polybutene-1 or a polymer having a melting initiation temperature of 120° C. or higher,   when viewed from a fiber cross-section, the first component occupies at least 20% of a surface of the conjugate fiber, and a centroid position of the second component not overlapping a centroid position of the conjugate fiber, and   the conjugate fiber is an actualized crimping conjugate fiber in which three-dimensional crimps have been developed or a latently crimpable conjugate fiber in which three-dimensional crimps are developed by heating.   
     
     
         2 . The crimped conjugate fiber according to  claim 1 , wherein the three-dimensional crimps are at least one selected from wavy crimps and spiral crimps. 
     
     
         3 . The crimped conjugate fiber according to  claim 1 , wherein the linear low density polyethylene is a copolymer polymerized with α-olefin using a metallocene catalyst. 
     
     
         4 . The crimped conjugate fiber according to  claim 1 , wherein the linear low density polyethylene has a melting peak temperature obtained from DSC measured according to JIS-K-7121 of 80 to 130° C. and a density measured according to JIS-K-7112 of 0.88 to 0.92 g/cm 3 . 
     
     
         5 . The crimped conjugate fiber according to  claim 1 , wherein the linear low density polyethylene has a flexural modulus measured according to JIS-K-7171 of 20 to 300 MPa. 
     
     
         6 . The crimped conjugate fiber according to  claim 1 , wherein the polymer having a melting peak temperature at least 20° C. higher than a melting peak temperature of polybutene-1 or the polymer having a melting initiation temperature of 120° C. or higher contained in the second component is a polyolefin-based polymer. 
     
     
         7 . The crimped conjugate fiber according to  claim 6 , wherein the polyolefin-based polymer contained in the second component is homopolypropylene, and the homopolypropylene is contained in the second component in a proportion of 75 to 100 mass %, when the entire second component being 100 mass %. 
     
     
         8 . The crimped conjugate fiber according to  claim 1 , wherein the polymer having a melting peak temperature at least 20° C. higher than a melting peak temperature of polybutene-1 or the polymer having a melting initiation temperature of 120° C. or higher contained in the second component is a polyester-based polymer. 
     
     
         9 . A fiber assembly comprising a crimped conjugate fiber in a proportion of 30 mass % or greater,
 the crimped conjugate fiber comprising a first component and a second component,   the first component comprising polybutene-1 and linear low density polyethylene,   the content of the linear low density polyethylene in the first component is 2 to 25 mass %,   the second component comprising a polymer having a melting peak temperature at least 20° C. higher than a melting peak temperature of polybutene-1 or a polymer having a melting initiation temperature of 120° C. or higher,   when viewed from a fiber cross-section, the first component occupies at least 20% of a surface of the conjugate fiber, and a centroid position of the second component not overlapping a centroid position of the conjugate fiber, and   the conjugate fiber is an actualized crimping conjugate fiber in which three-dimensional crimps have been developed or a latently crimpable conjugate fiber in which three-dimensional crimps are developed by heating.   
     
     
         10 . The fiber assembly according to  claim 9 , comprising, in addition to the crimped conjugate fiber, at least one fiber selected from synthetic fibers, chemical fibers, natural fibers, and inorganic fibers. 
     
     
         11 . A fiber product at least partially contains the fiber assembly of  claim 9  and formed into hard stuffing, bedding, a vehicle seat, a chair, a shoulder pad, a brassiere pad, a cloth, a hygienic material, a packaging material, a wet wipe, a filter, a sponge-like porous wiping material, a sheet-like wiping material, or wadding.