Optically dissimilar composition for polymeric reflective bodies

• US 5,278,694 A
• Filed: 05/17/1991
• Issued: 01/11/1994
• Est. Priority Date: 01/11/1990
• Status: Expired due to Term

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: The Dow Chemical Company (Dow, Inc.)
• Inventors: Wheatley, John A., Barger, Mark A., Ramanathan, Ravi, Schrenk, Walter J., Bales, Stephen E., Langhoff, Charles A.
• Primary Examiner(s): Sugarman, Scott J.
• Assistant Examiner(s): NGUYEN, THONG Q
• Application Number:
  US07/702,652
• Time in Patent Office: 970 Days
• Field of Search: 359/350, 359/352, 359/359-361, 359/577, 359/584-590, 359/500, 359/883, 359/884, 428/131, 428/156, 428/212-215, 428/423.1, 428/480, 428/513
• US Class Current: 359/359
• CPC Class Codes: B32B 2250/05 5 or more layers
• CPC Class Codes: B32B 2307/4026 within the layer by addition of a colorant, e.g. pigments, dyes
• CPC Class Codes: B32B 2307/416 Reflective
• CPC Class Codes: B32B 2307/418 Refractive
• CPC Class Codes: B32B 2307/738 Thermoformability
• CPC Class Codes: B32B 2439/00 Containers; Receptacles closures therefor B32B2435/00
• CPC Class Codes: B32B 2597/00 Tubular articles, e.g. hoses, pipes
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/20 using fillers, pigments, thixotroping agents
• CPC Class Codes: B32B 33/00 Layered products characterised by particular properties or particular surface features, e.g. particular surface coatings; Layered products designed for particular purposes not covered by another single class
• CPC Class Codes: B32B 7/023 Optical properties
• CPC Class Codes: G02B 5/0841 comprising organic materials, e.g. polymers
• CPC Class Codes: G02B 5/0883 with a refractive index gradient rugate filters G02B5/289
• CPC Class Codes: G02B 5/26 Reflecting filters G02B5/28 takes precedence
• CPC Class Codes: G02B 5/305 including organic materials, e.g. polymeric layers

Abstract

A multilayered reflective body which is thermoformable and capable of being fabricated into films, sheets and a variety of parts while maintaining a uniform reflective appearance is provided. The reflective polymeric body includes at least first and second diverse polymeric materials of a sufficient number of alternating layers of the first and second polymeric materials such that at least 30% of the light incident on the body is reflected. A substantial majority of the individual layers of the body have an optical thickness of not more than 0.09 micrometers or not less than 0.45 micrometers, and adjacent layers of the first and second polymeric materials differ from each other in refractive index by at least about 0.1. The reflective body may be fabricated into sheets, mirrors, noncorroding metallic appearing articles and parts, reflectors, reflective lenses, and the like.

Claims

1. A reflective polymeric body of at least first and second diverse polymeric materials, the body comprising a sufficient number of alternating layers of said first and second polymeric materials such that at least 30% of light incident on said body is reflected, a substantial majority of the individual layers of said body having an optical thickness of not more than 0.09 micrometers or not less than 0.45 micrometers, with at least one of said individual layers having an optical thickness of not less than 0.45 micrometers, wherein said first and second polymeric materials differ from each other in refractive index by at least about 0.1, and wherein one of said first and second polymeric materials comprises a copolycarbonate of bisphenol-A and 4,4'"'"'-thiodiphenol

2. The reflective polymeric body of claim 1 wherein said copolycarbonate comprises from 5-80 mole percent 4,4'"'"'-thiodiphenol and from 95-20 mole percent bisphenol A.

3. The reflective polymeric body of claim 1 wherein said 4,4'"'"'-thiodiphenol is present in a mole ratio of about 3 to 1 relative to said bisphenol-A.

4. The reflective polymeric body of claim 1 wherein the other of said first and second polymeric materials preferably comprises a blend of polymethyl methacrylate and polyvinylidene fluoride.

5. The reflective polymeric body of claim 1 in which said body comprises at least 500 layers.

6. The reflective polymeric body of claim 1 in which said polymeric body is thermoformable.

7. The reflective polymeric body of claim 1 in which a coloring agent is incorporated into at least one layer of said polymeric body.

8. The reflective polymeric body of claim 7 in which said coloring agent is selected from the group consisting of pigments and dyes.

9. The reflective polymeric body of claim 8 in which said coloring agent is incorporated into at least one surface layer of said polymeric body.

10. The reflective polymeric body o claim 8 in which said coloring agent is incorporated into at least one interior layer of said polymeric body.

11. The reflective polymeric body of claim 1 in which at least one surface layer has a brushed or roughened surface.

12. The reflective polymeric body of claim 1 in which at least one surface layer has been etched to provide a matte or pewter finish.

13. The reflective polymeric body of claim 1 in which at least one surface layer has been embossed.

14. The reflective polymeric body of claim 1 in which at least one of said first and second polymeric materials are elastomers.

15. The reflective polymeric body of claim 1 in which at least 75% of said layers have an optical thickness of at least 0.45 micrometers.

16. The reflective polymeric body of claim 1 in which said body is extruded as a profile.

17. The reflective polymeric body of claim 16 in which said body is in the form of a tube.

18. The reflective polymeric body of claim 1 in which said body is post formed into a profile.

19. The reflective polymeric body of claim 1 in which said body is a blow-molded container.

20. The reflective polymeric body of claim 1 in which said polymeric body is in the form of a sheet having two major surfaces.

21. The reflective polymeric body of claim 20 in which said body includes a permanent protective skin layer on at least one major surface thereof.

22. The reflective polymeric body of claim 1 which includes a barrier layer as an exterior layer of said body.

23. A reflective polymeric body of at least first and second diverse polymeric materials, the body comprising a sufficient number of alternating layers of said first and second polymeric materials such that essentially no visibly perceived iridescence is reflected, a substantial majority of the individual layers of said body having an optical thickness of not more than 0.09 micrometers or not less than 0.45 micrometers, with at least one of said individual layers having an optical thickness of not less than 0.45 micrometers, wherein said first and second polymeric materials differ from each other in refractive index by at least about 0.1, and wherein one of said first and second polymeric materials comprises a copolycarbonate of bisphenol-A and 4,4'"'"'-thiodiphenol.

24. A mirror like polymeric article having at least first and second major surfaces, said article comprising a sufficient number of alternating layers of first and second polymeric materials such that at least 30% of light incident on said article is reflected, a substantial majority of the individual layers of said article having an optical thickness of not more than 0.09 micrometers or not less than 0.45 micrometers, with at least one of said individual layers having an optical thickness of not less than 0.45 micrometers, wherein said first and second polymeric materials differ from each other in refractive index by at least about 0.1, wherein one of said major surfaces includes a light absorbent layer, and wherein one of said first and second polymeric materials comprises a copolycarbonate of bisphenol-A and 4,4'"'"'-thiodiphenol.

25. A mirror like polymeric article having at least first and second major surfaces, said article comprising a sufficient number of alternating layers of first and second polymeric materials such that at least 30% of light incident on said article is reflected, and at least one interior light absorbing layer, a substantial majority of the individual layers of said article having an optical thickness of not more than 0.09 micrometers or not less than 0.45 micrometers, with at least one of said individual layers having an optical thickness of not less than 0.45 micrometers, wherein said first and second polymeric materials differ from each other in refractive index by at least about 0.1, and wherein one of said first and second polymeric materials comprises a copolycarbonate of bisphenol-A and 4,4'"'"'-thiodiphenol.

26. A birefringent light polarizer which reflects light anisotropically, comprising multiple layers of at least first and second diverse polymeric materials, a substantial majority of the individual layers of said polarizer having an optical thickness of not more than 0.09 micrometers or not less than 0.45 micrometers, wherein said first and second polymeric materials differ from each other in refractive index by at least about 0.1 in one plane of the polarizer, and wherein one of said first and second polymeric materials comprises a copolycarbonate of bisphenol-A and 4,4'"'"'-thiodiphenol.

27. The birefringent light polarizer of claim 26 in which the difference in refractive index between said first and second polymeric materials is caused by stretching said materials in a uniaxial direction to orient said polymeric materials.

28. A reflective polymeric body of at least first and second diverse polymeric materials, the body comprising a sufficient number of alternating layers of said first and second polymeric materials such that at least 30% of light incident on said body is reflected, a substantial majority of the individual layers of said body having an optical thickness of not more than 0.09 micrometers or not less than 0.45 micrometers, wherein said first and second polymeric materials differ from each other in refractive index by at least about 0.1 and wherein one of said first and second polymeric materials comprises a copolymer of methyl methacrylate and vinylidene fluoride or miscible blend of polymethyl methacrylate and polyvinylidene fluoride.

29. The reflective polymeric body of claim 28 wherein said blend comprises from 95-5 weight percent polymethyl methacrylate and from 5-95 weight percent polyvinylidene fluoride.

30. The reflective polymeric body of claim 28 wherein said copolymer comprises from 95-5 mole percent methyl methacrylate and from 5-95 mole percent vinylidene fluoride.

31. The reflective polymeric body of claim 28 wherein said polymethyl methacrylate is present in a weight ratio of about 1:

1 relative to said polyvinylidene fluoride.

32. The reflective polymeric body of claim 28 wherein the other of said first and second polymeric materials comprise a bisphenol A polycarbonate or a copolycarbonate of thiodiphenol and bisphenol-A.

33. The reflective polymeric body of claim 28 wherein the other of said first and second polymeric materials comprises bisphenol-A polycarbonate.

34. The reflective polymeric body of claim 28 in which said body comprises at least 500 layers.

35. The reflective polymeric body of claim 28 in which said polymeric body is thermoformable.

36. The reflective polymeric body of claim 28 in which a coloring agent is incorporated into at least one layer of said polymeric body.

37. The reflective polymeric body of claim 36 in which said coloring agent is selected from the group consisting of pigments and dyes.

38. The reflective polymeric body of claim 37 in which said coloring agent is incorporated into at least one surface layer of said polymeric body.

39. The reflective polymeric body of claim 37 in which said coloring agent is incorporated into at least one interior layer of said polymeric body.

40. The reflective polymeric body of claim 28 in which at least one surface layer has a brushed or roughened surface.

41. The reflective polymeric body of claim 28 in which at least one surface layer has been etched to provide a matte or pewter finish.

42. The reflective polymeric body of claim 28 in which at least one surface layer has been embossed.

43. The reflective polymeric body of claim 28 in which said first and second polymeric materials are elastomers.

44. The reflective polymeric body of claim 28 in which at least 75% of said individual layers of said first polymeric material have an optical thickness of at least 0.45 micrometers.

45. The reflective polymeric body of claim 28 in which at least 75% of said individual layers of said first polymeric material have an optical thickness of 0.09 micrometers or less.

46. The reflective polymeric body of claim 28 in which said body is extruded as a profile.

47. The reflective polymeric body of claim 46 in which said body is in the form of a tube.

48. The reflective polymeric body of claim 28 in which said body is post formed into a profile.

49. The reflective polymeric body of claim 28 in which said body is a blow-molded container.

50. The reflective polymeric body of claim 28 in which said polymeric body is in the form of a sheet having two major surfaces.

51. The reflective polymeric body of claim 50 in which said body includes a permanent protective skin layer on at least one major surface thereof.

52. The reflective polymeric body of claim 28 which includes a barrier layer as an exterior layer of said body.

53. A reflective polymeric body of at least first and second diverse polymeric materials, the body comprising a sufficient number of alternating layers of said first and second polymeric materials such that at least 30% of light incident on said body is reflected, a substantial majority of the individual layers of said body having an optical thickness of not more than 0.09 micrometers or not less than 0.45 micrometers, with at least one of said individual layers having an optical thickness of not less than 0.45 micrometers, wherein said first and second polymeric materials differ from each other in refractive index by at least about 0.1 and wherein said first polymeric material comprises a blend of polymethyl methacrylate and a fluoropolymer, and wherein said fluoropolymer comprises a copolymer of vinylidene fluoride and a monomer selected from the group consisting of chlorofluoroethylene, chlorodifluoroethylene, chlorotrifluoroethylene, chlorotrifluoroethylene, hexafluoroacetone, hexafluoropropylene, hexafluoropropene, pentafluoropropylene, trifluoroethylene, tetrafluoroethylene, and vinyl fluoride.

54. The reflective polymeric body of claim 53 wherein said blend comprises from 95-5 weight percent polymethyl methacrylate and from 5-95 weight percent fluoropolymer.

55. The reflective polymeric body of claim 53 wherein said second polymeric material comprises a bisphenol A polycarbonate or a copolycarbonate of thiodiphenol and bisphenol-A.

56. A reflective polymeric body of at least first and second diverse polymeric materials, the body comprising a sufficient number of alternating layers of said first and second polymeric materials such that at least 30% of light incident on said body is reflected, a substantial majority of the individual layers of said body having an optical thickness of not more than 0.09 micrometers or not less than 0.45 micrometers, with at least one of said individual layers having an optical thickness of not less than 0.45 micrometers, wherein said first and second polymeric materials differ from each other in refractive index by at least about 0.1 and wherein one of said first and second polymeric materials comprises a copolymer of methyl methacrylate, vinylidene fluoride, and a fluorocarbon monomer selected from the group consisting of chlorofluoroethylene, chlorodifluoroethylene, chlorotrifluoroethylene, chlorotrifluoroethylene, hexafluoroacetone, hexafluoropropylene, hexafluoropropene, pentafluoropropylene, trifluoroethylene, tetrafluoroethylene, and vinyl fluoride.

57. The reflective polymeric body of claim 56 wherein said copolymer comprises from 90-10 mole percent polymethyl methacrylate, from 5-45 mole percent vinylidene fluoride, and from 5-45 mole percent fluorocarbon monomer.

58. The reflective polymeric body of claim 56 wherein the other of said first and second polymeric materials comprises a copolycarbonate of thiodiphenol and bisphenol-A.

59. A reflective polymeric body of at least first and second diverse polymeric materials, the body comprising a sufficient number of alternating layers of said first and second polymeric materials such that essentially no visibly perceived iridescence is reflected, a substantial majority of the individual layers of said body having an optical thickness of not more than 0.09 micrometers or not less than 0.45 micrometers, with at least one of said individual layers having an optical thickness of not less than 0.45 micrometers, wherein said first and second polymeric materials differ from each other in refractive index by at least about 0.1, and wherein one of said first and second polymeric materials comprises a copolymer of methyl methacrylate and vinylidene fluoride or a miscible blend of polymethyl methacrylate and polyvinylidene fluoride.

60. A mirror like polymeric article having at least first and second major surfaces, said article comprising a sufficient number of alternating layers of first and second polymeric materials such that at least 30% of light incident on said article is reflected, a substantial majority of the individual layers of said article having an optical thickness of at not more than 0.09 micrometers or not less than 0.45 micrometers, with at least one of said individual layers having an optical thickness of not less than 0.45 micrometers, wherein said first and second polymeric materials differ from each other in refractive index by at least about 0.1, wherein one of said major surfaces includes a light absorbent layer, and wherein one of said first and second polymeric materials comprises a copolymer of methyl methacrylate and vinylidene fluoride or miscible blend of polymethyl methacrylate and polyvinylidene fluoride.

61. A mirror like polymeric article having at least first and second major surfaces, said article comprising a sufficient number of alternating layers of first and second polymeric materials such that at least 30% of light incident on said article is reflected, and at least one interior light absorbing layer, a substantial majority of the individual layers of said article having an optical thickness of not more than 0.09 micrometers or not less than 0.45 micrometers, with at least one of said individual layers having an optical thickness of not less than 0.45 micrometers, wherein said first and second polymeric materials differ from each other in refractive index by at least about 0.1, and wherein one of said first and second polymeric material comprises a copolymer of methyl methacrylate and vinylidene fluoride or miscible blend of polymethyl methacrylate and polyvinylidene fluoride.

62. A birefringent light polarizer which reflects light anisotropically, comprising multiple layers of at least first and second diverse polymeric materials, a substantial majority of the individual layers of said polarizer having an optical thickness of not more than 0.09 micrometers or not less than 0.45 micrometers, with at least one of said individual layers having an optical thickness of not less than 0.45 micrometers, wherein said first and second polymeric materials differ from each other in refractive index by at least about 0.1 in one plane of the polarizer, and wherein one of said first and second polymeric materials comprises a copolymer of methyl methacrylate and vinylidene fluoride or a miscible blend of polymethyl methacrylate and polyvinylidene fluoride.

63. The birefringent light polarizer of claim 62 in which the difference in refractive index between said first and second polymeric materials is caused by stretching said materials in a uniaxial direction to orient said polymeric materials.

64. A reflective polymeric body of at least first and second diverse polymeric materials, the body comprising a sufficient number of alternating layers of said first and second polymeric materials such that at least 30% of light incident on said body is reflected, a substantial majority of the individual layers of said body having an optical thickness of not more than 0.09 micrometers or not less than 0.45 micrometers, with at least one of said individual layers having an optical thickness of not less than 0.45 micrometers, wherein said first and second polymeric materials differ from each other in refractive index by at least about 0.03 and wherein said first polymeric material comprises polymethyl methacrylate and said second polymeric material comprises a copolymer of methyl methacrylate and vinylidene fluoride or a miscible blend of polymethyl methacrylate and polyvinylidene fluoride.

65. The reflective polymeric body of claim 64 wherein said blend comprises from 0-60 weight percent polymethyl methacrylate and from 100-40 weight percent polyvinylidene fluoride.

66. The reflective polymeric body of claim 64 wherein said copolymer comprises from 0-60 mole percent methyl methacrylate and from 100-40 mole percent vinylidene fluoride.

67. A reflective polymeric body of at least first and second diverse polymeric materials, the body comprising a sufficient number of alternating layers of said first and second polymeric materials such that at least 30% of light incident on said body is reflected, a substantial majority of the individual layers of said body having an optical thickness of not more than 0.09 micrometers or not less than 0.45 micrometers, with at least one of said individual layers having an optical thickness of not less than 0.45 micrometers, wherein said first and second polymeric materials differ from each other in refractive index by at least about 0.03 and wherein said first polymeric material comprises polyvinylidene fluoride and said second polymeric material comprises a copolymer of methyl methacrylate and vinylidene fluoride or a miscible blend of polymethyl methacrylate and polyvinylidene fluoride.

68. The reflective polymeric body of claim 67 wherein said blend comprises from 100-45 weight percent polymethyl methacrylate and from 0-55 weight percent polyvinylidene fluoride.

69. The reflective polymeric body of claim 67 wherein said copolymer comprises from 100-45 mole percent methyl methacrylate and from 0-55 mole percent vinylidene fluoride.

70. A reflective polymeric body of at least first and second diverse polymeric materials, the body comprising a sufficient number of alternating layers of said first and second polymeric materials such that at least 30% of light incident on said body is reflected, a substantial majority of the individual layers of said body having an optical thickness of not more than 0.09 micrometers or not less than 0.45 micrometers, with at least one of said individual layers having an optical thickness of not less than 0.45 micrometers, wherein said first and second polymeric materials differ from each other in refractive index by at least about 0.03 and wherein said first polymeric material comprises polymethyl methacrylate and said second polymeric material comprises a copolymer of methyl methacrylate, vinylidene fluoride, and a fluorocarbon monomer selected from the group consisting of chlorofluoroethylene, chlorodifluoroethylene, chlorotrifluoroethylene, chlorotrifluoroethylene, hexafluoroacetone, hexafluoropropylene, hexafluoropropene, pentafluoropropylene, trifluoroethylene, tetrafluoroethylene, and vinyl fluoride.

71. The reflective polymeric body of claim 70 wherein said copolymer comprises from 0-80 mole percent methyl methacrylate, from 60-10 mole percent vinylidene fluoride, and from 40-10 mole percent fluorocarbon monomer.