| 摘要 |
PURPOSE:To obtain such a film that has same charge holding property as an electret film comprising tetrafluoroethylene-hexafluoropropylene copolymers or the like, can be easily formed on a conductive sleeve by coating and drying, and produce no crack even when long time has passed after coating and drying is performed, by producing an electret film comprising a blended material of specified polymers. CONSTITUTION:The polymers to form the electret film is a combination of styrene copolymers and fluorinated vinylidene/tetrafluoroethylene copolymers. A polystyrene electret film shows decrease in the charge holding rate immediately after coating and drying to about 60%, while the obtd. film shows slow decrease arid when the rate is decreased to about 70%, the rate becomes static. Thus, the charge holding rate and its stability are effectively improved. A polystylene electret film causes peeling from a base metal in about three days after coating and drying, while the obtd. film causes no peeling even 10 days after. |
