Composite Interlayer For Laminated Glass

Abstract

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 process for forming a laminate, said process comprising:
 coextruding a plasticized polyvinyl butyral layer, a first polyurethane layer, and a second polyurethane layer to form a composite interlayer, wherein said polyvinyl butyral layer is between said first polyurethane layer and said second polyurethane layer; and,   laminating said composite interlayer between two rigid substrates to form said laminate.   
     
     
         2 . The process of  claim 1 , wherein at least one of said first polyurethane layer and said second polyurethane layer has a thickness of less than 5 mils. 
     
     
         3 . The process of  claim 1 , wherein both of said first polyurethane layer and said second polyurethane layer have a thickness of less than 5 mils. 
     
     
         4 . The process of  claim 1 , wherein said rigid substrates comprise glass. 
     
     
         5 . The process of  claim 1 , wherein said rigid substrates comprise rigid plastic glazing panels. 
     
     
         6 . The process of  claim 1 , wherein said first polyurethane layer and said second polyurethane layer are plasticized by migration of plasticizer from said plasticized polyvinyl butyral layer after the layers are combined. 
     
     
         7 . The process of  claim 1 , wherein one of said first polyurethane layer and said second polyurethane layer comprises an aliphatic isocyanate-polyether urethane. 
     
     
         8 . The process of  claim 1 , wherein one of said first polyurethane layer and said second polyurethane layer comprises an aliphatic isocyanate-polyester urethane. 
     
     
         9 . The process of  claim 1 , wherein both of said first polyurethane layer and said second polyurethane layer comprise an aliphatic isocyanate-polyester urethane. 
     
     
         10 . The process of  claim 1 , wherein both of said first polyurethane layer and said second polyurethane layer comprise an aliphatic isocyanate-polyether urethane. 
     
     
         11 . A laminated glass panel produced by the process comprising the steps of: coextruding a plasticized polyvinyl butyral layer, a first polyurethane layer, and a second polyurethane layer to form a composite interlayer, wherein said polyvinyl butyral layer is between said first polyurethane layer and said second polyurethane layer; and, laminating said composite interlayer between two rigid substrates to form said laminate. 
     
     
         12 . The panel of  claim 11 , wherein at least one of said first polyurethane layer and said second polyurethane layer has a thickness of less than 5 mils. 
     
     
         13 . The panel of  claim 11 , wherein both of said first polyurethane layer and said second polyurethane layer have a thickness of less than 5 mils. 
     
     
         14 . The panel of  claim 11 , wherein said rigid substrates comprise glass. 
     
     
         15 . The panel of  claim 11 , wherein said rigid substrates comprise rigid plastic glazing panels. 
     
     
         16 . The panel of  claim 11 , wherein said first polyurethane layer and said second polyurethane layer are plasticized by migration of plasticizer from said plasticized polyvinyl butyral layer after the layers are combined. 
     
     
         17 . The panel of  claim 11 , wherein one of said first polyurethane layer and said second polyurethane layer comprises an aliphatic isocyanate-polyether urethane. 
     
     
         18 . The panel of  claim 11 , wherein one of said first polyurethane layer and said second polyurethane layer comprises an aliphatic isocyanate-polyester urethane. 
     
     
         19 . The panel of  claim 11 , wherein both of said first polyurethane layer and said second polyurethane layer comprise an aliphatic isocyanate-polyester urethane. 
     
     
         20 . The panel of  claim 11 , wherein both of said first polyurethane layer and said second polyurethane layer comprise an aliphatic isocyanate-polyether urethane.