Articles containing nanofibers for use as barriers

Abstract

The present invention is directed to articles comprising nanofibers. Preferred articles include diapers, training pants, adult incontinence pads, catamenials products such as feminine care pads and pantiliners, tampons, personal cleansing articles, personal care articles, and personal care wipes including baby wipes, facial wipes, body wipes, and feminine wipes. The nanofiber webs can be used as a barrier, wipe, absorbent material, and other uses. The nanofibers, having a diameter of less than 1 micron, must comprise a significant number of the fibers in at least one nanofiber layer of the nonwoven web. The nonwoven web may have a hydrohead to basis weight ratio of greater than about 10 mbar/gsm. The nanofibers may be produced from a melt film fibrillation process.

What is claimed is: 
     
         1 . A nonwoven web comprising:
 a nanofiber layer comprising at least 50% nanofibers with a diameter of less than 1 micron,   wherein the nonwoven web has an air permeability greater than 1 m/min and a hydrohead;   and wherein a product of the hydrohead and the air permeability divided by the basis weight is greater than about 500 mbar*meter per minute per gsm.   
     
     
         2 . The nonwoven web of  claim 1  wherein said nanofiber layer having a basis weight of less than about 25 gsm. 
     
     
         3 . The nonwoven web of  claim 1  wherein the nanofiber layer comprises a mean pore diameter of less than about 15 microns. 
     
     
         4 . The nonwoven web of  claim 1  wherein the nanofiber layer comprises at least 90% nanofibers. 
     
     
         5 . The nonwoven web of  claim 1  wherein the nanofibers are comprised of a composition selected from the group consisting of at least one of: polypropylene and polyethylene. 
     
     
         6 . The nonwoven web of  claim 1  further comprising a basis weight of from about 5 gsm to about 100 gsm. 
     
     
         7 . The nonwoven web of  claim 1  further comprising a layer of spunbond fibers. 
     
     
         8 . An article comprising the nonwoven web of  claim 1  wherein the article is selected from the group consisting of diapers, training pants, adult incontinence pads, catamenials products such as feminine care pads and pantiliners, tampons, personal cleansing articles, personal care articles, and personal care wipes such as baby wipes, facial wipes, body wipes and feminine wipes, and combinations thereof. 
     
     
         9 . A nonwoven web comprising:
 a nanofiber layer having at least 50% nanofibers with a diameter of less than 1 micron,   wherein the nonwoven web has a hydrohead to nanofiber layer basis weight ratio of at least 10 mbar/gsm.   
     
     
         10 . The nonwoven web of  claim 9  further comprising an air permeability greater than 1 m/min. 
     
     
         11 . The nonwoven web of  claim 9  wherein said nanofiber layer comprises a basis weight of less than about 25 gsm. 
     
     
         12 . The nonwoven web of  claim 9  wherein the nanofiber layer comprises a mean pore diameter of less than about 15 microns. 
     
     
         13 . The nonwoven web of  claim 9  wherein the nanofiber layer has a basis weight of from about 0.5 gsm to about 3 gsm and the ratio is greater than about 20 mbar/gsm. 
     
     
         14 . The nonwoven web of  claim 9  wherein the nanofiber layer has a basis weight of from about 3 gsm to about 15 gsm and the ratio is greater than about 12 gsm. 
     
     
         15 . The nonwoven web of  claim 9  wherein the ratio is greater than about 15 mbar/gsm. 
     
     
         16 . An article comprising the nonwoven web of  claim 9  wherein the article from the group consisting of diapers, training pants, adult incontinence pads, catamenials products such as feminine care pads and pantiliners, tampons, personal cleansing articles, personal care articles, and personal care wipes such as baby wipes, facial wipes, body wipes and feminine wipes, and combinations thereof. 
     
     
         17 . An article comprising:
 an outer layer, an inner layer and an absorbent core located between the outer layer and the inner layer; and   a nonwoven;   wherein the nonwoven comprises a nanofiber layer having at least 50% nanofibers with a diameter of less than 1 micron, and   wherein the nonwoven web has a hydrohead greater than 10 mbar and air permeability greater than 1 m/min, wherein a product of the hydrohead and the air permeability divided by the basis weight is greater than about 500 mbar*meter per minute per gsm.   
     
     
         18 . The article of  claim 17  wherein the nonwoven is disposed between the absorbent core and the outer layer. 
     
     
         19 . The article of  claim 17  wherein the nonwoven is disposed between the absorbent core and the inner layer. 
     
     
         20 . The article of  claim 17  wherein the nonwoven comprises a basis weight ranging from about 5 gsm to about 100 gsm.