Elastomeric optical interference films
AssigneeThe Dow Chemical Company
InventorsWalter J. Schrenk, William E. Shrum, John A. Wheatley
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Abstract
The present invention provides improved elastomeric interference films which are readily coextruded, have improved transparency, and have greater mismatches of refractive indices than those of the prior art. An improved elastomeric optical interference film comprising at least 100 alternating layers of at least first and second divergent substantially transparent elastomeric polymeric materials is provided. Adjacent layers of the first and second polymeric materials differ from each other in refractive index by at least about 0.05, and the thickness of the layers is from about 0.05 to about 0.5 micrometers. Stretching the films results in different wavelengths of light being reflected.
Claims23
An elastomeric optical interference film comprising at least 100 alternating layers of at least first and second divergent substantially transparent elastomeric polymeric materials, wherein said first and second polymeric materials are selected from the group consisting of polytetramethylene glycol ether thermoplastic polyurethanes, polyadipate ester thermoplastic polyurethanes, polyether block amides, and flexible copolyesters, and wherein adjacent layers of said first and second polymeric materials differ from each other in refractive index by at least about 0.05 and the thickness of said layers is from about 0.05 to about 0.5 micrometers.
An elastomeric optical interference film comprising at least 100 alternating layers of at least first and second divergent substantially transparent elastomeric polymeric materials, wherein said first and second polymeric materials are selected from the group consisting of polytetramethylene glycol ether thermoplastic polyurethanes, polyadipate ester thermoplastic polyurethanes, polyether block amides, and flexible copolyesters, and wherein adjacent layers of said first and second polymeric materials differ from each other in refractive index by at least about 0.05 and the thickness of said layers is from about 0.05 to about 0.5 micrometers, said film including at least one skin layer on an exterior surface of said film, said skin layer comprising a blend of (a) a substantially transparent, elastomeric polymeric material and (b) a substantially transparent, nonelastomeric polymeric material having substantially the same index of refraction as said elastomeric polymeric material in said blend.
Dependencies are inferred from the claim text.