摘要 |
PURPOSE:To prevent an excessive escape of an agent vapor, by attaching an active agent of naphthalene, etc. on a thermoplastic synthetic resin which is impermeable to the active agent, and covering a part of it with a thermoplastic synthetic resin which is permeable to the active agent. CONSTITUTION:A thermoplastic synthetic resin 1 which is impermeable to an active agent of naphthalene etc. and a thermoplastic synthetic resin 2 which is permeable to the active agent are extruded in the manner that the former being a part of a tube having a section layer than a semicircle and the latter being a part of the tube having a section smaller than a semicircle, and the active agent 3 is sprayed between these synthetic resin layers. Then, two synthetic resin layers flow together within a die and are made to a laminated product. |