Optical article having an antistatic layer

• US 8,092,904 B2
• Filed: 03/31/2006
• Issued: 01/10/2012
• Est. Priority Date: 03/31/2006
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Pellerite, Mark J., Lee, Tzu-Chen, Flaherty Haus, Eileen M.
• Primary Examiner(s): Speer, Timothy
• Assistant Examiner(s): Krupicka, Adam
• Application Number:
  US11/278,172
• Publication Number:
  US 20070231561A1
• Time in Patent Office: 2,111 Days
• Field of Search: None
• US Class Current: 428/323
• CPC Class Codes: B32B 2264/102 Oxide or hydroxide
• CPC Class Codes: B32B 2264/108 Carbon, e.g. graphite particles
• CPC Class Codes: B32B 2307/202 Conductive
• CPC Class Codes: B32B 2307/21 Anti-static
• CPC Class Codes: B32B 2307/42 Polarizing, birefringent, filtering
• CPC Class Codes: B32B 2457/202 LCD, i.e. liquid crystal displays
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/18 characterised by the use of special additives
• CPC Class Codes: C09K 2323/00 Functional layers of liquid crystal optical display excluding electroactive liquid crystal layer characterised by chemical composition
• CPC Class Codes: G02B 2207/121 Antistatic or EM shielding layer
• CPC Class Codes: Y10S 977/952 Display
• 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 428/256 Heavy metal or aluminum or compound thereof
• CPC Class Codes: Y10T 428/265 1 mil or less
• CPC Class Codes: Y10T 428/292 In coating or impregnation
• CPC Class Codes: Y10T 428/30 Self-sustaining carbon mass or layer with impregnant or other layer
• CPC Class Codes: Y10T 428/31507 Of polycarbonate
• CPC Class Codes: Y10T 428/3154 Of fluorinated addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31551 Of polyamidoester [polyurethane, polyisocyanate, polycarbamate, etc.]
• CPC Class Codes: Y10T 428/31721 Of polyimide
• CPC Class Codes: Y10T 428/31725 : Of polyamide
• CPC Class Codes: Y10T 428/31786 : Of polyester [e.g., alkyd, etc.]
• CPC Class Codes: Y10T 428/31935 : Ester, halide or nitrile of addition polymer
• CPC Class Codes: Y10T 428/31938 : Polymer of monoethylenically unsaturated hydrocarbon
• CPC Class Codes: Y10T 428/31971 : Of carbohydrate

Abstract

Disclosed herein is an optical article having a first optical layer; a second optical layer; and an antistatic layer disposed between the first and second optical layers, the antistatic layer having conducting particles having an aspect ratio greater than about 10. The conducting particles may comprise vanadium oxide particles or carbon nanotubes. The optical article may be a brightness enhancement film, a retro-reflecting film, or a reflective polarizer, and be used in a display device, for example, a liquid crystal display device.

Claims

1. An optical article comprising:

a first optical layer;

a second optical layer; and

an antistatic layer disposed between the first and second optical layers, the antistatic layer comprising conducting particles having an aspect ratio greater than about 10 and comprising single-walled carbon nanotubes having a length of 100 um or less and a diameter of 2 nm or less, wherein the antistatic layer has an average total thickness of less than about 10 nm and exhibits a surface resistivity of greater than about 1×

10⁸ ohms/sq.

2. The optical article of claim 1 having a charge decay time of less than about 2 seconds, wherein charge decay time is measured by the time required for static charge of the article to decay to 10% of its initial value.

3. The optical article of claim 1, the first and second optical layers having an adhesion of at least 3 according to ASTM D 3359.

4. The optical article of claim 1, at least one of the first and second optical layers comprising a microstructured surface.

5. The optical article of claim 1, at least one of the first and second optical layers comprising a multilayer optical film, the multilayer optical film comprising alternating layers of at least two different polymeric materials.

6. The optical article of claim 1, the antistatic layer in substantial contact with the first and/or second optical layers.

7. A display device comprising:

a light source;

a display panel; and

the optical article of claim 1 disposed between the light source and the display panel.

8. The display device of claim 7, the display panel comprising a liquid crystal display panel.

9. The optical article of claim 1, the antistatic layer consisting essentially of the conducting particles and a surfactant.

10. The optical article of claim 9, the surfactant comprising a nonionic surfactant.

11. An optical article comprising:

a first optical layer;

a second optical layer; and

an antistatic layer disposed between the first and second optical layers, the antistatic layer comprising conducting particles having an aspect ratio greater than about 10 and comprising multi-walled carbon nanotubes having a length of 100 um or less and a diameter of 30 nm or less, wherein the antistatic layer has an average total thickness of less than about 10 nm and exhibits a surface resistivity of greater than about 1×

10⁸ ohms/sq.

12. The optical article of claim 11 having a charge decay time of less than about 2 seconds, wherein charge decay time is measured by the time required for static charge of the article to decay to 10% of its initial value.

13. The optical article of claim 11, the first and second optical layers having an adhesion of at least 3 according to ASTM D 3359.

14. The optical article of claim 11, at least one of the first and second optical layers comprising a microstructured surface.

15. The optical article of claim 11, at least one of the first and second optical layers comprising a multilayer optical film, the multilayer optical film comprising alternating layers of at least two different polymeric materials.

16. The optical article of claim 11, the antistatic layer in substantial contact with the first and/or second optical layers.

17. A display device comprising:

a light source;

a display panel; and

the optical article of claim 11 disposed between the light source and the display panel.

18. The display device of claim 17, the display panel comprising a liquid crystal display panel.

19. The optical article of claim 11, the antistatic layer consisting essentially of the conducting particles and a surfactant.

20. The optical article of claim 19, the surfactant comprising a nonionic surfactant.