Durable optical element

• US 7,524,543 B2
• Filed: 10/30/2007
• Issued: 04/28/2009
• Est. Priority Date: 09/12/2003
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Goenner, Emily S., Jones, Clinton L., Kolb, Brant U., Haak, Christopher A., Brady, John T.
• Primary Examiner(s): WU, SHEAN CHIU
• Application Number:
  US11/927,760
• Publication Number:
  US 20080050560A1
• Time in Patent Office: 546 Days
• Field of Search: 428/1.1, 428/148, 428/1.3, 428/500, 264/299, 977/779
• US Class Current: 428/1.3
• 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: C09K 2323/03 Viewing layer characterised by chemical composition
• CPC Class Codes: C09K 2323/031 Polarizer or dye
• CPC Class Codes: C09K 2323/05 Bonding or intermediate layer characterised by chemical composition, e.g. sealant or spacer
• CPC Class Codes: C09K 2323/051 Inorganic, e.g. glass or silicon oxide
• CPC Class Codes: C09K 2323/053 Organic silicon compound, e.g. organosilicon
• CPC Class Codes: C09K 2323/06 Substrate layer characterised by chemical composition
• CPC Class Codes: G02B 5/0226 having particles on the surface
• CPC Class Codes: G02B 5/0231 the surface having microprismatic or micropyramidal shape macroscopic prism arrays G02B5/045
• CPC Class Codes: G02B 5/0284 used in reflection
• CPC Class Codes: G02B 5/045 Prism arrays
• CPC Class Codes: G02B 5/124 plural reflecting elements forming part of a unitary plate or sheet
• CPC Class Codes: G02B 6/0051 Diffusing sheet or layer
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02B 6/0056 for producing polarisation effects, e.g. by a surface with polarizing properties or by an additional polarizing elements
• CPC Class Codes: Y10S 428/913 Material designed to be responsive to temperature, light, moisture
• CPC Class Codes: Y10S 977/773 Nanoparticle, i.e. structure having three dimensions of 100 nm or less
• CPC Class Codes: Y10S 977/778 within specified host or matrix material, e.g. nanocomposite films
• CPC Class Codes: Y10S 977/779 Possessing nanosized particles, powders, flakes, or clusters other than simple atomic impurity doping
• CPC Class Codes: Y10S 977/84 Manufacture, treatment, or detection of nanostructure
• CPC Class Codes: Y10S 977/932 : for electronic or optoelectronic application
• CPC Class Codes: Y10S 977/939 : Electron emitter, e.g. spindt emitter tip coated with nanoparticles
• CPC Class Codes: Y10S 977/952 : Display
• CPC Class Codes: Y10S 977/962 : for carrying or transporting
• CPC Class Codes: Y10T 428/24355 : Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
• CPC Class Codes: Y10T 428/24413 : Metal or metal compound
• CPC Class Codes: Y10T 428/24479 : including variation in thickness
• CPC Class Codes: Y10T 428/24521 : with component conforming to contour of nonplanar surface
• CPC Class Codes: Y10T 428/24545 : Containing metal or metal compound
• CPC Class Codes: Y10T 428/24612 : Composite web or sheet
• 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 428/252 : Glass or ceramic [i.e., fired or glazed clay, cement, etc.] [porcelain, quartz, etc.]
• CPC Class Codes: Y10T 428/254 : Polymeric or resinous material
• CPC Class Codes: Y10T 428/256 : Heavy metal or aluminum or compound thereof
• CPC Class Codes: Y10T 428/257 : Iron oxide or aluminum oxide
• CPC Class Codes: Y10T 428/31504 : Composite [nonstructural laminate]
• CPC Class Codes: Y10T 428/31678 : Of metal
• CPC Class Codes: Y10T 428/31855 : Of addition polymer from unsaturated monomers

Abstract

A durable optical film or element includes a polymerized structure having a microstructured surface and a plurality of surface modified colloidal nanoparticles of silica, zirconia, or mixtures thereof. Display devices including the durable microstructured film are also described.

Claims

1. An optical film comprising:

a microstructured surface comprised of a polymerized composition comprising a resin and a plurality of surface modified colloidal nanoparticles wherein the surface modified colloidal nanoparticle comprise a combination of surface treatment agents.

2. The optical film of claim 1 wherein the resin has a refractive index of at least 1.50.

3. The optical film of claim 1 wherein the total composition has a refractive index greater than 1.56.

4. The optical film of claim 1 wherein the resin and nanoparticles comprise a substantially homogeneous composition.

5. The optical film of claim 1 wherein the surface treatment agents have a first end attached to the nanoparticle surface.

6. The optical film of claim 5 wherein the surface treatment agents have a second end that imparts compatibility of the nanoparticles with the resin.

7. The brightness enhancing film of claim 1 wherein at least one surface treatment agent is selected from the group consisting of alcohols, amines, carboxylic acid, sulfonic acids, phosphonic acids, silanes, titanates, and mixtures thereof.

8. The optical film of claim 6 wherein at least one surface treatment agent has a functional group co-polymerizable with the resin.

9. The optical film of claim 8 wherein the co-polymerizable group is an ethylenically unsaturated group.

10. The optical film of claim 9 wherein the ethylenically unsaturated group is methacrylate group, an acrylate group, or a vinyl group.

11. The optical film of claim 1 wherein at least one surface treatment agent is selected from the group consisting of isooctyl trimethoxy-silane, N-(3-triethoxysilylpropyl)methoxyethoxyethoxyethyl carbamate, N-(3-triethoxysilylpropyl)methoxyethoxyethoxyethyl carbamate, 3-(methacryloyloxy)propyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-(methacryloyloxy)propyltriethoxysilane, 3-(methacryloyloxy)propylmethyldimethoxysilane, 3-(acryloyloxypropyl)methyldimethoxysilane, 3-(methacryloyloxy)propyldimethylethoxysilane, 3-(methacryloyloxy)propyldimethylethoxysilane, vinyldimethylethoxysilane, phenyltrimethoxysilane, n-octyltrimethoxysilane, dodecyltrimethoxysilane, octadecyltrimethoxysilane, propyltrimethoxysilane, hexyltrimethoxysilane, vinylmethyldiacetoxysilane, vinylmethyldiethoxysilane, vinyltriacetoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, vinyltrimethoxysilane, vinyltriphenoxysilane, vinyltri-t-butoxysilane, vinyltris-isobutoxysilane, vinyltriisopropenoxysilane, vinyltris(2-methoxyethoxy)silane, styrylethyltrimethoxysilane, mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, acrylic acid, methacrylic acid, oleic acid, stearic acid, dodecanoic acid, 2-[2-(2-methoxyethoxy)ethoxy]acetic acid, beta-carboxyethylacrylate, 2-(2-methoxyethoxy)acetic acid, methoxyphenyl acetic acid, and mixtures thereof.

12. The optical film of claim 11 wherein at least one surface treatment agent is 2-[2-(2-methoxyethoxy)ethoxy]acetic acid.

13. The optical film of claim 11 wherein at least one surface treatment agent is beta-carboxyethylacrylate.

14. The optical film of claim 8 wherein the co-polymerizable group is a cyclic functional group subject to ring opening polymerization.

15. The optical film of claim 14 wherein the cyclic functional group comprises a heteratom selected from oxygen, sulfur, or nitrogen.

16. The optical film of claim 15 wherein the cyclic functional group comprises an epoxide.

17. The optical film of claim 1 wherein the nanoparticles comprise silica nanoparticles.

18. The optical film of claim 17 wherein the silica nanoparticles have a particle size from 5 to 75 nm.

19. The optical film of claim 17 wherein silica nanoparticles have a particle size from 10 to 30 nm.

20. The optical film of claim 17 wherein the silica nanoparticles comprise a silane surface treatment.

21. The optical film of claim 1 wherein the nanoparticles comprise zirconia, titania, antimony oxides, alumina, tin oxides, mixed metal oxides thereof, or mixtures thereof.

22. The optical film of claim 1 wherein the nanoparticles comprise zirconia.

23. The optical film of claim 22 wherein the zirconia nanoparticles have a particle size from 5 to 50 nm.

24. The optical film of claim 22 wherein the zirconia nanoparticles have a particle size from 5 to 15 nm.

25. The optical film of claim 22 wherein the zirconia nanoparticles comprise a silane surface treatment.

26. The optical film of claim 22 wherein the zirconia nanoparticles comprise a carboxylic acid surface treatment.

27. The optical film of claim 1 wherein the nanoparticles comprise silica and zirconia.

28. The optical film of claim 1 wherein the optical film is a brightness enhancing film.

29. The optical film of claim 28 wherein the microstructured surface comprises light-diffusing elements.

30. An optical film comprising:

a microstructured surface comprised of a polymerized composition comprising a resin, a plurality of surface modified colloidal silica nanoparticles, and a plurality of surface modified colloidal zirconia nanoparticles.

31. The optical film of claim 30 wherein the microstructured surface comprises light-diffusing elements.

32. A brightness enhancing film comprising

a microstructured surface comprised of a polymerized composition having a refractive index of at least 1.50 and a plurality of surface modified colloidal nanoparticles comprising a combination of surface treatment agents wherein the total composition has a refractive index greater than 1.56.

33. The brightness enhancing film of claim 32 wherein the surface modified nanoparticles comprise zirconia nanoparticles.

34. The brightness enhancing film of claim 33 wherein the zirconia nanoparticles comprise a carboxylic acid surface treatment.

35. The brightness enhancing film of claim 32 wherein the polymerized resin composition comprises a reactive diluent having a refractive index greater than 1.50.

36. The brightness enhancing film of claim 35 wherein the reactive diluent comprises 2-phenoxyethyl acrylate.

37. The brightness enhancing film of claim 32 wherein the polymerized composition comprises a reactive diluent, oligomer, and crosslinking monomer.

38. A method of preparing a microstructure-bearing article comprising

preparing a substantially solvent free polymerizable resin comprising a plurality of surface modified colloidal nanoparticles wherein the total composition has a refractive index greater than 1.56;

depositing the polymerizable resin composition onto a molding surface to fill cavities of the molding surface; and

curing the polymerizable composition between a preformed substrate and the molding surface.

39. The method of claim 38 wherein the polymerizable resin comprises photoinitiator and the polymerizable composition is cured by exposure to an ultraviolet light source.

40. A brightness enhancing film prepared by the method of claim 38.