ELASTOMERIC LAMINATE MATERIALS THAT DO NOT REQUIRE MECHANICAL ACTIVATION
An elastomeric laminate that does not require mechanical activation comprises an elastomeric polymer film layer bonded to one or more other substrate layers. The elastomeric film composition, physical properties of the substrate, and bonding conditions are selected and controlled to form an elastomeric laminate that is stretchable and recoverable without the use of excess material or post-lamination mechanical activation. The resulting elastomeric laminate may be manufactured on relatively simple high-speed equipment at lower cost and with improved physical properties.
1 . An elastomeric laminate, comprising:
a) an elastomeric film layer with a first surface and a second surface, wherein:
i) the film comprises one or more elastomeric polymers, such that the total amount of elastomeric polymers comprises at least about 50% of the elastomeric film composition; and
ii) the basis weight of the elastomeric film is no more than about 70 gsm; and
b) a substrate layer, comprising an extensible material, wherein:
i) the substrate layer has a tensile strain at break that is greater than about 100%; and
ii) the substrate layer has a tensile stress at break that is no greater than about 4 N/in;
wherein the elastomeric film layer is bonded on its first surface coextensively to a surface of the substrate layer;
wherein the bond strength between the elastomeric film layer and the substrate layer is no greater than about 50 N/in; and
wherein the elastomeric laminate is stretchable and recoverable without post-lamination mechanical activation.
2 . An elastomeric laminate according to claim 1 , wherein the elastomeric film layer comprises an elastomeric polymer selected from the group consisting of block copolymers of vinyl arylene and conjugated diene monomers, natural rubbers, polyurethane rubbers, polyester rubbers, polyolefinic rubbers and polyolefinic blends, elastomeric polyamides, copolymers thereof and combinations thereof.
3 . An elastomeric laminate according to claim 2 , wherein the elastomeric film layer comprises a plurality of said elastomeric polymers.
4 . An elastomeric laminate according to claim 1 , wherein the elastomeric film layer comprises an elastomeric polymer selected from the group consisting of styrenic block copolymers, polyolefinic elastomers, copolymers thereof and combinations thereof.
5 . An elastomeric laminate according to claim 4 , wherein the elastomeric film layer comprises a plurality of said elastomeric polymers.
6 . An elastomeric laminate according to claim 1 , wherein the elastomeric film layer is formed by cast extrusion or blown-film extrusion.
7 . An elastomeric laminate according to claim 1 , wherein the elastomeric film layer is a multilayer film.
8 . An elastomeric laminate according to claim 1 , wherein the elastomeric film layer has a basis weight of less than about 50 gsm.
9 . An elastomeric laminate according to claim 1 , wherein the elastomeric film layer has a basis weight of less than about 30 gsm.
10 . An elastomeric laminate according to claim 1 , wherein the substrate layer comprises a fabric.
11 . An elastomeric laminate according to claim 10 , wherein the substrate layer comprises a nonwoven fabric.
12 . An elastomeric laminate according to claim 11 , wherein the nonwoven fabric comprise a material selected from the group consisting of polyolefins, polyamides, polyesters, polyacrylates, rayon, and combinations thereof.
13 . An elastomeric laminate according to claim 11 , wherein the nonwoven fabric comprises a material selected from the group consisting of polyethylene, copolymers of polyethylene, polypropylene, copolymers of polypropylene, polyester, copolymers of polyesters, bicomponent combinations thereof, and other combinations thereof.
14 . An elastomeric laminate according to claim 1 , wherein the elastomeric film layer and the substrate layer are bonded coextensively across their first surfaces by extrusion lamination.
15 . An elastomeric laminate according to claim 1 , wherein the elastomeric film layer and the substrate layer are bonded coextensively across their first surfaces by vacuum, adhesive, thermal, ultrasonic, calender, point, or laser bonding.
16 . An elastomeric laminate according to claim 1 , wherein a third sheet-like substrate is bonded coextensively across the second surface of the elastomeric film layer.
17 . An elastomeric laminate according to claim 16 , wherein third sheet-like substrate comprises a woven fabric, knit fabric, scrim, netting, woven tape material, cross-laminated open mesh, flash-spun material, or combinations thereof.
18 . An elastomeric laminate according to claim 16 , wherein the third sheet-like substrate comprises a nonwoven fabric.
19 . An elastomeric laminate according to claim 16 , wherein third sheet-like substrate is bonded to the second surface of the elastomeric film layer by extrusion lamination.
20 . An elastomeric laminate according to claim 16 , wherein third sheet-like substrate is bonded to the second surface of the elastomeric film layer by vacuum, adhesive, ultrasonic, thermal, calender, point, or laser bonding.
21 . An elastomeric laminate according to claim 1 , wherein the bond strength between the elastomeric film layer and the substrate layer is no greater than about 40 N/in.
22 . An elastomeric laminate according to claim 1 , wherein the bond strength between the elastomeric film layer and the substrate layer is no greater than about 25 N/in.
23 . A method of forming an elastomeric laminate, comprising:
a) providing an elastomeric film layer with a first surface and a second surface, wherein:
i) the film comprises one or more elastomeric polymers, such that the total amount of elastomeric polymers comprises at least about 50% of the elastomeric film composition; and
ii) the basis weight of the elastomeric film is no more than about 70 gsm;
b) providing a substrate layer, comprising an extensible material, wherein:
i) the substrate layer has a tensile strain at break that is greater than about 100%; and
ii) the substrate layer has a tensile stress at break that is no greater than about 4 N/in;
c) coextensively bonding the elastomeric film layer on its first surface to a surface of the substrate layer, wherein the bond strength between the elastomeric film layer and the substrate layer is no greater than about 50 N/in;
wherein the elastomeric laminate so formed is stretchable and recoverable without post-lamination mechanical activation.
24 . A method according to claim 23 , wherein the elastomeric film layer comprises an elastomeric polymer selected from the group consisting of block copolymers of vinyl arylene and conjugated diene monomers, natural rubbers, polyurethane rubbers, polyester rubbers, polyolefinic rubbers and polyolefinic blends, elastomeric polyamides, copolymers thereof and combinations thereof.
25 . A method according to claim 25 , wherein the elastomeric film layer comprises a plurality of said elastomeric polymers.
26 . A method according to claim 23 , wherein the elastomeric film layer comprises an elastomeric polymer selected from the group consisting of styrenic block copolymers, polyolefinic elastomers, copolymers thereof and combinations thereof.
27 . A method according to claim 26 , wherein the elastomeric film layer comprises a plurality of said elastomeric polymers.
28 . A method according to claim 23 , wherein the elastomeric film layer is formed by cast extrusion or blown-film extrusion.
29 . A method according to claim 23 , wherein the elastomeric film layer is a multilayer film.
30 . A method according to claim 23 , wherein the elastomeric film layer has a basis weight of less than about 50 gsm.
31 . A method according to claim 23 , wherein the elastomeric film layer has a basis weight of less than about 30 gsm.
32 . A method according to claim 23 , wherein the substrate layer comprises a fabric.
33 . A method according to claim 32 , wherein the substrate layer comprises a nonwoven fabric.
34 . A method according to claim 33 , wherein the nonwoven fabric comprise a material selected from the group consisting of polyolefins, polyamides, polyesters, polyacrylates, rayon, and combinations thereof.
35 . A method according to claim 33 , wherein the nonwoven fabric comprises a material selected from the group consisting of polyethylene, copolymers of polyethylene, polypropylene, copolymers of polypropylene, polyester, copolymers of polyesters, bicomponent combinations thereof, and other combinations thereof.
36 . A method according to claim 23 , wherein the elastomeric film layer and the substrate layer are bonded coextensively across their first surfaces by extrusion lamination.
37 . A method according to claim 23 , wherein the elastomeric film layer and the substrate layer are bonded coextensively across their first surfaces by vacuum, adhesive, thermal, ultrasonic, calender, point, or laser bonding.
38 . A method according to claim 23 , wherein a third sheet-like substrate is bonded coextensively across the second surface of the elastomeric film layer.
39 . A method according to claim 38 , wherein third sheet-like substrate comprises a woven fabric, knit fabric, scrim, netting, woven tape material, cross-laminated open mesh, flash-spun material, or combinations thereof.
40 . A method according to claim 38 , wherein the third sheet-like substrate comprises a nonwoven fabric.
41 . A method according to claim 38 , wherein third sheet-like substrate is bonded to the second surface of the elastomeric film layer by extrusion lamination.
42 . A method according to claim 38 , wherein third sheet-like substrate is bonded to the second surface of the elastomeric film layer by vacuum, adhesive, ultrasonic, thermal, calender, point, or laser bonding.
43 . A method according to claim 23 , wherein the bond strength between the elastomeric film layer and the substrate layer is no greater than about 40 N/in.
44 . A method according to claim 23 , wherein the bond strength between the elastomeric film layer and the substrate layer is no greater than about 25 N/in.