Breathable diaper backsheet

Abstract

A breathable thermoplastic polymer film may be produced and adapted for use as a breathable diaper backsheet. The film may comprise a blend of LLDPE, mLLDPE and calcium carbonate, and may have improved tear strength and melt strength such that instances of tears or break offs during the machine direction orientation portion of the production process are significantly reduced or eliminated. In addition, the film may have sufficient tear strength to permit omission of CDI processing needed to strengthen weaker prior art films. In this regard, undesired streaking of colors or printed aspects of the film may be reduced or avoided completely.

What is claimed is: 
     
         1 . An absorbent article comprising a film, wherein the film comprises:
 a blend of a first linear low-density polyethylene and a second linear low-density polyethylene, wherein the first linear low-density polyethylene and the second linear low-density polyethylene each have a melt index of about 0.3 g/10 min to about 0.5 g/10 min; and   a breathability agent.   
     
     
         2 . The absorbent article of  claim 1 , wherein the first linear low-density polyethylene is super hexene linear low-density polyethylene and the second linear low-density polyethylene is metallocene-catalyzed linear low-density polyethylene. 
     
     
         3 . The absorbent article of  claim 2 , wherein the second linear low-density polyethylene is bimodal metallocene-catalyzed linear low-density polyethylene. 
     
     
         4 . The absorbent article of  claim 1 , wherein the film comprises a greater amount of the first linear low-density polyethylene than the second linear low-density polyethylene. 
     
     
         5 . The absorbent article of  claim 4 , wherein a ratio of the first linear low-density polyethylene to the second linear low-density polyethylene is about 3:2. 
     
     
         6 . The absorbent article of  claim 1 , wherein the film has a melt index of less than about 1.10 g/10 min. 
     
     
         7 . The absorbent article of  claim 1 , wherein the film has a melt index of less than about 0.7 g/10 min. 
     
     
         8 . The absorbent article of  claim 1 , wherein the breathability agent comprises calcium carbonate. 
     
     
         9 . The absorbent article of  claim 1 , wherein the breathability agent is present in an amount of at least about 60 percent by weight of the total weight of the film. 
     
     
         10 . An absorbent article comprising a film, the film having at least one layer comprising:
 a blend of a linear low-density polyethylene and a metallocene-catalyzed linear low-density polyethylene, wherein the linear low-density polyethylene and the metallocene-catalyzed linear low-density polyethylene each have a melt index of about 0.1 g/10 min to about 0.5 g/10 min and the linear low-density polyethylene is present in the blend in a greater amount than the metallocene-catalyzed linear low-density polyethylene; and   a breathability agent comprising calcium carbonate.   
     
     
         11 . The absorbent article of  claim 10 , wherein the linear low-density polyethylene is super hexene linear low-density polyethylene. 
     
     
         12 . The absorbent article of  claim 10 , wherein the metallocene-catalyzed low-density polyethylene is bimodal metallocene-catalyzed linear low-density polyethylene. 
     
     
         13 . The absorbent article of  claim 10 , wherein the breathability agent is present in an amount of at least about 70 percent by weight of the total weight of the film. 
     
     
         14 . The absorbent article of  claim 10 , wherein the linear low-density polyethylene and the metallocene-catalyzed linear low-density polyethylene each have a melt index of about 0.3 g/10 min to about 0.5 g/10 min. 
     
     
         15 . A diaper backsheet comprising a film, the film having a first layer, a second layer, and a third layer, wherein at least one of the layers comprises:
 a blend of a linear low-density polyethylene and a metallocene-catalyzed linear low-density polyethylene, wherein the linear low-density polyethylene and the metallocene-catalyzed linear low-density polyethylene each have a melt index of about 0.3 g/10 min to about 0.5 g/10 min and the linear low-density polyethylene is present in the blend in a greater amount than the metallocene-catalyzed linear low-density polyethylene; and   a breathability agent comprising calcium carbonate.   
     
     
         16 . The diaper backsheet of  claim 15 , wherein the blend of the linear low-density polyethylene and the metallocene-catalyzed linear low-density polyethylene is present in each of the first layer, the second layer, and the third layer. 
     
     
         17 . The diaper backsheet of  claim 15 , wherein the linear low-density polyethylene is super hexene linear low-density polyethylene and the metallocene-catalyzed low-density polyethylene is bimodal metallocene-catalyzed linear low-density polyethylene. 
     
     
         18 . The diaper backsheet of  claim 15 , wherein a ratio of the linear low-density polyethylene to the metallocene-catalyzed linear low-density polyethylene is about 3:2. 
     
     
         19 . The diaper backsheet of  claim 15 , wherein the breathability agent is present in an amount of at least about 60 percent by weight of the total weight of the film. 
     
     
         20 . The diaper backsheet of  claim 15 , wherein the film has a moisture vapor transmission rate of at least 2,000 gsm/day.