GB559261A - Improvements in or relating to flexible reflex light reflector sheet, method of making the same, and signs or markers adapted for outdoor exposure and including the improved reflex light reflector - Google Patents

Abstract

559,261. Reflex light reflectors for road signs &c. STEVENS, A. H. (Minnesota Mining & Manufacturing Co.). March 17, 1942, No. 3564. [Class 140] [Also in Groups XVIII and XX] A flexible weatherproof reflex light reflector sheet for use, e.g. in making road signs or markers consists of a backing 10, e.g. impregnated paper, a lightreturning layer of small transparent spheres 13 providing contiguous convex lens elements, a sphere-bonding coat 12 and a film 11 containing light-reflecting pigment, e.g. flaked aluminium or a reflecting metal foil which may serve also as a backing. A weatherproof backing 14 may be applied to constitute a sheet ready for use, and consists of impregnated cloth or paper, felted or woven fabrics of animal or vegetable fibre, metal fibre, glass fibre, cellulose derivative fibres, acetylated cellulose fibres, nylon fibres, or acetylated paper, parchmentized paper &c. Non- fibrous backings such as metal foils or films of cellulose acetate, rubber hydrochloride, polyvinyl acetals, the material known under the Registered Trade Mark "Butvar," synthetic rubbers, nylon &c. may be used. When the backing is fibrous resins, rubber, synthetic rubber &c. may be used as impregnating agent. The beads preferably have a refractive index of 1.5 to 2.0 and may be of lead glass ; their diameter is preferably within the range 3 mil to 38-46 mils. They may be spaced from the reflector by a distance from 20 per cent. to 40 per cent. of the average bead diameter. A road sign consisting of raised metal letters, e.g. STOP, may have reflection sheet arranged around the faces of the letters.