Glazing laminates

Abstract

An integument which contributes to the maintenance of surface integrity is disclosed, particularly a sheet for use in preparing laminates, such as vehicle windshields, in which an energy absorbing ply, for example, a ply of poly(vinyl butyral), is sandwiched between two glass plies, the sheet of this invention being applied to an exposed surface of one of the glass plies and having one surface layer comprising a thermoplastic polyurethane capable of adhering to a glass or plastic substrate and the other surface layer comprising a thermoset polyurethane having antilacerative, self-healing and anti-ablative properties; there is further disclosed the manufacture and application of such a sheet as a ply facing the interior of a vehicle, thereby forming a windshield the inwardly exposed surface of which comprises a thermoset polyurethane which protects the vehicle occupants from facial lacerations caused by windshield impact and which has self-healing properties.

What is claimed as new and desired to be secured by Letters Patent of the United States is: 
     
       1. A pre-formed polymeric sheet for use in preparing a glazing laminate, consisting essentially of one surface of said sheet comprising an amorphous thermoplastic material capable of adhering to a ply of said laminate and the other surface of said sheet comprising a thermoset material which imparts desired properties to said laminate, said thermoplastic material comprising a thermoplastic polyurethane comprised of the reaction product of (A) one or more of the following aliphatic diisocyanates: (i) a branched chain alicyclic diisocyanate; (ii) a non-branched alicyclic diisocyanate; and (iii) a branched chain noncyclic diisocyanate; and   (B) a branched chain polyester diol or branched chain polyether diol or mixture thereof; said diols having a molecular weight of about 500-4000, and wherein when reactant (A) comprises 85 to 100% of said non-branched alicyclic diisocyanate and when reactant (B) comprises said polyester diol, then said polyester diol is prepared from at least two different diols which result in chain branching in said polyester diol.     
     
     
       2. The pre-formed sheet of claim 1, wherein said aliphatic diisocyanate is selected from the group consisting of 1,6-hexanediisocyanate, 2,2,4 and 2,4,4-trimethyl-1,6-hexanediisocyanate, 1,3-bis(isocyanatomethyl)benzene, bis(4-isocyanatocyclohexyl)methane, bis(3-methyl-4-isocyanatocyclohexyl)methane, 2,2-bis (4-isocyanatocyclohexyl)propane and 3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate, said polyether diol is a diol prepared from polyethers elected from the group consisting of ethylene oxide, 1,2-propylene oxide and tetrahydrofuran, and said polyester diol is a diol prepared from a diacid selected from the group consisting of malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid and sebacic acid. 
     
     
       3. The pre-formed sheet of claim 1, wherein said thermoplastic polyurethane is prepared from a polyester comprising the reaction product of a polyol component prepared from the reaction product of adipic acid, 1,6-hexanediol, 2,2-dimethyl-1,3-propanediol and 1,2-propanediol and an isocyanate component comprising bis(4-isocyanatocyclohexyl)methane. 
     
     
       4. The pre-formed sheet of claim 1, wherein said thermoplastic polyurethane is prepared from molecules of substantially linear chains, with limited cross-linking, and said thermoset sheet is a thermosetting polyurethane with a high degree of cross-linking. .Iadd. 
     
     
       5.  A coated transparent article comprising: a) a rigid transparent substrate;   b) a transparent energy-absorbing elastomeric sheet, one surface of which is bonded to said rigid substrate; and   c) coated on the other surface of said elastomeric sheet, an abrasion-resistant branched polyurethane which is the reaction product of: (1) an aliphatic polyisocyanate and   (2) a polyol selected from the group consisting of polyether and polyester polyols having a molecular weight within the range of 450-4,000,     wherein at least one of said polyisocyanate and said polyol has a functionality greater than 2. .Iaddend. .Iadd.6. The coated article of claim 5, wherein said rigid transparent substrate is glass. .Iaddend. .Iadd.7. The coated article of claim 5, wherein said transparent energy-absorbing elastomeric sheet is comprised of polyurethane. .Iaddend. .Iadd.8. The article of claim 5, wherein said abrasion-resistant branched polyurethane is the reaction product of a branched polyisocyanate and a polyester polyol. .Iaddend. .Iadd.9. The article of claim 8, wherein said polyester polyol is obtained by the reaction of a polyfunctional alcohol and an aliphatic diacid. .Iaddend. .Iadd.10. The article of claim 5, wherein said polyol comprises the condensation product of propylene oxide with 2,2-bis(hydroxymethyl)-1-butanol. .Iaddend. .Iadd.11. The product of claim 8, wherein said polyisocyanate is bis (4-isocyanatocyclohexyl)methane. .Iaddend.