| 摘要 |
PURPOSE:To suppress the intrusion of contminants into a polymn. chamber and to produce a polymer having excellent light transmission performance stably on an industrial scale over a long period of time by introducing an inert gas into the chamber from an inflow port and passing the gas through the chamber and labyrinth section. CONSTITUTION:A mechanical seal 3 for shaft sealing of stirring vanes is provided to the upper part of a vapor phase section 2 and the stirring vanes are installed with the mechanical seal 3 as a fulcrum in the polymn. chamber. The inert gas selected from any one kind of nitrogen, argon, ammonia, carbon dioxide, and oxygen is admitted between the mechanical seal 3 and the polymn. chamber vapor phase section 2. The inert gas flowing down from the inert gas inflow port 4 to the vapor phase section 2 is held at 1cm/sec to 1m/sec linear velocity in the labyrinth section 6 and is discharged to the outside of the polymn. chamber by an inert gas discharge port 7. The shaft sealing function of the stirring vanes is stably maintained over a long period of time in this way and the polymer having high transparency is obtd. while prohibiting the intrusion of the external contaminants and the disturbance or reaction. |
