Laminar reflective platelets and compositions and articles comprising them

Abstract

Laminar reflective platelets are made by coating a first synthetic resin lamina on a carrier web and providing release means such as a release coat to provide for release of the lamina. A metallic lamina is coated onto the synthetic resin lamina by vapor deposition in vacuum and a third optional synthetic resin lamina may then be coated onto the metal layer. Each of the three laminae has a thickness on the order of one to 3 millionths of an inch. The thus-coated web is immersed in a releasing solvent to activate the release means. The laminate is removed from the carrier by reason of solution or partial solution of the release coat or release means in the solvent. Removal may be aided by mechanical means such as brushing or scraping. The solvent is agitated to reduce the laminar platelets to final size. Laminar platelets thus formed have a thickness of from 0.5 to 5 millionths of an inch; each has a diffuse reflectance of from 75 to 95%, and 90 to 100% pass through a 300 mesh screen. Concentration of the laminar platelets in the solvent may be increased to 50 to 80% as by decantation. Highly reflective sprayable coatings such as lacquers and enamels may be made therefrom. Weatherable, abrasion-resistant, highly reflective, extremely economical thermally transferable web, commonly referred to as hot stamp tape, is made as a laminate comprising a lamina comprising such platelets and an opaque lamina comprising conventional aluminum pigment and optionally a third lamina comprising a protective coating consisting essentially of methyl methacrylate.

Dependencies are inferred from the claim text.