Method and materials for preventing warping in optical films
Assignee3M Innovative Properties Company
InventorsTimothy J. Hebrink, Andrew J. Ouderkirk
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Abstract
A multilayer optical body having improved dimensional stability is disclosed. The optical body includes an optical film, such as an oriented multilayer optical film, and a dimensionally stable layer, such as a transparent polycarbonate layer. In addition, in specific implementations, the invention includes an intermediate layer between the optical film and the dimensionally stable layer. Methods of making the optical body are also disclosed.
Claims66
A multilayer optical body comprising:
- an optical film;
- an extrudable thermoplastic polymeric layer secured to the optical film;
- and
- a flexible, dimensionally stable layer secured to the polymeric layer, wherein the dimensionally stable layer comprises polystyrene or a polystyrene copolymer and the dimensionally stable layer is configured and arranged to permit cycling the optical body through temperatures of −30° C. and 85° C. every 1.5 hours for 400 hours without warping.
A multilayer optical body comprising:
- an oriented optical film;
- and
- a dimensionally stable layer comprising an acrylonitrile butadiene styrene copolymer.
A method of forming a warp-resistant optical body, the method comprising:
- providing a first film comprising an optical film;
- forming a second film comprising a thermoplastic polymeric material having a glass transition temperature greater than 85° C.;
- forming a third film, wherein the third film comprises a dimensionally stable layer that comprises an acrylonitrile butadiene styrene copolymer;
- and
- adhering the first film to the second film, and the second film to the third film, to form a dimensionally stable optical body.
The method of claimn 38, further comprising forming a diffuse pattern on at least a portion of a surface of the dimensionally stable layer of the third film.
A method of forming a warp-resistant optical body, the method comprising:
- providing an optical film;
- and
- coating the optical film by coextruding a thermoplastic polymeric layer and a dimensionally stable layer onto the optical film, wherein the dimensionally stable layer comprises polystyrene or a polystyrene copolymer and the dimensionally stable layer is configured and arranged to permit cycling of the optical body through temperatures of −30° C. and 85° C. every 1.5 hours for 400 hours without warping.
The method of clain 56, wherein the dimensionally stable layer comprises 1 to 30 wt. % of the polyester material.
A method of forming a warp-resistant optical body, the method comprising:
- providing an optical film;
- and
- securing a dimensionally stable layer to the optical film, wherein the dimensionally stable layer comprises polystyrene or a polystyrene copolymer and the dimensionally stable layer is configured and arranged to permit cycling of the optical body through temperatures of −30° C. and 85° C. every 1.5 hours for 400 hours without warping.
A multilayer optical body comprising:
- an optical film;
- and
- a flexible, dimensionally stable layer disposed on the optical film, wherein the dimensionally stable layer comprises a dimensionally stable material selected from polystyrene and polystyrene copolymers blended with a polyester material selected from CoPEN, CoPET, or combinations thereof.
Dependencies are inferred from the claim text.