MULTILAYER OPTICAL BODIES

• US 20020039235A1
• Filed: 11/22/1999
• Published: 04/04/2002
• Est. Priority Date: 11/22/1999
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: OUDERKIRK, ANDREW J., WHEATLEY, JOHN A., LIU, YAOQI J., RUFF, ANDREW T., ANDRUS, MILTON H. Jr., HEBRINK, TIMOTHY J., CONDO, PETER D.
• Granted Patent: US 6,498,683 B2
• Time in Patent Office: Days
• US Class Current: 359/589
• CPC Class Codes: B29C 55/023 using multilayered plates or sheets
• CPC Class Codes: B29D 11/00 Producing optical elements, e.g. lenses or prisms grinding or polishing of optical elements B24B; constructional form of optical elements G02B; optical parts of spectacles G02C7/00
• CPC Class Codes: B29K 2995/003 Reflective
• CPC Class Codes: B29K 2995/0034 Polarising
• CPC Class Codes: B32B 2307/416 Reflective
• CPC Class Codes: B32B 2307/42 Polarizing, birefringent, filtering
• CPC Class Codes: B32B 2551/00 Optical elements
• CPC Class Codes: B32B 2551/08 Mirrors
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/36 comprising polyesters
• CPC Class Codes: B32B 7/023 Optical properties
• CPC Class Codes: G02B 27/283 used for beam splitting or combining
• CPC Class Codes: G02B 5/0841 comprising organic materials, e.g. polymers
• CPC Class Codes: G02B 5/26 Reflecting filters G02B5/28 takes precedence
• CPC Class Codes: G02B 5/287 comprising at least one layer of organic material
• CPC Class Codes: G02B 5/3025 Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state G02B5/3008, G02B5/3016 take precedence
• CPC Class Codes: G02B 5/3041 comprising multiple thin layers, e.g. multilayer stacks
• CPC Class Codes: G02B 5/305 including organic materials, e.g. polymeric layers
• CPC Class Codes: G02B 5/3083 Birefringent or phase retarding elements G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001
• CPC Class Codes: G02F 1/133536 Reflective polarizers G02F1/13362 takes precedence
• CPC Class Codes: G02F 1/133545 : Dielectric stack polarisers
• CPC Class Codes: G02F 1/13362 : providing polarized light, e.g. by converting a polarisation component into another one
• CPC Class Codes: Y10S 428/91 : Product with molecular orientation
• CPC Class Codes: Y10T 428/24942 : including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/3154 : Of fluorinated addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31786 : Of polyester [e.g., alkyd, etc.]
• CPC Class Codes: Y10T 428/31797 : Next to addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31935 : Ester, halide or nitrile of addition polymer

Abstract

In various aspects, the present invention provides optical bodies configured and arranged to reflect at least a portion of light over at least one wavelength region, the bodies comprising a plurality of first optical layers comprising a polyester having terephthalate comonomer units and ethylene glycol comonomer units and a plurality of second optical layers disposed in a repeating sequence with the plurality of first optical layers. In other aspects, the invention provides optical bodies comprising a plurality of first optical layers, each first optical layer being oriented; and a plurality of second optical layers disposed in a repeating sequence with the plurality of first optical layers, each second optical layer comprising a blend of polymethylmethacrylate and polyvinylidene fluoride. The materials are chosen such that they have compatible glass transition temperatures for orienting the layers.

Claims

1. An optical body, comprising:

a plurality of first optical layers, each first optical layer being oriented and comprising a polyester having terephthalate comonomer units and ethylene glycol comonomer units and having a glass transition temperature less than or equal to about 90°

C.; and

a plurality of second optical layers disposed in a repeating sequence with the plurality of first optical layers, each second optical layer comprising a polymer composition;

the optical body being configured and arranged to reflect at least a portion of light over at least one wavelength region.

2. The optical body of claim 1, wherein the first and second optical layers are coextruded.

3. The optical body of claim 1, wherein the first optical layers are biaxially oriented.

4. The optical body of claim 1, wherein the first optical layers have an in-plane birefringence of at least about 0.05.

5. The optical body of claim 1, wherein z-axis refractive indices of the first and second optical layers differ by no more than about 0.04.

6. The optical body of claim 1, wherein at least one in-plane index of refraction of the first optical layers differs by at least about 0.1 from an in-plane index of refraction, in the same direction, of the second optical layers.

7. The optical body of claim 1, wherein the optical body is configured and arranged to reflect at least a substantial portion of light in one visible wavelength region.

8. The optical body of claim 1, wherein the optical body is configured and arranged to reflect at least a substantial portion of light in one ultraviolet wavelength region.

9. The optical body of claim 1, wherein the optical body is configured and arranged to reflect a substantial portion of light in one infrared wavelength region.

10. The optical body of claim 1, wherein the polymer composition of the second optical layers has a glass transition temperature less than or equal to about 90°

C.

11. The optical body of claim 1, wherein the polymer composition comprises a polymer selected from the group consisting of polyacrylates and aliphatic polyolefins.

12. The optical body of claim 11, wherein the polymer comprises a copolymer of polymethyl methacrylate that contains comonomer units that depress a glass transition temperature of the copolymer below a glass transition temperature of polymethyl methacrylate.

13. The optical body of claim 11, wherein the polymer comprises polymethyl methacrylate and the polymer composition further comprises a second polymer blended with polymethyl methacrylate to provide the polymer composition with a glass transition temperature below a glass transition temperature of polymethyl methacrylate.

14. The optical body of claim 1, wherein the polyester of the first optical layers comprises a homopolymer or copolymer of polyethylene terephthalate.

15. The optical body of claim 1, wherein the second optical layers have an isotropic refractive index.

17. The optical body of claim 16, wherein the second portion corresponds to a polymer having a glass transition temperature of at least about 160°

C.

18. The optical body of claim 16, wherein the second portion corresponds to a polymer having a glass transition temperature of at least about 200°

C.

19. The optical body of claim 16, wherein the polyester portion and the second portion are formed by copolymerization of monomers.

20. The optical body of claim 16, wherein the first polymer composition is formed by reactive blending of a polyester and a second polymer to form the polyester portion and the second portion, respectively.

21. The optical body of claim 16, wherein the second portion corresponds to a non-polyester polymer.

22. The optical body of claim 16, wherein a glass transition temperature of the first optical layers is at least about 100°

C.

23. The optical body of claim 16, wherein a glass transition temperature of the first optical layers is at least about 120°

C.

24. The optical body of claim 16 wherein said second polymer composition comprises polymethyl methacrylate.

26. The optical body of claim 25, wherein the polymer composition further comprises a plasticizer.

27. The optical body of claim 25, wherein the polymer is selected from the group consisting of copolymers of polymethyl methacrylate.

28. The optical body of claim 25, wherein the polymer is selected from the group consisting of aliphatic polyolefin copolymers.

30. The optical body of claim 29, wherein the polyvinylidene fluoride is present in an amount of no more than about 40% by weight with respect to the combined total of polymethyl methacrylate and polyvinylidene fluoride.

31. The optical body of claim 29, wherein the first and second optical layers are coextruded.

32. The optical body of claim 29, wherein the first optical layers are biaxially oriented.

33. The optical body of claim 29, wherein the first optical layers comprise a polyester.

34. The optical body of claim 33, wherein the polyester is selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate and blends and copolymers thereof.

35. The optical body of claim 29, wherein at least one in-plane index of refraction of the first optical layers differs by at least about 0.1 from an in-plane index of refraction, in the same direction, of the second optical layers.

36. The optical body of claim 29, wherein the optical body is configured and arranged to reflect at least a substantial portion of light in one visible wavelength region.

37. The optical body of claim 29, wherein the optical body is configured and arranged to reflect a substantial portion of light in one infrared wavelength region.

38. The optical body of claim 29, wherein the optical body is configured and arranged to reflect a substantial portion of light in one ultrviolet wavelength region.

16. An optical body, comprising:

a plurality of first optical layers, each first optical layer being oriented and comprising a first polymer composition, the first polymer composition comprising

(i) a polyester portion having terephthalate comonomer units and ethylene glycol comonomer units, and

(ii) a second portion corresponding to a polymer having a glass transition temperature of at least about 130°

C.; and

a plurality of second optical layers disposed in a repeating sequence with the plurality of first optical layers, each second optical layer comprising a second polymer composition.

25. An optical body, comprising:

a plurality of first optical layers, each first optical layer being oriented and comprising a polyester having terephthalate comonomer units and ethylene glycol comonomer units; and

a plurality of second optical layers disposed in a repeating sequence with the plurality of first optical layers, each second optical layer comprising a polymer composition, the polymer composition having a glass transition temperature of less than or equal to about 90°

C. and comprising a polymer selected from the group consisting of polyacrylates and aliphatic polyolefins.

29. An optical body, comprising:

a plurality of first optical layers, each first optical layer being oriented; and

a plurality of second optical layers disposed in a repeating sequence with the plurality of first optical layers, each second optical layer comprising a blend of polymethylmethacrylate and polyvinylidene fluoride;

the optical body being configured and arranged to reflect at least a portion of light over at least one wavelength region.