Aluminum-Coated Glass Microspheres, also called retroreflective microspheres, half-shell coated spheres or hemispherically coated spheres, have a half-shell aluminum coating applied to solid barium titanate glass microspheres. The spheres are hemispherically coated with a thin aluminum shell to produce a bright retroreflective response directed back to the light source and to the observer. The light bounces off the aluminum-coated half of the sphere produces the retro reflective effect that provides the desired high visibility in dark conditions.

Retroreflective microspheres can be used with all binders — water or solvent-borne paints, epoxy, thermoplastic, vinyl, polyester, PMMA, polyurethane, polyurea or powder coatings. Reflective coatings are easily applied to virtually any solid surface including metals, plastic or concrete using most application methods. Glass microspheres will not shatter or shear when used in most high speed spray guns, extruders or powder coating chambers.

P2453BTA microspheres are made of barium titanate glass hemispherically coated with aluminum. Barium titanate glass has a higher Refractive Index [RI] than soda lime glass: 1.9 compared to 1.5. The Refractive Index of a material measures the degree a ray of light bends when it moves from one medium to another. Its practical significance is that it indicates how light will reflect back to the viewer. Barium titanate glass with its higher RI will reflect back more directly to the viewer than soda lime glass, which will scatter to some degree. This direct reflection is particularly important for applications when retro reflectivity is desired such as guard rails, traffic signs or reflective tape or clothing.

• Retroreflect light straight back to the light source for night visibility
• Combine with colored spheres for a color flexible reflectivity
• Provide omni-angle reflectivity for a wider range of visibility
• Make coated objects visible at night in headlights up to 300 meters away