Brightness enhancing film composition

• US 20050124713A1
• Filed: 12/04/2003
• Published: 06/09/2005
• Est. Priority Date: 12/04/2003
• Status: Abandoned Application

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Chien, Bert T., Kaytor, Scott R., Wu, Jung-Sheng, Jones, Clinton L., Pokorny, Richard J., Tapio, Scott M., Olson, David B., Benson, Olester Jr., Toma, Tetsuya, Invie, Judith M., Hennen, Daniel W.
• Application Number:
  US10/727,830
• Publication Number:
  US 20050124713A1
• Time in Patent Office: Days
• US Class Current: 522/6
• CPC Class Codes: C08F 220/301 and one oxygen in the alcohol moiety
• CPC Class Codes: C08F 290/06 Polymers provided for in subclass C08G
• CPC Class Codes: C08F 290/061 Polyesters; Polycarbonates
• CPC Class Codes: C08F 290/067 Polyurethanes; Polyureas
• CPC Class Codes: C08L 33/16 Homopolymers or copolymers of esters containing halogen atoms
• CPC Class Codes: C09D 4/00 Coating compositions, e.g. paints, varnishes or lacquers, based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond ; Coating compositions, based on monomers of macromolecular compounds of groups C09D183/00 - C09D183/16
• CPC Class Codes: G02B 1/04 made of organic materials, e.g. plastics G02B1/08 takes precedence
• CPC Class Codes: G02B 5/045 Prism arrays
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer

Abstract

Polymerizable compositions particularly useful for brightness enhancing films.

Claims

1. A brightness enhancing film comprising the reaction product of a composition comprising:

a) at least 25% of a first monomer consisting of 2,4,6-tribromophenoxyethyl(meth)acrylate

b) less than 50% of a second monomer having a refractive index of at least 1.54;

c) at least one crosslinking agent; and

d) 1.5 pph to 5 pph of a photoinitiator having an absorbance greater than 0.5 at a wavelength of at least 360 nm for a 0.10 wt-% acetonitrile solution with a path length of 1 cm.

2. The brightness enhancing film of claim 1 wherein the absorbance of the photoinitiator is greater than about 0.75 at a wavelength of at least 360 nm.

3. The brightness enhancing film of claim 1 wherein the absorbance of the photoinitiator is greater than about 1 at a wavelength of at least 360 nm.

4. The brightness enhancing film of claim 1 wherein the absorbance of the photoinitiator approaches zero at a wavelength of about 400 nm.

5. The brightness enhancing film of claim 1 wherein the photoinitiator forms two free radicals.

6. The brightness enhancing film of claim 5 wherein the photoinitiator comprises a monoacylphosphine oxide.

7. The brightness enhancing film of claim 1 wherein the second monomer has a refractive index of at least 1.59.

8. The brightness enhancing film of claim 1 wherein the second monomer is a (meth)acrylate functional monomer.

9. The brightness enhancing film of claim 8 wherein a major amount of the second monomer has the structure

10. The brightness enhancing film of claim 8 wherein a major amount of the second monomer has the structure

11. The brightness enhancing film of claim 1 wherein the crosslinking agent comprises a hexa-functional aromatic urethane oligomer.

12. The brightness enhancing film of claim 1 wherein the composition further comprises at least one non-halogenated (meth)acrylate-functional comonomer.

13. The brightness enhancing film of claim 12 wherein the at least one non-halogenated (meth)acrylate-functional comonomer is present in the composition in an amount ranging from about 10 wt-% to 15 wt-%.

14. An article comprising the brightness enhancing film of claim 1 and a second optical film in contact with the brightness enhancing film.

15. The article of claim 14 wherein the second optical film is a diffuser.

16. The article of claim 14 wherein the second optical film is an absorbing polarizer.

17. The article of claim 14 wherein the second optical film is a reflective polarizer.

18. The article of claim 14 wherein the second optical film comprises a prismatic structure.

19. A brightness enhancing film comprising the reaction product of a composition comprising:

a) at least 25% of a first monomer consisting of 2,4,6-tribromophenoxyethyl(meth)acrylate;

b) less than 50% of a second monomer having a refractive index of at least 1.54;

c) at least one crosslinking agent; and

d) 0.75 wt-% to 3.0 wt-% of a bisacylphosphine oxide photoinitiator.

20. An article comprising the brightness enhancing film of claim 19 and a second optical film in contact with the brightness enhancing film.

21. The article of claim 20 wherein the second optical film is a diffuser.

22. The article of claim 20 wherein the second optical film is an absorbing polarizer.

23. The article of claim 20 wherein the second optical film is a reflective polarizer.

24. A polymerizable resin composition comprising:

a) at least 25% of a first monomer consisting of 2,4,6, tribromophenoxyethyl(meth)acrylate

b) less than 50% of a second monomer having a refractive index of at least 1.54;

c) at least one crosslinking agent; and

d) 1.5 pph to 5 pph of a photoinitiator having an absorbance greater than 0.5 at a wavelength of at least 360 nm for a 0.10 wt-% acetonitrile solution with a path length of 1 cm or 0.75 wt-% to 3.0 wt-% of a bisacylphosphine oxide photoinitiator.

25. An optical material comprising the reaction product of claim 24.

26. The optical material of claim 24 wherein the material is a film.

27. The optical material of claim 24 wherein the film comprises a microstructured surface.