Verfahren zur Verbesserung der durch energiereiche,ionisierende Strahlen induzierten Pfropfpolymerisation oder Pfropfcopolymerisation einer oder mehrerer radikalisch polymerisierbarer Verbindungen auf aus synthetischen Hochpolymeren bestehenden Flaechengebilden nicht textiler Art mit glatter Oberfla

1336445 Graft polymerization process INRESCOR AG FUR INDUSTRIELLE FORSCHUNG UND STRAHLENUTZUNG 8 Dec 1970 [12 Dec 1969 21 April 1970] 58310/70 Heading C3G A process for the graft polymerization or graft copolymerization of at least one radically polymerizable monomer onto an essentially smooth-surfaced, polymeric substrate comprising a polyester, a polyamide, a polyacrylate, a polyolefin or a halogenated polyolefin in the form of a sheet comprises heating the substrate to a temperature within the glass transition temperature range of the polymer therein and irradiating with UV or high energy ionizing radiation, a layer of carrier material being contacted with at least one surface of the substrate and impregnated with the polymerizable monomer whereby the polymerizable monomer is graft polymerized or graft copolymerized on to the substrate. The carrier material is conveniently impregnated with a solution or suspension of the polymerizable monomer. The substrate may be heated to a temperature within the glass transition temperature range prior to irradiation, and the substrate may be brought to the reaction temperature at least twice in successive heating stages. A separate irradiation step is associated with each heating stage. The substrate may be placed between two layers of carrier material which assembly is passed through the solution or suspension of the polymerizable monomer whereby the monomer penetrates the carrier material and is graft polymerized on to both surfaces of the substrate. Alternatively grafting may be effected onto one side only of two substrates by superimposing the two sheets with the surfaces to be treated outermost and then interposing the two sheets between two layers of carrier material which are either themselves impregnated initially or become impregnated by passing through the solution or suspension as before. Instead of two superimposed sheets a tubular structure in the flattened condition may be treated in similar way. In the examples which all refer to irradiating with high energy electrons methacrylic acid is grafted on to (1) polyethylene glycol terephthalate foil between two superimposed glass fibre sheets and acrylic acid is grafted on to (2) a copolymer of polyamide 6 and polyamide 66 sheet between two glass fibre sheets; (3) polyamide 12 foil placed on a fabric of polyethylene glycol terephthalate; (4) a tube of polyethylene glycol terephthalate, in flattened condition, between two superimposed glass fabric sheets; an