Soft extensible nonwoven webs containing multicomponent fibers with high melt flow rates

Abstract

The present invention provides nonwoven webs comprising multicomponent fibers that enable the nonwoven web to possess high extensibility. The multicomponent fibers will comprise a first component comprising a polypropylene composition having a melt flow rate of from about 100 to about 2000 grams per 10 minutes and a second component comprising a polymer composition having a melt flow rate lower than the melt flow rate of the first component. The first component comprises at least about 10% of a surface of the multicomponent fiber.

1 . A nonwoven web comprising multicomponent fibers comprising: 
 a. a first component comprising a polypropylene having a melt flow rate of from about 100 to about 2000 grams per 10 minutes and    b. a second component comprising a polymer having a melt flow rate lower than the melt flow rate of the first component,    wherein the first component comprises at least about 10% of a surface of the multicomponent fiber.    
     
     
         2 . The nonwoven web according to  claim 1  wherein the ratio of the first component to the second component is from about 10:90 to about 90:10.  
     
     
         3 . The nonwoven web according to  claim 1  wherein the first component comprises at least about 50% of the surface of the multicomponent fiber.  
     
     
         4 . The nonwoven web according to  claim 1  wherein the first component is a sheath and the second component is a core.  
     
     
         5 . The nonwoven web according to  claim 1  wherein the first component comprises a polypropylene having a melt flow rate of from about 100 to about 1000 grams per 10 minutes.  
     
     
         6 . The nonwoven web according to  claim 1  wherein the first component comprises a polypropylene composition containing at least two different polypropylenes.  
     
     
         7 . The nonwoven web according to  claim 1  wherein the first component comprises a polypropylene composition containing a polypropylene and a polymer.  
     
     
         8 . The nonwoven web according to  claim 1  wherein the second component has a melt flow rate of from about 10 to about 80 grams per 10 minutes.  
     
     
         9 . The nonwoven web according to  claim 1  wherein the polymer of the second component is polypropylene.  
     
     
         10 . The nonwoven web according to  claim 1  wherein the polymer of the second component is a polymer composition.  
     
     
         11 . The nonwoven web according to  claim 1  wherein the nonwoven web has a basis weight of from about 5 to about 100 grams per square meter.  
     
     
         12 . The nonwoven web according to  claim 1  wherein the multicomponent fibers have a diameter of from about 5 to about 50 microns.  
     
     
         13 . The nonwoven web according to  claim 1  additionally comprising different fibers.  
     
     
         14 . The nonwoven web according to  claim 1  wherein the nonwoven web has a strain at peak load in at least one direction of greater than about 80 percent.  
     
     
         15 . The nonwoven web according to  claim 1  wherein the nonwoven web has an extension ratio of greater than about 1.  
     
     
         16 . The nonwoven web according to  claim 1  wherein the nonwoven web is produced by a spunbond process.  
     
     
         17 . A disposable article comprising the nonwoven web according to  claim 1 .  
     
     
         18 . The nonwoven web according to  claim 1  wherein the web is an article selected from the group consisting of a topsheet for feminine hygiene pad, diaper, and/or adult incontinence product, stretchable ears for diapers, cleansing wipes for a hard surface or the skin, and combinations thereof.  
     
     
         19 . A nonwoven web comprising multicomponent fibers comprising: 
 a. a first component comprising a polypropylene having a melt flow rate of from about 100 to about 1000 grams per 10 minutes and    b. a second component comprising a polymer having a melt flow rate of from about 10 to about 80 grams per 10 minutes,    wherein the first component comprises at least about 10% of a surface of the multicomponent fiber.    
     
     
         20 . A multicomponent fiber comprising: 
 a. a first component comprising a polypropylene having a melt flow rate of from about 100 to about 2000 grams per 10 minutes and    b. a second component comprising a polymer having a melt flow rate lower than the melt flow rate of the first component,    wherein the first component comprises at least about 10% of a surface of the multicomponent fiber.