High Impact Polymer Layers
AssigneeSolutia Inc.
InventorsWenjie Chen, Aristotelis Karagiannis
Life of this patent
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Abstract
Multiple poly(vinyl butyral) layer interlayers that can be used in multiple layer glass panel type applications that require a high level of impact protection, for example in hurricane protection applications or in bullet proof glass applications. This effect is achieved by forming a poly(vinyl butyral) interlayer that has a relatively stiff poly(vinyl butyral) inner layer disposed between two relatively soft outer poly(vinyl butyral) layers, where the stiffness difference is achieved by a plasticizer differential that is achieved at least in substantial part by a residual hydroxyl content difference among the poly(vinyl butyral) layers.
Claims7
A method of making a multiple layer interlayer, comprising:
- forming a first polymer melt, a second polymer melt, and a third polymer melt, wherein the difference in phr of the plasticizer concentrations between any of said first polymer melt, said second polymer melt, and said third polymer melt is 2 phr or less;
- coextruding said first polymer melt, said second polymer melt, and said third polymer melt to form said interlayer having a first polymer layer, a second polymer layer, and a third polymer layer, with said second polymer layer disposed between said first polymer layer and said third polymer layer, thereby causing a migration of plasticizer from said second polymer layer into both said first polymer layer and said third polymer layer;
- wherein said second polymer layer has a residual hydroxyl content by weight that is at least 0.5% greater than the residual hydroxyl content by weight in said plasticized thermoplastic polymer of said first polymer layer and said plasticized thermoplastic polymer of said third polymer layer.
A method of making a multiple layer interlayer, comprising:
- forming a first polymer melt, a second polymer melt, and a third polymer melt;
- coextruding said first polymer melt, said second polymer melt, and said third polymer melt to form said interlayer having a first polymer layer, a second polymer layer, and a third polymer layer, with said second polymer layer disposed between said first polymer layer and said third polymer layer;
- wherein the amount of plasticizer in said plasticized thermoplastic polymer of said first polymer layer is at least 2 phr greater than the amount of plasticizer in said plasticized thermoplastic polymer of said second polymer layer;
- and,
- wherein the amount of plasticizer in said plasticized thermoplastic polymer of said third polymer layer is at least 2 phr greater than the amount of plasticizer in said plasticized thermoplastic polymer of said second polymer layer.
Dependencies are inferred from the claim text.