Retroreflective elements and articles
The present invention relates to retroreflective elements and retroreflective articles such as pavement markings comprising retroreflective elements, methods of making retroreflective elements, and laminates.
1. A pavement marking comprising retroreflective elements having an exposed outer viewing surface comprising optical elements having approximately the same refractive index partially embedded in a binder wherein the coefficient of retroreflected luminance of the pavement marking is at least 2000 mcd/m 2 /lux when dry and at least 1500 mcd/m 2 /lux when wet.
2. The pavement marking of claim 1 wherein the exposed outer viewing surface comprises preformed retroreflective sheeting.
3. The pavement marking of claim 2 wherein a cross-section of at least a portion of the retroreflective elements comprises an edge of the sheeting in a shape of at least one coil.
4. The pavement marking of claim 2 wherein a cross-section of at least a portion of the retroreflective elements comprises an edge of the sheeting in a substantially circular shape.
5. The pavement marking of claim 1 wherein at least a portion of the retroreflective elements comprise an outside diameter ranging from about 0.5 mm to 4 mm.
6. The pavement marking of claim 1 wherein at least a portion of the retroreflective elements comprise a substantially solid core.
7. The pavement marking of claim 1 wherein at least a portion of the retroreflective elements comprise a cavity.
8. The pavement marking of claim 7 wherein the cavity is discontinuous.
9. The pavement marking of claim 7 wherein the cavity of at least a portion of the retroreflective elements is at least partially filled with the binder.
10. The pavement marking of claim 2 where the retroreflective elements comprise a shrunk film layer beneath the preformed sheeting.
11. The pavement marking of claim 1 wherein the retroreflective elements comprise a discreet interior layer comprising optical elements.
12. The pavement marking of claim 1 wherein the optical elements comprise glass microspheres, glass-ceramic microspheres, cube corner elements, and combinations thereof.