To provide transparent solid spheres with high refractive index and large particle size. The transparent solid spheres of one aspect of the present disclosure include barium oxide, zirconium dioxide, and titanium dioxide on a theoretical oxide basis, and has a refractive index of at least 2.0 and a particle size of 600 micrometers or greater.

To provide transparent solid spheres with high refractive index and large particle size. The transparent solid spheres of one aspect of the present disclosure include barium oxide, zirconium dioxide, and titanium dioxide on a theoretical oxide basis, and has a refractive index of at least 2.0 and a particle size of 600 micrometers or greater.

The disclosed retroreflective element includes a polymeric core that is loaded with a plurality of first beads and second beads distributed at the perimeter of the core. The first beads are different than the second beads. Because of the beads in the core, the retroreflective element remains useful for returning light even after portions of the core begins to wear away. Further, when the retroreflective elements get wet, water will settle to the bottom of the perimeter of the core. Therefore, using the second beads with a refractive index suited for wet conditions, while the first beads have a refractive index suited for dry conditions allows the retroreflective element to be useful in both wet and dry conditions even while the retroreflective element wears during use.

The disclosed retroreflective element includes a polymeric core that is loaded with a plurality of first beads and second beads distributed at the perimeter of the core. The first beads are different than the second beads. Because of the beads in the core, the retroreflective element remains useful for returning light even after portions of the core begins to wear away. Further, when the retroreflective elements get wet, water will settle to the bottom of the perimeter of the core. Therefore, using the second beads with a refractive index suited for wet conditions, while the first beads have a refractive index suited for dry conditions allows the retroreflective element to be useful in both wet and dry conditions even while the retroreflective element wears during use.

Plurality of nanocrystalline percent by volume crystalline ceramic oxide beads, wherein the nanocrystalline ceramic oxide beads have an average crystallite size up to 250 nm, wherein each bead collectively comprises, on a theoretical oxides basis, at least one of Al.sub.2O.sub.3, SiO.sub.2, TiO.sub.2, or ZrO.sub.2 at least 40 weight percent, and at least 1 weight percent of at least one of a transition metal oxide or at least one Bi.sub.2O.sub.3 or CeO.sub.2, based on the total weight of the nanocrystalline ceramic oxide beads, and are visibly dark and infrared transmissive. The beads are useful, for example, in pavement markings.

The disclosed retroreflective element includes a polymeric core that is loaded with a plurality of first beads and second beads distributed at the perimeter of the core. The first beads are different than the second beads. Because of the beads in the core, the retroreflective element remains useful for returning light even after portions of the core begins to wear away. Further, when the retroreflective elements get wet, water will settle to the bottom of the perimeter of the core. Therefore, using the second beads with a refractive index suited for wet conditions, while the first beads have a refractive index suited for dry conditions allows the retroreflective element to be useful in both wet and dry conditions even while the retroreflective element wears during use.

The disclosed retroreflective element includes a polymeric core that is loaded with a plurality of first beads and second beads distributed at the perimeter of the core. The first beads are different than the second beads. Because of the beads in the core, the retroreflective element remains useful for returning light even after portions of the core begins to wear away. Further, when the retroreflective elements get wet, water will settle to the bottom of the perimeter of the core. Therefore, using the second beads with a refractive index suited for wet conditions, while the first beads have a refractive index suited for dry conditions allows the retroreflective element to be useful in both wet and dry conditions even while the retroreflective element wears during use.

A retroreflective article including a binder layer and a plurality of retroreflective elements. Each retroreflective element includes a transparent microsphere partially embedded in the binder layer. At least some of the retroreflective elements include a reflective layer that is a locally-laminated reflective layer that is embedded between the transparent microsphere and the binder layer. At least some of the locally-laminated reflective layers may be localized reflective layers.

A retroreflective composite bead for highway marking having high retroreflectivity both when initially installed and over the bead lifetime, allowing vehicle drivers to see highway marking lines at night and in adverse conditions during nighttime. When installed the retroreflective beads essentially retroreflect the base color of the highway marking material in which the retroreflective beads are embedded. The beads comprise a larger bead with a coating of smaller particles heat bonded to its surface.

The present disclosure generally relates to retroreflective elements including a core and a plurality of glass or glass-ceramic beads adjacent to the core. The retroreflective elements further include a plurality of particles having a diameter that is less than the diameter of the glass or glass ceramic beads in the retroreflective elements. The present disclosure also generally relates to articles (including, for example, retroreflective roadway liquid pavement markings) including these retroreflective elements and methods of making and using these retroreflective elements.