Elastomeric materials
View Patent ↗Some embodiments of the present invention include elastomeric films with a basis weight of about 40 gsm or less or about 25 gsm or less. Other embodiments include elastomeric laminates comprising the elastomeric film bonded to one or more substrates (such as nonwoven fabrics). Methods of the making the elastomeric films and elastomeric laminates are also provided.
1. A laminate comprising:
(1) an elastomeric film comprising a first surface and a second surface comprising:
(i) at least one non-styrenic elastomeric polymer selected from the group consisting of an olefin block copolymer, copolymers of polypropylene and polyethylene, and mixtures thereof in an amount of at least about 50% of said film;
(ii) at least one draw down polymer present in a combined amount of from about 5 wt % to about 25 wt % of said film, said at least one draw down polymer is selected from the group consisting of linear low density polyethylene, high density polyethylene, homopolymer polypropylene, and mixtures thereof,
wherein said elastomeric film has a basis weight of no more than about 25 gsm and said elastomeric film has a permanent set of no more than 14% after recovery from being initially stretched to twice its original size and;
(2) a first substrate laminated to said first surface to form said laminate.
2. The laminate of claim 1 , wherein said first substrate comprises a nonwoven fabric.
3. The laminate of claim 1 , wherein said first substrate comprises a nonwoven fabric selected from the group consisting of spunbond nonwoven webs, carded nonwoven webs, meltblown nonwoven webs, spunlaced nonwoven webs, spunbond meltblown spunbond nonwoven webs, spunbond meltblown meltblown spunbond nonwoven webs, unbonded nonwoven webs, and combinations thereof.
4. The laminate of claim 1 , wherein said first substrate has a basis weight of from about 3 gsm to about 100 gsm.
5. The laminate of claim 2 , wherein the nonwoven fabric comprises fibers with a cross section perpendicular to the fiber longitudinal axis that is rectangular, oblong, trilobal or triangular.
6. The laminate of claim 2 , wherein the nonwoven fabric comprises fibers with a cross section perpendicular to the fiber longitudinal axis having a longest axis and a shortest axis and the ratio of the length of the longest axis to the length of the shortest axis is about 1.1 to about 15.0.
7. The laminate of claim 2 , wherein said lamination occurs using adhesive bonding, thermal bonding, extrusion lamination, ultrasonic bonding, calendaring or combinations thereof.
8. The laminate of claim 1 , wherein said laminate further comprises a second substrate laminated to said second surface.
9. The laminate of claim 8 , wherein said first substrate and said second substrate are composed of the same nonwoven fabric material.
10. The laminate of claim 1 , wherein said laminate is activated by stretching.
11. The laminate of claim 10 , wherein said activation occurs using incremental stretching.
12. The laminate of claim 1 wherein said at least one non-styrenic elastomeric polymer is present in a combined amount of from 70% wt % to 90 wt % of said film.
13. The laminate of claim 1 , wherein said draw down polymer is a polyolefin prepared with a single site catalyst.
14. A laminate comprising:
(1) a multilayer elastomeric film, said film having a first surface and a second surface, comprising:
(a) a first layer comprising:
(i) at least one non-styrenic elastomeric polymer e selected from the group consisting of ethylene olefin block copolymers, propylene olefin block copolymers, copolymers of polypropylene and polyethylene and mixtures thereof, in an amount of at least about 50% of said film;
(ii) at least one draw down polymer present in a combined amount of from about 5 wt % to about 25 wt % of said film, said at least one draw down polymer is selected from the group consisting of linear low density polyethylene, high density polyethylene, homopolymer polypropylene, and mixtures thereof,
(b) a second layer comprising
(i) at least one elastomeric polymer and
(ii) at least one second draw down polymer
wherein said multilayer elastomeric film has a basis weight of no more than about 40 gsm, and said multilayer elastomeric film has a permanent set of no more than 14% after recovery from being initially stretched to twice its original size, and
(2) a first substrate laminated to said first surface to form said laminate.
15. The laminate of claim 14 , wherein said elastomeric polymer of said second layer is an olefinic elastomeric polymer.
16. The laminate of claim 15 , wherein said olefinic elastomeric polymer of said second layer is a non-styrenic elastomeric polymer selected from the group consisting of ethylene olefin block copolymers, propylene olefin block copolymers, ethylene olefin random copolymers, propylene olefin random copolymers, ethylene-propylene random copolymers, and mixtures thereof.
17. The laminate of claim 14 , wherein said first substrate comprises a nonwoven fabric.
18. The laminate of claim 17 , wherein said nonwoven fabric is selected from the group consisting of spunbond nonwoven webs, carded nonwoven webs, meltblown nonwoven webs, spunlaced nonwoven webs, spunbond meltblown spunbond nonwoven webs, spunbond meltblown meltblown spunbond nonwoven webs, unbonded nonwoven webs, and combinations thereof.
19. The laminate of claim 17 , wherein the nonwoven fabric comprises fibers with a cross section perpendicular to the fiber longitudinal axis that is rectangular, oblong, trilobal or triangular.
20. The laminate of claim 17 , wherein the nonwoven fabric comprises fibers with a cross section perpendicular to the fiber longitudinal axis having a longest axis and a shortest axis and the ratio of the length of the longest axis to the length of the shortest axis is about 1.1 to about 15.0.
21. The laminate of claim 14 , wherein said first substrate has a basis weight of from about 3 gsm to about 100 gsm.
22. The laminate of claim 14 , wherein said lamination occurs using adhesive bonding, thermal bonding, extrusion lamination, ultrasonic bonding, calendaring or combinations thereof.
23. The laminate of claim 14 , wherein said laminate further comprises a second substrate laminated to said second surface.
24. The laminate of claim 14 , wherein said laminate is activated by stretching.
25. The laminate of claim 24 , wherein said stretching is incremental stretching.
26. The laminate of claim 14 , wherein said draw down polymer is a polyolefin prepared with a single site catalyst.
27. A laminate comprising:
(1) an elastomeric film comprising a first surface and a second surface comprising:
(i) a non-styrenic olefin block copolymer in an amount of at least about 70% of said film;
(ii) at least one draw down polymer present in a combined amount of from about 5 wt % to about 25 wt % of said film, said at least one draw down polymer is selected from the group consisting of linear low density polyethylene, high density polyethylene, homopolymer polypropylene, and mixtures thereof,
wherein said elastomeric film has a basis weight of no more than about 25 gsm and said elastomeric film has a permanent set of no more than 14% after recovery from being initially stretched to twice its original size and;
(2) a first substrate laminated to said first surface to form said laminate.
28. A laminate comprising:
(1) an elastomeric film comprising a first surface and a second surface comprising:
(i) a non-styrenic elastomeric copolymer of polypropylene and polyethylene in an amount of at least about 70% of said film;
(ii) at least one draw down polymer present in a combined amount of from about 5 wt % to about 25 wt % of said film, said at least one draw down polymer is selected from the group consisting of linear low density polyethylene, high density polyethylene, homopolymer polypropylene, and mixtures thereof,
wherein said elastomeric film has a basis weight of no more than about 25 gsm and said elastomeric film has a permanent set of no more than about 14% after recovery from being initially stretched to twice its original size and;
(2) a first substrate laminated to said first surface to form said laminate.
29. The laminate of claim 1 , wherein said at least one substrate comprises a nonwoven fabric comprising fibers with a cross section perpendicular to the fiber longitudinal axis that is substantially non-circular.