Fluorescent articles having multiple film layers

• US 20030203212A1
• Filed: 01/30/2003
• Published: 10/30/2003
• Est. Priority Date: 04/30/2002
• Status: Active Grant

• Current Assignee: Avery Dennison Corporation
• Original Assignee: Avery Dennison Corporation
• Inventors: Buoni, Drew J., Wei, Guang-Xue
• Granted Patent: US 7,618,709 B2
• Time in Patent Office: Days
• US Class Current: 428/412
• CPC Class Codes: B32B 2307/422 Luminescent, fluorescent, phosphorescent
• CPC Class Codes: B32B 2590/00 Signboards, advertising panels, road signs
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/20 using fillers, pigments, thixotroping agents
• CPC Class Codes: B32B 27/308 comprising acrylic (co)polymers
• CPC Class Codes: B32B 27/365 comprising polycarbonates
• CPC Class Codes: G02B 5/124 plural reflecting elements forming part of a unitary plate or sheet
• CPC Class Codes: G02B 5/128 transparent spheres being embedded in matrix
• CPC Class Codes: Y10T 428/31504 Composite [nonstructural laminate]
• CPC Class Codes: Y10T 428/31507 Of polycarbonate
• CPC Class Codes: Y10T 428/31551 Of polyamidoester [polyurethane, polyisocyanate, polycarbamate, etc.]
• CPC Class Codes: Y10T 428/31786 Of polyester [e.g., alkyd, etc.]
• CPC Class Codes: Y10T 428/31855 Of addition polymer from unsaturated monomers

Abstract

Articles are provided which have fluorescent properties and which are suitable for use in making retroreflective articles such as safety and informational signage. The articles have at least two film layers, each film layer including a colorant dye. The multiple film layer sheeting exhibits excellent resistance to weathering and overall color durability while also providing chromaticity properties dictated by industry standards for a particular coloration. A method of preparing the articles is provided. In a particular application, the articles embody retroreflective properties and are fluorescent yellow signs.

Claims

1. An article comprising:

an underlayer colored fluorescent film comprising at least one first fluorescent dye within an underlayer polymer matrix;

an overlayer colored fluorescent film having at least one second fluorescent dye within an overlayer polymer matrix, said overlayer colored fluorescent film has better fluorescent color stability than said underlayer colored film;

the article has said overlayer colored fluorescent film over said underlayer colored fluorescent film; and

said article has a selected fluorescent coloration different from both said underlayer colored fluorescent film and said overlayer colored fluorescent film.

2. The article in accordance with claim 1, wherein said underlayer polymer matrix has a polymer structure selected from the group consisting of an acrylic resin, a polystyrene, a polyvinyl chloride, a polyester, a polyarylate, a styrene-acrylonitrile copolymer, a polyurethane, and combinations and copolymers thereof.

3. The article in accordance with claim 1, wherein said underlayer polymer matrix has a polymer structure selected from the group consisting of an acrylic resin, a polystyrene, and a polyvinyl chloride, and combinations and copolymers thereof.

4. The article in accordance with claim 1, wherein said overlayer polymer matrix has a polymer structure selected from the group consisting of a polycarbonate, an acrylic resin, a polyarylate resin, and combinations and copolymers thereof.

5. The article in accordance with claim 1, wherein said overlayer polymer matrix has a polymer structure selected from the group consisting of a polycarbonate, an acrylic resin, and combinations and copolymers thereof.

6. The article in accordance with claim 1, wherein said overlayer polymer matrix had been formed from a polycarbonate.

7. The article in accordance with claim 1, wherein said selected fluorescent coloration of the article is selected from the group consisting of fluorescent yellow, fluorescent yellow green, fluorescent orange, fluorescent red, fluorescent blue and fluorescent green as provided by dyes selected from the group consisting of benzoxanthenes, benzothiazines, perylenes, perylene imides, pereylene esters, thioxanthenes, thioindigoids, and combinations thereof.

8. The article in accordance with claim 1, wherein said selected fluorescent coloration of the article is fluorescent yellow.

9. The article in accordance with claim 1, wherein said selected fluorescent coloration is fluorescent yellow having “

x” and

“

y”

chromatcity coordinates which are bounded by the following “

x” and

“

y”

chromaticity coordinates;

(x=0.479, y=0.520), (x=0.446, y=0.483), (x=0.512, y=0.421) and (x=0.557, y=0.442).

10. The article in accordance with claim 1, wherein said overlayer colored fluorescent film has UV and visible light screening properties.

11. The article in accordance with claim 1, wherein said overlayer colored fluorescent film substantially blocks light having a wavelength from about 250 nm to about 520 nm.

12. The article in accordance with claim 1, wherein said overlayer colored fluorescent film substantially blocks light having a wavelength of from about 280 nm to about 450 nm.

13. The article in accordance with claim 1, wherein said second fluorescent dye has a greater daytime luminance factor “

Y %”

than said first dye.

14. The article in accordance with claim 1, wherein said overlayer film is less brittle than said underlayer film, and said article has greater impact resistance than said underlayer.

15. The article in accordance with claim 1, wherein said article includes retroreflective elements.

16. The article in accordance with claim 15, wherein said underlayer is between said overlayer and said retroreflective elements such that incident light passes through said overlayer, then passes into said underlayer, then encounters said retroflective element and retroreflects into said underlayer colored film and passes through said overlayer colored film and out of the article.

17. The article in accordance with claim 15, wherein said retroreflective elements are formed into said underlayer.

18. The article in accordance with claim 17, wherein said retroreflective elements are microprismatic elements.

19. The article in accordance with claim 16, wherein said retroreflective elements are arranged to provide an encapsulated lens retroreflective construction.

20. The article in accordance with claim 16, wherein said retroreflective elements are arranged to provide an enclosed lens construction.

21. The article in accordance with claim 15, wherein said article is signage which is suitable for outdoor use for at least three years.

22. The article in accordance with claim 1, further including a cap layer polymeric film overlying said overlayer colored fluorescent film, and wherein said article is signage which is suitable for outdoor use for at least three years, and the overlayer film and underlayer film combine to provide yellow coloration within the box defined by the following “

x” and

“

y”

chromaticity coordinates;

(x=0.479, y=0.520), (x=0.446, y=0.483), (x=0.512, y=0.421) and (x=0.557, y=0.442).

23. The article in accordance with claim 1, wherein said fluorescent dye of the overlayer is a benzoxanthene dye or a benzothiazine dye.

24. The article in accordance with claim 1, wherein said underlayer polymer matrix is an acrylic resin, the fluorescent dye of said underlayer film comprises at least one perylene imide dye, said overlayer polymer matrix is a polycarbonate resin, and said fluorescent dye of the overlayer comprises at least one benzothiazine dye.

25. The article in accordance with claim 1, wherein said underlayer polymer matrix is an acrylic resin, the fluorescent dye of said underlayer film comprises at least one perylene imide dye, said overlayer polymer matrix is an acrylic resin, and said fluorescent dye of the overlayer comprises at least one benzoxanthene dye.

26. The article in accordance with claim 1, further including a cap layer polymeric film overlying said overlayer colored fluorescent film, said cap layer being selected from the group consisting of an acrylic resin, a polyarylate, and combinations thereof.

27. The article in accordance with claim 1, wherein the article has a Δ

E* value after extended exposure to outdoor conditions which is substantially less than that of either said underlayer film or of said overlayer film.

28. The article in accordance with claim 1, wherein said article is a yellow fluorescent article, said underlayer polymer matrix is an acrylic resin, said first fluorescent dye comprises at least one perylene imide dye, said overlayer polymer matrix is a polycarbonate, and said second fluorescent dye comprises at least one benzothiazine dye.

29. The article in accordance with claim 1, further including a light stabilizer selected from the group consisting of a UV absorber, a HALS component and combinations thereof, said light stabilizer being within either or both of said underlayer and said overlayer.

30. The article in accordance with claim 1, wherein said first fluorescent dye is different from said second fluorescent dye.

31. The article in accordance with claim 1, wherein said underlayer colored fluorescent film and overlayer colored fluorescent film each are individually unsuitable to meet UV light durability requirements and coloration compliance standards for outdoor signage having said selected fluorescent coloration, while said article meets said requirements and standards.

32. An article having fluorescent coloration, comprising:

an underlayer colored film having at least one first dye within an underlayer acrylic resin polymer matrix;

an overlayer colored film having at least one second dye within an overlayer polymer matrix, said overlayer polymer matrix having been formed from a polycarbonate or an acrylic resin;

said overlayer colored film overlies said underlayer colored film; and

said first dye and said second dye are different from each other, the article has a selected fluorescent coloration different from the coloration of either said underlayer colored film or said overlayer colored film.

33. The article in accordance with claim 32, wherein said selected fluorescent coloration is fluorescent yellow having the following “

x” and

“

y”

chromaticity coordinates which are bounded by the following “

x” and

“

y”

chromaticity coordinates;

(x=0.479, y=0.520), (x=0.446, y=0.483), (x=0.512, y=0.421) and (x=0.557, y=0.442).

34. The article in accordance with claim 32, further including a cap layer film of an acrylic resin, a polyarylate resin, or combinations or copolymers thereof, said cap layer providing UV light screening properties, and said cap layer overlies said overlayer.

35. The article in accordance with claim 32, wherein said overlayer film is less brittle than said underlayer film, and said article has greater impact resistance than said underlayer.

36. The article of claim 32, where said article contains retroreflective elements.

37. The article in accordance with claim 32, wherein said article includes retroreflective elements, and said underlayer is between said overlayer and said retroreflective elements such that incident light passes through said overlayer, then passes into said underlayer, then encounters said retroflective elements and retroreflects into said underlayer colored film and passes through said overlayer colored film and out of the article.

38. The article in accordance with claim 36, wherein said retroreflective elements are formed into said underlayer.

39. The article in accordance with claim 36, wherein said retroreflective members are prismatic elements.

40. The article in accordance with claim 37, wherein said retroreflective elements are arranged to provide an encapsulated lens retroreflective construction.

41. The article in accordance with claim 37, wherein said retroreflective elements are arranged to provide an enclosed lens retroreflective construction.

42. The article in accordance with claim 36, wherein said article is signage which is suitable for outdoor use for at least three years.

43. The article in accordance with claim 32, wherein said article is signage which is suitable for outdoor use for at least three years, and the overlayer film and underlayer film combined to provide yellow coloration within the box defined by following “

x” and

“

y”

chromaticity coordinates;

(x=0.479, y=0.520), (x=0.446, y=0.483), (x=0.512, y=0.421) and (x=0.557, y=0.442).

44. The article in accordance with claim 32, wherein said fluorescent dye of the overlayer comprises at least one benzoxanthene dye.

45. The article in accordance with claim 32, wherein said fluorescent dye of the overlayer comprises at least one benzothiazine dye.

46. The article in accordance with claim 32, wherein said fluorescent dye of the underlayer comprises at least one perylene imide dye.

47. A method of manufacturing a fluorescent colored retroreflective sheeting, comprising:

combining a first polymer resin and at least one first dye into an underlayer formulation;

formulating a second polymer resin and at least one second dye into an overlayer formulation;

forming said underlayer formulation into an underlayer colored film, forming said overlayer formulation into an overlayer colored film, said overlayer colored film has greater color stability than said underlayer colored film, at least one of said colored films being a fluorescent colored film; and

placing said overlayer colored film onto said underlayer colored film to provide a multiple layered fluorescent sheeting having a selected fluorescent coloration.

48. The method in accordance with claim 47, further including adding retroreflective elements to the sheeting.

49. The method in accordance with claim 47, further including adding retroreflective elements into said underlayer of the sheeting.

50. The method in accordance with claim 47, further including adding retroreflective elements so that said underlayer colored film is between the overlayer colored film and the retroreflective elements.

51. The method in accordance with claim 47, further including placing a polymeric cap layer onto said overlayer colored film such that said overlayer colored film is between said cap layer and said underlayer colored film.

52. An article having fluorescent yellow coloration, comprising:

an underlayer fluorescent orange film having at least one perylene imide dye within an underlayer acrylic resin polymer matrix;

an overlayer fluorescent yellow-green film having at least one benzothiazine dye within an overlayer polymer matrix, said overlayer polymer matrix having been formed from a polycarbonate;

a cap layer film of an acrylic resin;

said overlayer colored film overlies said underlayer colored film, and said cap layer overlies said overlayer; and

said article has a fluorescent yellow coloration which results from the combination of said fluorescent yellow-green overlayer over said fluorescent orange underlayer.

53. The article in accordance with claim 52, wherein said fluorescent yellow coloration has the following “

x” and

“

y”

chromaticity coordinates which are bounded by the following “

x” and

“

y”

chromaticity coordinates;

(x=0.479, y=0.520), (x=0.446, y=0.483), (x=0.512, y=0.421) and (x=0.557, y=0.442).

54. The article in accordance with claim 52, wherein said overlayer film is less brittle than said underlayer film, and said article has greater impact resistance than said underlayer.

55. The article in accordance with claim 52, where said article contains retroreflective elements.

56. The article in accordance with claim 55, wherein said retroreflective elements are microprismatic elements.

57. The article in accordance with claim 56, wherein said retroreflective elements are formed into said underlayer.

58. The article in accordance with claim 55, wherein said retroreflective elements are arranged to provide an encapsulated lens retroreflective construction.

59. The article in accordance with claim 55, wherein said retroreflective elements are arranged to provide an enclosed lens retroreflective construction.

60. The article in accordance with claim 55, wherein said article is signage which is suitable for outdoor use for at least three years.

61. An article having fluorescent coloration, comprising:

an underlayer colored film having at least one first dye within an underlayer acrylic resin polymer matrix;

an overlayer colored film having at least one second dye within an overlayer polymer matrix, said overlayer polymer matrix having been formed from a polycarbonate or an acrylic resin;

a cap layer film of a polyarylate resin;

said overlayer colored film overlies said underlayer colored film, and said cap layer overlies said overlayer; and

said first dye and said second dye are different from each other, the article has a selected fluorescent coloration different from the coloration of either said underlayer colored film or said overlayer colored film.

62. The article in accordance with claim 61, wherein said selected fluorescent coloration is fluorescent yellow having the following “

x” and

“

y”

chromaticity coordinates which are bounded by the following “

x” and

“

y”

chromaticity coordinates;

(x=0.479, y=0.520), (x=0.446, y=0.483), (x=0.512, y=0.421) and (x=0.557, y=0.442).

63. The article in accordance with claim 62, where said article contains retroreflective elements.

64. The article in accordance with claim 63, wherein said retroreflective elements are microprismatic elements.

65. The article in accordance with claim 64, wherein said retroreflective elements are formed into said underlayer.

66. The article in accordance with claim 63, wherein said retroreflective elements are arranged to provide an encapsulated lens retroreflective construction.

67. The article in accordance with claim 63, wherein said retroreflective elements are arranged to provide an enclosed lens retroreflective construction.

68. The article in accordance with claim 61, wherein said article is signage which is suitable for outdoor use for at least three years.

69. The article in accordance with claim 61, wherein said fluorescent dye of the overlayer is selected from the group consisting of at least one benzoxanthene dye, at least one benzothiazine dye, and combinations thereof.

70. The article in accordance with claim 61, wherein said fluorescent dye of the underlayer is at least one perylene imide dye.

71. An article comprising:

an underlayer colored fluorescent film comprising at least one first fluorescent dye within an underlayer polymer matrix;

an overlayer colored fluorescent film comprising at least one second fluorescent dye within an overlayer polymer matrix;

a cap layer polymeric film comprising a polymeric resin, said polymeric resin comprising at least one polymer, or a mixture thereof, selected from the group consisiting of;

(i) polymers having a polymeric backbone comprising the following repeating moiety A;

wherein R is a non-interfering substitutent and P is the remainder of the polymer; and

whereby the polymers are able to absorb ultraviolet light; and

(ii) polymers having a polymeric back bone comprising the following repeating moiety B;

wherein R is a non-interfering substituent and P is the remainder of the polymer;

said moiety B being transformable to said moiety A by photo-pries rearrangement, whereby said polymer comprising moiety B can be transformed to an ultraviolet light absorbing polymer comprising moiety A.

the article has said overlayer colored fluorescent film over said underlayer colored fluorescent film and said cap layer overlies said overlayer; and

said article has a selected fluorescent coloration different from both said underlayer colored fluorescent film and said overlayer colored fluorescent film.

72. The article in accordance with claim 71, wherein said cap layer comprises a polyarylate resin.

74. The article in accordance with claim 71, wherein the cap layer comprises a blend of polyarylate and at least one additional polymer.

75. The article in accordance with claim 74, wherein said additional polymer is selected from the group consisting of polycarbonate, poly(cyclohexanedimethanol terephthalae), poly(cyclohexanedimethenol-co-ethylene terephthalate), and blends thereof.

76. The article in accordance with claim 75, wherein said additional polymer is the cap layer comprises polycarbonate.

77. The article in accordance with claim 71, wherein said overlayer colored fluorescent film has better fluorescent color stability than said underlayer colored film;

78. The article in accordance with claim 71, wherein said underlayer polymer matrix has a polymer structure selected from the group consisting of an acrylic resin, a polystyrene, a polyvinyl chloride, a polyester, a polyarylate, a styrene-acrylonitrile copolymer, a polyurethane, and combinations and copolymers thereof.

79. The article in accordance with claim 71, wherein said overlayer polymer matrix has a polymer structure selected from the group consisting of a polycarbonate, an acrylic resin, a polyarylate resin, and combinations and copolymers thereof.

80. The article in accordance with claim 79, wherein said selected fluorescent coloration of the article is fluorescent yellow.

81. The article in accordance with claim 71, wherein said overlayer colored fluorescent film substantially blocks light having a wavelength from about 250 nm to about 520 nm.

82. The article in accordance with claim 71, wherein said article includes retroreflective elements formed into said underlayer.

83. The article in accordance with claim 71, wherein said fluorescent dye of the overlayer is a benzoxanthene dye, a benzothiazine dye or combination thereof.

84. The article in accordance with claim 71, wherein said fluorescent dye of said underlayer film is at least one perylene imide dye.

73. The article in accordance with cliam 72, wherein the polyarylate resin comprises at leastone polymer selected from the group consisting of polyarylate polymers comprising one or both of the following repeating structures I and II: