Crimped fibers and nonwoven fabric

Abstract

The present invention relates to a crimped fiber including one component thereof containing a thermoplastic resin (A) and another component thereof containing a thermoplastic resin (B) and a thermoplastic resin (C), wherein a half-crystallization time at 25° C. of the thermoplastic resin (A) is shorter than a half-crystallization time at 25° C. of the thermoplastic resin (B), and a half-crystallization time at 25° C. of the thermoplastic resin (C) is longer than the half-crystallization time at 25° C. of the thermoplastic resin (B).

1 . A crimped fiber, comprising one component comprising a thermoplastic resin (A) and another component comprising a thermoplastic resin (B) and a thermoplastic resin (C), wherein
 a half-crystallization time at 25° C. of the thermoplastic resin (A) is shorter than a half-crystallization time at 25° C. of the thermoplastic resin (B), and a half-crystallization time at 25° C. of the thermoplastic resin (C) is longer than the half-crystallization time at 25° C. of the thermoplastic resin (B), and   the thermoplastic resin (A) is a polyethylene-based resin.   
     
     
         2 . The crimped fiber of  claim 1 , wherein the half-crystallization time at 25° C. of the thermoplastic resin (A) is 0.01 seconds or less. 
     
     
         3 . The crimped fiber of  claim 1 , wherein the half-crystallization time at 25° C. of the thermoplastic resin (B) is more than 0.01 seconds and 0.06 seconds or less. 
     
     
         4 . The crimped fiber of  claim 1 , wherein the half-crystallization time at 25° C. of the thermoplastic resin (C) is more than 0.06 seconds. 
     
     
         5 . The crimped fiber of  claim 1 , wherein a melt flow rate (MFR) of the thermoplastic resin (A) measured at a temperature of 190° C. and a load of 2.16 kg in conformity with JIS K7210 is 1 g/10 min or more and 70 g/10 min or less. 
     
     
         6 . The crimped fiber of  claim 1 , wherein a melt flow rate (MFR) of the thermoplastic resin (B) measured at a temperature of 230° C. and a load of 2.16 kg in conformity with JIS K7210 is 10 g/10 min or more and 500 g/10 min or less. 
     
     
         7 . The crimped fiber of  claim 1 , wherein a melt flow rate (MFR) of the thermoplastic resin (C) measured at a temperature of 230° C. and a load of 2.16 kg in conformity with JIS K7210 is 10 g/10 min or more and 5,000 g/10 min or less. 
     
     
         8 . The crimped fiber of  claim 1 , wherein a melting point (Tm-D) of the thermoplastic resin (A) defined as a peak top of a peak observed on the highest temperature side of a melting endothermic curve obtained by holding under a nitrogen atmosphere at −10° C. for 5 minutes and then increasing the temperature at a rate of 10° C./min by using a differential scanning calorimeter (DSC) is 90° C. or higher and 135° C. or lower. 
     
     
         9 . The crimped fiber of  claim 1 , wherein a melting point (Tm-D) of the thermoplastic resin (B) defined as a peak top of a peak observed on the highest temperature side of a melting endothermic curve obtained by holding under a nitrogen atmosphere at −10° C. for 5 minutes and then increasing the temperature at a rate of 10° C./min by using a differential scanning calorimeter (DSC) is 120° C. or higher and 200° C. or lower. 
     
     
         10 . The crimped fiber of  claim 1 , wherein a melting point (Tm-D) of the thermoplastic resin (C) defined as a peak top of a peak observed on the highest temperature side of a melting endothermic curve obtained by holding under a nitrogen atmosphere at −10° C. for 5 minutes and then increasing the temperature at a rate of 10° C./min by using a differential scanning calorimeter (DSC) is 50° C. or higher and 100° C. or lower. 
     
     
         11 . (canceled) 
     
     
         12 . The crimped fiber of  claim 1 , wherein the thermoplastic resin (B) is a polypropylene-based resin. 
     
     
         13 . The crimped fiber of  claim 12 , wherein the thermoplastic resin (B) is a propylene homopolymer. 
     
     
         14 . The crimped fiber of  claim 1 , wherein in the thermoplastic resin (C), a melting endotherm (AH-D) obtained from a melting endothermic curve obtained by holding a sample under a nitrogen atmosphere at −10° C. for 5 minutes and then increasing the temperature at a rate of 10° C./min by using a differential scanning calorimeter (DSC) is 0 J/g or more and 80 J/g or less. 
     
     
         15 . The crimped fiber of  claim 1 , wherein a molecular weight distribution (Mw/Mn) of the thermoplastic resin (C) is less than 3.0. 
     
     
         16 . The crimped fiber of  claim 1 , wherein a content of the thermoplastic resin (C) based on a sum total of the thermoplastic resin (A), the thermoplastic resin (B), and the thermoplastic resin (C) is 1% or more and 50% or less. 
     
     
         17 . The crimped fiber of  claim 1 , wherein the crimped fiber is a side-by-side type fiber. 
     
     
         18 . The crimped fiber of  claim 17 , wherein a resin constituting the inside of a crimp in the side-by-side type fiber comprises the thermoplastic resin (A). 
     
     
         19 . (canceled) 
     
     
         20 . The crimped fiber of  claim 17 , wherein a resin constituting the inside of a crimp in the side-by-side type fiber comprises the thermoplastic resin (B). 
     
     
         21 . (canceled) 
     
     
         22 . A nonwoven fabric comprising the crimped fiber of  claim 1 . 
     
     
         23 . A multilayered nonwoven fabric comprising a laminate of two or more layers, wherein at least one of the two or more layers is the nonwoven fabric of  claim 22 .