| 摘要 |
PURPOSE:To improve discharge property when used for a long time while maintaining the same when used for a short time by having two water-repellent films with specified air permeability superposed and placed on the lower side of an air pole. CONSTITUTION:Two in total of a water-repellent film 3a (an upper side) and a water-repellent film 3b (a lower side) which have the almost same diameters as a separator 5 and an air pole 4 are superposedly placed on the lower side of the air pole 4. The water-repellent films 3a, 3b are set to 31000-70000sec. and 90-170sec. in air permeability, respectively. In this way, the water-repellent film 3a (an upper side) with low air permeability is used to bring about discharge even when used for a long time while restraining self-exhausion and to improve discharge duration. As the water-repellent film 3b (a lower side) which has air permeability close to that of an air diffusion paper is placed on the lower side of the water-repellent film 3a, it brings effect in the air diffusion paper to maintain discharge duration in a regular measure even when used for a short time. |
