Immisible polymer filled optical elements

• US 20040234724A1
• Filed: 05/22/2003
• Published: 11/25/2004
• Est. Priority Date: 05/22/2003
• Status: Abandoned Application

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Bourdelais, Robert P., Brickey, Michael R., Kaminsky, Cheryl J.
• Application Number:
  US10/443,204
• Publication Number:
  US 20040234724A1
• Time in Patent Office: Days
• US Class Current: 428/141
• 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: Y10T 428/24355 Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
• CPC Class Codes: Y10T 428/24479 including variation in thickness

Abstract

Disclosed is a light directing polymeric film bearing on a surface thereof a three-dimensional features having an Ra of at least 3, the features containing a polymer dispersion comprising a continuous phase thermoplastic first polymeric material and a discontinuous phase thermoplastic second polymeric material that is immiscible with the first polymeric material and is dispersed in elongated micro-regions.

Claims

1. A light directing polymeric film bearing on a surface thereof three-dimensional features having an Ra of at least 3 micrometers, the features containing a polymer dispersion comprising a continuous phase first thermoplastic polymeric material and a discontinuous phase second thermoplastic polymeric material that is immiscible with the first polymeric material and is dispersed in elongated micro-regions.

2. The light direction polymeric film of claim 1 wherein the elongated micro-regions are spherical, elliptical, or fibrillar.

3. The light directing polymeric film of claim 1 wherein the elongated micro-regions conform to the geometry of the three dimensional features.

4. The light directing polymeric film of claim 1 wherein the elongated micro-regions and the longitudinal direction of the three-dimensional features are substantially parallel.

5. The light directing polymeric film of claim 1 wherein the micro-regions have an aspect ratio of at least 100.

6. The light directing polymeric film of claim 1 that further comprises a third thermoplastic polymeric material phase.

7. The light directing film of claim 1 where the second thermoplastic polymeric material comprises 15 to 30% by volume relative to the first thermoplastic polymeric material.

8. The light directing polymeric film of claim 1 wherein the first and second thermoplastic polymeric materials have indices of refraction that differ by less than 0.05 along a first axis and by more than 0.05 along a second axis orthogonal to the first axis.

9. The light directing polymeric film of claim 1 wherein the film has a gain of at least 1.2 at the normal to the film when illuminated by a standard LCD backlight.

10. The light directing polymeric film of claim 1 wherein the three dimensional features are substantially void-free.

11. The light directing polymeric film of claim 1 wherein the polymeric film is voided.

12. The light directing polymeric film of claim 1 wherein the polymeric film comprises minute layered particles.

13. The light directing film of claim 1 wherein the composition of the first and second thermoplastic polymers varies across the film.

14. The light directing film of claim 1 wherein the three dimensional features are on both sides of the light directing polymeric film.

15. The light directing film of claim 1 wherein the three dimensional features having an Ra of at least 10 micrometers.

16. The light directing film of claim 1 wherein the three dimensional features have an aspect ratio of from 0.1 to 7.

17. The light directing film of claim 1 wherein the first thermoplastic polymer comprises a polyethylene napthalate.

18. The light directing film of claim 1 wherein the second thermoplastic polymer comprises a polystryene.

19. The light directing film of claim 1 wherein the second thermoplastic polymer comprises poly(methyl)methacrylate.

20. The light directing film of claim 1 wherein the first or second thermoplastic polymer is polycarbonate.

21. The light directing film of claim 1 wherein the first or second thermoplastic polymer is polyethylene.

22. The light directing polymeric film of claim 1 wherein the light directing film is oriented in the machine direction more than the transverse direction.

23. The light directing polymeric film of claim 1 wherein the light directing film is oriented unconstrained.

24. The light directing polymeric film of claim 1 wherein the three dimensional features are individual optical elements.

25. The light directing polymeric film of claim 1 wherein the three dimensional features are individual optical elements with one curved side and one flat side.

26. The light directing polymeric film of claim 1 wherein the three dimensional features are random.

27. The light directing polymeric film of claim 1 wherein the three dimensional features are lenticular in shape.

28. The light directing polymeric film of claim 1 wherein the film transmits at least 60% of one polarization and reflects at least 60% of the opposite polarization.

29. The light directing polymeric film of claim 1 wherein the film scatters collimated light asymmetrically to an angle of view of at least 80 degrees in a first direction and less than 10 degrees in a second direction orthogonal to the first direction.

30. The light directing polymeric film of claim 1 wherein the three dimensional features comprise nanoparticles.

31. The light directing polymeric film of claim 1 wherein the light directing polymeric film further comprises a substrate.

32. The light directing polymeric film of claim 1 wherein the continuous phase thermoplastic first polymeric material and the discontinuous phase second thermoplastic polymeric material are located substantially only in the three-dimensional features.

33. A process for forming the layer of claim 1 comprising extruding a melt of a dispersion containing a continuous phase thermoplastic first polymeric material and a discontinuous phase second thermoplastic polymeric material into a nip between a patterned roller and a pressure roller, cooling the melt to solid state, heating the solid film and orienting the film and features in at least one direction.

34. The process of claim 33 in which the pressure roll has a pattern.

35. The process of claim 33 in which the stretching is unconstrained.

36. The process of claim 33 in which the optical features are dimensionally modified by at least 5% by the application of heat after the step of cooling the melt.