| 摘要 |
<p>PURPOSE:To make it possible to recycle polyvinyl chloride and polystyrene by a method wherein waste masking material is immersed in solvent, in which polystyrene is soluble and polyvinyl chloride is insoluble. CONSTITUTION:Masking material is generally produced by expansion-molding polystyrene expandable beads into the predetermined shape through heating it in a mold. Polyvinyl chloride sol is applied after the masking material is attached to a portion, to which said sol must not be applied. Polyvinyl chloride- coated layer is gelled by heating so as to be turned into viscoelastic film, while the masking material is removed. By immersing waste masking material in solvent, in which polystyrene is soluble and polyvinyl chloride is insoluble, the polystyrene melts and polyvinyl chloride is insoluble, the polystyrene melts and the polyvinyl chloride precipitates. As the solvent, ethyl acetate, n-bytyl acetate, triol, xylol and the like are exampled. The precipitated polyvinyl chloride can be recovered by filtering, centrifuging or the like and turned into sol again for reuse.</p> |
