OPTICAL ARTICLE AND METHOD OF MAKING

• US 20080252980A1
• Filed: 04/16/2007
• Published: 10/16/2008
• Est. Priority Date: 04/16/2007
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Hebrink, Timothy J., Yu, Ta-Hua, Jonza, James M., Bay, Randy S., Clarke, Graham M., Collier, Terry O., Lucking, Raymond L.
• Granted Patent: US 7,604,381 B2
• Time in Patent Office: Days
• US Class Current: 359/599
• CPC Class Codes: B29D 11/0073 Optical laminates
• CPC Class Codes: B29D 11/00798 Producing diffusers
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: C09K 2323/03 Viewing layer characterised by chemical composition

Abstract

Disclosed herein is an optical article having a top layer with a structured surface that collimates light, a core layer secured to the top layer opposite the structured surface, and a bottom layer secured to the core layer opposite the top layer. Either the top layer or the core layer includes a first extrudable polymer having a flexural modulus of greater than 2.5 GPa, and the other layer includes a second extrudable polymer having a flexural modulus of 2.5 GPa or less, an impact strength of greater than about 40 J/m, and tensile elongation at break of greater than about 5%. The bottom layer includes a third extrudable polymer. The bottom layer of the optical article may be structured to diffuse light. One or two optical articles may be secured to an optical film such as a polarizer film. Methods and display devices are also disclosed herein.

Claims

1. An optical article, comprising:

a top layer having a top structured surface that collimates light;

a core layer secured to the top layer opposite the top structured surface; and

a bottom layer secured to the core layer opposite the top layer;

wherein;

either the top layer or the core layer comprises a first extrudable polymer having a flexural modulus of greater than 2.5 GPa as measured according to ASTM D790, and the other layer comprises a second extrudable polymer, the second extrudable polymer having a flexural modulus of 2.5 GPa or less as measured according to ASTM D790, an impact strength of greater than about 40 J/m as measured according to ASTM D256, and tensile elongation at break of greater than about 5% as measured according to ASTM D638; and

the bottom layer comprises a third extrudable polymer.

2. The optical article of claim 1, wherein the top structured surface diffuses light.

3. The optical article of claim 1, wherein the top structured surface comprises a plurality of structures having lenticular or prismatic shapes, or a combination thereof.

4. The optical article of claim 3, wherein the structures have random shapes and sizes.

5. The optical article of claim 1, wherein the top structured surface comprises a plurality of structures having hemispherical, ellipsoidal, conical, parabolic, or pyramidal shapes, or combinations thereof.

6. The optical article of claim 5, wherein the structures have random shapes and sizes.

7. The optical article of claim 1, wherein the top structured surface comprises a plurality of structures having random shapes and sizes.

8. The optical article of claim 1, wherein the top structured surface comprises a plurality of structures, each structure having a dimension of from about 1 to about 100 um.

9. The optical article of claim 1, the first extrudable polymer having a flexural modulus greater than about 3 GPa as measured according to ASTM D790.

10. The optical article of claim 1, the top layer comprising the first extrudable polymer, and the first extrudable polymer having a Tg of less than about 140°

C.

11. The optical article of claim 10, the first extrudable polymer having a Tg of from about 85 to about 120°

C.

12. The optical article of claim 1, the first extrudable polymer comprising one or more polymers selected from the group consisting of styrene acrylonitrile copolymers;

styrene (meth)acrylate copolymers;

polymethylmethacrylate;

styrene maleic anhydride copolymers;

nucleated semi-crystalline polyesters;

copolymers of polyethylenenaphthalate;

polyimides;

polyimide copolymers;

polyetherimide;

polystyrenes;

syndiodactic polystyrene;

polyphenylene oxides; and

copolymers of acrylonitrile, butadiene, and styrene.

13. The optical article of claim 1, the top layer comprising fibers, spheres, nanoparticles, or a combination thereof.

14. The optical article of claim 1, the second extrudable polymer having a tensile elongation at break of greater than about 10% as measured according to ASTM D638.

15. The optical article of claim 1, the top layer comprising the second extrudable polymer, and the second extrudable polymer having a Tg of less than about 140°

C.

16. The optical article of claim 15, the second extrudable polymer having a Tg of from about 85 to about 120°

C.

17. The optical article of claim 1, the second extrudable polymer comprising one or more polymers selected from the group consisting of polycarbonates;

polyesters;

blends of polycarbonates and polyesters;

copolymers of styrene;

copolymers of acrylonitrile, butadiene, and styrene;

block copolymers of styrene with alkene-polymerized midblocks;

acid and/or anhydride functionalized polyolefins; and

copolymers of polyethylene and polypropylene.

18. The optical article of claim 1, the core layer comprising fibers, spheres, nanoparticles, or a combination thereof.

19. The optical article of claim 1, wherein the top layer comprises the first extrudable polymer, and the first and third extrudable polymers are the same.

20. The optical article of claim 1, the third extrudable polymer comprising one or more polymers selected from the group consisting of polyesters, functionally-modified polyolefins, and polyurethanes.

21. The optical article of claim 1, the bottom layer comprising a bottom structured surface opposite the core layer, wherein the bottom structured surface diffuses light.

22. The optical article of claim 1, the bottom layer comprising a bottom structured surface opposite the core layer, wherein the bottom structured surface decollimates light less than the top structured surface collimates light.

23. The optical article of claim 1,

the top structured surface comprising a plurality of convex structures;

and

the bottom layer comprising a bottom structured surface opposite the core layer, the bottom structured surface comprising a plurality of concave structures.

24. The optical article of claim 1,

the structured surface comprising a plurality of concave structures;

and

the bottom layer comprising a bottom structured surface opposite the core layer, the bottom structured surface comprising a plurality of convex structures.

25. The optical article of claim 23, further comprising:

a rough strippable skin layer operatively connected to the bottom structured surface, the rough strippable skin layer comprising a continuous phase and a disperse phase, the continuous phase comprising a continuous phase polymer, and the disperse phase comprising particles or a disperse phase polymer, the disperse phase polymer being immiscible with the continuous phase polymer.

26. The optical article of claim 1, further comprising:

a rough strippable skin layer operatively connected to the top structured surface, the rough strippable skin layer comprising a continuous phase and a disperse phase, the continuous phase comprising a continuous phase polymer, and the disperse phase comprising particles or a disperse phase polymer, the disperse phase polymer being immiscible with the continuous phase polymer.

27. The optical article of claim 1, further comprising:

a first rough strippable skin layer operatively connected to the top structured surface, the first rough strippable skin layer comprising a first continuous phase and a first disperse phase, the first continuous phase comprising a first continuous phase polymer, and the first disperse phase comprising first particles or a first disperse phase polymer, the first disperse phase polymer being immiscible with the first continuous phase polymer; and

a second rough strippable skin layer operatively connected to the bottom structured surface, the second rough strippable skin layer comprising a second continuous phase and a second disperse phase, the second continuous phase comprising a second continuous phase polymer, and the second disperse phase comprising second particles or a second disperse phase polymer, the second disperse phase polymer being immiscible with the second continuous phase polymer.

28. The optical article of claim 1, wherein the optical article has a birefringence of less than about 0.01.

33. An optical body comprising:

the optical article of claim 1, and

an optical film secured to the bottom layer opposite the core layer, the optical film comprising a polarizer film, a reflective polarizer film, a diffuse blend reflective polarizer film, a diffuser film, a brightness enhancing film, a turning film, a mirror film, or a combination thereof.

34. The optical body of claim 33, further comprising:

a rough strippable skin layer operatively connected to the top structured surface, the rough strippable skin layer comprising a continuous phase and a disperse phase, the continuous phase comprising a continuous phase polymer, and the disperse phase comprising particles or a disperse phase polymer, the disperse phase polymer being immiscible with the continuous phase polymer.

43. A method of making an optical body, comprising:

providing the optical article of claim 1;

providing an optical film comprising a polarizer film, a reflective polarizer film, a diffuse blend reflective polarizer film, a diffuser film, a brightness enhancing film, a turning film, a mirror film, or a combination thereof, and

securing the optical film to the bottom layer opposite the core layer.

46. A display device comprising:

a display panel,

one or more light sources, and

the optical article of claim 1 disposed between the display panel and the one or more light sources.

47. A display device comprising:

a display panel,

one or more light sources, and

the optical body of claim 33 disposed between the display panel and the one or more light sources.

29. A method of making an optical article, comprising:

providing a first extrudable polymer having a flexural modulus greater than 2.5 GPa as measured according to ASTM D790;

providing a second extrudable polymer having a flexural modulus of 2.5 GPa or less as measured according to ASTM D790, an impact strength of greater than about 40 J/m as measured according to ASTM D256, and a tensile elongation at break of greater than about 5% as measured according to ASTM D638;

providing a third extrudable polymer;

coextruding the first, second, and third extrudable polymers to form top, core, and bottom layers, respectively, the core layer secured to the top and bottom layers; and

structuring a top surface of the top layer using a molding tool, thereby forming a top structured surface that collimates light.

30. The method of claim 29, further comprising:

structuring a bottom surface of the bottom layer to form a bottom structured surface that diffuses light, wherein structuring comprises;

contacting the bottom surface with a molding tool;

or

operatively connecting a rough strippable skin layer to the bottom surface, the rough strippable skin layer comprising a continuous phase and a disperse phase, the continuous phase comprising a continuous phase polymer, and the disperse phase comprising particles or a disperse phase polymer, the disperse phase polymer being immiscible with the continuous phase polymer.

31. A method of making an optical article, comprising:

providing a first extrudable polymer having a flexural modulus greater than 2.5 GPa as measured according to ASTM D790;

providing a second extrudable polymer having a flexural modulus of 2.5 GPa or less as measured according to ASTM D790, an impact strength of greater than about 40 J/m as measured according to ASTM D256, and a tensile elongation at break of greater than about 5% as measured according to ASTM D638;

providing a third extrudable polymer;

coextruding the second, first, and third extrudable polymers to form top, core, and bottom layers, respectively, the core layer secured to the top and bottom layers; and

structuring a top surface of the top layer using a molding tool, thereby forming a top structured surface that collimates light.

32. The method of claim 31, further comprising:

structuring a bottom surface of the bottom layer to form a bottom structured surface that diffuses light, wherein structuring comprises;

contacting the bottom surface with a molding tool;

or

operatively connecting a rough strippable skin layer to the bottom surface, the rough strippable skin layer comprising a continuous phase and a disperse phase, the continuous phase comprising a continuous phase polymer, and the disperse phase comprising particles or a disperse phase polymer, the disperse phase polymer being immiscible with the continuous phase polymer.

35. An optical body comprising:

a first optical article comprising;

a first top layer having a first top structured surface that collimates light;

a first core layer secured to the first top layer opposite the first top structured surface; and

a first bottom layer secured to the first core layer opposite the first top layer;

wherein;

either the first top layer or the first core layer comprises a first extrudable polymer having a flexural modulus of greater than 2.5 GPa as measured according to ASTM D790, and the other layer comprises a second extrudable polymer, the second extrudable polymer having a flexural modulus of 2.5 GPa or less as measured according to ASTM D790, an impact strength of greater than about 40 J/m as measured according to ASTM D256, and tensile elongation at break of greater than about 5% as measured according to ASTM D638; and

the first bottom layer comprises a third extrudable polymer;

a second optical article comprising;

a second top layer having a second top structured surface that diffuses light;

a second core layer secured to the second top layer opposite the second top structured surface; and

a second bottom layer secured to the second core layer opposite the second top layer;

wherein;

either the second top layer or the second core layer comprises a fourth extrudable polymer having a flexural modulus of greater than 2.5 GPa as measured according to ASTM D790, and the other layer comprises a fifth extrudable polymer, the fifth extrudable polymer having a flexural modulus of 2.5 GPa or less as measured according to ASTM D790, an impact strength of greater than about 40 J/m as measured according to ASTM D256, and tensile elongation at break of greater than about 5% as measured according to ASTM D638; and

the second bottom layer comprises a sixth extrudable polymer; and

an optical film secured to the first and second bottom layers, the optical film comprising a polarizer film, a reflective polarizer film, a diffuse blend reflective polarizer film, a diffuser film, a brightness enhancing film, a turning film, a mirror film, or a combination thereof.

36. The optical body of claim 35, further comprising:

a rough strippable skin layer operatively connected to the first top structured surface, the rough strippable skin layer comprising a continuous phase and a disperse phase, the continuous phase comprising a continuous phase polymer, and the disperse phase comprising particles or a disperse phase polymer, the disperse phase polymer being immiscible with the continuous phase polymer.

37. The optical body of claim 35, further comprising:

a rough strippable skin layer operatively connected to the second top structured surface, the rough strippable skin layer comprising a continuous phase and a disperse phase, the continuous phase comprising a continuous phase polymer, and the disperse phase comprising particles or a disperse phase polymer, the disperse phase polymer being immiscible with the continuous phase polymer.

38. The optical body of claim 35, further comprising:

a first rough strippable skin layer operatively connected to the first top structured surface, the first rough strippable skin layer comprising a first continuous phase and a first disperse phase, the first continuous phase comprising a first continuous phase polymer, and the first disperse phase comprising first particles or a first disperse phase polymer, the first disperse phase polymer being immiscible with the first continuous phase polymer; and

a second rough strippable skin layer operatively connected to the second top structured surface, the second rough strippable skin layer comprising a second continuous phase and a second disperse phase, the second continuous phase comprising a second continuous phase polymer, and the second disperse phase comprising second particles or a second disperse phase polymer, the second disperse phase polymer being immiscible with the second continuous phase polymer.

48. A display device comprising:

a display panel,

one or more light sources, and

the optical body of claim 35 disposed between the display panel and the one or more light sources.

39. An optical body comprising:

a first optical article comprising;

a first top layer having a first top structured surface that collimates light;

a first core layer secured to the first top layer opposite the first top structured surface; and

a first bottom layer secured to the first core layer opposite the first top layer;

wherein;

either the first top layer or the first core layer comprises a first extrudable polymer having a flexural modulus of greater than 2.5 GPa as measured according to ASTM D790, and the other layer comprises a second extrudable polymer, the second extrudable polymer having a flexural modulus of 2.5 GPa or less as measured according to ASTM D790, an impact strength of greater than about 40 J/m as measured according to ASTM D256, and tensile elongation at break of greater than about 5% as measured according to ASTM D638; and

the first bottom layer comprises a third extrudable polymer;

a second optical article comprising;

a second top layer having a second top structured surface that diffuses light; and

a second bottom layer secured to the second top layer opposite the second top structured surface;

wherein;

the second top layer comprises either;

a fourth extrudable polymer having a flexural modulus of greater than 2.5 GPa as measured according to ASTM D790, or

a fifth extrudable polymer having a flexural modulus of 2.5 GPa or less as measured according to ASTM D790, an impact strength of greater than about 40 J/m as measured according to ASTM D256, and tensile elongation at break of greater than about 5% as measured according to ASTM D638; and

the second bottom layer comprises a sixth extrudable polymer; and

an optical film secured to the first and second bottom layers, the optical film comprising a polarizer film, a reflective polarizer film, a diffuse blend reflective polarizer film, a diffuser film, a brightness enhancing film, a turning film, a mirror film, or a combination thereof.

40. The optical body of claim 39, further comprising:

a rough strippable skin layer operatively connected to the first top structured surface, the rough strippable skin layer comprising a continuous phase and a disperse phase, the continuous phase comprising a continuous phase polymer, and the disperse phase comprising particles or a disperse phase polymer, the disperse phase polymer being immiscible with the continuous phase polymer.

41. The optical body of claim 39, further comprising:

a rough strippable skin layer operatively connected to the second top structured surface, the rough strippable skin layer comprising a continuous phase and a disperse phase, the continuous phase comprising a continuous phase polymer, and the disperse phase comprising particles or a disperse phase polymer, the disperse phase polymer being immiscible with the continuous phase polymer.

42. The optical body of claim 39, further comprising:

a first rough strippable skin layer operatively connected to the first top structured surface, the first rough strippable skin layer comprising a first continuous phase and a first disperse phase, the first continuous phase comprising a first continuous phase polymer, and the first disperse phase comprising first particles or a first disperse phase polymer, the first disperse phase polymer being immiscible with the first continuous phase polymer; and

a second rough strippable skin layer operatively connected to the second top structured surface, the second rough strippable skin layer comprising a second continuous phase and a second disperse phase, the second continuous phase comprising a second continuous phase polymer, and the second disperse phase comprising second particles or a second disperse phase polymer, the second disperse phase polymer being immiscible with the second continuous phase polymer.

49. A display device comprising:

a display panel,

one or more light sources, and

the optical body of claim 39 with the rough strippable skin layer removed, the optical body disposed between the display panel and the one or more light sources.

44. A method of making an optical body, comprising:

providing a first extrudable polymer having a flexural modulus greater than 2.5 GPa as measured according to ASTM D790;

providing a second extrudable polymer having a flexural modulus of 2.5 GPa or less as measured according to ASTM D790, an impact strength of greater than about 40 J/m as measured according to ASTM D256, and a tensile elongation at break of greater than about 5% as measured according to ASTM D638;

providing a third extrudable polymer;

coextruding the first, second, and third extrudable polymers onto an optical film to form top, core, and bottom layers, respectively, on the optical film, the core layer secured to the top and bottom layers, the optical film secured to the bottom layer opposite the core layer; and

contacting the top layer with a molding tool thereby forming a top structured surface that collimates light.

45. A method of making an optical body, comprising:

providing a first extrudable polymer having a flexural modulus greater than 2.5 GPa as measured according to ASTM D790;

providing a second extrudable polymer having a flexural modulus of 2.5 GPa or less as measured according to ASTM D790, an impact strength of greater than about 40 J/m as measured according to ASTM D256, and a tensile elongation at break of greater than about 5% as measured according to ASTM D638;

providing a third extrudable polymer;

coextruding the second, first, and third extrudable polymers onto an optical film to form top, core, and bottom layers, respectively, on the optical film, the core layer secured to the top and bottom layers, the optical film secured to the bottom layer opposite the core layer; and

contacting the top layer with a molding tool thereby forming a top structured surface that collimates light.