Composite interlayer for laminates glass
A composite interlayer suitable for using laminated glass includes a layer of plasticized polyvinyl butyral sandwiched between second and third polymeric layers. In a preferred embodiment, at least one and preferably both of the second and third layers are less than 5 mils thick and formed of polyurethane.
1 . A glass laminate comprising:
a first layer comprising a plasticized polyvinyl butyral and having a top surface and a bottom surface;
a first polyurethane layer adjacent said top surface of said first layer;
a second polyurethane layer adjacent said bottom surface of said first layer;
wherein at least one of said first and second polyurethane layers comprises polyurethane having a thickness of less than 5 mils for lamination to a rigid glass substrate;
a first glass layer adjacent said second polyurethane layer; and
a second glass layer adjacent said first polyurethane layer.
2 . The glass laminate of claim 1 wherein both of said polyurethane layers comprise polyurethane having a thickness of less than 5 mils.
3 . The glass laminate of claim 2 wherein said polyurethane is plasticized by migration of plasticizer from the first layer after the layers are combined.
4 . A multilayer composite suitable for use in glass laminates comprising:
a first layer comprising plasticized polyvinyl butyral and a second layer adjacent to said first layer comprising polyurethane, wherein plasticizer has migrated from said polyvinyl butyral to said polyurethane.
5 . The multilayer composite of claim 4 wherein the polyurethane layer has a thickness of less than 5 mils.
6 . The multilayer composite of claim 4 further comprising a third layer comprising polyurethane on a side of the polyvinyl butyral layer opposite the second layer.
7 . The multilayer composite of claim 6 wherein the second and third polyurethane layers each have a thickness of less than 5 mils.