Light management films with zirconia particles

• US 7,833,621 B2
• Filed: 10/14/2008
• Issued: 11/16/2010
• Est. Priority Date: 03/11/2005
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Jones, Clint L., Goenner, Emily S., Kolb, Brant U., Olson, David B., Cowher, John T.
• Primary Examiner(s): Shosho; Callie E
• Assistant Examiner(s): ROBINSON, ELIZABETH A
• Application Number:
  US12/250,660
• Publication Number:
  US 20090047486A1
• Time in Patent Office: 763 Days
• Field of Search: 428/323
• US Class Current: 428/323
• CPC Class Codes: C01G 25/00 Compounds of zirconium
• CPC Class Codes: C01G 25/02 Oxides
• CPC Class Codes: C01P 2002/52 containing elements as dopants
• CPC Class Codes: C01P 2002/72 by d-values or two theta-values, e.g. as X-ray diagram
• 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: Y10T 428/24893 including particulate material
• CPC Class Codes: Y10T 428/25 Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles

Abstract

Light management films and methods of making light management films are described. The light management films contain an optical layer that contains polymeric material and zirconia particles. The zirconia particles are colloidal, crystalline, substantially non-associated, and have a narrow size distribution.

Claims

1. A light management film comprising an optical layer having a microstructured surface, the optical layer comprising

(a) a polymeric material;

and

a plurality of zirconia particles surface-modified with a carboxylic acid, wherein the zirconia particles comprise 1 to 8 weight percent yttrium based on a weight of inorganic oxides in the zirconia particles, and the zirconia particles have an average primary particle size no greater than 30 nanometers and a ratio of intensity-average particle size to volume-average particle size no greater than 3.0.

2. The light management film of claim 1, wherein the light management film is selected from a brightness enhancement film, a reflective film, or a turning film.

3. The light management film of claim 1, wherein the light management film is a brightness enhancement film.

4. The light management film of claim 1, further comprising a base layer adjacent to the optical layer.

5. The light management film of claim 1, wherein the optical layer comprises up to 80weight percent zirconia particles based on the weight of the optical layer.

6. The light management film of claim 1, wherein the polymeric material has a refractive index of at least 1.50 and is a reaction product of a polymerizable composition comprising an oligomeric material, a reactive diluent, and a multi-functional cross-linking monomer.

7. The light management film of claim 1, wherein the polymeric material is a reaction product of a polymerizable composition comprising a cross-linking agent and a monomer of Formula I

8. The light management film of claim 7, the polymerizable composition further comprising a monomer of Formula II

9. The light management film of claim 7 wherein each X is hydrogen.

10. The light management film of claim 7 wherein Y is selected from —

C(CH₃)₂— and

—

CH₂—

.

11. The light management film of claim 1, wherein the polymeric material is a reaction product of a polymerizable composition comprising a monomer of Formula II

12. The light management film of claim 1, wherein the polymeric material is the reaction product of a polymerizable composition comprising a brominated, alkyl-substituted phenyl (meth)acrylate.

13. The light management film of claim 1, wherein the polymerizable composition comprises a monomer of Formula III, a monomer of Formula IV, or a combination thereof

14. The light management film of claim 1, wherein the polymerizable composition comprises a monomer of Formula V

15. The light management film of claim 1, wherein the polymeric material is a thermoplastic material.

16. The light management film of claim 1, wherein the zirconia particles are surface modified with a first carboxylic acid that is free of a polymerizable group and a second carboxylic acid that contains a polymerizable group.

17. The light management film of claim 1, wherein the zirconia particles are surface-modified with a silane.

18. The light management film of claim 1 wherein the zirconia particles have a dispersion index of 1 to 3.

19. The light management film of claim 1 wherein the zirconia particles have a crystal structure that is at least 70 percent cubic, tetragonal, or a combination thereof.

20. The light management film of claim 1 wherein the zirconia particles have a dispersion index of 1 to 3, a ratio of intensity-average particle size to volume-average particle size no greater than 3.0, and a crystal structure that is at least 70 percent cubic, tetragonal, or a combination thereof.

21. A light management film comprising an optical layer having a microstructured surface, the optical layer comprising

(a) a polymeric material;

and

(b) a plurality of zirconia particles surface-modified with beta-carboxyethylethyl acrylate, mono-2-(methacryloxyethyl)succinate, or a combination thereof;

wherein the zirconia particles comprise 1 to 8 weight percent yttrium based on a weight of inorganic oxides in the zirconia particles, and the zirconia particles have an average primary particle size no greater than 30 nanometers and a ratio of intensity-average particle size to volume-average particle size no greater than 3.0.

22. The light management film of claim 21 wherein the zirconia particles have a dispersion index of 1 to 3.

23. The light management film of claim 21 wherein the zirconia particles have a crystal structure that is at least 70 percent cubic, tetragonal, or a combination thereof.

24. The light management film of claim 21 wherein the zirconia particles have a dispersion index of 1 to 3, a ratio of intensity-average particle size to volume-average particle size no greater than 3.0, and a crystal structure that is at least 70 percent cubic, tetragonal, or a combination thereof.

25. A light management film comprising an optical layer having a microstructured surface, the optical layer comprising

(b) a polymeric material;

and

a plurality of zirconia particles surface-modified with a carboxylic acid, wherein the zirconia particles comprise 1 to 8 weight percent yttrium based on a weight of inorganic oxides in the zirconia particles, and the zirconia particles have an average primary particle size no greater than 30 nanometers and a dispersion index of 1 to 3.

26. A light management film comprising an optical layer having a microstructured surface, the optical layer comprising

(a) a polymeric material;

and

(b) a plurality of zirconia particles surface-modified with beta-carboxyethylethyl acrylate, mono-2-(methacryloxyethyl)succinate, or a combination thereof wherein the zirconia particles comprise 1 to 8 weight percent yttrium based on a weight of inorganic oxides in the zirconia particles, and the zirconia particles have an average primary particle size no greater than 30 nanometers and a dispersion index of 1 to 3.