Elastic Bicomponent Fiber Having Unique Handfeel

Abstract

An elastomeric bicomponent fiber, including at least one sheath and a core, with non-blocking properties and a garment-like feel is provided. The core includes an elastomer and a secondary amide, and the sheath includes a non-elastomeric polyethylene. Further, the sheath can be present as a small portion of the total elastomeric composition, and the secondary amide can be present as a small portion of the core, while forming a bicomponent fiber with non-blocking properties and a garment-like feel.

What is claimed: 
     
         1 . An elastomeric bicomponent fiber comprising:
 a core comprising a polypropylene based elastomer and a secondary amide; and   at least one sheath;   wherein the at least one sheath comprises less than 50 wt. % of the total weight of the bicomponent fiber.   
     
     
         2 . The elastomeric bicomponent fiber of  claim 1 , wherein the polypropylene based elastomer comprises an ethylene copolymer, α-olefin copolymer, or a combination thereof. 
     
     
         3 . The elastomeric bicomponent fiber of  claim 1 , wherein the sheath comprises a non-elastomeric polymer. 
     
     
         4 . The elastomeric bicomponent fiber of  claim 1 , wherein the sheath comprises a polyethylene polymer. 
     
     
         5 . The elastomeric bicomponent fiber of  claim 1 , wherein the secondary amide is present in the core in an amount of about 0.1% to about 10% by weight based upon the weight of the core. 
     
     
         6 . The elastomeric bicomponent fiber of  claim 1 , wherein the secondary amide is present in the core in an amount of about 0.25% to about 5% by weight based upon the weight of the core. 
     
     
         7 . The elastomeric bicomponent fiber of  claim 1 , wherein the secondary amide is a fatty acid amide. 
     
     
         8 . The elastomeric bicomponent fiber of  claim 1 , the secondary amide having the structure of one of Formulas (I)-(III): 
       
         
           
           
               
               
           
         
         wherein, 
         R 14 , R 15 , R 16 , and R 18  are independently selected from C 7 -C 27  alkyl groups and C 7 -C 27  alkenyl groups; and 
         R 17  is selected from C 8 -C 28  alkyl groups and C 8 -C 28  alkenyl groups. 
       
     
     
         9 . The elastomeric bicomponent fiber of  claim 8 , the secondary amide having the structure of Formula (I) where R 14  is —CH 2 (CH 2 ) 10 CH═CH(CH 2 ) 7 CH 3  and R 15  is —CH 2 (CH 2 ) 15 CH 3 , or where R 15  is —CH 2 (CH 2 ) 6 CH═CH(CH 2 ) 7 CH 3  and R 15  is —CH 2 (CH 2 ) 13 CH 3 . 
     
     
         10 . The elastomeric bicomponent fiber of  claim 1 , wherein the polypropylene based elastomer comprises a propylene/ethylene copolymer. 
     
     
         11 . The elastomeric bicomponent fiber of  claim 1 , wherein the core contains a second elastomer. 
     
     
         12 . The elastomeric bicomponent fiber of  claim 1 , wherein pigment particles are present in the at least one of the sheath and the core in an amount of about 0.1% to about 5% by weight based upon the weight of the sheath or the core. 
     
     
         13 . The elastomeric bicomponent fiber of  claim 1 , wherein the at least one sheath comprises 40 wt. % or less of the total weight of the bicomponent fiber. 
     
     
         14 . A spunbond nonwoven web comprising
 elastomeric bicomponent fibers according to  claim 1 .   
     
     
         15 . The spunbond nonwoven web of  claim 14 , wherein the nonwoven web is post-bonded. 
     
     
         16 . The spunbond nonwoven web of  claim 14 , wherein the nonwoven web is apertured. 
     
     
         17 . The spunbond nonwoven web of  claim 14 , wherein the nonwoven web exhibits a cup crush bending stiffness of about 20 grams-force (gf) or less based upon a nonwoven web having a basis weight of about 48 grams per square meter (gsm) or a normalized cup crush bending stiffness of about 2.1 gf/gsm or less. 
     
     
         18 . An elastomeric laminate comprising a spunbond nonwoven web facing and a backing, the spunbond nonwoven web comprising elastomeric bicomponent fibers, wherein the elastomeric bicomponent fibers comprise a core comprising a polypropylene based elastomer and a secondary amide; and
 at least one sheath;   wherein the at least one sheath comprises less than 50 wt. % of the total weight of the bicomponent fiber.   
     
     
         19 . The elastomeric laminate of  claim 18 , wherein the backing comprises an elastic film. 
     
     
         20 . An absorbent article formed from the nonwoven web of  claim 14 .