Materials, configurations, and methods for reducing warpage in optical films

• US 20040219338A1
• Filed: 05/01/2003
• Published: 11/04/2004
• Est. Priority Date: 05/01/2003
• Status: Abandoned Application

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Hebrink, Timothy J., Strobel, Joan M., Hamer, Kevin M., Rosell, Barry S.
• Application Number:
  US10/427,422
• Publication Number:
  US 20040219338A1
• Time in Patent Office: Days
• US Class Current: 428/202
• CPC Class Codes: B32B 2307/42 Polarizing, birefringent, filtering
• CPC Class Codes: B32B 2307/734 Dimensional stability
• CPC Class Codes: B32B 2551/00 Optical elements
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/30 comprising vinyl (co)polymers; comprising acrylic (co)polymers
• CPC Class Codes: B32B 27/302 comprising aromatic vinyl (co)polymers, e.g. styrenic (co)polymers
• CPC Class Codes: B32B 27/36 comprising polyesters
• CPC Class Codes: C09K 2323/05 Bonding or intermediate layer characterised by chemical composition, e.g. sealant or spacer
• CPC Class Codes: G02B 1/10 Optical coatings produced by application to, or surface treatment of, optical elements G02B1/08 takes precedence
• CPC Class Codes: G02B 1/14 Protective coatings, e.g. hard coatings
• CPC Class Codes: G02B 1/16 having an anti-static effect, e.g. electrically conducting coatings
• CPC Class Codes: G02B 5/305 including organic materials, e.g. polymeric layers
• CPC Class Codes: Y10T 428/2486 with outer strippable or release layer
• CPC Class Codes: Y10T 428/2839 with release or antistick coating
• CPC Class Codes: Y10T 428/31909 Next to second addition polymer from unsaturated monomers

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 (warp-resistant) layer that includes a combination of i) polystyrene or a first polystyrene copolymer and ii) a second polystyrene copolymer or the layer includes a norbornene-based polymer. 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.

Claims

1. An optical body, comprising:

an optical film; and

at least one warp-resistant layer disposed on the optical film, the at least one warp-resistant layer comprising an intimate mixture of i) polystyrene or a first polystyrene copolymer and ii) a second polystyrene copolymer.

2. The optical body of claim 1, wherein the optical body comprises at least two warp-resistant layers disposed with one of the warp-resistant layers disposed on each of two opposing sides of the optical film.

3. The optical body of claim 1, wherein the at least one warp-resistant layer comprises i) a first polystyrene copolymer and ii) a second polystyrene copolymer.

4. The optical body of claim 3, wherein the first polystyrene copolymer is styrene acrylonitrile copolymer.

5. The optical body of claim 4, wherein the second polystyrene copolymer is selected from acrylonitrile butadiene styrene copolymers, styrene butadiene copolymers, acrylic styrene acrylonitrile copolymers, and styrene methyl methacrylate copolymers.

6. The optical body of claim 3, wherein the second polystyrene copolymer is provided in an amount of 3 to 30 wt. % based on the total weight of the warp-resistant layer.

7. The optical body of claim 1, wherein the warp-resistant layer further comprises a material selected from coPEN or coPET.

8. The optical body of claim 1, wherein the warp-resistant layer further comprises an anti-static material.

9. The optical body of claim 1, wherein the optical film is a multilayer, polymeric optical film.

10. The optical body of claim 1, further comprising at least one strippable skin layer disposed over the at least one warp-resistant layer.

11. The optical body of claim 10, wherein the at least one strippable skin layer comprises a polyolefin.

12. The optical body of claim 11, wherein the polyolefin is selected from syndiotactic polypropylene, ethylene octene copolymers, copolymers of polypropylene/polyethylene, and blends thereof.

13. The optical body of claim 10, wherein the at least one strippable skin layer comprises a dye.

14. The optical body of claim 1, further comprising at least one anti-static layer disposed over the at least one warp-resistant layer.

15. An optical body, comprising:

an optical film; and

at least one warp-resistant layer disposed on the optical film, the at least one warp-resistant layer comprising a norbornene-based polymer.

16. A method of making an optical body, the method comprising:

forming at least one warp-resistant layer over an optical film, the at least one warp-resistant layer comprising an intimate mixture of i) polystyrene or a first polystyrene copolymer and ii) a second polystyrene copolymer.

17. The method of claim 16, wherein the step of forming comprises disposing the at least one warp-resistant layer onto the optical film.

18. The method of claim 16, wherein the step of forming comprises co-extruding the at least one warp-resistant layer with the optical film.

19. The method of claim 16, further comprising forming at least one strippable skin layer over the at least one warp-resistant layer.