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.

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 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.

A robust sintered retroreflective composite comprising, a core bead, a peripheral bead, and an interphase coating. The bead can be used in typical retroreflective indicia and uses.

A robust sintered retroreflective composite comprising, a core bead, a peripheral bead, and an interphase coating. The bead can be used in typical retroreflective indicia and uses.

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 method of forming a titania-coated inorganic particle comprising the steps of: (a) agitating a mixture of inorganic particle and organic solvent; (b) adding titania precursor dropwise into the mixture of step (a) under agitation; and (c) adding catalyst to the mixture of step (b) thereby converting said titania precursor to titania which then forms a coating on said inorganic particle; wherein steps (a) to (c) are performed at neutral pH and ambient temperature.

A method of forming a titania-coated inorganic particle comprising the steps of: (a) agitating a mixture of inorganic particle and organic solvent; (b) adding titania precursor dropwise into the mixture of step (a) under agitation; and (c) adding catalyst to the mixture of step (b) thereby converting said titania precursor to titania which then forms a coating on said inorganic particle; wherein steps (a) to (c) are performed at neutral pH and ambient temperature.