Absorbent garments with microporous films having zoned breathability

Abstract

Breathable microporous films are provided having controlled regional breathability with thick high WVTR regions and thinner low WVTR regions. The zoned breathable microporous films can be made by selectively applying heat and pressure to the microporous film such as by feeding a microporous film through a pair of heated nip rollers with one of the rolls having a raised surface area.

We claim:  
     
       1. A disposable, breathable absorbent garment defining an initial expanded shape having longitudinal and transverse axes, a front waist region, a back waist region, said front waist region and said back waist region being generally oppositely disposed on said longitudinal axis and a crotch region disposed between said front waist region and said back waist region and comprising: 
       a breathable film backing member comprising:  
       a first microporous region having a WVTR of at least 800 g/m 2 /24 hours;  
       a second region having a WVTR less than said first region wherein the  
       WVTR of said second region is at least 15% less than said WVTR of said first region;  
       a aqueous liquid pervious body-side liner joined to said backing member approximate a periphery of said joined body-side liner and said backing member;  
       a generally rectangular absorbent pad, having a front end edge, a back end edge and a pair of opposing side end edges, positioned between said body-side liner and said backing member in board of the periphery of said joined body-side liner and backing member; and,  
       leg elastics aligned along longitudinally extending margins of said periphery, rendering said garment elastically contractible and body-conforming adjacent the crotch of a wearer.  
     
     
       2. The garment of claim  1 , wherein said backing member is a thermoplastic polymer. 
     
     
       3. The garment of claim  1 , wherein said second region of said breathable film backing member is adjacent said absorbent pad. 
     
     
       4. The garment of claim  3 , wherein said backing member is a thermoplastic polymer. 
     
     
       5. The garment of claim  1 , wherein said first region of said breathable film backing member is disposed in said front waist region of said garment. 
     
     
       6. The garment of claim  5 , wherein said backing member is a thermoplastic polymer. 
     
     
       7. The garment of claim  1 , wherein said first region of said breathable film backing member is disposed in said back waist region of said garment. 
     
     
       8. The garment of claim  7 , wherein said backing member is a thermoplastic polymer. 
     
     
       9. The garment of claim  1 , wherein said first region of said breathable film backing member is disposed in said front waist region and said back waist region of said garment. 
     
     
       10. The garment of claim  3 , wherein said backing member is a thermoplastic polymer. 
     
     
       11. The garment of claims  2 , wherein said second region of said backing member has a minimum dimension of 3 cm by 3 cm. 
     
     
       12. The garment of claims  3 , wherein said second region of said backing member has a minimum dimension of 5 cm by 5 cm. 
     
     
       13. The garment of claim  2 , wherein said thermoplastic polymer is a polyolefin polymer. 
     
     
       14. The garment of claim  4 , wherein said thermoplastic polymer is a polyolefin polymer. 
     
     
       15. The garment of claim  1 , wherein said first region has a WVTR in excess of 2500 g/m 2 /24 hours and said second region has a WVTR less than 1500 g/m 2 /24 hours and further wherein said second region comprises from about 5% to about 75% of the area of said backing member. 
     
     
       16. The garment of claim  2 , wherein said second region has a WVTR at least about 25% less than the WVTR of said first region and wherein each of said first and second regions have a basis weight less than about 35 g/m 2 . 
     
     
       17. The garment of claim  16 , wherein said first region has a thickness less than about 95% of the thickness of said second region and said second region comprises from about 5% to about 75% of the area of said backing member. 
     
     
       18. The garment of claim  2 , wherein said second region has a WVTR at least 50% less than the WVTR of said first region and wherein each of said first and second regions have a basis weight less than about 35 g/m 2 . 
     
     
       19. The garment of claim  18 , wherein said first region is less than 90% of the thickness of said second region and wherein the basis weight of said first and second regions are substantially similar. 
     
     
       20. The garment of claim  2 , wherein said second region has a WVTR at least about 75% less than the WVTR of said first region and wherein each of said first and second regions have a basis weight less than about 35 g/m 2 . 
     
     
       21. The garment of claim  1 , further comprising a third region, said third region having a WVTR intermediate to the WVTR of said first region and the WVTR of said second region and wherein said second region comprises from about 5% to about 75% of the area of said backing member. 
     
     
       22. The garment of claim  18 , further comprising a third region, said third region having a WVTR and thickness intermediate to the WVTR and thickness of said first region and said second region and wherein said third region is contiguous with said first and second regions. 
     
     
       23. The garment of claim  2 , wherein said backing member comprises at least about 50% by weight of said thermoplastic polymer and a filler. 
     
     
       24. The garment of claim  1 , wherein said second region extends at least 5 cm in the cross-machine direction and extends substantially continuously in the machine direction of said backing member. 
     
     
       25. The garment of claim  1 , wherein said second region is positioned symmetrically along the longitudinal axis of said garment. 
     
     
       26. The garment of claim  25 , wherein said backing member has a WVTR gradient. 
     
     
       27. A disposable, breathable absorbent garment defining an initial expanded shape having longitudinal and transverse axes, a front waist region, a back waist region, said front waist region and said back waist region being generally oppositely disposed on said longitudinal axis and a crotch region disposed between said front waist region and said back waist region and comprising: 
       a film backing member having regions of varied breathability comprising:  
       a first microporous region comprising a polyolefin polymer and a filler;  
       a second region comprising a polyolefin polymer and a filler;  
       wherein said first and second regions comprise a continuous backing member and wherein the WVTR of said second region is less than the WVTR of said first region and the thickness of said first region is less than the thickness of said second region;  
       a aqueous liquid pervious body-side liner joined to said backing member approximate a periphery of said joined body-side liner and said backing member;  
       a generally rectangular absorbent pad, having a front end edge, a back end edge and a pair of opposing side end edges, positioned between said body-side liner and said backing member in board of the periphery of said joined body-side liner and backing member; and,  
       leg elastics aligned along longitudinally extending margins of said periphery, rendering said garment elastically contractible and body-conforming adjacent the crotch of a wearer.  
     
     
       28. The garment of claim  27 , wherein said first and second regions have a basis weight less than about 35 g/m 2  and said second region has a minimum dimension of 3 cm by 3 cm. 
     
     
       29. The garment of claim  28 , wherein said second region comprises from about 5% to about 75% of the area of the backing member. 
     
     
       30. The garment of claim  29 , wherein said first region has a WVTR between about 2000 g/m 2 /24 hours and about 5000 g/m 2 /24 hours and said second region has a WVTR less than about 1000 g/m 2 /24 hours. 
     
     
       31. The garment of claim  29 , wherein said second region has a WVTR less than about 1500 g/m 2 /24 hours and said first region has a WVTR in excess of about 2500 g/m 2 / 24 hours. 
     
     
       32. The garment of claim  30 , wherein said second region has a WVTR less than about 300 g/m 2 /24 hours and comprises from about 5% to about 60% of the area of said backing member. 
     
     
       33. The garment of claim  28 , wherein said first and second regions each have substantially similar basis weights. 
     
     
       34. The garment of claim  27 , wherein said second region has a WVTR at least about 50% less than the WVTR of said first region and comprises from about 5% to about 75% of the area of said backing member. 
     
     
       35. The garment of claim  29 , wherein said first and second regions comprise at least about 40% by weight of filler. 
     
     
       36. The garment of claim  35 , wherein said polyolefin polymer of said first region and said polyolefin polymer of said second region comprise polyethylene. 
     
     
       37. The garment of claim  35 , wherein said polyolefin polymer of said first region and said polyolefin polymer of said second region comprise polypropylene. 
     
     
       38. The garment of claim  28 , wherein said backing member further comprises a third region having a WVTR less than the WVTR of said first region and greater than the WVTR of said second region. 
     
     
       39. The garment of claim  38 , wherein said third region is contiguous with said second region and further wherein said second and third regions together comprise from about 5% to about 75% of the area of said backing member. 
     
     
       40. The garment of claim  38 , wherein said second region has a dimension on the cross-machine direction less than the cross-machine dimension of said third region. 
     
     
       41. The garment of claim  40 , wherein said second and third regions are contiguous and further wherein aid second region comprises from about 5% to about 60% of the area of said backing member.