POST-FORMABLE MULTILAYER OPTICAL FILMS AND METHODS OF FORMING

• US 20090155540A1
• Filed: 02/24/2009
• Published: 06/18/2009
• Est. Priority Date: 01/13/1998
• Status: Abandoned Application

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Jouza, James M., Keller, Janet T., Weber, Michael F., Ouderkirk, Andrew J., Benson, Olester JR., Merrill, William W., Stumo, Roger J.
• Application Number:
  US12/391,738
• Publication Number:
  US 20090155540A1
• Time in Patent Office: Days
• US Class Current: 428/172
• CPC Class Codes: B32B 2307/418 Refractive
• CPC Class Codes: B32B 2307/42 Polarizing, birefringent, filtering
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/36 comprising polyesters
• CPC Class Codes: B32B 3/28 characterised by a layer comprising a deformed thin sheet , i.e. the layer having its entire thickness deformed out of the plane, e.g. corrugated, crumpled B32B29/08 takes precedence
• CPC Class Codes: B32B 7/023 Optical properties
• CPC Class Codes: B41M 3/14 Security printing securities B42D25/29
• CPC Class Codes: B42D 25/29 Securities; Bank notes
• CPC Class Codes: B44F 1/14 Iridescent effects
• CPC Class Codes: G02B 5/0841 comprising organic materials, e.g. polymers
• CPC Class Codes: G02B 5/287 comprising at least one layer of organic material
• CPC Class Codes: G02B 5/3033 in the form of a thin sheet or foil, e.g. Polaroid
• CPC Class Codes: G02B 5/305 including organic materials, e.g. polymeric layers
• CPC Class Codes: G02B 5/3083 Birefringent or phase retarding elements G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001
• CPC Class Codes: G02B 5/32 Holograms used as optical elements
• CPC Class Codes: Y10S 428/91 Product with molecular orientation
• CPC Class Codes: Y10T 428/24479 including variation in thickness
• CPC Class Codes: Y10T 428/24612 Composite web or sheet
• CPC Class Codes: Y10T 428/24628 Nonplanar uniform thickness material
• CPC Class Codes: Y10T 428/24694 Parallel corrugations
• CPC Class Codes: Y10T 428/31504 : Composite [nonstructural laminate]
• CPC Class Codes: Y10T 428/31855 : Of addition polymer from unsaturated monomers

Abstract

Articles including post-formed multilayer optical films with layers of at least one strain-induced birefringent material, methods of manufacturing such articles by post-forming multilayer optical films, and multilayer optical films that are particularly well-suited to post-forming operations are disclosed. The articles, methods and multilayer optical films of the present invention allow for post-forming of multilayer optical films including strain-induced index of refraction differentials while retaining the desired optical properties of the multilayer optical films.

Claims

1. An article comprising a portion formed from a moldable material and a multilayer optical film having a first major surface attached to the portion and a second major surface disposed generally opposite the first major surface, the multilayer optical film comprising an optical stack having a plurality of layers, the layers comprising at least one birefringent polymer and at least one second polymer, wherein the optical stack comprises a first index of refraction differential between layers in the optical stack along a first axis and a second index of refraction differential along a second axis that is perpendicular to the first axis, wherein the second index of refraction differential is different than the first index of refraction differential, and wherein at least the second major surface comprises a three-dimensional permanent deformation.

2. The article of claim 1, wherein the three-dimensional permanent deformation has a curved shape.

3. The article of claim 1, wherein the three-dimensional permanent deformation comprises a depressed area.

4. The article of claim 1, wherein the three-dimensional permanent deformation comprises a raised area.

5. The article of claim 1, wherein the three-dimensional permanent deformation comprises a raised area in the second major surface and a depressed area in the first major surface, wherein the raised area is disposed opposite the depressed area.

6. An article comprising a multilayer optical film comprising an optical stack having a plurality of layers, the layers comprising at least one birefringent polymer and at least one second polymer, wherein the optical stack comprises a first index of refraction differential between layers in the optical stack along a first axis and a second index of refraction differential along a second axis that is perpendicular to the first axis, wherein the second index of refraction differential is different than the first index of refraction differential, and wherein the first and second major surfaces each comprise a plurality of undulations comprising arcuate portions, valley portions, and intermediate portions connecting the arcuate portions and the valley portions.

7. The article of claim 6, wherein the undulations have sinusoidal shapes.

8. The article of claim 6, wherein the arcuate portions and the valley portions are generally flat.

9. The article of claim 6, wherein the multilayer optical film comprises a reflective polarizer.

10. The article of claim 6, wherein the multilayer optical film comprises a mirror.