Polyphenylene sulfide composite fiber and nonwoven fabric

Abstract

Provided are a composite fiber which consists primarily of resins comprising polyphenylene sulfide as their main constituents and which has both thermal dimensional stability and excellent thermal bondability, and a nonwoven fabric. The composite fiber consists primarily of component A and component B, the component A being a resin that includes polyphenylene sulfide as its main constituent, the component B being a resin that includes polyphenylene sulfide as its main constituent, having a higher melt flow rate than the component A, and forming at least part of the surface of the fiber.

1 . A polyphenylene sulfide composite fiber consisting primarily of component A and component B,
 the component A being a resin that comprises polyphenylene sulfide as its main constituent,   the component B being a resin that comprises polyphenylene sulfide as its main constituent, having a higher melt flow rate than the component A, and forming at least part of the surface of the fiber.   
     
     
         2 . The polyphenylene sulfide composite fiber according to  claim 1 , wherein at least part of the surface of the fiber has a lower crystallinity than the center of the cross section of the fiber when the crystallinity of the fiber surface is measured in the region from the fiber surface to 1 μm in the radially inward direction of the fiber. 
     
     
         3 . The polyphenylene sulfide composite fiber according to  claim 1  or  2 , wherein the melt flow rate of the component A (MFR (A)) and the melt flow rate of the component B (MFR (B)) satisfy the following formula:
   10 (g/10 min)≦MFR(B)−MFR(A)≦1000 (g/10 min).
 
 
     
     
         4 . The polyphenylene sulfide composite fiber according to  claim 1  or  2 , which is a core-sheath composite fiber comprising the component A as a core component and the component B as a sheath component. 
     
     
         5 . A nonwoven fabric made from the polyphenylene sulfide composite fiber according to  claim 1  or  2 . 
     
     
         6 . The nonwoven fabric according to  claim 5 , which is a spunbonded nonwoven fabric. 
     
     
         7 . The nonwoven fabric according to  claim 6 , which is produced by integrating the polyphenylene sulfide composite fiber by thermal bonding.