Abstract: A process for treating expanded polystyrene which comprises the step of softening a waste material of expanded polystyrene by immersing the material in a petroleum organic solvent mainly comprising liquid hydrocarbons in the neighborhood of the site yielding the waste material to form a dough-form intermediate product, the step of separating the intermediate product from the solvent by physical means, and the step of recovering and reclaiming the polystyrene contained in the intermediate product. The organic solvent is suitable a mixture mainly comprising aromatic hydrocarbons and aliphatic hydrocarbons and having the content of the aromatic hydrocarbons of 20 to less than 60 Wt %. According to this process, a low-tack intermediate product can be produced in a short time with an inexpensive organic solvent, and high quality polystyrene can be reclaimed from the intermediate product.

Abstract: An inner bag made of an acrylonitrile-type thermoplastic resin film and having a volatile substance hermetically sealed therein is packed and sealed in an outer bag made of a gas-permeable film to provide a package packed with the volatile substance, which can keep the volatile substance from escaping therefrom during storage thereof, but permits the volatile substance to escape therefrom in service.

Abstract: An improved composition consisting essentially of an alkali solution and 3,5-dimethyl pyrazole, for removing a photosensitive resin film from a baseboard for an integrated circuit following formation of a tin-lead solder circuit on the baseboard. A method for removing the photosensitive resin without dissolving the tin-lead circuit by applying the improved composition.