Polyester copolymers for use in optical films
Assignee3M Innovative Properties Company
InventorsStephen A. Johnson, Carl A. Stover, Kristopher J. Derks, Richard Yufeng Liu
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Abstract
Polyester copolymeric materials include 40 to 51 mol % substituted naphthalate units, such as dimethyl-2,6-naphthalene dicarboxylate units, 10 to 40 mol % ethylene units, and 10 to 40 mol % hexane units. The polyester copolymers can be used to prepare multi-layer optical films by coextrusion and/or co-stretching. The copolyester polymeric materials have desirable optical properties and permit thermal processing at lower temperatures.
Claims12
An optical film, comprising first and second polymeric layers co-extruded and co-stretched with one another, the first polymeric layer comprising a substituted naphthalate, hexanediol and ethylenediol copolyester, the second polymeric layer comprising at least 70% by weight of polyethylene terephthalate.
Dependencies are inferred from the claim text.