GB812422A - Improvements in or relating to self-adhesive sheets or tapes - Google Patents

Abstract

812,422. Pressure sensitive adhesive tapes and sheets. BEIERSDORF & CO. A.G., P. Jan. 25, 1956 [Jan. 27, 1955], No. 2509/56. Class 140. A pressure sensitive adhesive tape or sheet comprises a flexible support of an organic hydrophilic or hydrophobic material, an intermediate layer comprising a polyvinyl ether and a copolymer of acrylonitrile and a substance polymerizable therewith, and a pressure sensitive adhesive coating. The intermediate layer may consist essentially of a mixture of from 10 to 80 per cent of the acrylonitrile copolymer and from 90 to 20 per cent of the polyvinyl ether, and may be applied as a solution in an organic solvent, e.g. toluene, trichloroethylene, or as an aqueous emulsion or dispersion, such that the weight of the dried intermediate layer is from 1 to 3 grams per square metre of support. Materials, which may take the form of a foil, film or fabric support, are regenerated cellulose, cellulose ethers or esters, e.g. cellulose acetate, acetate-butyrate, or nitrate, vinyl or vinylidene halide polymers or copolymers, e.g. polyvinyl chloride, polyvinylidene chloride, polystyrene, acrylonitrile copolymers, acrylic or methacrylic ester polymers or copolymers, polyesters of dibasic acids and polyvalent alcohols, polyurethanes, and polyamides. Specified polyvinyl ethers are polyvinyl methyl ether, polyvinylethylether, polyvinylbutylether, polyvinylisobutylether, polyvinyldccylether. Acrylonitrile copolymers disclosed are acrylonitrile-styrene, butadiene, vinyl ether, acrylic acid ester or methacrylic acid ester. The pressure sensitive adhesive may be natural or synthetic rubber, e.g. polyisobutylene, polyvinylether, e.g. polyvinylisobutyl ether, or polyacrylic acid esters. Fillers, elastomers, e.g. polychlorobutadiene or polyvinylchlorobutadiene latex, natural or artificial resins, e.g. phenol-formaldehyde, maleic acid resin, polystyrene and copolymers thereof with vinyl chloride, acetate or ether, wetting and/or thickening agents, e.g. polyacrylic acid salts containing amino groups, silicic acid, dehydroabietylamino acetate, may also be present in the intermediate layer.