GB1344483A - Retro-reflective liquid coating compsition - Google Patents

Abstract

1344483 Paints MINNESOTA MINING & MFG CO 19 April 1971 [26 March 1970] 25322/71 Heading C4A [Also in Division C3] A composition, suitable for making marks that actuate photoscanning devices, comprises a gelled vehicle and retroreflective elements dispersed in the vehicle. The vehicle comprises at least 80% by volume of a volatile solvent, and a gelling agent for the vehicle that amounts to at least 25% by volume of all non-volatile binder in the vehicle. The reflective elements may comprise at least 90% by volume of the non-volatiles in the composition and are kept in a suspended condition by the gel character of the composition. The gel agent may be the sole binder, or another binder may also be present. The reflective elements may be glass beads, which may be hemispherically coated, or may be used together with a powdered metallic pigment. The compositions in the Examples comprise: (1) methanol, methyl ethyl ketone, carboxyl-terminated vinyl polymer and glass beads hemispherically coated with aluminium, (2) methanol, hydroxy-propyl-methyl-cellulose, and beads as before; (3) methyl ethylketone, isophorone, an organic derivative of magnesium montmorillonite and beads as before; (4) methanol, carboxyl-terminated vinyl polymer, wood rosin and beads as before; (5) as Example (1) but using uncoated glass beads and a paste of aluminium pigment in mineral spirits; and (6) water, carboxyl-terminated vinyl polymer and coated glass beads as in Example (1). Other solvents referred to are methyl propyl ketone, n-propyl acetate, ethyl acetate, toluene, heptane, ethanol, iso-propanol, diethyl ketone, 1,1,2-trichlorethane and isopropyl acetate.