Breathable and elastic composite materials and methods
View Patent ↗In one embodiment, a breathable, incrementally stretched elastic composite material comprises an inner elastomeric film extrusion-laminated to an outer nonwoven web at each film surface. The inner elastomeric film has a random pattern of incremental stretch-formed macroholes therein and is substantially free of pore-forming filler. In another embodiment, a breathable, incrementally stretched elastic composite material comprises an elastomeric film extrusion-laminated to a nonwoven web at one or both of the film surfaces. The elastomeric film has a random pattern of incremental stretch-formed macroholes therein and is substantially free of pore-forming filler. Methods of manufacturing the composite materials comprise extrusion laminating and incremental stretching. Garments and disposable articles are formed at least in part from the composite material.
1. A breathable, incrementally stretched elastic composite material comprising an inner elastomeric film extrusion-laminated to an outer nonwoven web at each film surface, wherein the inner elastomeric film has a random pattern of incremental stretch-formed macroholes having an average diameter of from about 10 μm to about 100 μm therein, and wherein the inner elastic film contains an insufficient amount of pore-forming filler to render the film microporous upon incremental stretching due to microvoid formation adjacent the filler, wherein the concentration of macroholes therein is in a range of from about 5 to about 500 per inch 2 .
2. The composite material of claim 1 , having an air permeability of at least about 10 cc/min/cm 2 when a pressure of about 60 psi is applied thereto.
3. The composite material of claim 1 , having a stretchability of at least about 200% with a permanent set of no more than about 25%.
4. The composite material of claim 1 , wherein the inner elastomeric film comprises elastomeric block copolymer, elastomeric metallocene olefin polymer or copolymer, elastomeric polyurethane, elastomeric polysiloxane, or mixtures thereof.
5. The composite material of claim 4 , wherein the inner elastomeric film comprises an elastomeric styrenic block copolymer.
6. The composite material of claim 5 , wherein the inner elastomeric film comprises poly(styrene-butadiene-styrene), poly(styrene-isoprene-styrene), poly(styrene-ethylene-butylene-styrene), or combinations thereof.
7. The composite material of claim 5 , wherein the inner elastomeric film comprises a blend of an elastomeric styrenic block copolymer and an elastomeric metallocene polyethylene copolymer.
8. The composite material of claim 1 , wherein the inner elastomeric film is a monolayer film.
9. The composite material of claim 1 , wherein the inner elastomeric film comprises a multilayer film.
10. The composite material of claim 9 , wherein the inner elastomeric film comprises a core layer including an elastomeric styrene block copolymer, coextruded at each surface with a polyolefin cap layer.
11. The composite material of claim 1 , wherein the nonwoven webs individually comprise spun bonded polyolefin.
12. The composite material of claim 1 , wherein each nonwoven web has a weight of less than about 40 g/m 2 .
13. The composite material of claim 1 , wherein, each nonwoven web has a weight of about 12 g/m 2 .
14. A garment formed at least in part from the composite material of claim 1 .
15. A disposable article formed at least in part from the composite material of claim 1 .
16. The disposable article of claim 15 , comprising a diaper.
17. A breathable, incrementally stretched elastic composite material comprising an inner elastomeric film including a blend of an elastomeric styrenic block copolymer and an elastomeric metallocene polyethylene copolymer extrusion-laminated to an outer nonwoven spun bonded polyolefin web at each film surface, wherein the inner elastomeric film has a random pattern of incremental-stretch formed macroholes having an average diameter of from about 10 μm to about 100 μm therein, and wherein the inner elastic film contains an insufficient amount of pore-forming filler to render the film microporous upon incremental stretching due to microvoid formation adjacent the filler, wherein the concentration of macroholes therein is in a range of from about 5 to about 500 per inch 2 .
18. A garment formed at least in part from the composite material of claim 17 .
19. A disposable article formed at least in part from the composite material of claim 17 .
20. The disposable article of claim 19 , comprising a diaper.
21. A breathable, incrementally stretched elastic composite material, comprising an elastomeric film extrusion-laminated to a nonwoven web at one or both of the film surfaces, wherein the elastomeric film has a random pattern of incremental stretch-formed macroholes having an average diameter of from about 10 μm to about 100 μm therein, and wherein the elastic film contains an insufficient amount of pore-forming filler to render the film microporous upon incremental stretching due to microvoid formation adjacent the filler, wherein the concentration of macroholes therein is in a range of from about 5 to about 500 per inch 2 .
22. A garment formed at least in part from the composite material of claim 21 .
23. A disposable article formed at least in part from the composite material of claim 21 .
24. The disposable article of claim 23 , comprising a diaper.
25. A method of manufacturing a breathable elastomeric composite material as defined in claim 1 , comprising
extrusion laminating the inner elastomeric film to the outer nonwoven web at each film surface to tightly bond the nonwoven webs thereto; and
incrementally stretching the resulting laminate to form the random pattern of macroholes in the inner elastomeric film.
26. The method of claim 25 , wherein the extrusion lamination is conducted at a nip pressure of greater than about 50 pounds per linear inch.
27. The method of claim 25 , wherein the incremental stretching comprises cross direction (CD) intermesh stretching.
28. The method of claim 27 , wherein the CD intermesh stretching employs an intermeshing roll engagement of at least about 0.12 inch.
29. The method of claim 25 , wherein the composite material has an air permeability of at least about 10 cc/min/cm 2 when a pressure of about 60 psi is applied thereto.
30. The method of claim 25 , wherein the composite material has a stretchability of at least about 200% with a permanent set of no more than about 25%.
31. The method of claim 25 , wherein the inner elastomeric film comprises an elastomeric styrenic block copolymer.
32. The method of claim 25 , wherein the inner elastomeric film comprises a blend of an elastomeric styrenic block copolymer and an elastomeric metallocene polyethylene copolymer.
33. The method of claim 25 , wherein the inner elastomeric film comprises a core layer including an elastomeric styrene block copolymer, coextruded at each surface with a polyolefin cap layer.
34. The method of claim 25 , wherein the nonwoven webs individually comprise spun bonded polyolefin.
35. The method of claim 25 , wherein each nonwoven web has a weight of less than about 40 g/m 2 .
36. The method of claim 25 , wherein, each nonwoven web has a weight of about 12 g/m 2 .
37. A method of manufacturing a breathable elastomeric composite material as defined in claim 21 , comprising
extrusion laminating the elastomeric film to the outer nonwoven web at one or both of the film surfaces to tightly bond the nonwoven web thereto; and
incrementally stretching the resulting laminate to form the random pattern of macroholes in the elastomeric film.
38. The composite material of claim 1 , wherein the macroholes have an average diameter of from about 10 μm to about 50 μm.
39. The composite material of claim 1 , wherein the macroholes have an average diameter of from about 15 μm to about 35 μm.
40. The composite material of claim 1 , wherein the concentration of macroholes therein is in a range of from about 10 to about 100 per inch 2 .
41. The composite material of claim 1 , wherein the concentration of macroholes therein is in a range of from about 25 to about 75 per inch 2 .
42. The composite material of claim 17 , wherein the macroholes have an average diameter of from about 10 μm to about 50 μm.
43. The composite material of claim 17 , wherein the macroholes have an average diameter of from about 15 μm to about 35 μm.
44. The composite material of claim 17 , wherein the concentration of macroholes therein is in a range of from about 10 to about 100 per inch 2 .
45. The composite material of claim 17 , wherein the concentration of macroholes therein is in a range of from about 25 to about 75 per inch 2 .
46. The composite material of claim 21 , wherein the macroholes have an average diameter of from about 10 μm to about 50 μm.
47. The composite material of claim 21 , wherein the macroholes have an average diameter of from about 15 μm to about 35 μm.
48. The composite material of claim 21 , wherein the concentration of macroholes therein is in a range of from about 10 to about 100 per inch 2 .
49. The composite material of claim 21 , wherein the concentration of macroholes therein is in a range of from about 25 to about 75 per inch 2 .
50. The composite material of claim 1 , wherein the inner elastomeric film contains less than about 10 weight percent pore-forming filler.
51. The composite material of claim 1 , wherein the inner elastomeric film contains less than about 5 weight percent pore-forming filler.
52. The composite material of claim 1 , wherein the inner elastomeric film contains less than about 1 weight percent pore-forming filler.
53. The composite material of claim 17 , wherein the inner elastomeric film contains less than about 10 weight percent pore-forming filler.
54. The composite material of claim 17 , wherein the inner elastomeric film contains less than about 5 weight percent pore-forming filler.
55. The composite material of claim 17 , wherein the inner elastomeric film contains less than about 1 weight percent pore-forming filler.
56. The composite material of claim 21 , wherein the elastomeric film contains less than about 10 weight percent pore-forming filler.
57. The composite material of claim 21 , wherein the elastomeric film contains less than about 5 weight percent pore-forming filler.
58. The composite material of claim 21 , wherein the elastomeric film contains less than about 1 weight percent pore-forming filler.
59. A breathable, incrementally stretched elastic composite material comprising an inner elastomeric film extrusion-laminated to an outer nonwoven web at each film surface, wherein the inner elastomeric film has a random pattern of incremental stretch-formed macroholes having an average diameter of from about 10 μm to about 100 μm therein and contains less than about 20 weight percent pore-forming filler, wherein the concentration of macroholes therein is in a range of from about 5 to about 500 per inch 2 .
60. A breathable, incrementally stretched elastic composite material comprising an inner elastomeric film including a blend of an elastomeric styrenic block copolymer and an elastomeric metallocene polyethylene copolymer extrusion-laminated to an outer nonwoven spun bonded polyolefin web at each film surface, wherein the inner elastomeric film has a random pattern of incremental-stretch formed macroholes having an average diameter of from about 10 μm to about 100 μm therein and contains less than about 20 weight percent pore-forming filler, wherein the concentration of macroholes therein is in a range of from about 5 to about 500 per inch 2 .
61. A breathable, incrementally stretched elastic composite material, comprising an elastomeric film extrusion-laminated to a nonwoven web at one or both of the film surfaces, wherein the elastomeric film has a random pattern of incremental stretch-formed macroholes having an average diameter of from about 10 μm to about 100 μm therein and contains less than about 20 weight percent pore-forming filler, wherein the concentration of macroholes therein is in a range of from about 5 to about 500 per inch 2 .