MULTILAYER OPTICAL FILMS HAVING ONE OR MORE REFLECTION BANDS

• US 20090323180A1
• Filed: 04/30/2009
• Published: 12/31/2009
• Est. Priority Date: 01/13/1998
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Ruff, Andrew T., Wheatley, John A., Weber, Michael F., Ouderkirk, Andrew J., Nevitt, Timothy J., Jonza, James M., Boettcher, Jeffrey A., Liu, Yao Qi
• Granted Patent: US 7,851,054 B2
• Time in Patent Office: Days
• US Class Current: 359/359
• CPC Class Codes: B29C 48/08 flexible, e.g. films
• CPC Class Codes: B29C 48/914 cooling drums
• CPC Class Codes: B29C 48/9165 Electrostatic pinning
• CPC Class Codes: B32B 2307/416 Reflective
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 7/023 Optical properties
• CPC Class Codes: B32B 7/12 using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: B44F 1/14 Iridescent effects
• CPC Class Codes: G02B 5/0841 comprising organic materials, e.g. polymers
• CPC Class Codes: G02B 5/281 designed for the infrared light
• 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: Y10S 428/916 Fraud or tamper detecting
• CPC Class Codes: Y10T 428/12229 Intermediate article [e.g., blank, etc.]
• CPC Class Codes: Y10T 428/1225 Symmetrical
• CPC Class Codes: Y10T 428/12278 Same structure at both ends of plural taper
• CPC Class Codes: Y10T 428/12313 Arranged to avoid lateral displacement
• CPC Class Codes: Y10T 428/24851 Intermediate layer is discontinuous or differential
• CPC Class Codes: Y10T 428/24868 Translucent outer layer
• CPC Class Codes: Y10T 428/24942 : including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/25 : Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• CPC Class Codes: Y10T 428/28 : Web or sheet containing structurally defined element or component and having an adhesive outermost layer
• CPC Class Codes: Y10T 428/2848 : Three or more layers
• CPC Class Codes: Y10T 428/29 : Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
• CPC Class Codes: Y10T 428/31504 : Composite [nonstructural laminate]
• CPC Class Codes: Y10T 428/31786 : Of polyester [e.g., alkyd, etc.]

Abstract

Multilayer optical films having one or more reflection bands are provided. The films include alternating polymeric layers configured to selectively reflect and transmit visible light at a design angle of incidence, where the selective reflection includes first and second visible reflection bands. At least one of the first and second visible reflection bands is a first-order reflection.

Claims

1. A multilayer optical film comprising alternating polymeric layers configured to selectively reflect and transmit visible light at a design angle of incidence, the selective reflection comprising first and second visible reflection bands, wherein at least one of the first and second visible reflection bands is a first-order reflection.

2. The film of claim 1, wherein the film is further configured to selectively reflect infrared light in an infrared reflection band at the design angle of incidence.

3. The film of claim 2, wherein the first visible reflection band comprises a first-order reflection and the second visible reflection band is an overtone of the infrared reflection band.

4. The film of claim 1, wherein the alternating polymeric layers comprise at least a first and second distinguishable set of alternating polymeric layers, and further wherein the reflection bands correspond respectively to the at least first and second sets of layers.

5. The film of claim 4, wherein the first set of layers comprises an f-ratio of less than about 0.5.

6. The film of claim 5, wherein the second set of layers comprises an f-ratio of about 0.5.

7. The film of claim 5, wherein the first set of layers comprises an f-ratio of less than about 0.3.

8. The film of claim 4, wherein the first set of layers comprises an f-ratio of greater than about 0.5.

9. The film of claim 8, wherein the second set of layers comprises an f-ratio of about 0.5

10. The film of claim 8, wherein the first set of layers comprises an f-ratio of greater than about 0.7.

11. The film of claim 1, wherein the first and second visible reflection bands have bandwidths of about 50 nm or less.

12. The film of claim 1, wherein the selective reflection for visible light further comprises a third visible reflection band.

13. The film of claim 12, wherein the film is further configured to selectively reflect infrared light in an infrared reflection band at the design angle of incidence, and further wherein the first and third visible reflection bands are overtones of the infrared reflection band.