GB879371A - Adhesive sheets - Google Patents

Abstract

879,371. Adhesive sheeting; laminates. WEINBERG, M. A. Nov. 4, 1957 [Nov. 9, 1956], No. 34388/57. Class 140. An adhesive sheet comprises a sheet of a vinyl chloride polymer or copolymer having a maximum thermoplastic flow of 12 square centimetres and formed from polyvinyl chloride or a vinyl chloride copolymer having an intrinsic viscosity of at least 1.25, the sheet having directly coated on at least one surface a solventactivatable or heat-activatable adhesive composition having a minimum thermoplastic flow of 12 square centimetres, the adhesive composition comprising a low molecular weight vinyl chloride copolymer containing a minor amount of a polar carboxy or hydroxy group, and having an intrinsic viscosity not greater than about 0.57 and being in an amount from 10 to 100% by weight of the total adhesive composition. The thermoplastic flow is measured by placing a pellet of one gram of the material between glassine papers in a heatsealing press having two eight-inch by eightinch platens, subjecting the pellet to a temperature of 300‹ F. at a total pressure of 250 pounds for 20 seconds and recording the area of the pressed pellet. The vinyl chloride copolymer of the adhesive composition may be a low molecular weight tripolymer of vinyl chloride, vinyl acetate, and maleic acid having an intrinsic viscosity of 0.53, and the tripolymer of vinyl chloride, vinyl alcohol and vinyl acetate having an intrinsic viscosity of 0.57, which may contain various modifying agents, e.g. vinyl chloride-vinyl acetate copolymers of intrinsic viscosity 0.24, and a vinyl chloride copolymer of relative viscosity of 1.35, plasticizers, e.g. di-2-ethyl hexyl phthalate, or butadiene-acrylontrile. The vinyl chloride copolymers of the sheet may be of vinyl chloride and a minor amount of vinyl acetate or vinylidene chloride which may have an intrinsic viscosity of 1.52 or 1.25. Suitable high molecular weight polyvinyl chloride resin may have a specific viscosity of 0.57. The sheet of vinyl chloride polymer or copolymer may be extruded or first formed on a sheet of paper and coated with the adhesive, or the adhesive first coated on to a release-coated paper and. the sheet applied thereto, the -coated sheet being subsequently stripped from the paper. The sheet may be coated with an adhesive primer prior to coating with the adhesive. The adhesive sheet may be laminated to clean or phosphated sheet metals or foils, wall boards, e.g. plywood, chipboard, or " Masonite " (Registered Trade Mark), panels of phenolic, melamine, polyester, and epoxy resins, cloth, paper, glass, plastics, e.g. polymers of vinyl chloride, acrylics, vinylidene chloride, polyamides, phenolics, ureas, melamines, polyesters, " Cellophane " (Registered Trade Mark), " Mylor (Registered Trade Mark) films, and leather goods.