Bilayer laminate and preformed sheet for use therein
AssigneeSaint-Gobain Vitrage
InventorsJean L. Bravet, Daniel Colmon, Gerard Daude, Michel J. Moncheaux
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Abstract
Preformed, energy-absorbing, scratch resistant, optical, flexible, and self-healing polyurethane sheets, which are adhesive under the influence of heat and pressure; bilayer glazing laminates and bilayer safety windshields including said sheets; wherein said polyurethane sheet is prepared preferably by reactive-casting on a horizontal support and formed preferably from a polyisocyanate monomer including about 2 to about 10 wt. % of urea groups.
Claims26
A preformed flexible transparent sheet effective for use in a glazing laminate having optical, moisture resistant, and energy-absorbing properties and comprising polyurethane which is substantially non-tacky at room temperature, but which is capable of itself being adhesive under the influence of heat and pressure, said sheet characterized in that, as an exposed ply in a glazing laminate, it is capable of maintaining, in the absence of an adhesion promoter, effective adhesion as measured by the temperature and moisutre conditions of ANSI-Z26, Test Nos. 3 and 4, said polyurethane being prepared from a solvent-free mixture of monomers comprising:
- (A) a cycloaliphatic polyisocyanate component including about 2 to about 10 wt. % of urea groups and about 30 to about 33 wt. % of NCO groups;
- (B) a polyol component including:
- (1) about 30 to about 45 OH equivalent percent of a polymeric diol having a MW of about 500 to about 4000;
- (2) about 20 to about 70 OH equivalent percent of a chain extender diol;
- and
- (3) about 0 to about 35 OH equivalent percent of a polyol having an OH functionality greater than two;
- and
- (C) a polyurethane-forming catalyst;
- wherein the NCO/OH ratio of said mixture is about 0.8:1 to about 1:1.
A preformed sheet according to claim 11 wherein said sheet has self-healing properties.
A preformed transparent sheet having optical properties, comprising an energy absorbing polyurethane ply, characterized in that said polyurethane ply is prepared by reactive casting, on a level horizontal support, a reaction mixture including:
- an isocyanate component, having a viscosity of less than 5000 mPaS at 40.degree. C., and comprising an aliphatic diisocyanate, a cycloaliphatic diisocyanate or an isocyanate prepolymer;
- and, a polyol component comprising a polymeric diol having a MW of about 500 to about 4000, and a short chain diol.
A composition which is liquid at a temperature greater than about 25.degree. C. and which exhibits a viscosity at about 35.degree. to about 45.degree. C. sufficient to permit the formation on a horizontal support of a uniformly thick and level film thereof, and comprising a solvent-free mixture which is capable of forming a solid polyurethane upon heating, and which cqmprises:
- (A) a cycloaliphatic polyisocyanate component including about 2 to about 10 wt. % of urea groups and about 30 to about 33 wt. % of NCO groups;
- (B) a polyol component including:
- (1) about 30 to about 45 OH equivalent percent of a polymeric diol having a MW of about 500 to about 3000;
- (2) about 20 to about 70 OH equivalent percent of a chain extender diol;
- and
- (3) about 0 to about 35 OH equivalent percent of a polyol having greater than two OH functionality;
- and
- (C) a polyurethane-forming catalyst;
- wherein the NCO/OH ratio of said mixture is about 0.8:1 to about 1:1.
Dependencies are inferred from the claim text.