Method of Surface Treating Shaped Articles of Thermoplastic Synthetic Polymers

摘要

1,178,751. Surface roughening of shaped articles, films and filaments. SEKISUI KAGAKU KOGYO K.K. 13 Feb., 1967 [11 Feb., 1966; 1 March, 1966; 8 March, 1966], No. 6763/67. Headings B5A and B5B. [Also in Divisions B6 and C3] Shaped articles, films, sheets and filaments of thermoplastic synthetic polymer material have their surfaces uniformly roughened, so enabling them to be written or printed upon, by impregnating the surface layer of the said articles with a thermally decomposable foaming agent in the liquid state, and then thermally decomposing said impregnated foaming agent to evolve a gas which erupts and escapes from the thermally softened surface of the said article. The article, film or filament may be at a temperature below the decomposition temperature of the foaming agent, and the said film or filament, impregnated with the foaming agent is then heated, or the article, film or filament may be impregnated with the foaming agent immediately after the formation of the said article, film or filament and while its temperature is higher than the decomposition temperature of the foaming agent, the foaming agent then being decomposed by the heat of the article, film or filament. Such impregnation of a shaped article may be effected, for example, immediately after its extrusion from a die, or after rolling between forming rolls, or after injection moulding. Foaming agents may be used alone if they are liquids per se or they may be dissolved in a solvent. The foaming agent solution may contain a second solvent for the polymer if necessary, and may also contain other additives such as thickeners, fillers, antistatic agents and permeation inhibitors. The foaming agent may also be applied to a stretched film or filament, or during the stretching thereof. Specified foaming agents are paratoluene sulphoazide, diethylazodicarboxylate and benzene sulphoazide, azobisisobutyronitrile, dinitrosopentamethylene tetramine, azodicarbonamide, N,N1- dimethyl - N,N1 - dinitroso terephthalamide, benzene sulphonyl hydrazide, p-toluene-sulphonyl hydrazide, diphenyl sulphone, 4-41-dihydroxybisazodicarbamic acid amide, trihydrazine triamine, diazoaminobenzene, and 4,41-oxybisbenzene sulphonyl hydrazide. Examples include the treatment of nylon filaments, of films of polycarbonates, polypropylene, polyacrylonitrile, polyvinyl. chloride, polystyrene, polystyrene - polybutadiene, styrene - butadiene copolymer and of a blend of the latter copolymer with polystyrene; of sheets of nylon, polyvinyl chloride and polystyrene; of a foamed sheet of polystyrene; of a polymethyl methacrylate plate; and of vessels of polycarbonates, polyethylene and polystyrene.