摘要 |
<p>A surface of a shaped structure made from thermoplastic synthetic material is exposed to an electrical discharge in an atmosphere containing a halogen gas in the presence of a polymerizable monomer, thereby producing a sealable surface. The structure may be a film, sheet, pipe, tubing or fabric of e.g. a polyolefin such as polypropylene or polyethylene, polybutadiene, polyvinyl chloride, or polyethylene terephthalate and the monomer may be vinyl acetate, vinyl chloride, acrylic acid or an ester thereof, alpha-methyl styrene, styrene, acrylonitrile, 2-chloroacrylonitrile, a vinyl ether, vinylidene chloride, maleic anhydride, diallyl itaconate or hexachlorobutadiene, or a mixture of such monomers. The halogens specified are Cl2 and Br2, alone or mixed with each other or with an inert gas, e.g. air or N2. Gaseous monomers are introduced with the halogen supply. Non-gaseous monomers may be supplied by dissolving them in e.g. trichloroethylene and blowing N2 through the solution and thence into the reactone zone. Alternatively, the non-gaseous monomer is applied by spraying or dipping. In examples, a polypropylene film is treated with Cl2 and hexachlorobutadiene and a polyethylene film is treated with Cl2 and styrene, the carrier gas used being N2.</p> |