Pavement markings containing transparent non-vitreous ceramic microspheres
AssigneeMinnesota Mining and Manufacturing Company
InventorRoger W. Lange
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Abstract
Pavement marking comprising ceramic microspheres held by a binder, said microspheres being solid, transparent, non-vitreous, ceramic particles which serve as lens elements in the retroreflective pavement markings. The ceramic microspheres formed by various sol gel techniques are characterized by having: A. at least one metal oxide phase; and B. an average minimum dimension of up to 125 micrometers. The inventive pavement markings retain reflectivity for a surprisingly long time.
Claims8
A pavement marking comprising ceramic microspheres held by a binder said microspheres being solid, transparent, non-vitreous microspheres having an average particle size of up to 125 micrometers, comprising zirconia and silica, and containing at most only minor amounts of titanium dioxide.
A coating composition comprising a mixture of binder material and ceramic microspheres which are solid, transparent, non-vitreous microspheres having an average particle size of up to 125 micrometers and which are comprised of zirconia and silica and contain at most only minor amounts of titania.
Dependencies are inferred from the claim text.