Patent GB-1162171-A (GB)
Title: Sheet Materials
Inventor: CALVETE LOUIS GERALD
IPC: B32B27/00
Filed: 1966-09-13
Abstract: 1,162,171. Ornamenting. IMPERIAL CHEMICAL INDUSTRIES Ltd. 25 Aug., 1967 [13 Sept., 1966], No. 40817/66. Heading B6G. [Also in Division G5] An embossed sheet of thermoplastic, synthetic, polymeric material is made by contacting under conditions of heat and pressure a layer of the synthetic thermoplastic polymeric material with a layer of powdered or granular material that is infusible at the temperature of pressing and that is bonded to a substrate, a thin layer of flexible material that does not adhere to the layer of synthetic thermoplastic polymeric material being interposed between the layer of powdered or granular material and the layer of synthetic thermoplastic polymeric material during the pressing operation. Synthetic thermoplastic polymeric materials that may be used include homopolymers and copolymers of olefines, such as polyethylene and polypropylene, homopolymers and copolymers of vinyl halides such as polyvinyl chloride and copolymers of vinyl chloride with vinyl acetate, vinylidene chloride, vinyl ethers, alkyl acrylates and methacrylates, chlorinated polyvinyl chloride, polymers and copolymers of alkyl acrylates or methacrylates, polymers and copolymers of styrenes and substituted styrenes, copolymers of butadiene with styrene, methyl methacrylate and/or acrylonitrile. The polymeric material may be compounded with 1 or 2% of plasticizers, heat and light stabilizers, lubricants, pigments, fillers, impact modifiers. The polymeric material may be formed into sheet form for pressing by extrusion or calendering. Suitable powdered or granular materials include inorganic materials such as sand, glass and carborundum bonded to a substrate such as a fabric, paper. Preferred materials include sandpaper, glass paper and emery cloths. The material for the parting layer may be aluminium foil, thermoplastic polymeric film, e.g. polyethylene terephthalate. A sheet of the polymeric material may be interposed between two platens of a press with a parting layer and a layer of powdered or granular material bonded to a substrate in that order interposed between the sheet and one or both platens. The platens are then brought together under pressure and heated and subsequently cooled. Alternatively the sheet may be fed from an extruder between a pair of rollers, which may be heated or cooled as necessary, one or both rollers being provided with a sleeve of powdered or granular material bonded to fabric or paper, and the parting layer being formed as a sleeve over the. sleeve and powdered or granular material or may be fed separately from a reel on one side of the rollers and taken up by a second reel on the other side of a roller. The sheet of polymeric material may be formed by lamination of a plurality of foils of polymeric material, this lamination being carried out during the embossing process. Laminates mentioned include laminates made from a plurality of foils of polyvinyl chloride, and laminates of polyvinyl chloride with chlorinated polyvinyl chloride or polyvinyl acrylate. The sheet of polymeric material may be embossed on one or both sides, and portions of the surface may be left unembossed or embossed to a different degree. The sheets may be used for wall facings, decorative panels, advertising signs.