| 摘要 |
PURPOSE:To obtain a thermoplastic resin film having small optical rotation property without deteriorating its properties by a method in which a static electricity is applied to the film, and the film is fixed to a cooling roll and cooled without giving it a tension. CONSTITUTION:A film extruded from a die 1 is subjected to application of static electricity from an electrode 3 set in parallel with the withwise direction of the film on a cooling roll 2 and closely fixed to the cooling roll 2 by the static electricity. In this case, DC high voltage of 3-10kV is applied to the electrode and the interval between the rolls is kept in 10-20mm.. The film closely fixed by the static electricity is cooled and solidified without undergoing tension from the molten state to the temperature of Tg, and therefore, the film having non-optical rotary propety can be stably manufactured without deteriorating its mechanical, electrical, transparent, and other characteristics. |
