Luminous materials

• US 20040021407A1
• Filed: 08/11/2003
• Published: 02/05/2004
• Est. Priority Date: 06/08/2000
• Status: Active Grant

• Current Assignee: Visual 24/7, Ltd.
• Original Assignee: Dualglo Technology, PLC
• Inventors: Lambert, Stephen, Baillie, Craig Jameson
• Granted Patent: US 7,507,352 B2
• Time in Patent Office: Days
• US Class Current: 313/111
• CPC Class Codes: C09K 11/02 Use of particular materials as binders, particle coatings or suspension media therefor
• CPC Class Codes: C09K 11/025 non-luminescent particle coatings or suspension media
• CPC Class Codes: C09K 11/08 containing inorganic luminescent materials
• CPC Class Codes: F21K 2/00 Non-electric light sources using luminescence using excitation by radioactivity G21H3/02, H01J65/06, H01J65/08; using excitation by an external electromagnetic field or by external corpuscular radiation H01J65/04; Light sources using electrochemiluminescence
• CPC Class Codes: H01H 9/185 Fluorescent or phosphorescent symbols or distinguishing marks H01H9/181 takes precedence
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps
• CPC Class Codes: Y10T 428/24355 Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]
• CPC Class Codes: Y10T 428/252 Glass or ceramic [i.e., fired or glazed clay, cement, etc.] [porcelain, quartz, etc.]
• CPC Class Codes: Y10T 428/2852 Adhesive compositions

Abstract

A luminous material comprising a rubber, glass or plastics material matrix. A luminescent material is dispersed throughout the matrix, and a colorant dispersed throughout the matrix. The colourant gives the matrix a colour when it is observed under substantially white light, and the colourant allowing substantial transmission of light emitted by the luminous material.

Claims

1. A luminous material comprising a rubber, glass or plastics material matrix, a luminescent material dispersed throughout the matrix, and a colorant dispersed throughout the matrix, the colourant giving the matrix a colour when it is observed under substantially white light, and the colourant allowing substantial transmission of light emitted by the luminous material.

2. A luminous material according to claim 1, in which the luminescent material comprises a rare earth metal, such as europium or dysprosium.

3. A luminous material according to claim 2, in which the luminescent material is in the form of a metal, an oxide or an aluminate.

4. A luminous material according to claim 2, in which the luminescent material further comprises an alkaline earth metal, such as strontium.

5. A luminous material according to claim 4 in which the alkaline earth metal is in the form of a metal, an oxide or an aluminate.

6. A luminous material according to claim 1, in which the luminescent material comprises particles having dimensions between 8 and 100 micrometres.

7. A luminous material according to claim 1, in which the percentage by weight of the luminescent material to the matrix is between 4% and 32.5%.

8. A luminous material according to claim 7, in which the percentage by weight of the luminescent material is between 4% and 20%.

9. A luminous material according to claim 7, in which the percentage by weight of the luminescent material is between 6% and 12%.

10. A luminous material according to claim 1, in which the colourant comprises a fluorescent material.

11. A luminous material according to claim 10, in which the fluorescent material comprised in the colourant is in the fluorescent yellow colour spectrum.

12. A luminous material according to claim 1, in which the matrix material is polyurethane, a co-polymer of styrene and butadiene, a polyolefin (particularly polypropylene or polyethylene), acrylic, ABS, polyethylene-terephthalate or polycarbonate.

13. A luminous material according to claim 12, in which the matrix material has a high clarity.

14. A luminous material according to claim 1 in which the luminescent material constitutes at least 90% by weight of the combined weight of the luminescent material and the colourant.

15. A luminous material according to claim 14, in which luminescent material constitutes between 94% and 99% by weight of the combined weight of the luminescent material and the colourant.

16. A luminous material according to claim 14, in which luminescent colorant material constitutes between 94 to 96% thereof by weight of the combined weight of luminescent material and the colorant.

17. A luminous material according to claim 1, in which the percentage by weight of the colourant to the matrix material is between 0.2% and 1%.

18. A luminous material according to claim 10, in which the fluorescent material comprised in the colourant is a pigment.

19. A luminous material according to claim 18, in which the pigment is organic.

20. A luminous material according to claim 19, in which the pigment is provided in a polyamide co-condensate carrier.

21. A luminous material according to claim 1, in which the matrix material is an engineering grade polymer.

22. A luminous material according to claim 21, in which the polymer has a high clarity.

23. A luminous material according to claim 21, in which the polymer is one of acrylic, ABS, polycarbonate or a polyamide such as nylon or a polyamide elastomer.

24. A luminous material according to claim 1, in which the percentage by weight of the luminescent material to the combined weight of the luminescent material and the colourant is at least 99%.

25. A luminous material according to claim 24, in which the percentage by weight of the luminescent material to the combined weight of the luminescent material and the colourant is between 99.1% and 99.98%.

26. A luminous material according to claim 24, in which the percentage by weight of the luminescent material to the combined weight of the luminescent material and the colourant is between 99.7% and 99.9%.

27. A luminous material according to claim 21, in which the percentage by weight of the colourant to the engineering grade polymer matrix is between 0.005% and 0.05%.

28. A luminous material according to claim 21, in which the colourant used with an engineering grade polymer matrix is a dye-type colourant.

29. A luminous material according to claim 1 in which the colourant is substantially white.

30. A luminous material according to claim 29, in which the percentage by weight of the luminescent material to the combined weight of the luminescent material and the white colourant is at least 97%.

31. A luminous material according to claim 30, in which the percentage by weight of the luminescent material to the combined weight of the luminescent material and the white colourant is between 98.2% and 99.67%.

32. A luminous material according to claim 29, in which the percentage by weight of the white colourant to the matrix material is between 0.33% and 3%.

33. A luminous material according to claim 29, in which the matrix material used with the white colourant is of a high clarity and preferably is one of polyurethane, a co-polymer of styrene and butadiene, a polyolefin (particularly polyethylene or polypropylene), acrylic, ABS, polyethyleneterephthalate, a polycarbonate, or a polyamide.

34. A luminous material according to claim 29, in which the white colourant comprises one or more of titanium dioxide, calcium carbonate, silicon dioxide and other translucent white colourants.

35. A luminous material according to claims 29 to 33, in which the white colourant comprises a combination of titanium dioxide and silicon dioxide.

36. A luminous material according to claim 1, in which the luminous material further comprises an optical brightener dispersed in the matrix. This gives the advantage that both the visibility of the material in daylight, and the visibility in the dark, via the luminescence, is enhanced.

37. A luminous material according to claim 36, in which the optical brightener is a fluorescent blue dye.

51. An article made from luminous material according to claim 1.

52. A non-luminous article provided with a coating, or outer layer, of luminous material according to claim 1.

53. An article according to claim 51, in which the article is made by moulding the luminous material.

54. An article according to claim 53 in which the moulding is formed by injection or co-injection.

55. An article according to claim 51, in which the article is made by extruding the luminous material.

56. An article according to claim 51, in which the article comprises a substantially reflective layer on its reverse or inner side.

57. An article according to claim 56, in which the reflective layer is white.

58. An article according to claim 51, in which the article has applied thereto a layer containing reflective glass beads or the like.

59. An article according to claim 51, in which the article is an adhesive tape, film or layer.

60. An article according to claim 58, in which the luminescent material constitutes not more than 65% by weight of the total of the luminescent material, the colourant and the matrix material used to make the tape.

61. An article according to claim 51, in which the article is a switch.

62. An article according to claim 61, in which the switch is a light switch suitable for use in controlling an electric light. Alternatively, the switch is suitable for use as part of a computer keyboard.

63. An article according to claim 61, in which the light switch comprises an electrical light emitting device controlled by the switch such that light is emitted when the switch is in the on position.

64. An article according to claim 61, in which the switch is water-proof.

65. An article according to claim 61, in which the colourant in the luminous material of the switch gives the switch a white colour.

66. An article according to claim 61, in which the switch is made from the material retarded against fire.

67. An article according to claim 51, in which the article is a flashlight casing, or part therefor, which is a rubber or plastics moulding.

68. An article according to claim 67, in which the mouldings for the casing or part thereof is shaped from a matrix comprising a rubber or plastics material (which may be thermoplastic, which is preferred, or, in some embodiments, thermoset) with colorant materials dispersed therein.

69. An article according to claim 51, in which the article is an electrical plug which is made from the material retarded against fire.

38. A method for making a luminous material as described above, comprising the steps of:

c) compounding a colourant into a rubber, glass or plastics matrix material; and

d) compounding a luminescent material including at least one alkaline earth metal and at least one rare earth metal in the matrix material.

39. A method according to claim 38, in which step a) and step b) are reversed.

40. A method according to claim 38, in which the compounding steps of a) and b) are combined into a single blending step.

41. A method according to claim 38, in which the making of the luminous material is carried out using machinery adapted to reduce shearing of the material.

42. A colourant combination comprising a colourant and a luminescent material, the colourant combination being suitable for adding to a rubber, glass or plastics material matrix for the creation of a luminous material as described above.

43. A colourant combination according to claim 42, in which the colourant combination is prepared in a universal masterbatch carrier, which is advantageously ethylene-based, such as polyethylene methacrylate or polyethylene vinyl acetate.

44. A colourant combination according to claim 43, in which the colourant combination is prepared in the carrier at up to 65% by weight.

45. A colourant combination according to claim 42, in which the colourant combination is added in concentration over 10%.

46. A colourant combination according to claim 42, in which strontium crystals and colourant particles act as fillers.

47. A colourant combination according to claim 42, in which the colourant combination is compounded into the thermoplastic.

48. A colourant combination according to claim 42, in which the colourant combination is prepared in a machine fitted with a low shear screw.

49. A colourant combination according to claim 42, in which the colourant combination is prepared by adding the luminescent material and the colourant to the carrier when the carrier is substantially heated or melted.

50. A colourant combination according to claim 42, in which the colorant combination further comprises optical brighteners.