Brightness enhancement film

• US 10,001,587 B2
• Filed: 03/27/2015
• Issued: 06/19/2018
• Est. Priority Date: 03/27/2015
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Liu, Richard Y.
• Primary Examiner(s): Zhang, Ruiyun
• Application Number:
  US14/671,148
• Publication Number:
  US 20160282523A1
• Time in Patent Office: 1,180 Days
• Field of Search: 428 11, 428 13, 428 131, 428480, 349 61, 349 62, 349 64, 349112, 359599, 359625
• CPC Class Codes: C08L 67/00 Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain of polyester-amides C08L77/12; of polyester-imides C08L79/08; Compositions of derivatives of such polymers
• CPC Class Codes: C09K 2323/03 Viewing layer characterised by chemical composition
• CPC Class Codes: C09K 2323/031 Polarizer or dye
• CPC Class Codes: G02B 1/04 made of organic materials, e.g. plastics G02B1/08 takes precedence
• CPC Class Codes: G02B 1/14 Protective coatings, e.g. hard coatings
• CPC Class Codes: G02B 5/0294 adapted to provide an additional optical effect, e.g. anti-reflection or filter
• CPC Class Codes: G02B 5/045 Prism arrays

Abstract

A brightness enhancement film including a monolithic layer and a microstructured layer adjacent the monolithic layer. The microstructured layer has a first major surface and an opposing second major surface. The first major surface includes a first plurality of microstructures and the second major surface faces the first monolithic layer. The monolithic layer includes a polyester that includes at least about 70 mole percent naphthalenedicarboxylate groups based on total carboxylate groups. The polyester may include one or more catalysts having a total concentration by weight in a range of 10 to 1000 ppm. The first monolithic layer has a thickness in the range of about 5 μm to about 300 μm. The first monolithic layer may be substantially free of non-catalyst particulate matter and may have a haze of less than 1 percent.

Claims

1. A brightness enhancement film comprising:

a first monolithic layer;

a first microstructured layer adjacent the first monolithic layer, the first microstructured layer having a first major surface and an opposing second major surface, the first major surface comprising a first plurality of microstructures, and the second major surface facing the first monolithic layer;

a second monolithic layer immediately adjacent the first monolithic layer opposite the first microstructured layer; and

a third monolithic layer immediately adjacent the second monolithic layer opposite the first monolithic layer,

wherein the first monolithic layer comprises a first polyester including at least about 70 mole percent naphthalenedicarboxylate groups based on total carboxylate groups and including one or more catalysts having a total concentration by weight in a range of 10 to 1000 ppm;

wherein each of the first and third monolithic layers has a thickness in the range of about 5 μ

m to about 300 μ

m, and the second monolithic layer has a thickness greater than the thickness of the first monolithic layer; and

wherein each of the first and third monolithic layers is substantially free of light scattering, non-catalyst particulate matter.

2. The brightness enhancement film of claim 1, further comprising a second microstructured layer disposed between the first microstructured layer and the first monolithic layer, the second microstructured layer including light diffusing microstructures.

3. The brightness enhancement film of claim 1, further comprising a durable layer adjacent the first monolithic layer opposite the first microstructured layer.

4. The brightness enhancement film of claim 3, wherein the durable layer has a microstructured surface, the microstructured surface including light diffusing microstructures.

5. The brightness enhancement film of claim 1, wherein the first monolithic layer has an out-of-plane birefringence having an absolute value of at least about 0.15.

6. The brightness enhancement film of claim 1,

wherein the third monolithic layer comprises a second polyester including at least about 70 mole percent naphthalenedicarboxylate groups based on total carboxylate groups and including one or more catalysts having a total concentration by weight in a range of 10 to 1000 ppm.

7. The brightness enhancement film of claim 1, further comprising a second microstructured layer adjacent the first monolithic layer opposite the first microstructured layer.

8. The brightness enhancement film of claim 7, wherein the first plurality of microstructures include linear prisms extending in a first direction and the second microstructured layer includes a second plurality of microstructures, wherein the second plurality of microstructures include linear prisms extending in a second direction different from the first direction.

9. The brightness enhancement film of claim 1, wherein the first monolithic layer has a haze less than about 1 percent.

10. A display comprising the brightness enhancement film of claim 1.

23. The brightness enhancement film of claim 1 having an overall thickness less than about 300 μ

m.

11. A brightness enhancement film comprising:

a first monolithic layer;

a first microstructured layer adjacent the first monolithic layer, the first microstructured layer having a first major surface and an opposing second major surface, the first major surface comprising a first plurality of microstructures, and the second major surface facing the first monolithic layer;

a second monolithic layer immediately adjacent the first monolithic layer opposite the first microstructured layer; and

a third monolithic layer immediately adjacent the second monolithic layer opposite the first monolithic layer,

wherein the first monolithic layer comprises a first polyester including at least about 70 mole percent naphthalenedicarboxylate groups based on total carboxylate groups;

wherein each of the first and third monolithic layers has a thickness in the range of about 5 μ

m to about 300 μ

m, and the second monolithic layer has a thickness greater than the thickness of the first monolithic layer; and

wherein each of the first and third monolithic layers has a haze less than about 1 percent.

12. The brightness enhancement film of claim 11, further comprising a second microstructured layer disposed between the first microstructured layer and the first monolithic layer, the second microstructured layer including light diffusing microstructures.

13. The brightness enhancement film of claim 11, further comprising a durable layer adjacent the first monolithic layer opposite the first microstructured layer.

14. The brightness enhancement film of claim 13, wherein the durable layer has a microstructured surface, the microstructured surface including light diffusing microstructures.

15. The brightness enhancement film of claim 11, wherein the first monolithic layer has an out-of-plane birefringence having an absolute value of at least about 0.15.

16. The brightness enhancement film of claim 11,

wherein the third monolithic layer comprises a second polyester including at least about 70 mole percent naphthalenedicarboxylate groups based on total carboxylate groups.

17. The brightness enhancement film of claim 11, further comprising a second microstructured layer adjacent the first monolithic layer opposite the first microstructured layer.

18. The brightness enhancement film of claim 17, wherein the first plurality of microstructures include linear prisms extending in a first direction and the second microstructured layer includes a second plurality of microstructures wherein the second plurality of microstructures include linear prisms extending in a second direction different from the first direction.

19. The brightness enhancement film of claim 11, wherein the first monolithic layer is substantially free of non-catalyst particulate matter.

20. The brightness enhancement film of claim 11, wherein the first monolithic layer comprises one or more catalysts having a total concentration by weight in a range of 10 to 1000 ppm.

21. A display comprising the brightness enhancement film of claim 11.

22. The brightness enhancement film of claim 11 having an overall thickness less than about 300 μ

m.