GB586595A - Improvements in or relating to reflex reflectors suitable for road or advertising signs or markers - Google Patents

Abstract

586,595. Coated fabrics. MINNESOTA MINING & MANUFACTURING CO. Nov. 8, 1943, No. 18529. Convention date, Jan. 23. [Class 140] [Also in Groups XVIII, XX and XL] In a reflex reflector of the kind comprising a layer of small transparent spheres 13, Fig. 1, adhesively secured to a reflecting backing 10, 11, the surface exposed between the spheres is opaque and contrasts with the colour of the reflecting backing to give a different appearance by day and by night. The exposed surface (a) may be that of the sphere-bonding adhesive 12 which may be opaque, or, as shown in Fig. 4, may be a coating 28 applied over a transparent or opaque sphere-bonding adhesive 26 and removed, e.g., by buffing or brushing, from the exposed surfaces of the spheres 27, or a layer produced by modifying the surface of the spherebonding adhesive by applying dyes which penetrate to a' certain depth, or by applying pigment to the temporarily-softened surface. The applied pigment may be a fluorescent or phosphorescent powder. The sphere-bonding adhesive may be in several differently-coloured superimposed layers to give zones of different reflex reflection when seen from different angles. A transparent spacing layer 25, Fig. 4, may be applied and cured upon the reflecting backing 23, 24 before applying the sphere-bonding adhesive. In certain areas, e.g., lettering, the opaque coating may be left over the surfaces of the spheres so that these areas and letters remain black by night. The backing may be metal sheet, plywood, metal foil, waterproof paper, or a flexible film of synthetic rubbery material, coated if necessary with a metallic. white, or light-coloured reflecting coating, e.g., a solution of nitrocellulose, tricresyl phosphate, and alkyd resin containing titanium dioxide and a trace of ultramarine. The pigmented sphere-bonding layer and/or the opaque surface layer may comprise urea-formaldehyde resin, an alkyd resin, a non-drying fatty oil or fatty acid, a pigment, and an aromatic petroleum solvent. An alternative pigmented sphere-bonding adhesive which, is suitable for surface dyeing includes propyl methacrylate resin and titanium dioxide pigment. Specifications 556,935 and 586,594 are referred to.