Long life self-luminous microspheres

• US 20070200074A1
• Filed: 02/23/2007
• Published: 08/30/2007
• Est. Priority Date: 02/24/2006
• Status: Abandoned Application

• Current Assignee: Michael P. Kohnen
• Original Assignee: Michael P. Kohnen
• Inventors: Kohnen, Michael P.
• Application Number:
  US11/710,345
• Publication Number:
  US 20070200074A1
• Time in Patent Office: Days
• US Class Current: 250/462.100
• CPC Class Codes: C08K 3/38 Boron-containing compounds
• CPC Class Codes: C08K 7/28 Glass
• CPC Class Codes: C08K 9/10 Encapsulated ingredients
• CPC Class Codes: C08L 2205/20 Hollow spheres
• CPC Class Codes: C09D 5/22 Luminous paints luminescent compositions C09K11/00
• CPC Class Codes: C09D 7/48 Stabilisers against degradation by oxygen, light or heat
• CPC Class Codes: C09D 7/61 inorganic
• CPC Class Codes: C09D 7/65 macromolecular C09D7/41-C09D7/48 take precedence
• CPC Class Codes: C09D 7/70 characterised by shape, e.g. fibres, flakes or microspheres
• CPC Class Codes: C09K 11/025 non-luminescent particle coatings or suspension media
• CPC Class Codes: C09K 11/7712 Borates
• CPC Class Codes: Y10T 428/2982 Particulate matter [e.g., sphere, flake, etc.]

Abstract

This invention relates to a means for more efficiently and more safely providing self-luminous lighting devices for use in signs, markers, indicators and the like. The present invention provides self luminosity by means of a plurality of glass or polymer microspheres containing both a light-emitting phosphor and a radioactive gas. The “soft” emission of electrons from the beta emitting gas cannot penetrate the glass or polymer wall of the microspheres, thereby constituting no radiation hazard. A further advantage of the present invention is that the plurality of individual containment microspheres minimizes the escape of radioactive gas in the event of any physical damage to an assembly of such microspheres. A still further advantage of the invention is that the radioactive gas completely surrounds the phosphor particles, thus causing light emission from one hundred percent of the surface of the particles.

Claims

1. A self-luminous microsphere comprising:

(a) a gas tight, visible light transparent, envelope;

(b) a radioactive gas confined within the envelope; and

(c) at least one phosphor particle disposed within the envelope and responsive to the radiation from the gas to become luminous, characterized by said particle being loose within the envelope to thereby receive radiation on all sides, the particle comprising strontium aluminate borate and being resistant to ultraviolet degradation, thereby rendering the self-luminous microsphere useful for outdoor applications.

2. A self-luminous microsphere as set forth in claim 1, wherein the gas is tritium.

3. A self-luminous microsphere as set forth in claim 1, wherein the gas confined within the envelope is at a pressure greater than atmospheric pressure.

4. A self-luminous microsphere as set forth in claim 1, wherein the visible light transparent envelope is selected from the group consisting of glass and polymer.

5. A plurality of microspheres as set forth in claim 1, disposed on a flat surface to act as a sign useful for outdoor applications.

6. A plurality of microspheres as set forth in claim 1, disposed in a transparent binder to form a luminous paint useful for outdoor applications.

7. A self-luminous microsphere comprising:

(a) a gas tight, visible light transparent, envelope;

(b) tritium gas confined within the envelope; and

(c) at least one phosphor particle disposed within the envelope and free to move within the envelope, and responsive to radiation from the radioactive tritium gas to become luminous, the particle comprising strontium aluminate borate and being resistant to ultraviolet degradation, thereby rendering the self-luminous microsphere useful for outdoor applications.

8. A self-luminous microsphere of claim 7, wherein the gas tight, visible light transparent, envelope is fabricated from borosilicate glass.

9. A self-luminous microsphere of claim 7, wherein the gas tight, visible light transparent, envelope is fabricated from a polymer resistant to radiation from the tritium gas.