Bilayer windshield and preformed two-ply sheet for use therein
AssigneeSaint-Gobain Vitrage
InventorsJean L. Bravet, Daniel Colmon, Gerard Daude, Michel J. Moncheaux
Life of this patent
Estimating the term…
Abstract
Preformed, two-ply, optical, energy-absorbing, flexible polyurethane sheet including a self-healing surface and a surface which is adhesive under the influence of heat and pressure; bilayer glazing laminates and bilayer automotive safety windshields including said two-ply sheet; said two-ply sheet comprises a self-healing ply and an energy-absorbing adhesive polyurethane ply which is prepared preferably by reactive-casting on a horizontal support and formed preferably from a polyisocyanate monomer including from about 2 to about 10 wt. % of urea groups.
Claims18
A preformed flexible multi-ply transparent sheet effective for use in a bilayer glazing laminate, having optical, moisture-resistant, and energy-absorbing properties effective for use in a bilayer glazing laminate, one ply of which comprises a self-healing thermoset polymeric material, the other ply of which comprises an energy-abosrbing polyurethane ply which is substantially non-tacky at room temperature but which is capable of itself being adhesive under the influence of heat and pressure, wherein said sheet is capable of maintaining, in the absence of an adhesion promoter, effective adhesion as measured by the temperature and moisture conditions of ANSI-Z26 Test Nos. 3 and 4, said energy-absorbing polyurethane being prepared by reactive casting a solvent-free mixture of monomers;
- and wherein said multi-ply transparent sheet is produced by:
- (1) depositing on a horizontal support a liquid film comprising a solvent-free mixture of monomers capable of forming a thermoset polymeric material;
- (2) forming a solid underlying film of said thermoset polymeric material by polymerizing the monomers while on said support;
- (3) depositing on said supported underlying film a liquid film comprising:
- (a) an aliphatic or a cycloaliphatic diisocyanate containing about 2 to about 10 wt. % of urea groups,
- (b) a polyol component including
- (i) about 30 to about 45 OH equivalent percent of a polymeric diol having a molecular weight of about 500 to about 3,000,
- (ii) about 20 to about 70 OH equivalent percent of a chain extender diol having a molecular weight of less than about 300, and
- (iii) about 0 to about 35 OH equivalent percent of a polyol having a OH functionality greater than 2;
- and
- (c) a polyurethane catalyst, wherein the NCO/OH ratio of said mixture is about 0.8:1 to about 1:1;
- (4) forming a solid, optical, energy-absorbing overlying polyurethane ply within about an hour, thereby forming said multi-ply sheets;
- and
- (5) removing said multi-ply sheet from said support.
Dependencies are inferred from the claim text.