| 摘要 |
PURPOSE:To contrive a reduction of content of an acrylonitrile monomer in a biaxially oriented blow vessel and the amount of formation of HCN of a secondary product, by a method wherein upon application of electron rays or gamma rays to the perform of a bottomed cylindrical body, heat treatment at a specific temperature is performed. CONSTITUTION:Electron rays or gamma rays are applied beforehand to preform of a bottomed cylindrical body of thermoplastic resin mainly comprised of acrylonitrile resin. Then ordinary biaxial orientation blow molding is performed after an acrylonitrile monomer is made under 0.1ppm by heat-treating the same immediately at a temperature of at least 40 deg.C. with this construction, a vessel comprised of a biaxially oriented blow molded body with the acrylonitrile resin is obtained. Then polymerization of the acrylonitrile monomer in the preform is contrived by applying the electron rays or the gamma rays to the same. To make amount of HCN produced secondarily as little as possible, low does, for example, of 0.01-0.8 megarad and 0.01-0.8 megaroentgen are used respectively for an absorbed does of the electron rays and an exposed does of the gamma rays. |
