LIGHT-TRANSMISSIVE RETROREFLECTIVE SHEETING

• US 3,790,431 A
• Filed: 01/24/1972
• Issued: 02/05/1974
• Est. Priority Date: 01/24/1972
• Status: Expired due to Term

• Current Assignee: Chi Fang Tung
• Original Assignee: Chi Fang Tung
• Inventors: Tung, Chi Fang
• Primary Examiner(s): Ansher, Harold
• Application Number:
  US05/220,152
• Time in Patent Office: 743 Days
• Field of Search: 40/13B,13J,132R,134 161/3.5,4,83,92,408-410,DIG.5
• US Class Current: 442/44
• CPC Class Codes: F21V 11/14 with many small apertures
• CPC Class Codes: G02B 5/128 transparent spheres being embedded in matrix
• CPC Class Codes: G09F 13/0472 Traffic signs
• CPC Class Codes: Y10T 428/268 Monolayer with structurally defined element
• CPC Class Codes: Y10T 428/31515 As intermediate layer
• CPC Class Codes: Y10T 442/174 Including particulate material other than fiber in coating or impregnation
• CPC Class Codes: Y10T 442/2115 At least one coating or impregnation functions to fix pigments or particles on the surface of a coating or impregnation

Abstract

Light-transmissive retroreflective sheeting comprising an open web of filaments that are encased around their whole circumference at least over those parts of their length that define open spaces of the web by a monolayer of minute retroreflective microspheres. One use of the sheeting is in internally illuminated signs, where the light-transmissive retroreflective sheeting is incorporated between the internal illumination source and the sign face so as to retroreflect light beamed against the sign face and make the signs retroreflective.

Claims

2. Sheeting of claim 1 in which the spaces between the encased filaments occupy between 40 and 60 percent of the area covered by the sheeting.

3. Sheeting of claim 1 in which the encased filaments have a diameter less than 500 microns.

4. Sheeting of claim 1 in which the smallest dimension of the spaces between the encased filaments is less than one millimeter.

5. Sheeting of claim 1 in which the web is a fabric of interwoven filaments.

6. Sheeting of claim 1 in which the retroreflective microspheres are partially embedded in a layer of binder material coated on the filaments and comprise glass microspheres covered over their partially embedded surface with reflective material.

7. Sheeting of claim 1 in which the microspheres are held to the filaments by a layer of elastomeric material.

8. Sheeting of claim 7 in which the elastomeric material comprises epoxy resin and a water-insoluble polyether polyamine of high amine functionality.

9. Light-transmissive retroreflective sheeting comprising an open fabric of interwoven filaments that are encased around their whole circumference over those parts of their length that define open spaces of the fabric by a monolayer of minute retroreflective microspheres, the microspheres being partially embedded in a layer of elastomeric binder material coated on the filaments after the filaments have been woven into a fabric, the encased filaments having a diameter less than 500 microns, the spaces between the encased filaments occupying between 20 and 80 percent of the area covered by the fabric, and the smallest dimension of the spaces being less than one millimeter.

10. Sheeting of claim 9 in which the elastomeric material comprises epoxy resin and a water-insoluble polyether polyamine of high amine functionality.

11. Sheeting of claim 9 in which the retroreflective microspheres comprise glass microspheres covered over their partially embedded surface with reflective material.

12. Sheeting of claim 9 in which the spaces between the encased filaments occupy 40-60 percent of the area occupied by the sheeting.

13. Light-transmissive retroreflective sheeting comprising an open-mesh fabric of interwoven filaments that are encased around their whole circumference over those parts of their length that define open spaces of the fabric by a monolayer of minute retroreflective microspheres, the microspheres being partially embedded in a layer of binder material coated on the filaments after the filaments have been woven into a fabric, the spaces between the encased filaments occupying between 20 and 80 percent of the area covered by the fabric.