Method for making optical devices from homopolymers
Assignee3M Innovative Properties Company
InventorsRichard C. Allen, Susan L. Kent, Ronald J. Tabar, Elisa M. Cross, William Ward Merrill, Stephen A. Johnson, Peter D. Condo, Timothy J. Hebrink, Joseph A. Gangi
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Abstract
An improved optical film having a continuous/disperse phase morphology and a method for making the same is provided. At least one of the continuous and disperse phases comprises a blend of homopolymers which are inter-reacted, as by transesterification. The resulting films exhibit a higher degree of birefringence for a given level of strain than analogous films in which the blend is replaced by a random copolymer.
Claims19
A method of forming an optical device, comprising the steps of:
- providing first and second monomers;
- inter-reacting said first and second monomers to form a copolymer Pn which has a lower degree of randomness than a statistically random copolymer Pr formed from the same monomers;
- and
- stretching the copolymer Pn in at least one direction such that copolymer Pn exhibits a birefringence b, wherein |b|>|k|, and wherein k is the maximum birefringence obtainable by the statistically random copolymer Pr at the same stretch ratio and under the same stretching conditions.
Dependencies are inferred from the claim text.