GB1274516A - Process for making moulded resin articles provided with a relief pattern - Google Patents

Abstract

1,274,516. Casting articles with relief patterns. Y. KURASHIMA. 16 June, 1969 [18 June, 1968; 13 Aug., 1968], No. 30453/69. Heading B5A. [Also in Division B6] Synthetic resin articles, having a decorative surface in relief, are moulded by casting a resin prepolymer into a cavity provided with a surface over which a film is applied and which is either deformed by the resin against one or more inserts on the surface, or wrinkles during the heat curing of the prepolymer, the film either comprising part of the article and optionally including a coloured pattern printed thereon or being stripped therefrom when the film may also have printed thereon a coloured design which is transferred to the article. The casting resins may comprise thermoplastic polymethyl methacrylate or thermosetting polyester, and may be coloured, and after curing, e.g. at 30‹ to 60‹ C., the article, e.g. a plate, tube or rod, is annealed, e.g. at 90‹ C., and cooled before removal from the mould. Examples are given in which the moulding cavity is defined between a pair of plane glass plates surrounded by a frame and in which; (1), a methyl methacrylate prepolymer is cast against a nylon film laid over a hexagonally latticed wire netting matrix, the film being stripped from the article; (2), a cardboard sheet matrix provided with a plurality of circular openings and a polyvinyl alcohol film are alternatively employed in example (1); (3), a plurality of phenol-formaldehyde resin discs, iron rods, wire configured as flowers, and polyethylene resin cubes are alternatively employed as matrices in example (2), secured to the mould surface by adhesive tape or gum arabic; (4), a polypropylene film was used which wrinkled during heat curing of polymethyl methacrylate; (5), the film of example (4) was replaced by a polyvinyl chloride film which was photogravure colour printed and wrinkled during the casting process, and was incorporated into the cast article. The moulds may also comprise metal, and the matrices may also comprise glass, wood, stone or cement, and may also be of hemispheric, or truncated conic shape, or may comprise wire configured in the shape of a bird. The matrices may be embedded in the article to comprise part thereof together with the film. The film may also comprise polycarbonate, cellulose acetate, or polyvinylidene chloride. The cast articles may also comprise doors, screens, furnishings and lamp shades.