| 摘要 |
PURPOSE:To prepare a membrane with a uniform thickness at high speed by melting and extruding filmily a polyester composition containing a specified quantity of polyalkylene glycol and/or its derivative and a specified quantity of alkaline metal salt derivative of sulfonic acid as alkaline metal, adhering electrostatically to a rotating cooling roll, cooling and solidifying quickly. CONSTITUTION:Polyalkylene glycol and-or its derivative, 0.1-10wt% against polyester, is added. In case of forming alkaline metal salt of sulfonic acid, sulfonic acid and alkaline metal compound are added to polymerization process at an optional stage. Only when alkaline salt derivative of sulfonic acid is used, the effect of combination of polyalkylene glycol to enhance electrostatic tight layer properties is developed. The adding quantity of alkaline salt derivative of sulfonic acid against polyester is 0.0003-0.1wt% as alkaline metal. As the structure of electrostatic application device, structure of electrode, whether counter electrode is or not, relationship of position between electrode and counter electrode and current value as electrostatic application terms are to be set optionally. |
