Bicomponent filaments

Abstract

A bicomponent filament comprising a first region comprising an ethylene-based polymer; a second region comprising a propylene-based polymer; and a compatibilizer comprising a crystalline block composite having (1) a crystalline ethylene-based polymer (2) a crystalline alpha-olefin-based polymer, and (3) a block copolymer having a crystalline ethylene block and a crystalline alpha-olefin block, wherein the crystalline ethylene block is essentially the same composition as the crystalline ethylene-based polymer and the crystalline alpha-olefin block is essentially the same composition as the crystalline alpha-olefin-based polymer; wherein the compatibilizer is present in at least one of the first region or the second region.

1 . A bicomponent filament comprising:
 a first region comprising an ethylene-based polymer;   a second region comprising a propylene-based polymer; and   a compatibilizer comprising a crystalline block composite having (1) a crystalline ethylene-based polymer (2) a crystalline alpha-olefin-based polymer, and (3) a block copolymer having a crystalline ethylene block and a crystalline alpha-olefin block, wherein the crystalline ethylene block is essentially the same composition as the crystalline ethylene-based polymer and the crystalline alpha-olefin block is essentially the same composition as the crystalline alpha-olefin-based polymer;   wherein the compatibilizer is present in at least one of the first region or the second region.   
     
     
         2 . The bicomponent filament of  claim 1 , wherein the crystalline ethylene-based polymer has an ethylene content of greater than 90 mol. %. 
     
     
         3 . The bicomponent filament of  claim 1 , wherein the crystalline alpha-olefin-based polymer has greater than 90 mol. % units derived from propylene and a comonomer selected from the group consisting of C 4 -C 10  alpha-olefins. 
     
     
         4 . The bicomponent filament of  claim 1 , wherein the ethylene-based polymer has a density of 0.920 to 0.965 g/cc and a melt index, I 2 , of 0.5 to 150 g/10 minutes determined according to ASTM D1238 at 190° C. and 2.16 kg. 
     
     
         5 . The bicomponent filament of  claim 1 , wherein the compatibilizer is present only in the first region in an amount of from 1 wt. % to less than 50 wt. %, based on the total weight of polymers present in the first region. 
     
     
         6 . The bicomponent filament of  claim 1 , wherein the compatibilizer is present only in the second region in an amount of from 1 wt. % to less than 50 wt. %, based on the total weight of polymers present in the second region. 
     
     
         7 . The bicomponent filament of  claim 1 , wherein the compatibilizer is present in the first region and in the second region in an amount of from 1 wt. % to less than 50 wt. %, based on the total weight of polymers present in the first region and the second region. 
     
     
         8 . The bicomponent filament of  claim 1 , wherein the first region and the second region are arranged in the form of a sheath/core, tipped tri-lobal fibers, segmented cross, side-by-side, conjugate, islands in the sea or a segmented pie. 
     
     
         9 . The bicomponent filament of  claim 1 , wherein the first region is a sheath of the bicomponent filament and the second region is a core of the bicomponent filament. 
     
     
         10 . The bicomponent filament of  claim 9 , wherein the core to sheath weight ratio is 50:50 to 90:10. 
     
     
         11 . A method of manufacturing a bicomponent filament, the method comprising:
 blending a composition comprising an ethylene-based polymer, a propylene-based polymer, and a compatibilizer, wherein the compatibilizer comprises a crystalline block composite having (1) a crystalline ethylene-based polymer (2) a crystalline alpha-olefin based polymer, and (3) a block copolymer having a crystalline ethylene block and a crystalline alpha-olefin block, wherein the crystalline ethylene block is essentially the same composition as the crystalline ethylene-based polymer and the crystalline alpha-olefin block is essentially the same composition as the crystalline alpha-olefin based polymer; and   extruding the composition to form a bicomponent filament;   wherein the bicomponent filament comprises
 a first region comprising the ethylene-based polymer; 
 a second region comprising the propylene-based polymer; and the compatibilizer is present in at least one of the first region or the second region. 
   
     
     
         12 . A nonwoven fabric formed from the bicomponent filament of  claim 1 . 
     
     
         13 . A method of manufacturing a nonwoven fabric, the method comprising:
 providing two or more bicomponent filaments, each bicomponent filament comprising   a first region comprising an ethylene-based polymer;   a second region comprising a propylene-based polymer; and   a compatibilizer comprising a crystalline block composite having (1) a crystalline ethylene-based polymer (2) a crystalline alpha-olefin-based polymer, and (3) a block copolymer having a crystalline ethylene block and a crystalline alpha-olefin block, wherein the crystalline ethylene block is essentially the same composition as the crystalline ethylene-based polymer and the crystalline alpha-olefin block is essentially the same composition as the crystalline alpha-olefin-based polymer; wherein the compatibilizer is present in at least one of the first region or the second region; and   bonding the two or more bicomponent filaments to each other to form a nonwoven fabric.